ANODES

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent

Application No. 62/634,463, filed February 23, 2018, and titled

“ELECTROPLATING SYSTEM WITH INERT AND ACTIVE ANODES ,” which is incorporated herein by reference in its entirety and for all purposes.

TECHNICAL FIELD

[0002] The present disclosure relates to the control of electroplating solution concentration, and in particular to such control as conducted on an electrochemical plating apparatus for semiconductor substrates.

BACKGROUND [0003] Electrochemical deposition process is widely used in the semiconductor industry for metallization of integrated circuit manufacturing. One such application is copper (Cu) electrochemical deposition, which may involve depositing of Cu lines into the trenches and/or vias that are pre-formed in dielectric layers. In this process, a thin adherent metal diffusion-barrier film is pre-deposited onto the surface by utilizing physical vapor deposition (PVD) or chemical vapor deposition (CVD). A copper thin seed layer will then be deposited on top of the barrier layer, typically by a PVD deposition process. The features (vias and trenches) are then filled electrochemically with Cu through an electrochemical deposition process, during which the copper anion is reduced electrochemically to copper metal. Another application is cobalt (Co) deposition in the same or different contexts.

[0004] This Background section is for the purpose of presenting a context of the disclosure. Work by the inventors, to the extent presented in this Background section or in other portions of the description, that does not otherwise qualify as prior art, is not admitted as prior art against the present disclosure. SUMMARY

[0005] In an electrochemical plating apparatus that has isolated anolyte and catholyte portions and an active anode in the anolyte portion, the concentration of catholyte components (e.g., acid, anions, cations, additives, etc.) may be controlled by using an inert anode in conjunction with an active anode. The inert anode may balance the metal cation generation and consumption rate in the plating process by instituting a hydrogen ion generation reaction that does not also generate metal cations. The inert anode receives a fraction of the apparatus’s total anodic current (vis-a-vis the active anode) so that metal cation generation (at the active anode) and hydrogen ion generation (at the inert anode) are in a desired proportion. That proportion may be based on the current efficiency of the plating reaction at the cathode (workpiece or substrate such as a semiconductor wafer). The fraction of current delivered to the inert anode may be controlled in various ways such as by the relative electrolyte facing surface areas of the active anode and the inert anode, circuitry dividing current between the anodes, and/or on the fraction of time the inert anode operates (again vis- a-vis the active anode). In other words, while the inert anode is available, it might be used only to a limited degree, often determined, at least in part, by the current efficiency of plating onto the cathode. For example, the inert anode might only be operated during 30% of an electroplating run. [0006] One aspect of this disclosure pertains to a method of electroplating metal onto a substrate during fabrication of a device. Such method may be characterized by the following operations: (a) providing an electroplating solution to an electroplating system that includes (i) a cathode portion configured to hold the substrate while electroplating the metal onto the substrate, (ii) an electroplating solution comprising ions of the metal, (iii) an active anode, and (iv) an inert anode; (b) providing a first fraction of a total current for electroplating the metal onto the substrate to the active anode; and (c) providing a second fraction of the total current for electroplating metal onto the substrate to the inert anode In these method, the first fraction and the second fraction may approximate fractions of metal plating and one or more parasitic reactions at the substrate, respectively. Further, providing the first faction of the total current and providing the second fraction of the total current cause the metal to electroplate onto the substrate. [0007] In certain embodiments, the metal is cobalt and wherein the active anode includes cobalt. In certain embodiments, the one or more parasitic reactions comprise hydrogen ion reduction. In certain embodiments, the electroplating solution includes cobalt ion, an acid, borate ion, and organic plating additives. [0008] An aspect of the disclosure pertains to a system for electroplating metal onto a substrate during fabrication of a device. Such system may be characterized by the following elements: (a) an electroplating cell including an anode portion and a cathode portion, and configured to hold the substrate in the cathode portion while electroplating the metal onto the substrate; (b) an active anode comprising the metal; (c) an inert anode; and (d) a controller. In some implementations, the controller includes instructions for: (i) providing a first fraction of a total current for electroplating the metal onto the substrate to the active anode; and (ii) providing a second fraction of the total current for electroplating metal onto the substrate to the inert anode. The first fraction and the second fraction may approximate fractions of metal plating and one or more parasitic reactions at the substrate, respectively.

[0009] In some embodiments, the electroplating cell further includes an ion transfer separator between the anode portion and the cathode portion, and configured to provide a path for ionic communication between the electroplating solution in the anode portion and the cathode portion. The ion transfer separator may include a cation exchange membrane. In certain embodiments, the electroplating cell additionally includes one or more auxiliary electrode chambers, which may include one or more auxiliary cathodes.

[0010] In some embodiments, the device may be an integrated circuit. In some embodiments, the metal may be copper and/or cobalt. [0011] These and other features will be described below with reference to the associated drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Exemplary embodiments will now be described in conjunction with the drawings, in which: [0013] Figure 1 is a schematic diagram of an exemplary plating electrolyte, or electroplating solution, recirculation and/or dosing system.

[0014] Figure 2 illustrates an electroplating bath-side vs. metal ion partition effect, e.g., showing the movement of metal ions selectively through a semi-permeable membrane. [0015] Figures 3A-3C show various graphs illustrating electroplating bath concentration trends without the introduction of a supplemental, or secondary, electroplating solution to the system.

[0016] Figures 4A-4C show various graphs illustrating electroplating bath concentration trends with acid dosing, e.g., to replenish acid, and de-ionized (DI) water dosing to control cobalt ion concentration [C0 ²⁺ ]

[0017] Figures 5a and 5b show an example system having an inert anode and active anode both located in an anode portion of an electroplating system.

[0018] Figures 6a and 6b show an example system having an auxiliary cathode that serves as an inert anode during a portion of electroplating cell operation. [0019] Figures 7a and 7b show an example system having an inert anode used in conjunction with an auxiliary cathode.

[0020] Figure 8 shows a schematic of a top view of an example electrodeposition apparatus.

[0021] Figure 9 shows a schematic of a top view of an alternative example electrodeposition apparatus.

[0022] Figure 10 shows a cross-section of an electroplating cell in which an inert anode and an active anode both reside in an anode chamber. DETAILED DESCRIPTION

[0023] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented embodiments. The disclosed embodiments may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail to not unnecessarily obscure the disclosed embodiments. While the disclosed embodiments will be described in conjunction with the specific embodiments, it will be understood that it is not intended to limit the disclosed embodiments.

Introduction and Context

[0024] Control of the composition and concentration of the electroplating solution used in an electroplating system may be important to the performance of the electrochemical deposition process. Typically, there are multiple components in a given electroplating solution. For example, the composition of electroplating solution used for the deposition of copper on a wafer may vary, but may include sulfuric acid, copper salt (e.g., CuS0 ₄ ), chloride ion, and a mixture of organic additives. In the case of cobalt deposition, the electroplating solution composition may include sulfuric acid, boric acid, cobalt salt (e.g., CoS0 ₄ ), and a mixture of organic additives. The composition of electroplating solution is selected to balance the rate and uniformity of electroplating inside features of the wafer, or in the field of the wafer, e.g., an area without features formed on or in the wafer. During the plating process, cobalt salt serves as the source of cobalt cation, and also provides conductivity to the electroplating solution; further, in certain embodiments, sulfuric acid enhances electroplating solution conductivity by providing hydrogen ions as charge carriers. Also, organic additives, generally known in the art as accelerators, suppressors, and/or levelers, are capable of selectively enhancing or suppressing rate of cobalt deposition on different surfaces and wafer features. Boric acid is useful in buffering the electroplating solution.

[0025] Separation of anodic and cathodic regions of an electroplating cell by a semi- permeable membrane may be desirable since chemical processes occurring at the anode and at the cathode during electroplating may not be compatible. For example, during operation, insoluble particles may form on the anode. Protection of the wafer from such insoluble particles is desirable to avoid interference of such particles with subsequent metal deposition processes conducted on the wafer. Also, the restriction of organic additives to the cathodic portion of the plating cell may also be desirable to prevent such additives from contacting and/or reacting with the anode. A suitable separating membrane may allow for the flow of ions, and hence, current, between the anodic and cathodic region of the plating cell, but still restricts unwanted particles and/or organic additives from passing through the separating membrane. Thus, usage of the separating membrane during electrodeposition will create different chemical environments in the cathodic and anodic regions of a plating cell equipped with the separating membrane. Electrolyte contained in the anodic region of the plating cell may be referred to as the“anolyte.” Likewise, electrolyte contained in the cathodic region of the plating cell may be referred to as the“catholyte.”

[0026] An electroplating apparatus having a membrane to separate the anodic region from the cathodic region is described in further detail in U.S. Patent No. 6,527,920 entitled“Copper Electroplating Apparatus” to Mayer et al. and is incorporated in its entirety herein by reference. As discussed above, such a separating membrane allows current to flow between the anodic region and the cathodic region, but may be further configured to selectively restrict current flow depending on the type of ion. That is, the membrane separating the catholyte and anolyte may demonstrate selectivity for different types of ions. For example, for a Cu or Co plating application, the separating membrane may allow passage of hydrogen ions (H ⁺ ) at a faster rate than the passage rate of copper or cobalt ions, e.g., Cu ²⁺ , Cu ⁺ , or Co ²⁺ . Depending on the selectivity of the membrane, the mobility of particular types of ions or current more generally may be predominantly carried by hydrogen ions, until a certain molar ratio between, for example, Cu ²⁺ and H ⁺ concentrations is achieved. After this ratio is achieved, copper ions and hydrogen ions may begin to carry current across the membrane proportionally so that Cu ²⁺ and acid concentration in the anodic portion of the electrochemical cell stabilize. Therefore, until a certain molar ratio between copper ions and hydrogen ions is achieved, the anolyte may be continuously depleted of its acidic component, since hydrogen ions are the main current carriers under these conditions. Concurrent with the depletion of the acidic component of the anolyte, the concentration of copper salt is increased, especially when a copper-containing anode is used. The above effect, e.g., depletion of acid from the anolyte with a commensurate increase in copper salt, may be referred to in the art as an“acid/metal ion partition effect” taking place inside the anode chamber, or“anode chamber depletion effect,” since acid is depleted in the anode over a period of time. [0027] The acid/metal partition processes described above may also inadvertently result in several undesirable side effects on the plating system. Several such side effects are described in US Patent No. 8,128,791 (herein the‘791 patent) entitled “Control of Electrolyte Composition in a Copper Electroplating Apparatus” to Buckalew et al, incorporated by reference in its entirety herein. Undesirable side effects include potential crystallization, or precipitation, of excess salt from the electroplating solution onto the anode surface inside the anode chamber. Also, water may seep across the membrane due to the electro-osmotic effect by creating pressure gradient between the anodic portion and cathodic portion of the apparatus, which may ultimately lead to membrane damage and failure. U.S. Patent 8,128,791 describes ways of controlling the anodic electrolyte composition by frequently replenishing the anode chamber with plating electrolyte. Such a process may be referred to in the art as“bleed and feed.” Alternative to bleed and feed, diluted electrolyte may be added into the anode chamber of the plating cell.

[0028] The acid and cation partition effect, described above, may also create undesirable electroplating solution concentration fluctuation on the cathodic side of an electroplating cell, which, in turn, may impact electroplating process performance. A few examples are described below.

[0029] In addition to the partition effect, concentration changes in the anode and cathode portions of the system may result from electroplating current inefficiencies. Current efficiency is defined as the metal plating (Me ⁺ + e - Me) current as a percentage of the total current received by the cathode. The degree of inefficiency is a function of the electrochemistry employed. Copper generally plates on semiconductor substrates with high current efficiencies (approaching 100%), while cobalt generally plates on such substrates with significantly lower current efficiencies (e.g., about 50-90%). In a cobalt plating process, the plating current efficiency is primarily determined by the availability of protons at the substrate surface. Plating current inefficiencies may thus be magnified at lower current densities because at lower plating current densities a significant portion of the current is carried by hydrogen ion reduction on the surface.

[0030] To elaborate, current efficiency in a metal plating process represents competition between metal deposition (mainly Me ⁺ + e - Me) and hydrogen ion reduction (FT + e - H ₂ ). Each reaction may be characterized by a reduction potential; the more positive the reduction potential, the more easily the reaction proceeds. Considering three relevant reactions, the standard reduction potentials are: Cu ²⁺ + 2e 0.28 V. In a copper deposition reaction, Cu deposition is thermodynamically preferred over hydrogen ion reduction, such that current efficiency of the deposition reaction is typically relatively high. However, current efficiency drops when copper ions are supplied at a rate that is lower than the total deposition rate, which is dictated by applied current density. At high currents, which may be beyond the limiting current, the copper plating current efficiency drops. In cobalt deposition processes, because hydrogen ion reduction is thermodynamically favored over cobalt deposition, the current efficiency of plating cobalt increases when hydrogen ions are supplied slowly relative to the overall deposition rate. Thus at high plating currents, particularly when relatively low acid concentration electrolytes are used, cobalt current efficiency may increase.

[0031] In an example plating reaction, metal (e.g., Co) is removed from the anode through the following reaction: Co -> Co ²⁺ + 2e. At the cathode surface, however, due to less than 100% plating current-efficiency for metal plating, two reactions happen at the same time: Co ²⁺ + 2e - Co and 2H ⁺ + 2e - ¾. The amount of current consumed by each reaction varies between plating process settings. Over a long term, the net effects (of the de-plating process at the anode and the plating process at cathode) on the plating bath electrolyte are: (1) metal ion concentration increases since more is released from anode than is consumed at cathode; (2) acid concentration decreases since acid is only consumed on the cathode without being supplied from the anode; (3) boric acid concentration does not change since boric acid is not actively involved in the reaction. This is illustrated in Figures 3A-C. Note that if the acid metal ion partition effect occurs in the anodic side and the amount of charge carried by acid through the membrane is significant, the metal ion and acid concentration can shift even further. But in some applications, due to the much lower concentration of acid as compared to the metal ion concentration, the partition effect becomes negligible.

[0032] With the net consumption of acid from the plating electrolyte, acid addition/dosing to the plating bath is typically implemented in the electroplating system. Metal ion concentration is also controlled by, e.g., diluting the electroplating solution; in some cases deionized water is added. As a result of both acid and DI water dosing, the boric acid concentration drops. This is illustrated in Figures 4A-C. Since boric acid (any other component of similar function in other metal electroplating solution) may be required at a particular concentration for the metal electroplating process, its concentration must be increased by some mechanism.

[0033] Dosing and similar modes of controlling composition of the electroplating solution in the anode and cathode portions of the electroplating system can be expensive. High replenish rates of electroplating solution components can make the plating process prohibitively expensive.

[0034] A typical electrolyte management system is illustrated in Figure 1. As shown, there are a few major segments, e.g., an anode solution loop 132 and/or a cathode solution loop 118, in an electrolyte management system 100. Typically, there is a central bath 102 that provides electroplating solution to a plating cell 148 and a main cathode chamber 122. The central bath 102 includes a solution recirculation loop (not shown in Figure 1). Additionally, in certain embodiments or configurations, the central bath may also have a temperature control, and a dosing system such as that for additive dosing, deionized water (DI) dosing, and dosing of other active bath components. Further, in some embodiments, the central bath 102 may be equipped with a draining or overflow line 146 leading away from the central bath 102 to remove unwanted electroplating solution when appropriate. Moreover, in a plating apparatus, such as the plating cell 148, with separate anodic and cathodic portions, the anodic portion, such as main anode chamber 126, may have a dedicated recirculation loop 132, and dosing line (not shown in Figure 1), and overflow and/or drain line (not shown in Figure 1). In such a configuration, the main cathode chamber 122 may be configured to receive plating electrolyte from the central bath 102, circulate the electrolyte toward the plating cell 148 by a feed line 112 and direct overflow back to the central plating bath 102 by cell and/or overflow drain line 142. One skilled in the art will appreciate that the configuration shown in Figure 1 is exemplary and many other suitable configurations may exist without departing from the scope of the disclosure.

[0035] The electrolyte management system 100 shown in Figure 1 will be used to describe variants of the system 100 in relation to supplying a secondary, or supplemental, electrolyte to various system 100 components to regulate undesirable electroplating solution concentration fluctuation on either the cathodic or anodic sides of the plating cell 148. Generally, system 100 shown in Figure 1 includes the cathode solution loop 118 and the anode solution loop 132, which, in certain embodiments, may be in fluid communication with one another through the bath 102 contained in an electroplating solution reservoir 150. During normal operation of system 100, incoming plating electrolyte, sometimes called make-up solution, having a defined concentration of metal ion in solution with acid, is provided to system 100 via line 108. Various regulation points 110, such as valves, pressure, and/or flow controllers may be installed on line 108, and/or other lines similar thereto, to regulate fluid flow through the line upon which the regulation point 110 is installed. Similarly, mixing point 112 may receive fluid flow from an incoming line 108. Mixing points 112 may likewise be installed as needed throughout system 100 to regulate delivery and quantity of fluid flowing through lines 108, etc. [0036] Thus, incoming plating electrolyte may flow through regulation point 110 to enter bath 102 to accumulate in the reservoir 150 intended to hold bath 102. In certain embodiments, organic additives are flowed into bath 102 via line 104. Similarly, de-ionized (DI) water may be flowed into bath 102 via line 106 to regulation concentration levels of the various components, or ingredients, of bath 102. Operation of system 100 may involve the pumping of bath 102 fluid through line 116 toward the cathode side 122 of the plating cell 148 for accumulation therein. In certain embodiments, a cathode 128 may be at least partially submerged in the cathode side 122 and electrically connected to an anode 130, which may be similarly submerged in the anode side 126 to complete an electric circuit 134. Further, electrical current (or more precisely the electrons carrying the current) is generally from the negatively charged anode 130 to the positively charged cathode 128. The electric current drives reaction of metal ions, e.g., cobalt ions, Co ²⁺ , in solution with acid in the cathode side, or compartment, 122, allowing for electroplating of such metal on a wafer 200, as shown in Figure 2, positioned in the cathode side 122 of the plating cell 148.

[0037] Solution from the cathode side 122 may be pumped through a cell overflow, or drain, line 138 back to bath 102 as needed. Similarly, solution from the anode side

126 may be pumped through an anode drain line 142 also to the bath 102 as needed. Overflow from bath 102 may be intermittently pumped out of system 100 through a bath overflow, or drain, line 146, which may be referred to more generally as a bath dosing and overflow control loop 144. In certain embodiments, the bath dosing and overflow control loop may include a recirculation pump (not shown), a dosing line

(not shown), the bath overflow line 146, and a temperature control apparatus and/or mechanism (not shown). Together supplying make-up solution via line 108 and dumping electrolyte from the reservoir 150 holding primary electroplating solution, or bath, 102 serves as the bleed and feed process. [0038] As described earlier, a factor to consider during supply of plating electrolyte to the cathodic side 122 to conduct electroplating on a wafer contained therein is the acid metal anion partition effect. This effect can be observed in a copper plating process and may apply to other similar plating system. As illustrated in Figure 2, on the anode, Co or Cu ions, e.g., shown as metal ions, or Me ⁺ , are de-plated into the anodic solution due to the passing of direct electric current through the oxidation reaction of

Cu - Cu ²⁺ + 2e. On the cathode side 122, the Cu ²⁺ ions are extracted from the solution through the reaction of Cu ²⁺ + 2e - Cu. Analogously, across membrane 124 on the anode side 126, due to acid carrying a large portion of the plating current, the anodic electrolyte, which had become metal ion rich, slowly depletes acid or H ⁺ ions, over time. On the cathode side 122, since metal ions (e.g., cupric ions for Cu plating) are removed from solution upon electroplating or electrodeposition upon wafer 200 contained therein, while the solution flowing across the separation membrane (from anode chamber to cathode chamber) is acid rich. As mentioned, ionic transfer through the membrane favors hydrogen ions over copper ions. Thus, copper ion concentration in the cathode side 122 would drop over time, while acid concentration therein would increase. As described elsewhere, the acid metal ion partition effect may be obviated by adopting a high electrolyte replenish rate to the anodic side 126 and/or on the bath 102, which in fluid communication with the cathodic side 122 in many configurations. But high replenish rates can unnecessarily waste electroplating solution and increase the operation cost of the electroplating apparatus.

[0039] The acid/metal ion partition effect may have a substantial impact on electroplating solutions having a relatively low metal ion concentration (e.g., about 5 g/l or lower). In such solutions, a concentration change of as little as a few tenths of a gram per liter can greatly impact the overall concentration of the metal ion in the solution and hence overall electroplating performance. For example, if the target copper ion concentration is about 2g/l and the concentration drift depletes about 0.6 g/l of copper from the catholyte, the concentration has now dropped by 30% and the plating performance may therefore experience a significant negative impact.

[0040] As mentioned, in some systems such as those employing a relatively low acid concentration (e.g., about pH 2-4), the partition effect may be insignificant. However some such systems (e.g., certain cobalt plating systems) may exhibit a low metal plating efficiency. Observed variations of plating with cobalt are shown in Figures through 4A-C, which assumes that dosing is employed to control acid and cobalt ion concentration in the electroplating solution. As mentioned, the cobalt plating electrolyte may include cobalt salts, sulfuric acid, organic additives, and boric acid as a buffer solution.

[0041] On a plating apparatus, it is sometimes desirable to have an auxiliary cathode, as disclosed in US patent 8,308,931 entitled “Method and Apparatus for Electroplating” to Reid et al. , and US patent 8,475,644 entitled “Method and Apparatus for Electroplating” to Mayer et al. both incorporated herein by reference in their entireties. Implementing an auxiliary cathode, or auxiliary anode, in an electrolyte management system provide certain advantages. The auxiliary cathodes are usually contained in small isolated chambers to avoid contacting with the main cathode (wafer substrate in a plating apparatus), and they are usually of smaller size as compared to the main cathode (wafer substrate). It is sometimes desirable to have different concentration for the electrolyte in the auxiliary cathode chamber. For example, it is sometimes preferred to have higher anion concentration (than in the plating electrolyte for main cathode) in the auxiliary cathode chamber so that higher current could be applied on the auxiliary cathode. [0042] While this disclosure presents examples of cobalt and copper electroplating, the disclosure is not limited to these plating applications. The embodiments and concepts presented herein apply to any metal plating system in which the metal plating current efficiency is less than 100%. Particular examples include those in which the thermodynamic electroplating potential is negative (by comparison to that of the hydrogen ion reduction reaction). Additionally, the disclosed embodiments and concepts apply not only to plating reactions in which hydrogen ion reduction is the primary reaction competing with metal plating, but to any plating application in which a parasitic reaction occurs

Definitions

[0043] The following terms are used intermittently throughout the instant disclosure:

[0044] Substrate” - In this application, the terms“semiconductor wafer,”“wafer,” “substrate,”“wafer substrate” and“partially fabricated integrated circuit” are used interchangeably. One of ordinary skill in the art would understand that the term “partially fabricated integrated circuit” can refer to a silicon wafer during any of many stages of integrated circuit fabrication thereon. A wafer or substrate used in the semiconductor device industry typically has a diameter of 200 mm, or 300 mm, or 450 mm. Further, the terms“electrolyte,”“electroplating bath,” “plating bath,” “bath,”“electroplating solution,” and“plating solution” are used interchangeably. The following detailed description assumes the embodiments are implemented on a wafer. However, the embodiments are not so limited. The work piece may be of various shapes, sizes, and materials. In addition to semiconductor wafers, other work pieces that may take advantage of the disclosed embodiments include various articles such as printed circuit boards, magnetic recording media, magnetic recording sensors, mirrors, optical elements, micro-mechanical devices and the like.

[0045] “Metal” - a material (an element, compound, or alloy) that is, for the purposes of this disclosure, desirable for plating onto a substrate or wafer. Examples include copper, cobalt, tin, silver, nickel, and alloys or combinations of any of these.

[0046] “Electroplating cell” - a cell, typically configured to house an anode and a cathode, positioned opposite to each other. Electroplating, which takes place on the cathode in an electroplating cell, refers to a process that uses electric current to reduce dissolved metal cations so that they form a thin coherent metal coating on an electrode. In certain embodiments, an electroplating has two compartments, one for housing the anode and the other for housing the cathode. In certain embodiments, an anode chamber and a cathode chamber are separated by a semi-permeable membrane that permits for the selective movement of concentrations of ionic species therethrough. The membrane may be an ion exchange membrane such as a cation exchange membrane. For some implementations, versions of Nafion™ (e.g., Nafion 324) are suitable. [0047] “Anode chamber” - a chamber within the electroplating cell designed to house an anode. The anode chamber may contain a support for holding an anode and/or providing one or more electronic connections to the anode. The anode chamber may be separate from the cathode chamber by a semi-permeable membrane. The electrolyte in the anode chamber is sometimes referred to as anolyte. [0048] “Cathode chamber” - a chamber within the electroplating cell designed to house a cathode. Often in the context of this disclosure, the cathode is a substrate such as a wafer such as a silicon wafer having multiple partially fabricated semiconductor devices. The electrolyte in the cathode chamber is sometimes referred to as catholyte. [0049] “Electroplating solution (or electroplating bath or plating electrolyte)” - a liquid of dissociated metal ions, often in solution with a conductivity enhancing component such as an acid or base. The dissolved cations and anions disperse uniformly through the solvent. Electrically, such a solution is neutral. If an electric potential is applied to such a solution, the cations of the solution are drawn to the electrode that has an abundance of electrons, while the anions are drawn to the electrode that has a deficit of electrons.

[0050] “Make-up solution” - a type of electroplating solution that typically contains all or nearly all components of the primary electroplating solution. Make-up solution is provided to an electroplating solution to maintain the concentration of solution components within desired ranges, chosen to maintain good electroplating performance. This approach is used because concentrations of components vary in the in the solution drift or vary with time due to any of a number of factors as described below. Make-up solution is often provided as the“feed” of a bleed and feed system. Often the concentrations of components in the make-up solution are similar or identical to the target concentrations for those components. Some make-up solutions do not include organic plating additives.

[0051] “Recirculation system” - provision of fluid substances back into a central reservoir for subsequent re-use. A recirculation system may be configured to efficiently re-use electroplating solution and also to control and/or maintain concentration levels of metal ions within the solution as desired. A recirculation system may include pipes or other fluidic conduits together with a pump or other mechanism for driving recirculation.

[0052] “Target concentration” - a concentration level of metal ions and/or other components in the electroplating solution used to achieve desired plating performance. In various embodiments, components of the make up solution are provided at the target concentrations.

[0053] “Active anode” - an anode that donates metal ions to the electroplating solution when current passes through the anode. A cobalt metal anode that donates cobalt ions to the solution during electroplating is an example of an active anode. The electrochemical reaction taking place at an active anode is often of the form Me - Me ⁺ + e (assuming the anode metal produces valence +1 metal ions in solution). An active anode is consumed during electroplating.

[0054] “Inert anode” - an anode that does not donate metal ions or other material to the electroplating solution when current passes through the anode. In many systems, a platinum anode is an inert anode. An example of an electrochemical reaction taking place at an inert anode is 2 H ₂ 0 - 4H ⁺ + 0 ₂ + 4e. An inert anode is not consumed during electroplating.

[0055] Concentrations recited in g/l refer to the total mass of a component in grams per one liter of solution. For example, a 10 g/l concentration of component A means that 10 grams of component A are present in a one liter volume of the solution containing component A. When specifying a concentration of an ion such as copper ion or cobalt ion in g/l, the concentration value refers to the mass of the ion alone (not the salt or salts from which the ion was produced) per unit volume of solution. For example, a concentration of 2 g/l of copper ion contains 2 g of copper ion per liter of solution in which the copper ion is solubilized. It does not refer to 2 grams of copper salt (e.g., copper sulfate) per liter of solution or otherwise refer to the mass of the anion. However, when referring to the concentration of an acid such as sulfuric acid, methane sulfonic acid, or boric acid, the concentration value refers the mass of the entire acid (hydrogen and anion) per unit volume. For example, a solution having 10 g/l sulfuric acid contains 10 grams of H ₂ S0 ₄ per liter of solution.

[0056] When specifying concentration values,“substantially the same” means within about +1-5% from a specified target value. For example, a concentration that is substantially the same as 2 g/l may be within a range of about 1.9 to 2.1 g/l. Unless otherwise noted when specifying concentration values,“significantly deviate from,” “is significantly different than,” and the like mean that the more concentrated component has a concentration that is between about 1.3 times and 50 times the concentration of the less concentrated component. In some cases, the concentration difference of a component in (a) a secondary electroplating solution and (b) a primary electroplating solution’s target concentration or a make up solution, is between about 5 to 50 times. For example, the concentration of component A is about 5 to 50 times greater in the secondary electroplating solution than in the primary electroplating solution, or vice versa. In another example, the concentration of component A is about 5 to 20 times greater in the secondary electroplating solution than in the primary electroplating solution, or vice versa. In yet another example, the concentration of component A is about 15 to 30 times greater in the secondary electroplating solution than in the primary electroplating solution, or vice versa.

Electroplating Systems Using an Inert Anode together with an Active Anode

[0057] As described previously, component concentration drift in a plating electrolyte may be common. This is especially true for a plating apparatus with separate anodic and cathodic portions, but may not be necessarily tied to that kind of design. To maintain both catholyte and anolyte concentration to acceptable level to ensure acceptable electrochemical plating performance, a general approach in controlling the electrolyte concentration is to adopt a high electrolyte replenish (e.g.,“bleed and feed”) rate. However, doing so may increase operational costs of running plating processes significantly, and sometimes make the plating process prohibitively expensive. In addition, in some cases, application and/or usage of a high bleed and feed rate alone may not adequately address the electrochemical plating performance related problems. A second approach that could be used is to have separate dosing for each and every component in the electrolyte. However, doing so could make the dosing algorithm extremely complicated. Additionally, dosing of every component to the plating electrolyte would generate a diluting effect to all other components in the plating electrolyte. Thus, the plating apparatus could end up being in dosing/calculating status all the time. Accordingly, this approach is generally avoided.

[0058] One approach to addressing these issues is by adopting a“complementary” secondary electroplating solution, and thereby significantly reduce the replenish rate while minimizing concentration drift in the electroplating solution. By designing the secondary electrolyte properly, the usage of secondary electrolyte could be minimized so that adopting secondary electrolyte would not contribute toward substantial additional costs to setting up and running the plating apparatus. This approach is detailed in PCT Patent Application No. PCT/US2018/057105, filed on October 23, 2018, and naming Zhian He et al. as inventors, which is incorporated herein by reference in its entirety. Use of a secondary electrolyte may be optionally implemented in conjunction with the methods and systems employing inert anodes and described herein.

[0059] Certain embodiments described herein employ electroplating cells having an active anode and an inert anode. These cells operate (or are configured to operate) the active and inert anodes in a way that produces and/or consumes ions to match or approximate the plating efficiency at the workpiece cathode (e.g., a semiconductor wafer). For example, the active anode may be operated to produce metal ions and the inert anode may be operated to produce hydrogen ions. The relative amounts of metal and hydrogen ions produced by the active and inert anodes, respectively, may match the relative amounts of these ions consumed during electroplating on the workpiece.

The active and inert anodes may be controlled to produce this result by dividing the total current between the two anodes. The current may be delivered to the two electrodes simultaneously and/or at different times.

[0060] In various embodiments, the electroplating cell is operated in a way that (1) removes metal ions from the electroplating solution by plating on an electrode surface other than the workpiece, and/or (2) adds hydrogen ions to the electroplating solution by an electrochemical reaction that does not provide metal ions to the solution. Operation (1) reduces the concentration of metal ions in the electroplating solution and operation (2) increases the concentration of hydrogen ions in the electroplating solution. Examples of electrodes on which metal may be plated in (1) include an auxiliary cathode (optionally used for other purposes as well) and the active anode.

To plate onto the active anode, the electroplating cell is operated in a somewhat reversed fashion; i.e., a negative potential is applied the active anode, temporarily converting it to a cathode.

[0061] The electroplating systems disclosed herein employ a power supply with circuitry for dividing current between the inert anode and the active anode. In some implementations, the two anodes are controlled separately by two different power supply units. In other implementations, the two anodes are controlled by two separate channels of the same power supply. In some cases, the anodes are controlled sequentially (separate or overlapping but distinct times) by same channel of the same power supply. Regardless of how the power supply is configured, a controller may be employed to control the relative amounts of anodic current delivered to the inert anode and the active anode. The relative amounts may be determined, at least in part, by the current efficiency of the plating reaction on a semiconductor substrate.

[0062] In certain embodiments, the electroplating system is configured to electroplate cobalt onto the substrate. In embodiments presented herein, cobalt electroplating solutions may include a cobalt salt (e.g., cobalt sulfate), and acid (e.g., sulfuric acid), boric acid, organic additives, and deionized water. Typical concentration ranges for such components include about 2-40 (Co ²⁺ )g/l, about 10-40 g (H ₃ B0 ₃ )/l (boric acid), about 0.01-0. lg acid (e.g., sulfuric acid), and about 20-400 ppm organic plating additives. [0063] By using an inert anode, the metal ion generation and consumption rate may be balanced to provide long-term electroplating bath stability. The following three examples further elaborate the concepts.

Inert Anode and Active Anode both Located in an Anode Portion of Electroplating System

[0064] As illustrated in Figure 5a, an inert anode is provided in the plating apparatus such as the one described in Figures 1 and 2. In this example, the inert anode may be provided anywhere inside the anode loop. For demonstration purposes, in Figure 5a, the inert anode is located around the active anode. It may be mechanically isolated from the main cathode. It may optionally be electrically connected to the active anode depending on whether it is used at the same time as the active anode. See Figure 10. Used alone, this approach simply uses a fraction of the anodic current to generate hydrogen ions. Together the active and inert anodes produce metal ions and hydrogen ions in a ratio that more closely approximates the current efficiency of the cathode than would occur if the active anode was used alone. In certain embodiments, the active and inert anodes produce metal ions and hydrogen ions in a ratio that is substantially the same as the ratio that these ions are consumed at the cathode. [0065] During the plating process, while the active anode generates metal ions in the electroplating solution through reaction of Me -> Me ⁺ + e, the inert anode uses part of the total current to drive the following reaction: 2I¾0- 0 ₂ + 4H ⁺ + 4e. At the cathode side, the following two reactions happen simultaneously: Me ⁺ + e - Me, and 2H ⁺ + 2e - H _2. By properly choosing the amount of current used by the inert anode to match the amount of current consumed by the H ₂ evolution reaction on the cathode, the metal ion generation and consumption rates can be tailored to match. Thus over a long term, there will be little or no metal ion concentration drift.

[0066] As for the acid, if acid generated by, e.g., 2H ₂ 0 -> 0 ₂ + 4H ⁺ + 4e is released to the electroplating solution, the acid generation and consumption rates will also be balanced.

[0067] There is a potential issue in that the acid generation reaction also generates gas (0 ₂ in this case), which could impact the plating process by releasing gas into the anolyte and/or catholyte. In certain embodiments, such gas is vented from the solution and/or a portion of the electroplating solution is bled from the system and acid is replenished by a dosing process. The total amount of acid dosing may be small and would not cause significant concentration drop in metal ion or other component (e.g., boric acid) concentration. Alternatively, oxygen may be removed from the system by using an oxygen control system such as described in US Patent No. 9,816,913, filed December 13, 2011 and US Patent No. 9,816,196, filed April 24, 2013, each of which is incorporated herein by reference in its entirety.

[0068] Approaches that employ an inert anode in the anode loop can be applied in a manner where the active anode and inert anodes are activated at different times (not simultaneously). For example, if the current efficiency for plating onto the wafer substrate is >50%, the main anode may be used for majority of the wafer plating; and during this time, the electroplating solution receives more metal ion than is removed, thus producing a net increase in metal ion concentration. Once the metal ion concentration reaches a trigger level, the inert anode may be used instead of the active anode. During this time period, the electroplating solution receives no metal ions but consumes metal ions on the cathode. Thus there is a net loss of metal ion in the electroplating solution. By alternating between active and inert anodes, metal ion concentration may be balanced over long-term. This is illustrated in Figure 5B.

Auxiliary Cathode serves as an Inert Anode

[0069] An example of this approach is illustrated in Figure 6A and Figure 6b. In this approach, the inert anode resides in the cathode side and is operated (passes current) as an anode only at certain times, and often when a workpieces is not present in a holder. In certain embodiments, the inert anode operates at times between when substrates (i.e., after one substrate is removed from the electroplating solution and before the next sequential substrate is provided to the electroplating solution. In certain embodiments, during plating process, the inert anode is inactive; i.e., it does not participate in an electrochemical reaction. Thus, during the plating process, the metal ion generation rate on the anode side is greater than the metal ion consumption rate on the cathode side; i.e., there is a net addition of metal ion to the electroplating solution. [0070] At certain times, typically outside of substrate plating operations (e.g., during post plating wafer handling or during an idle time for the electroplating cell), the inert anode is turned on, and the active anode is biased to act as a cathode. At the inert anode, the reaction of 2H ₂ 0 -> 0 ₂ + 4H ⁺ + 4e occurs, which does not generate or consume metal ions. On the anode side (now acting as cathode), the reaction Me ⁺ + e - Me occurs such that the process consumes metal ions from the electroplating solution. Conducting this“reverse” plating operation under conditions that provide a high current efficiency of metal plating at the active anode, which is now serving as a cathode, the above reactions cause a net metal ion consumption. The reactions may also cause a net hydrogen ion production. These effects tend to balance the net metal ion generation in the previous wafer plating step. Note that operating the active anode at a relatively high plating current tends to produce a high current efficiency for the Me ⁺ + e - Me reaction. For certain cobalt electroplating solution compositions, the current efficiency reaches 80-90% when current is in the range of about 1-2 A (about 1.5 - 3 mA/cm ² ); the current efficiency approaches 100% when current is in the range of about 4-6A (about 5 - 9 mA/cm ² ).

[0071] On certain electroplating tools (e.g., the Sabre® family of tools available from Lam Research, Inc. of Fremont, CA), one or more auxiliary cathodes are included to help address the terminal effect (i.e., the auxiliary help improve current uniformity over the face of the substrate, particularly at the edge of the substrate). In certain embodiments, the auxiliary cathode includes a noble metal coating (Pt for example). Such electrodes may be used as the inert anode in this approach. Examples of electroplating tools with one or more auxiliary cathodes are provided in US Patent No. 7,854,828, filed August 16, 2006; US Patent No. 8,858,774, filed April 3, 2012; and US Patent Application No. 14/734,882, filed June 9, 2015, each of which is incorporated herein by reference in its entirety.

[0072] In embodiments where the electroplating tool employs an auxiliary cathode as an inert anode, during normal plating some metal may be plated to the auxiliary cathode. Nevertheless the disclosed processes, will still work after the metal is stripped from the auxiliary cathode (by a de-plating process), beyond which acid generation will occur on the auxiliary cathode surface (2H ₂ 0 -> 0 ₂ + 4H ⁺ + 4e). Concurrently, on the active anode surface (now a cathode), metal ion is consumed through the reaction of Me ⁺ + e - Me. Thus, a net consumption of metal ion occurs.

Inert Anode in Conjunction with Auxiliary Cathode

[0073] An example of this approach is illustrated in Figure 7A and Figure 7B. In this approach, both an inert anode and an auxiliary electrode are used. During normal substrate plating, both the inert anode and the auxiliary cathode are inactive and are not involved in the plating process. Thus during the plating process, the metal ion generation rate on the anode side exceeds the metal ion consumption rate on the cathode side, and the electroplating solution experiences a net addition of metal ion. Outside of the normal substrate plating process (e.g., during post plating substrate handling or during tool idle time), the inert anode is turned on, and the auxiliary cathode is biased to act as a cathode. At the inert anode, the reaction of 2H ₂ 0 -> 0 ₂ + 4H ⁺ + 4e occurs and no metal ion is generated or consumed in the electroplating solution. At the auxiliary cathode side, the reaction Me ⁺ + e - Me occurs which pulls metal ions from the electroplating solution. By employing an appropriate plating time and current (thus total coulombs), this supplemental process of net metal ion consumption tends to balance the net metal ion generated during the normal substrate plating process. Over long term, the two processes (normal substrate plating and supplemental metal ion consumption) tend to stabilize the metal ion concentration in the electroplating solution.

Apparatus

[0074] Many apparatus configurations may be used in accordance with the embodiments described herein. One example apparatus includes a clamshell fixture that seals a wafer’s backside away from the plating solution while allowing plating to proceed on the wafer’s face. The clamshell fixture may support the wafer, for example, via a seal placed over the bevel of the wafer, or by means such as a vacuum applied to the back of a wafer in conjunction with seals applied near the bevel. [0075] The clamshell fixture should enter the bath in a way that allows good wetting of the wafer’s plating surface. The quality of substrate wetting is affected by multiple variables including, but not limited to, clamshell rotation speed, vertical entry speed, and the angle of the clamshell relative to the surface of the plating bath. These variables and their effects are further discussed in U.S. Patent No. 6,551,487, incorporated by reference herein. In certain implementations, the electrode rotation rate is between about 5-125 RPM, the vertical entry speed is between about 5-300 mm/s, and the angle of the clamshell relative to the surface of the plating bath is between about 1-10 degrees. One of the goals in optimizing these variables for a particular application is to achieve good wetting by fully displacing air from the wafer surface.

[0076] The electrodeposition methods disclosed herein can be described in reference to, and may be employed in the context of, various electroplating tool apparatuses. One example of a plating apparatus that may be used according to the embodiments herein is the Lam Research Sabre tool. Electrodeposition, including substrate immersion, and other methods disclosed herein can be performed in components that form a larger electrodeposition apparatus. Figure 8 shows a schematic of a top view of an example electrodeposition apparatus. The electrodeposition apparatus 1400 can include three separate electroplating modules 1402, 1404, and 1406. The electrodeposition apparatus 1400 can also include three separate modules 1412, 1414, and 1416 configured for various process operations. For example, in some embodiments, one or more of modules 1412, 1414, and 1416 may be a spin rinse drying (SRD) module. In other embodiments, one or more of the modules 1412, 1414, and 1416 may be post-electrofill modules (PEMs), each configured to perform a function, such as edge bevel removal, backside etching, and acid cleaning of substrates after they have been processed by one of the electroplating modules 1402, 1404, and 1406.

[0077] The electrodeposition apparatus 1400 includes a central electrodeposition chamber 1424. The central electrodeposition chamber 1424 is a chamber that holds the chemical solution used as the electroplating solution in the electroplating modules 1402, 1404, and 1406. The electrodeposition apparatus 1400 also includes a dosing system 1426 that may store and deliver additives for the electroplating solution. A chemical dilution module 1422 may store and mix chemicals to be used as an etchant. A filtration and pumping unit 1428 may filter the electroplating solution for the central electrodeposition chamber 1424 and pump it to the electroplating modules.

[0078] A system controller 1430 provides electronic and interface controls required to operate the electrodeposition apparatus 1400. The system controller 1430 (which may include one or more physical or logical controllers) controls some or all of the properties of the electroplating apparatus 1400. The system controller 1430 typically includes one or more memory devices and one or more processors. The processor may include a central processing unit (CPU) or computer, analog and/or digital input/output connections, stepper motor controller boards, and other like components.

Instructions for implementing appropriate control operations as described herein may be executed on the processor. These instructions may be stored on the memory devices associated with the system controller 1430 or they may be provided over a network. In certain embodiments, the system controller 1430 executes system control software.

[0079] The system logic (e.g., control software) in the electrodeposition apparatus 1400 may include instructions for controlling the timing, mixture of electrolyte components (including the concentration of one or more electrolyte components), inlet pressure, plating cell pressure, plating cell temperature, substrate temperature, current and potential applied to the substrate and any other electrodes, substrate position, substrate rotation, and other parameters of a particular process performed by the electrodeposition apparatus 1400. The system control logic may also include instructions for electroplating under conditions that are tailored to be appropriate for a low copper concentration electrolyte. For example, the system control logic may be configured to provide a relatively low current density during the bottom-up fill stage and/or a higher current density during the overburden stage. The control logic may also be configured to provide certain levels of mass transfer to the wafer surface during plating. For example, the control logic may be configured to control the flow of electrolyte to ensure sufficient mass transfer to the wafer during plating such that the substrate does not encounter depleted copper conditions. In certain embodiments the control logic may operate to provide different levels of mass transfer at different stages of the plating process (e.g., higher mass transfer during the bottom -up fill stage than during the overburden stage, or lower mass transfer during the bottom-up fill stage than during the overburden stage). Further, the system control logic may be configured to maintain the concentration of one or more electrolyte components within any of the ranges disclosed herein. As a particular example, the system control logic may be designed or configured to maintain the concentration of copper cations between about 1-10 g/l. System control logic may be configured in any suitable way. For example, various process tool component sub-routines or control objects may be written to control operation of the process tool components used to carry out various process tool processes. System control software may be coded in any suitable computer readable programming language. The logic may also be implemented as hardware in a programmable logic device (e.g., an FPGA), an ASIC, or other appropriate vehicle.

[0080] In some embodiments, system control logic includes input/output control (IOC) sequencing instructions for controlling the various parameters described above. For example, each phase of an electroplating process may include one or more instructions for execution by the system controller 1430. The instructions for setting process conditions for an immersion process phase may be included in a corresponding immersion recipe phase. In some embodiments, the electroplating recipe phases may be sequentially arranged, so that all instructions for an electroplating process phase are executed concurrently with that process phase.

[0081] The control logic may be divided into various components such as programs or sections of programs in some embodiments. Examples of logic components for this purpose include a substrate positioning component, an electrolyte composition control component, a pressure control component, a heater control component, and a potential/current power supply control component.

[0082] In some embodiments, there may be a user interface associated with the system controller 1430. The user interface may include a display screen, graphical software displays of the apparatus and/or process conditions, and user input devices such as pointing devices, keyboards, touch screens, microphones, etc.

[0083] In some embodiments, parameters adjusted by the system controller 930 may relate to process conditions. Non-limiting examples include bath conditions (temperature, composition, and flow rate), substrate position (rotation rate, linear (vertical) speed, angle from horizontal) at various stages, etc. These parameters may be provided to the user in the form of a recipe, which may be entered utilizing the user interface.

[0084] Signals for monitoring the process may be provided by analog and/or digital input connections of the system controller 1430 from various process tool sensors. The signals for controlling the process may be output on the analog and digital output connections of the process tool. Non-limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (such as manometers), thermocouples, optical position sensors, etc. Appropriately programmed feedback and control algorithms may be used with data from these sensors to maintain process conditions.

[0085] In one embodiment, the instructions can include inserting the substrate in a wafer holder, tilting the substrate, biasing the substrate during immersion, and electrodepositing a copper containing structure on a substrate.

[0086] A hand-off tool 1440 may select a substrate from a substrate cassette such as the cassette 1442 or the cassette 1444. The cassettes 1442 or 1444 may be front opening unified pods (FOUPs). A FOUP is an enclosure designed to hold substrates securely and safely in a controlled environment and to allow the substrates to be removed for processing or measurement by tools equipped with appropriate load ports and robotic handling systems. The hand-off tool 1440 may hold the substrate using a vacuum attachment or some other attaching mechanism.

[0087] The hand-off tool 1440 may interface with a wafer handling station 1432, the cassettes 1442 or 1444, a transfer station 1450, or an aligner 1448. From the transfer station 1450, a hand-off tool 1446 may gain access to the substrate. The transfer station 1450 may be a slot or a position from and to which hand-off tools 1440 and 1446 may pass substrates without going through the aligner 1448. In some embodiments, however, to ensure that a substrate is properly aligned on the hand-off tool 1446 for precision delivery to an electroplating module, the hand-off tool 1446 may align the substrate with an aligner 1448. The hand-off tool 1446 may also deliver a substrate to one of the electroplating modules 1402, 1404, or 1406 or to one of the three separate modules 1412, 1414, and 1416 configured for various process operations.

[0088] An example of a process operation according to the methods described above may proceed as follows: (1) electrodeposit copper onto a substrate to form a copper containing structure in the electroplating module 1404; (2) rinse and dry the substrate in SRD in module 1412; and, (3) perform edge bevel removal in module 1414.

[0089] An apparatus configured to allow efficient cycling of substrates through sequential plating, rinsing, drying, and PEM process operations may be useful for implementations for use in a manufacturing environment. To accomplish this, the module 1412 can be configured as a spin rinse dryer and an edge bevel removal chamber. With such a module 1412, the substrate would only need to be transported between the electroplating module 1404 and the module 1412 for the copper plating and EBR operations.

[0090] In some implementations, a controller (e.g., system controller 1430) is part of a system, which may be part of the above-described examples. The controller may contain control logic or software and/or execute instructions provided from another source. Such systems can include semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system. [0091] Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operations described herein, enable cleaning operations, enable endpoint measurements, metrology, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and/or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer.

[0092] The controller, in some implementations, may be a part of or coupled to a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus as described above, the controller may be distributed, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0093] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition

(ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and/or manufacturing of semiconductor wafers. [0094] As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.

[0095] An alternative embodiment of an electrodeposition apparatus 1500 is schematically illustrated in Figure 9. In this embodiment, the electrodeposition apparatus 1500 has a set of electroplating cells 1507, each containing an electroplating bath, in a paired or multiple“duet” configuration. In addition to electroplating per se, the electrodeposition apparatus 1500 may perform a variety of other electroplating related processes and sub-steps, such as spin-rinsing, spin-drying, metal and silicon wet etching, electroless deposition, pre-wetting and pre-chemical treating, reducing, annealing, photoresist stripping, and surface pre-activation, for example. The electrodeposition apparatus 1500 is shown schematically looking top down in Figure 9, and only a single level or“floor” is revealed in the figure, but it is to be readily understood by one having ordinary skill in the art that such an apparatus, e.g. the Lam Sabre™ 3D tool, can have two or more levels“stacked” on top of each other, each potentially having identical or different types of processing stations.

[0096] Referring once again to Figure 9, the substrates 1506 that are to be electroplated are generally fed to the electrodeposition apparatus 1500 through a front end loading FOUP 1501 and, in this example, are brought from the FOUP to the main substrate processing area of the electrodeposition apparatus 1500 via a front-end robot 1502 that can retract and move a substrate 1506 driven by a spindle 1503 in multiple dimensions from one station to another of the accessible stations— two front-end accessible stations 1004 and also two front-end accessible stations 1008 are shown in this example. The front-end accessible stations 1504 and 1508 may include, for example, pre-treatment stations, and spin rinse drying (SRD) stations. Lateral movement from side-to-side of the front-end robot 1502 is accomplished utilizing robot track l502a. Each of the substrates 1506 may be held by a cup/cone assembly (not shown) driven by a spindle 1503 connected to a motor (not shown), and the motor may be attached to a mounting bracket 1509. Also shown in this example are the four“duets” of electroplating cells 1507, for a total of eight electroplating cells 1507. The electroplating cells 1507 may be used for electroplating copper for the copper containing structure and electroplating solder material for the solder structure. A system controller (not shown) may be coupled to the electrodeposition apparatus 1500 to control some or all of the properties of the electrodeposition apparatus 1500.

The system controller may be programmed or otherwise configured to execute instructions according to processes described earlier herein.

[0097] The electroplating apparatus/methods described hereinabove may be used in conjunction with lithographic patterning tools or processes, for example, for the fabrication or manufacture of semiconductor devices, displays, LEDs, photovoltaic panels and the like. Generally, though not necessarily, such tools/processes will be used or conducted together in a common fabrication facility. Lithographic patterning of a film generally includes some or all of the following steps, each step enabled with a number of possible tools: (1) application of photoresist on a work piece, i.e., a substrate, using a spin-on or spray-on tool; (2) curing of photoresist using a hot plate or furnace or UV curing tool; (3) exposing the photoresist to visible, UV, or x-ray light with a tool such as a wafer stepper; (4) developing the resist so as to selectively remove resist and thereby pattern it using a tool such as a wet bench; (5) transferring the resist pattern into an underlying film or work piece by using a dry or plasma- assisted etching tool; and (6) removing the resist using a tool such as an RF or microwave plasma resist stripper. [0098] When numerical ranges are presented endpoints in those ranges are not limited to the exact values with more significant digits than used. Unless otherwise specified, the endpoints include some variability while conforming with any of the goals of this disclosure. For example, end points may be interpreted to include values within +/- 10% of the recited value. [0099] It is to be understood that the configurations and/or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. As such, various acts illustrated may be performed in the sequence illustrated, in other sequences, in parallel, or in some cases omitted.

Likewise, the order of the above described processes may be changed.

[0100] The subject matter of the present disclosure includes all novel and nonobvious combinations and sub-combinations of the various processes, systems and configurations, and other features, functions, acts, and/or properties disclosed herein, as well as any and all equivalents thereof.