TECHNICAL FIELD

[0001] The present disclosure relates generally to methods of forming contacts for semiconductor devices. In particular, the disclosure relates to processes for forming self-aligned contacts with critical dimension control.

BACKGROUND

[0002] The semiconductor industry is using an increasing variety of chemistries for chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes that come in liquid or solid form. The precursor is typically inside a closed vessel or ampoule with a single inlet and a single outlet.

[0003] Precursors with a low vapor pressure frequently use a carrier gas to carry the vapor out of the ampoule to the process reactor. For these types of processes there are two types of ampoules typically used: a bubbler where the inlet carrier gas goes into a tube that is submerged into the precursor; and a cross-flow ampoule where the carrier gas sweeps the headspace in the ampoule. There are situations where a bubbler cannot be used due to entrainment of the precursor nor a cross-flow ampoule because the flux of the precursor does not meet the process parameters.

[0004] Therefore, there is a need in the art for ampoules and methods to provide a higher flux of precursor than a cross-flow ampoule. SUMMARY

[0005] One or more embodiments of the disclosure are directed to an ampoule for semiconductor manufacturing precursors. The ampoule comprises a container having a bottom, sidewalls and a lid enclosing a cavity. An inlet port is in fluid communication with the cavity. The inlet port has a showerhead on an end of the inlet port located within the cavity. The showerhead comprises at least two angled nozzle to direct a flow of gas so that when a liquid is present in the container. The flow of gas is not perpendicular to a surface of the liquid. An outlet port is in fluid communication with the cavity. [0006] Additional embodiments of the disclosure are directed to an ampoule for a semiconductor manufacturing precursor. The ampoule comprises a container having a bottom, sidewalls and a lid enclosing a cavity. An inlet port is in fluid communication with the cavity. The inlet port has a showerhead on an end of the inlet port located within the cavity. The showerhead comprises three angled nozzles to direct a flow of gas so that when a liquid is present in the container, the flow of gas from each nozzle is independently in the range of about 5 ^Q to about 7- measured relative to a line orthogonal to the surface of the liquid. An outlet port is in fluid communication with the cavity. [0007] Further embodiments of the disclosure are directed to methods of providing a flow of precursor. A carrier gas is flowed through an inlet port of a precursor ampoule having a liquid precursor therein. The flow of carrier gas is directed within the ampoule with a showerhead at an end of the inlet port. The showerhead comprises at least two angled nozzles to direct the flow of gas at an angle no perpendicular to a surface of the liquid precursor. The carrier gas and precursor is flowed out of the ampoule through an outlet port.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. [0009] FIG. 1 shows a sectioned view of an ampoule in accordance with one or more embodiment of the discourse;

[0010] FIG. 2 shows an expanded region 2 of FIG. 1 ;

[0011] FIG. 3 shows a partial cross-sectional of an ampoule in accordance with one or more embodiment of the disclosure; and [0012] FIG. 4 shows a schematic view of an ampoule and plumbing in accordance with one or more embodiment of the disclosure.

[0013] In the appended figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label. The cross-hatch shading of the components in the figures are intended to aid in visualization of different parts and do not necessarily indicate different materials of construction.

DETAILED DESCRIPTION

[0014] Before describing several exemplary embodiments of the invention, it is to be understood that the invention is not limited to the details of construction or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or being carried out in various ways.

[0015] Some embodiments of the disclosure advantageously provide ampoules with higher flux than cross-flow ampoules. Some embodiments advantageously provide ampoules with a gas flow that does not bubble through the liquid precursor. Some embodiments advantageously provide gas flows that are not orthogonal to the precursor surface.

[0016] In some embodiments, a showerhead is provided on an inlet of the ampoule with a plurality of nozzles that are angled over the liquid within. A distance between the level of the liquid and the showerhead is maintained so that the showerhead is not submerged in the liquid.

[0017] FIG. 1 shows an ampoule 100 for use with semiconductor manufacturing reagents. The term "precursor" is used to describe the contents of the ampoule 100 and refers to any reagent that flowed into the process environment. [0018] The ampoule 100 includes a container 1 1 0 with a bottom 1 1 2, sidewalls 1 14 and a lid 1 1 6 enclosing a cavity 1 1 8. An inlet port 1 20 and outlet port 1 30 are in fluid communication with the cavity 1 1 8.

[0019] The inlet port 1 20 is generally configured to allow a connection to a gas source and may have suitable threaded or sealing connections. The inlet port 1 20, as shown in FIGS. 1 and 2, has a passage 1 21 with an inner diameter defining a cross- sectional width of the passage 1 21 . The passage 1 21 has a bottom end 1 25 that can be curved, tapered or come to a flat end.

[0020] The inlet port 1 20 has a showerhead 1 22 on an end 1 23 of the inlet port 1 20 located within the cavity 1 1 8. The showerhead 122 is the portion of the inlet port 1 20 located between the bottom end 1 25 of the passage 1 21 and the end 1 23 of the inlet port 1 20. The showerhead 122 comprises at least two angled nozzles 140 to direct a flow of gas 141 . The number of nozzles 1 40 in the showerhead 1 22 can be in the range of about 2 to about 24, or in the range of about 2 to about 1 8, or in the range of about 2 to about 12, or in the range of about 2 to about 1 0 or in the range of about 2 to about 8, or in the range of about 2 to about 6, or in the range of about 2 to about 4. In some embodiments, there are three nozzles 140 in the showerhead 1 22.

[0021 ] The nozzles 140 are configured to provide an angled flow of gas 141 , measured relative to a line orthogonal to the surface 1 51 of a liquid 1 50 within the ampoule 1 00. With reference to FIGS. 2 and 3, each nozzle 140 has axis 144 that is directed at an angle Θ relative to the line orthogonal 145 to the surface 1 51 .

[0022] The angle Θ can be any suitable angle that is not perpendicular to the surface 151 of the liquid 1 50. Each nozzle 140 can have a difference angle Θ than any other nozzle 140. In some embodiments, the angle Θ is greater than 1 ^Q , 2 ^Q , 3 ^Q or A- relative to the line orthogonal 145 to the surface 1 51 . In some embodiments, the angle Θ is in the range of about 2- to about 25 ^Q , or in the range of about 2.5 ^Q to about 1 5 ^Q , or in the range of about 3 ^Q to about 1 2 ^Q , or in the range of about A- to about 10 ^Q , or in the range of about 5 ^Q to about 7 ^Q . In some embodiments, the flow of gas exiting the nozzle is not perpendicular to the surface 1 51 of a liquid 1 50 within the container 1 1 0. [0023] An outlet port 130 is also in fluid communication with the cavity 1 1 8 in the container 1 10. The outlet port 130 is generally configured to be able to connect to a line to allow the gases exiting the container 1 10 to flow to a processing chamber (or other component). The outlet port 130 may have a threaded connection to allow a gas line to be connected.

[0024] In some embodiments, as shown in FIG. 1 , the lid 1 16 is a separate component from the bottom 1 12 and sidewalls 1 14. The lid 1 16 can be connected to the sidewalls 1 14 of the container 1 10 using removable bolts through appropriately shaped openings 160. The openings 160 may have a threaded portion to allow for easy connection of a threaded bolt. The bolts can be removed to allow the lid 1 16 to be removed from the container 1 10 so that the precursor in the container 1 10 can be changed or added. In some embodiments, the container 1 10 includes an O-ring 162 positioned between the lid 1 16 and the sidewalls 1 14 to form a fluid tight seal.

[0025] In some embodiments, as shown in FIG. 4, the lid 1 16 can be integrally formed with the sidewalls 1 14 and bottom 1 12 of the container 1 10. Different plumbing configurations can be connected to the lid 1 16 to allow the ampoule 100 to be added to a process chamber. In some embodiments, an inlet line 170 is connected to the inlet port 120. An inlet valve 172 can be positioned on the inlet line 170 between gas source 175 and the inlet port 120. The inlet valve 172 can be integrally formed with the lid 1 16 or connected to the lid 1 16 as a separate component. An outlet line 180 can be connected to the outlet port 130. The outlet line 180 of some embodiments includes an outlet valve 182 located between the outlet port 130 and the processing chamber 185. The inlet valve 172 and outlet valve 182 can be used to isolate the ampoule 100 so that the contents of the cavity 1 18 are isolated from the environment outside of the container 1 10. In some embodiments, there are multiple valves along the inlet line 170 and/or the outlet line 180. The valves 172, 182 can be manual valves or pneumatic valves.

[0026] In some embodiments, the ampoule 100 includes a liquid 150 within the cavity 1 18. The liquid 150 can be a precursor for use with a semiconductor manufacturing process. The liquid 150 of some embodiments comprises dicobalt hexacarbonyl tert-butylacetylene (CCTBA). [0027] Referring to FIG. 3, the distance D of the showerhead 122 to the surface 151 of the liquid 150 can vary over time and use of the precursor. As the precursor is used, the volume within the container 1 10 will decrease so that the distance D increases. The distance D is sufficient to prevent the showerhead 122 from contacting or being submerged in the liquid 150.

[0028] In some embodiments, the gas flow 141 through the inlet port 120 and showerhead 122 is sufficient to disturb a liquid/gas interface of the liquid precursor without bubbling. In some embodiments, disturbing the liquid/gas interface forms a dimple 153 in the surface 151 of the liquid 150. The dimple 153 can have a depth up to about 3 mm. In some embodiments, the dimple has a depth (measured from the surface 151 ) that is greater than or equal to about 0.1 mm. In some embodiments, the dimple 153 has a depth less than or equal to about 2.5 mm, 2 mm, 1 .5 mm, 1 mm or 0.5 mm. The gas flow 141 can be adjusted during processing as the level of liquid 150 decreases to maintain a sufficient disturbance of the liquid/gas interface. The gas flow 141 of some embodiments, has a maximum velocity sufficient to prevent condensation of the liquid 150 at the outlet port 1 30.

[0029] Reference throughout this specification to "one embodiment," "certain embodiments," "one or more embodiments" or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Thus, the appearances of the phrases such as "in one or more embodiments," "in certain embodiments," "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the invention. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0030] Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and apparatus of the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention include modifications and variations that are within the scope of the appended claims and their equivalents.