NOVEL PAD-IN-A-BOTTLE (PIB) TECHNOLOGY FOR ADVANCED CHEMICAL- MECHANICAL PLANARIZATION (CMP) SLURRIES AND PROCESSES

CROSS REFERENCE TO RELATED APPLICATION(S)

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63/022,737 filed May 11 , 2020, which is incorporated herein by reference as if fully set forth.

BACKGROUND OF THE INVENTION

[0002] This invention relates generally to a novel pad-in-a-bottle (PIB) technology for advanced chemical-mechanical planarization (CMP) slurries, systems and processes. Specifically, present invention relates to PIB technology for ceria-based CMP Shallow Trend Isolation (STI) slurries, systems and processes.

[0003] A polishing pad is used in a conventional chemical-mechanical polishing (CMP). The surface asperities of a polishing pad play a key in the slurry.

[0004] The asperities on a pad such as a polyurethane (PU) pad are irreversibly deformed due to wafer contact and are also abraded by slurry particles. A pad with deformed asperities often generates micro-scale scratches on the surfaces being polished. Furthermore, poorly controlled shapes of pad asperities cause high variable contact area distributions resulting in variations in removal rate (RR), and wafer-level topography.

[0005] As such, the pad surface must be continuously renewed with a diamond disc to ensure process stability. During the renewing process, the diamond disk cuts the pad surface to eliminate old asperities and create new ones, thus the thickness of a pad is gradually getting so thin resulting in a replacement (Figure 1).

[0006] Thus, large amounts of waste are created due to frequent replacement of pads and conditioners from the conventional CMP processes.

[0007] Work has been done to mitigate the issue caused by pad asperities.

[0008] This invention discloses PIB technology for ceria-based CMP STI slurries, systems and processes developed to meet challenging requirements. BRIEF SUMMARY OF THE INVENTION

[0009] The needs are satisfied by using the disclosed compositions, methods, and planarization systems for CMP of oxide-containing substrate.

[0010] In one aspect, CMP polishing compositions is provided. The CMP polishing composition comprises: polyurethane (PU) beads; nano-sized abrasive particles; a dispersing agent; water; and optionally, pH adjuster; biocide; wherein the formulation has a pH from 2 to 12; 4 to 10, or 5 to 9 .

[0011] In another aspect, CMP polishing method is provided. The CMP polishing method comprises: providing the semiconductor substrate having a surface containing silicon dioxide; providing a polishing pad; providing the chemical mechanical polishing (CMP) formulation stated above; contacting the surface of the semiconductor substrate with the polishing pad and the chemical mechanical polishing formulation; and polishing the surface of the semiconductor substrate; wherein at least a portion of the surface containing silicon dioxide is in contact with both the polishing pad and the chemical mechanical polishing formulation.

[0012] In yet another aspect, CMP polishing system is provided. The CMP polishing system comprises: a semiconductor substrate having a surface containing silicon dioxide; providing a polishing pad; providing the chemical mechanical polishing (CMP) formulation in claim stated above; wherein at least a portion of the surface containing silicon dioxide is in contact with both the polishing pad and the chemical mechanical polishing formulation.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS [0013] Figure 1 (Prior art) shows a conventional CMP polishing with a polyurethane pad 146.

[0014] Figure 2 shows PIB CMP polishing with a polyurethane pad 146 and polyurethane beads (130).

DETAILED DESCRIPTION OF THE INVENTION [0015] The present invention discloses a new technology where the role of pad asperities is played by high-quality polyurethane (PU) beads having a size ranging from 2micron to lOOmicron, 10 micron to 80 micron, 20 micron to 70 micron, or 30micron to 50micron that are comparable to the sizes of pores and asperities in commercial polishing pads. The beads are suspended in polishing slurry having abrasive particles, such as a calcined ceria, colloidal silica or composite particles with the assistance of a surfactant (or a wetting agent) as the dispersing agent to disperse polyurethane beads in aqueous slurries.

[0016] The beads come into contact with the wafer surface by a means described below to promote polishing in much the same way as conventional asperities (Figure 1). [0017] By selecting both the size of the beads, and their concentration in the slurry, much better control of the height, curvature, and area density of the “summits” that come in contact with the wafer are achieved, substantially reducing the process variability associated with conventional asperity contact.

[0018] Use of beads still requires a second surface, or counter-face, for polishing to occur, which in our case continues to be a conventional polyurethane -based pad, but one that requires minimal conditioning as it is no longer the primary surface where polishing takes place. Alternatively, one can use an inexpensive and partially-conditioned pad as the counter-face as shown in Figure 2.

[0019] A commercial polisher may use 2 to 3 pads and conditioners simultaneously. End-of-life for a pad and a conditioning discs typically reached after only 2 days of continuous use. Each platen in a CMP tool, therefore, uses hundreds of pads and conditioners annually, and since wafer fabrication facilities can have dozens of tools (with 2 or 3 platens on each tool), the total cost for pads and pad conditioners alone is substantial.

[0020] Since it can take several hours to remove an old pad, and install then qualify a new one, the engineering and product loss due to tool downtime and consumables used to qualify the new pad are significant. Used PU pads and discarded diamond disc conditioners represent waste from the CMP processes.

[0021] In the case of pads, only about two-thirds of the total pad thickness is used before the pad has to be stripped and discarded. For conditioners, only a few hundred diamonds out of tens of thousands control the product lifetime, after which the conditioner must be discarded. Furthermore, recycle or reuse options are not available for pads and conditioners. The waste also causes Environment, Health, and Safety (EHS)issue. The present invention addresses the above EHS issues and offers a novel solution to the current standard CMP processes by reducing and ultimately eliminating the use of a conventional polishing pad and diamond disc conditioners.

[0022] Several specific aspects of the present invention are outlined below.

Aspect 1 : A CMP polishing composition comprising: polyurethane (PU) beads; abrasive particles; dispersing agent; water; and optionally, pH adjuster; biocide; wherein the formulation has a pH from 2 to 12; 4 to 10, or 5 to 9 .

Aspect 2: A CMP polishing method comprising: providing the semiconductor substrate having a surface containing silicon dioxide; providing a polishing pad; providing the chemical mechanical polishing (CMP) formulation stated above; contacting the surface of the semiconductor substrate with the polishing pad and the chemical mechanical polishing formulation; and polishing the surface of the semiconductor substrate; wherein at least a portion of the surface containing silicon dioxide is in contact with both the polishing pad and the chemical mechanical polishing formulation.

Aspect 3: A CMP polishing system comprising: a semiconductor substrate having a surface containing silicon dioxide; providing a polishing pad; providing the chemical mechanical polishing (CMP) formulation stated above; wherein at least a portion of the surface containing silicon dioxide is in contact with both the polishing pad and the chemical mechanical polishing formulation.

[0023] The polyurethane (PU) beads have micron-size ranged from 2 micron to 100 micron, 10 micron to 80 micron, 20 micron to 70 micron, or 30 micron to 50 micron.

[0024] The concentration of polyurethane (PU) beads can range from about 0.010 wt.% to about 5.0 wt.%, about 0.025 wt.% to about 2.5 wt.%, about 0.05 wt.% to about 1 .0 wt.%, or 0.10 wt.% to about 0.50 wt.%. The weight percent is relative to the composition.

[0025] The abrasive particles include, but are not limited to inorganic oxide particles, metal oxide-coated inorganic oxide particles, metal-oxide-coated organic polymer particles, and combinations thereof.

[0026] The inorganic oxide particles include but are not limited to ceria, colloidal silica, high purity colloidal silica, fumed silica, colloidal ceria, alumina, titania, zirconia particles.

[0027] The metal oxide-coated inorganic oxide particles include but are not limited to the ceria-coated inorganic oxide particles, such as, ceria-coated colloidal silica, ceria- coated high purity colloidal silica, ceria-coated alumina, ceria-coated titania, ceria-coated zirconia, or any other ceria-coated inorganic oxide particles.

[0028] The metal oxide-coated organic polymer particles are selected from the group consisting of ceria-coated organic polymer particles, zirconia-coated organic polymer

[0029] The abrasive particles have a Mean-Particle-Size (MPS) from 20nm to 500nm, 50nm to 400nm, 100nm to 350nm, or 180nm to 220nm. The MPS can be measured by Dynamic Light Scattering (DLS) method.

[0030] The concentration of abrasive can range from about 0.01 wt.% to about 30 wt.%, the preferred is from about 0.05 wt.% to about 10 wt.%, the more preferred is from about 0.1 and about 2 wt.%. The weight percent is relative to the composition.

[0031] The dispersing agents are any agents that can disperse polyurethane beads in aqueous solution.

[0032] Examples of dispersing agents have the following general molecular structures

(1): wherein a is ranged from 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, or 1 to 5; b, c and a’ can be the same or different, and each is independently ranged from 0 to 50, 0 to 40, 0 to 30, 0 to 20, 0 to 10, or 0 to 5; n and m can be the same or different, and each is independently ranged from 0 to 12, 0 to 8, 1 to 5, or 2 to 4; side chain R and R groups can be the same or different, and each is independently selected from the group consisting of: hydrogen;

-(CH ₂ ) CH3 alkyl group with p ranging from 1 to 12 or 2 to 5, preferably 2 to 5; -NH ₂ group;

-NH(CH ₂ ) _q -NH ₂ group with q ranged from 1 to 12 or 2 to 5, preferably; ethylene oxide(EO) and propylene oxide (PO) repeating groups: -(EO)e-(PO)d-OH with d and e each independently ranged from 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, or 1 to 5, preferably 1 to 10, more preferably 1 to 5;

-COOH;

- R ¹ COOH with R ¹ being -(CH ₂ ) _m with m ranged from 1 to 12;

- R ¹ S0 ₃ H; -(0 ₆ H ₄ ) _h with n ranged from 1 to 4;

-COOM with M being Na ⁺ _, K ⁺ , or NH4 ⁺ , preferably K ⁺ or NH4 ⁺ ;

- R ¹ COOM;

-COOR ² with R ² being -(CH ₂ ) _m H, -(CH ₂ ) _m COOH (m = 1 to 12), or -(CH ₂ ) _m COOM (M = Na ⁺ ’ K ⁺ , or NH4 ⁺ , preferably K ⁺ , or NH4 ⁺ ), preferably-(CH ₂ ) _m H or -(CH ₂ ) _m COOH (m = 1 to 12); - R ¹ COOR ² ;

SO ₃ H;

-SO ₃ M; phosphonic acid; phosphate salt selected from sodium, potassium or ammonium salts; aromatic group selected from sodium benzyl, di-benzyl or other aromatic moieties.

[0033] Examples are silsulf E608, silquat DI-25 PG, silsulf J208-6, silsulf A008-AC-UP, silplex J2-S, silquat CR4000, silquat D2, silsulf CR1115, and silsulf A208 supplied by SILTECH CORPORATION 225 Wicksteed Avenue Toronto, Ontario, Canada, M4H 1G5.

[0034] Silsulf type of dispersing agents are silicon-containing polyether molecules with EO-PO repeating side chain functional groups. Silsulf type of dispersing agents are preferred.

[0035] The concentration of the dispersing agent ranges from about 0.0025 wt.% to about 5.0 wt.%, about 0.01 wt.% to about 2.5 wt.%, 0.025 wt.% to about 1.0 wt.%, or 0.050 wt.% to about 0.50 wt.%.

[0001] The pH of the CMP composition is about 2 to 12; 4 to 10, or 5 to 9.

[0002] The pH of the composition may be adjusted using an appropriate pH adjuster, such as a suitable acid, base, amine, or any combination thereof. Preferably, a pH adjuster used in the composition does not contain metal ions, such that undesirable metal components are not introduced into the composition. Suitable pH adjuster include amines, ammonium hydroxide, nitric acid, phosphoric acid, sulfuric acid, organic acids, and/or salts thereof, and any combination thereof.

[0003] The composition may comprise from 0 weight percent to 1 weight percent, preferably 0.005 weight percent to 0.5 weight percent, more preferably 0.02 weight percent to 0.2 weight percent of the pH adjuster selected from the group consisting of nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, other inorganic or organic acids, and mixtures thereof for acidic pH conditions, or selected from the group consisting of sodium hydride, potassium hydroxide, ammonium hydroxide, tetraalkyl ammonium hydroxide, organic quaternary ammonium hydroxide compounds, organic amines, and combinations thereof for alkaline pH conditions. [0004] the CMP composition may comprise biological growth inhibitors or preservatives to prevent bacterial and fungal growth during storage.

[0005] The biological growth inhibitors include, but are not limited to, tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride, alkylbenzyldimethylammonium chloride, and alkylbenzyldimethylammonium hydroxide, wherein the alkyl chain ranges from 1 to about 20 carbon atoms, sodium chlorite, and sodium hypochlorite.

[0006] Some of the commercially available preservatives include KATHONP ^iv' and NEOLENE ^; product families from Dow Chemicals, and Preventol^ family from Lanxess. More are disclosed in U.S. Pat. No. 5,230,833 (Romberger et al.) and US Patent Application No. US 20020025762. The contents of which are hereby incorporated by reference as if set forth in their entireties.

[0007] The use of biocide in enclosed CMP polishing compositions reduces or eliminates bacteria and other microorganisms, especially when the pH values of the CMP polishing compositions is close or around neutral pH conditions. The biocide ranges from about 0.0001 weight percent to about 0.03 weight percent of the CMP composition.

Working example

[0008] Examples using 15micron or 35-micron PU beads, a wetting agent, a broken-in IC-1070 pad, and a commercially available calcined ceria-based STI 21 OOF series (Versum Materials) slurry containing nano-sized abrasive particles have shown nearly comparable silicon dioxide average RR and wafer-to-wafer RR stability on blanket wafers with an existing , while resulting in significantly improved step height, dishing and erosion results on patterned STI wafers.

[0009] The PIB technology has also shown to reduce the lateral vibration of the wafer during polishing significantly.

[0010] The following non-limiting examples are presented to further illustrate the present invention.

CMP Methodology

[0011] In the examples presented below, CMP experiments were run using the procedures and experimental conditions given below. GLOSSARY

COMPONENTS

[0012] Chemical additive, Silsulf E608 was supplied by SILTECH CORPORATION 225 Wicksteed Avenue Toronto, Ontario, Canada, M4H 1G5.

[0013] 15micron and 35micron sized polyurethane beads were supplied by Dainichiseika Color & Chemicals Mfg. Co., Ltd. Akabane & Sakura Production Plant 1-4- 3 Ukima, Kita-ku Tokyo JAPAN.

[0014] TEOS: tetraethyl orthosilicate [0015] Polishing Pad: Polishing pad, IC1070 and other pads were used during

CMP, supplied by DOW-Dupont, Inc.

PARAMETERS

General

[0016] A or A: angstrom(s) - a unit of length [0017] BP: back pressure, in psi units

[0018] CMP: chemical mechanical planarization = chemical mechanical polishing [0019] CS: carrier speed

[0020] DF: Down force: pressure applied during CMP, units psi [0021] min: minute(s)

[0022] ml: milliliter(s)

[0023] mV: millivolt(s)

[0024] psi: pounds per square inch

[0025] PS: platen rotational speed of polishing tool, in rpm (revolution(s) per minute) [0026] SF: slurry flow, ml/min

[0027] Wt. %: weight percentage (of a listed component)

[0028] TEOS Removal Rates: Measured TEOS removal rate at a given down pressure. The down pressure of the CMP tool was set at different psi in the examples listed. Metrology

[0029] Films were measured with a ResMap CDE, model 168, manufactured by Creative Design Engineering, Inc, 20565 Alves Dr., Cupertino, CA, 95014. The ResMap tool is a four-point probe sheet resistance tool. Forty-nine-point diameter scan at 5mm edge exclusion for film was taken. CMP Tool

[0030] The CMP tool that was used is a 200mm Mirra, manufactured by Applied Materials, 3050 Boweres Avenue, Santa Clara, California, 95054. An IC1070 pad supplied by DOW-Dupont, Inc, 451 Bellevue Rd., Newark, DE 19713 was used on platen 1 for blanket and pattern wafer studies.

[0031 ] The IC1070 pad or other pad was broken in by conditioning the pad for 18 mins. At 7 lbs. down force on the conditioner. To qualify the tool settings and the pad break-in two tungsten monitors and two TEOS monitors were polished with Versum® STI2305 slurry, supplied by Versum Materials Inc. at baseline conditions.

Wafers

[0032] Polishing experiments were conducted using PECVD TEOS wafers. These blanket wafers were purchased from Silicon Valley Microelectronics, 2985 Kifer Rd., Santa Clara, CA 95051.

Polishing Experiments

[0033] In blanket wafer studies, oxide blanket wafers were polished at baseline conditions with slurry flow of 200 ml/min. [0034] The slurry was used in polishing experiments on patterned wafers (MIT860), supplied by SWK Associates, Inc. 2920 Scott Blvd. Santa Clara, CA 95054. These wafers were measured on the Veeco VX300 profiler/AFM instrument. The 3 different sized pitch structures were used for oxide dishing measurement. The wafer was measured at center, middle, and edge die positions. [0035] In all working Examples, the reference sample (Ref. sample) was made using

0.5 wt.% calcined ceria having a mean particle size(MPS) (measured by Dynamic light scattering (DLS) ranging from 180nm-220nm as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide. pH was adjusted to 5.15 Example 1

[0036] The testing sample one was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, and 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent. pH was adjusted to 5.15. [0037] The testing sample two (PIB sample) was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent, and 0.25 wt.% 15 micron sized polyurethane beads. pH was adjusted to 5.15. [0038] The third testing sample (PIB sample) was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent, and 0.25 wt.% 35 micron sized polyurethane beads. pH was adjusted to 5.15.

Table 1. TEOS Removal Rate (A/min.) Comparison

Ό039] The polishing testing were conducted using 200mm Mirra Polisher (from AMAT Company), DowDupont IP1070 polishing pad and Saesol diamond conditioning disk. The slurry flow rate applied was 200ml_/min. TEOS blanket wafers were polished. The polishing results were listed in Table 1.

[0040] As the TEOS removal rate results shown in Table 1 , the TEOS removal rate was reduced after adding the dispersing agent Silsulf E608 into the reference sample at same pH conditions due to the passivation generated by the dispersing agent on oxide film surfaces. Similar TEOS film removal rates were obtained from the samples using 15micron and 35 micron sized polyurethane beads.

Example 2

[0041] The testing sample (PIB sample) was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent, and 0.25 wt.% 35micron sized polyurethane beads (Called PU Beads). pH was adjusted to 5.15. [0042] Both reference and testing sample were used to polish oxide patterned wafers, the effects of PIB-type oxide polishing composition vs reference sample on the remaining SiN thickness were compared and the results were listed in Table 2. Table 2. Effects of PIB-Type STI Slurry on the Remaining SiN Thickness

[0043] As the results shown in Table 2, PIB type STI slurry sample provided more remaining SiN film thickness on 30% density features, and similar SiN film remaining thickness on 50% and 70% density features. It is preferred to have more SiN film thickness remained while polishing oxide patterned wafers.

Example 3

[0044] The testing sample one was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, and 0.05 wt.% silsulf E608 as dispersing agent. pH was adjusted to 5.15.

[0045] The testing sample two (PIB sample) was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent, and 0.25 wt.% 35 micron sized polyurethane beads (PU Beads). pH was adjusted to 5.15.

[0046] Both testing samples were used to polish oxide patterned wafers, the effects of PIB-type oxide polishing composition vs non-PIB sample on the remaining SiN thickness were compared and the results were listed in Table 3. Table 3. Effects of PIB-Type STI Slurry on the Remaining SiN Thickness

[0047] As the results shown in Table 3, PIB type STI slurry sample provided more remaining SiN film thickness on all 4 density features than non-PIB sample while both samples used the same wt.% dispersing agents and at same pH condition. It is preferred to have more SiN film thickness remained while polishing oxide patterned wafers.

Example 4

[0048] In Example 4, the testing sample one was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, and 0.05 wt.% silsulf E608 as dispersing agent. pH was adjusted to 5.15. [0049] The testing sample two (PIB sample) was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.%

Kathon II as biocide, 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent, and 0.25 wt.% 35micron sized polyurethane beads. pH was adjusted to 5.15.

[0050] Both testing samples were used to polish oxide patterned wafers, the effects of PIB-type oxide polishing composition vs non-PIB sample on the remaining SiN thickness on all 50% density of lOOmicron, 200micron and 500micron features were compared and the results were listed in Table 4.

Table 4. Effects of PIB-Type STI Slurry on the Remaining SiN Thickness

[0051] As the results shown in Table 4, PIB type STI slurry sample provided more remaining SiN film thickness on 50% density of lOOmicron, 200micron, and 500micron features than non-PIB sample while both samples used the same wt.% dispersing agents and at same pH conditions. It is preferred to have more SiN film thickness remained while polishing oxide patterned wafers.

Example 5

[0052] The testing sample (PIB sample) was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide plus 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent, and 0.25 wt.% 35micron sized polyurethane beads. pH was adjusted to 5.15. [0053] Both reference and testing sample were used to polish oxide patterned wafers, the effects of PIB-type oxide polishing composition vs reference sample on the oxide trench dishing on four difference density features were compared and the results were listed in Table 5.

Table 5. Effects of PIB-Type STI Slurry on the Oxide Trench Dishing (A)

[0054] As the results shown in Table 5, PIB type STI slurry sample provided lower oxide trench dishing on all four tested density features than the non-PIB reference sample which did not use the dispersing agent. It is preferred to have lower oxide trench dishing while polishing oxide patterned wafers.

Example 6 [0055] In Example 6, the testing sample one was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, and 0.05 wt.% silsulf E608 as dispersing agent. pH was adjusted to 5.15. [0056] The testing sample two (PIB sample) was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent, and 0.25 wt.% 35micron sized polyurethane beads. pH was adjusted to 5.15. [0057] Both testing samples were used to polish oxide patterned wafers, the effects of PIB-type oxide polishing composition vs non-PIB sample on the oxide trench dishing were compared and the results were listed in Table 6.

Table 6. Effects of PIB-Type STI Slurry on Oxide Trench Dishing (A) lower oxide trench dishing on all 4 density features than non-PIB sample while both samples used the same wt.% dispersing agents and at same pH conditions. It is preferred to have lower and reduced oxide trench dishing while polishing oxide patterned wafers.

Example 7 [0059] In Example 7, the testing sample one was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, and 0.05 wt.% silsulf E608 as dispersing agent. pH was adjusted to 5.15. [0060] The testing sample two (PIB sample) was made using 0.5 wt.% calcined ceria as abrasives, 0.077 wt.% polyacrylate salt as chemical additive, 0.0002 wt.% Kathon II as biocide, 0.05% Silsurf E608 (a silicon-containing polyether compound) as dispersing agent and 0.25 wt.% 35micron sized polyurethane beads. pH was adjusted to 5.15. [0061] Both testing samples were used to polish oxide patterned wafers, the effects of PIB-type oxide polishing composition vs non-PIB sample on the oxide trench dishing on all 50% density of lOOmicron, 200micron and 500micron features were compared and the results were listed in Table 7.

Table 7. Effects of PIB-Type STI Slurry on the Oxide Trench Dishing (A)

[0062] As the results shown in Table 7, PIB type STI slurry sample provided lower oxide trench dishing on 50% density of lOOmicron, 200micron, and 500micron features than non-PIB sample while both samples used the same wt.% dispersing agents and at same pH conditions. It is preferred to have lower and reduced oxide trench dishing while polishing oxide patterned wafers.

[0063] The embodiments of this invention listed above, including the working example, are exemplary of numerous embodiments that may be made of this invention.

It is contemplated that numerous other configurations of the process may be used, and the materials used in the process may be elected from numerous materials other than those specifically disclosed.