Compositions and methods for performing material removal operations

Abstract

In one embodiment, the polishing composition can include abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water. The polishing composition can have a high copper removal rate of at least 3500 Å / min, and a copper to silicon dioxide (Cu:SiO2) polishing selectivity of at least 2.5:1. In another embodiment, the combination product can include a first polishing composition and a second polishing composition, each of which can include abrasive particles comprising zirconia and an oxidizing agent comprising hydroxylamine, and the weight percent ratio of hydroxylamine in the first polishing composition to the second polishing composition can be at least 5:1.

Description

[Technical Field]

[0001] The present disclosure relates to compositions for performing material removal operations, specifically aqueous polishing compositions comprising abrasive particles comprising zirconia and an oxidizing agent comprising hydroxylamine. [Background technology]

[0002] Polishing slurries have a wide variety of applications, for example, for polishing glass, ceramic, or metal materials, and are often designed to perform chemical mechanical planarization (CMP) processes. In a typical CMP process, the relative motion of the slurry with respect to the substrate being polished chemically and mechanically interacts with the outer surface of the substrate, aiding the planarization (polishing) process by removing unwanted material. Polishing is performed until a desired smooth outer surface with low surface roughness is obtained. A need exists for the development of cost-effective polishing slurries that have high material removal rates and result in polished substrates with low surface roughness. [Brief explanation of the drawings]

[0003] The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. [Figure 1A] FIG. 1 is a diagram illustrating a patterned wafer before the polishing method of the present disclosure is performed. [Figure 1B] FIG. 1 is a diagram illustrating a patterned wafer before the polishing method of the present disclosure is performed. [Figure 1C] 1C is a diagram illustrating the patterned wafer shown in FIG. 1A or FIG. 1B after performing a polishing method according to an embodiment. [Figure 1D] 1D is a magnified line drawing of a cross section of the patterned wafer shown in FIG. 1C to illustrate copper dishing values according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0004] As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of features is not necessarily limited to only those features and may include other features that are not expressly listed or that are inherent to such process, method, article, or apparatus.

[0005] As used herein, unless clearly stated to the contrary, "or" refers to an inclusive "or" and not an exclusive "or." For example, a condition A or B can be satisfied by any one of the following: A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist).

[0006] Additionally, the use of "a" or "an" is used to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one, and the singular also includes the plural unless it is clear that otherwise is meant.

[0007] In one embodiment, the present disclosure relates to a polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water. The polishing composition may have a copper to silicon dioxide (Cu:SiO) polishing selectivity of at least 2.5:1.

[0008] In certain embodiments, the copper to silicon dioxide selectivity can be at least 3:1, or at least 3.5:1, or at least 4:1.

[0009] In another embodiment, the polishing composition of the present disclosure can be adapted to polish copper-containing materials at a mean material removal rate (MMR) of at least 3500 Å / min, or at least 3800 Å / min, or at least 4000 Å / min, or at least 4200 Å / min, according to the Copper Polishing Test described herein. In further embodiments, the mean material removal rate can be no more than 15000 Å / min or no more than 10,000 Å / min, according to the Copper Polishing Test. The polishing composition can have a mean material removal rate within a range including any of the minimum and maximum values above.

[0010] In one embodiment, the zirconia-containing abrasive particles may comprise at least 80% by weight zirconia, or at least 85% by weight zirconia, or at least 90% by weight zirconia, or at least 95% by weight zirconia, or at least 97% by weight zirconia, or at least 98% by weight zirconia, or at least 99% by weight zirconia, or at least 99.5% by weight zirconia.

[0011] In one particular embodiment, the abrasive material can consist essentially of zirconia, which herein means that the abrasive particle material comprises at least 99.5% by weight zirconia.

[0012] In another particular embodiment, the zirconia-containing abrasive particles can include zirconia particles containing Cl-containing species. In a particular embodiment, the Cl-containing species can be inorganic and can be chloride (Cl). - ) may contain chloride (Cl - ) may be at least 1 ppm, or at least 50 ppm, or at least 100 ppm, or at least 200 ppm, and not more than 3000 ppm, or not more than 2000 ppm, or not more than 1000 ppm, or not more than 500 ppm.

[0013] As used herein, the phrase "zirconia-containing abrasive particles" is used interchangeably with the phrase "zirconia particles" unless otherwise indicated.

[0014] The average particle size (D50) of the zirconia particles can be at least 30 nm, or at least 50 nm, or at least 60 nm, or at least 80 nm, or at least 100 nm, or at least 130 nm, or at least 150 nm, or at least 200 nm. In another embodiment, the zirconia particles can have a D50 size of 500 nm or less, or 400 nm or less, or 300 nm or less, or 200 nm or less, or 150 nm or less, or 100 nm or less. The D50 size of the zirconia particles can be a value within a range between any of the minimum and maximum values recited above.

[0015] The amount of zirconia particles can be at least 1 wt.%, or at least 1.5 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 5 wt.%, based on the total weight of the polishing composition. In other embodiments, the amount of zirconia particles in the abrasive composition can be 10 wt.% or less, or 8 wt.% or less, or 6 wt.% or less, or 5 wt.% or less, or 4 wt.% or less. The amount of zirconia particles in the abrasive composition can be within a range between any of the above minimum and maximum values.

[0016] In further embodiments, the amount of hydroxylamine in the polishing composition can be at least 0.1 wt.%, or at least 0.5 wt.%, or at least 1.0 wt.%, or at least 1.3 wt.%, or at least 1.5 wt.%, or at least 2 wt.%, or at least 3 wt.%, or at least 4 wt.%, or at least 5 wt.%, based on the total weight of the polishing composition. In other embodiments, the amount of hydroxylamine can be 10 wt.% or less, or 8 wt.% or less, or 5 wt.% or less, or 3 wt.% or less, or 2 wt.% or less, based on the total weight of the polishing composition. The amount of hydroxylamine can be within a range between any of the minimum and maximum values recited above.

[0017] In certain embodiments, the oxidizing agent can consist essentially of hydroxylamine. As used herein, an oxidizing agent consisting essentially of hydroxylamine means that the oxidizing agent is at least 99% by weight hydroxylamine, based on the total weight of the oxidizing agent.

[0018] In one particular embodiment, the polishing composition of the present disclosure can comprise hydroxylamine in an amount of 0.5 wt % to 3.0 wt %, zirconia particles in an amount of 3 wt % to 8 wt %, and water in an amount of at least 90 wt %.

[0019] In another particular embodiment, the oxidizing agent may include, in addition to hydroxylamine, one or more other oxidizing agents, non-limiting examples of which may be, for example, bromates, chlorates, iodates, iron (III) salts (e.g., nitrates, sulfates), cerium (IV) salts, permanganates (such as potassium permanganate), potassium persulfate, or iodic acid.

[0020] The pH of the polishing composition can be at least 2.5, or at least at least 3.0, at least 3.5, at least 4.0, at least 4.5, at least 5.0, or at least 5.5. In other embodiments, the pH can be 11.0 or less, or 9.0 or less, or 8.0 or less, or 7.0 or less, or 6.5 or less, or 6 or less, or 5.8 or less, or 5.5 or less, or 5.0 or less. In certain embodiments, the pH can be in the range of 3.0 to 5.8.

[0021] In an embodiment, the polishing composition may contain optional additives, such as surfactants and corrosion protectants. Non-limiting examples of corrosion protectants may be triazole, benzimidazole, benzothiazole, and derivatives thereof, such as their hydroxy-, amino-, imino-, carboxy-, mercapto-, nitro-, urea-, thiourea-, or alkyl-substituted derivatives. Most preferably, the at least one heterocyclic compound may be benzotriazole.

[0022] In certain embodiments, the polishing composition of the present disclosure may be essentially free of aminosilane compounds. As used herein, "essentially free of aminosilane compounds" means that the polishing composition contains less than 0.01 wt. % of aminosilane compounds, based on the total weight of the polishing composition.

[0023] In yet another embodiment, the polishing composition of the present disclosure may be essentially free of organic phosphonic acid. As used herein, essentially free of organic phosphonic acid means that the polishing composition contains less than 0.001 wt. % organic phosphonic acid, based on the total weight of the polishing composition.

[0024] In another embodiment, the polishing composition may be essentially free of glycine. As used herein, essentially free of glycine means that the polishing composition contains less than 0.01 wt. % glycine, based on the total weight of the polishing composition.

[0025] In further embodiments, the polishing composition of the present disclosure can also have a high polishing selectivity for copper relative to silicon nitride. In one embodiment, the polishing selectivity for copper to silicon nitride (Cu:SiN) can be at least 2.5:1, or at least 3:1, or at least 3.5:1, or at least 4:1.

[0026] In a further embodiment, the polishing composition has a copper to silicon nitride to silicon dioxide (Cu:SiN:SiO 2 ) polishing selectivity in the range of 2.5:1:1 to 5:1:1 or 3:1:1 to 4.5:1:1.

[0027] In one embodiment, the present disclosure relates to a method for polishing a substrate using the above-mentioned polishing composition. The method can have the surprising advantage of being able to polish a copper-containing substrate at a high copper removal rate. In one aspect, the polishing of the substrate can be adapted so that the copper material removal rate (MMR) during polishing of the substrate can be at least 3500 Å / min, or at least 3800 Å / min, or at least 4000 Å / min, or at least 4200 Å / min.

[0028] A polishing method can include providing the polishing composition of the present disclosure described above, directly contacting the polishing composition with a substrate, and polishing the surface of the substrate. In one aspect, the substrate can be polished with a polishing pad, in which the polishing pad and the substrate are moving relative to each other and the polishing composition is in contact with the substrate and the polishing pad.

[0029] In one embodiment, the temperature of the polishing composition during polishing can be at least 22°C, or at least 25°C, or at least 30°C, or at least 40°C, or at least 45°C, or at least 50°C, or at least 55°C, or at least 60°C, or at least 65°C. In another embodiment, the temperature of the composition during polishing can be 90°C or less, or 85°C or less, or 80°C or less, or 75°C or less, or 70°C or less. The temperature of the composition during polishing can be within a range between any of the minimum and maximum values listed above. In a specific embodiment, the polishing temperature can be between 22°C and 25°C.

[0030] The present disclosure further relates to a combination product comprising a first polishing composition and a second polishing composition, both of which may comprise abrasive particles comprising zirconia and an oxidizing agent comprising hydroxylamine, and the weight percent ratio of the first polishing composition to the second polishing composition may be at least 5:1. In certain embodiments, the weight percent ratio of the hydroxylamine of the first polishing composition to the second polishing composition may be at least 8:1 or at least 10:1.

[0031] In one embodiment, the amount of hydroxylamine in the first polishing composition may be in the range of at least 0.8 wt % to 20 wt % or less, based on the total weight of the first polishing composition, and the amount of hydroxylamine in the second polishing composition may be in the range of at least 0.05 wt % to 5 wt % or less.

[0032] In certain embodiments, the first polishing composition of the combination product may be the polishing composition of the present disclosure described above having high polishing selectivity for copper, while the second polishing composition may be adapted to have a higher polishing selectivity for silicon nitride (SiN) relative to copper (Cu).

[0033] In one embodiment, the first polishing composition may have a copper to silicon nitride (Cu:SiN) polishing selectivity of at least 2.5:1, or at least 3:1, or at least 3.5:1, or at least 4:1, and the second polishing composition may have a copper to silicon nitride (Cu:SiN) polishing selectivity of 1:15 or less, or 1:20 or less, or 1:25 or less, or 1:30 or less.

[0034] In one embodiment of the combination product, the second polishing composition can include abrasive particles containing the same amount and type of zirconia as the first polishing composition.

[0035] In another embodiment, the average particle size (D50) ratio ZP1:ZP2 of the zirconia particles of the first polishing composition (ZP1) to the zirconia particles of the second polishing composition (ZP2) can be 1:1.1 or less, or 1:1.3 or less, or 1:1.5 or less, or 1:1.7 or less, or 1:1.8 or less.

[0036] In one embodiment, the first polishing composition of the combination product can be adapted to add water to reach a 2x to 10x volume increase based on the original volume of the first polishing composition.

[0037] In another embodiment of the combination product, the second polishing composition can be adapted to add water to reach a 2x to 10x volume increase based on the original volume of the second polishing composition.

[0038] In one embodiment, both the first polishing composition and the second polishing composition may be diluted with water before using the compositions in the polishing process, and in another embodiment, only the first polishing composition or only the second polishing composition may be diluted with water before use.

[0039] The combination product of the present disclosure can be used to polish a substrate. In one embodiment, the method of polishing a substrate of the present disclosure can have the following sequence: polishing a substrate with a first polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, wherein the amount of hydroxylamine is at least 1.0 wt % based on the total weight of the first polishing composition; and polishing a substrate with a second polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, wherein the amount of hydroxylamine is at least 0.05 wt % but not more than 0.5 wt % based on the total weight of the second polishing composition.

[0040] In certain aspects, the substrate used in the polishing method can be a patterned wafer.

[0041] In one embodiment, the patterned wafer may be a copper TSV (through-silicon-via) wafer.

[0042] In one embodiment, as shown in Figure 1A, a patterned wafer (100A) may include a copper layer (101A) and a dielectric layer (102A), and the copper layer may include vertical pillar portions extending through the thickness direction (z) of the dielectric layer. In another embodiment, as shown in Figure 1B, a patterned wafer (100B) may include isolated copper pillars (101B) extending vertically (in the z-direction) through the wafer's dielectric layer (102B).

[0043] The dielectric layer of the patterned wafer may be a single layer or a combination of two or more dielectric layers. In certain embodiments, the dielectric layer may include a silicon dioxide layer and a silicon nitride layer. Figure 1C shows the patterned wafer after polishing, in which the copper pillars (101C) are approximately flush with the outer surface of the dielectric layer (102C).

[0044] It has been surprisingly found that patterned wafers such as those described in Figures 1A and 1B can be polished with high efficiency according to a two-step polishing process using the combination product of the present disclosure. Using the combination product of the present disclosure can have the advantage that copper dishing can be very small. As used herein, "copper dishing" refers to the formation of depressions or indentations (103) after the polishing process removes the protruding portions of the copper layer / pillars, see Figures 1C and 1D. "Copper dishing" refers to the copper dishing value Cu, which is the maximum depth of the depressions (103) measured in the orthogonal direction (z direction) from the plane of the wafer (x direction). d In certain embodiments, the copper dishing value Cu d can be 200 Å or less, or 150 Å or less, or 100 Å or less, or 80 Å or less, or 60 Å or less.

[0045] As further demonstrated in the examples below, the present disclosure provides compositions suitable as polishing slurries for polishing substrates, particularly for chemical-mechanical polishing of substrates.

[0046] Many different aspects and embodiments are possible. Some of these aspects and embodiments are described herein. After reading this specification, those skilled in the art will understand that these aspects and embodiments are merely exemplary and do not limit the scope of the invention. An embodiment may follow any one or more of the embodiments listed below.

[0047] Embodiment Embodiment 1. A polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, wherein the polishing composition has a copper to silicon dioxide (Cu:SiO2) polishing selectivity of at least 2.5:1.

[0048] Embodiment 2. A polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, wherein the polishing composition is designed to polish a copper substrate at a mean material removal rate (MMR) of at least 3500 Å / min according to a copper polishing test.

[0049] Embodiment 3. A polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, the polishing composition having a stability factor (SF) of at least 7.

[0050] Embodiment 4. The polishing composition of embodiment 3, having a stability factor (SF) of at least 10, or at least 15, or at least 20, or at least 30.

[0051] Embodiment 5. The polishing composition of embodiment 2, wherein the polishing selectivity of Cu:SiO2 is at least 3:1, or at least 3.5:1, or at least 4:1.

[0052] Embodiment 6. The abrasive composition of embodiment 1 or 2, wherein the abrasive particle material comprises at least 80 wt.% zirconia, or at least 85 wt.% zirconia, or at least 90 wt.% zirconia, or at least 95 wt.% zirconia, or at least 98 wt.% zirconia, or at least 99 wt.% zirconia, or at least 99.5 wt.% zirconia.

[0053] Embodiment 7. The polishing composition of any one of embodiments 1 to 6, wherein the average (D50) particle size of the abrasive particles is at least 30 nm, or at least 50 nm, or at least 60 nm, or at least 80 nm, or at least 100 nm, or at least 130 nm, or at least 150 nm, or at least 200 nm.

[0054] Embodiment 8. The polishing composition according to any one of embodiments 1 to 7, wherein the average (D50) particle size of the abrasive particles is 500 nm or less, or 400 nm or less, or 300 nm or less, or 200 nm or less, or 150 nm or less, or 100 nm or less.

[0055] Embodiment 9. The polishing composition of any one of embodiments 1 to 8, wherein the amount of hydroxylamine is at least 0.1 wt %, or at least 0.5 wt %, or at least 1.0 wt %, or at least 1.3 wt %, or at least 1.5 wt %, or at least 2 wt %, or at least 3 wt %, or at least 5 wt %, based on the total weight of the polishing composition.

[0056] Embodiment 10. The polishing composition of any one of embodiments 1 to 9, wherein the amount of hydroxylamine is 10 wt. % or less, or 8 wt. % or less, or 5 wt. % or less, or 3 wt. % or less, or 2 wt. % or less, based on the total weight of the polishing composition.

[0057] Embodiment 11. The polishing composition of any one of embodiments 1 to 10, wherein the amount of abrasive particles is at least 1 wt. %, or at least 1.5 wt. %, or at least 2 wt. %, or at least 3 wt. %, or at least 5 wt. %, based on the total weight of the polishing composition.

[0058] Embodiment 12. The polishing composition of any one of embodiments 1 to 11, wherein the amount of abrasive particles is 10% by weight or less, or 8% by weight or less, or 6% by weight or less, or 5% by weight or less.

[0059] Embodiment 13. The polishing composition of any one of embodiments 1 to 12, wherein the copper to silicon nitride (Cu:SiN) selectivity of the polishing composition is at least 2.5:1, or at least 3:1, or at least 3.5:1, or at least 4:1.

[0060] Embodiment 14. The polishing composition of any one of embodiments 1 to 13, wherein the copper to silicon nitride to silicon dioxide (Cu:SiN:SiO2) selectivity of the polishing composition is in the range of 2.5:1:1 to 5:1:1 or 3:1:1 to 4.5:1:1.

[0061] Embodiment 15. The polishing composition of embodiment 2, designed to polish a copper substrate at a mean material removal rate (MMR) of at least 3800 Å / min, or at least 4000 Å / min, or at least 4200 Å / min according to the Copper Polishing Test.

[0062] Embodiment 16. The polishing composition of embodiment 1, adapted to polish a silicon dioxide-containing material at a mean material removal rate (MMR) of at least 800 Å / min, or at least 1000 Å / min, or at least 1500 Å / min, or at least 2000 Å / min, according to a Silicon Dioxide Polishing Test.

[0063] Embodiment 17. The polishing composition of any one of embodiments 1 to 16, wherein the oxidizing agent consists essentially of hydroxylamine.

[0064] Embodiment 18. The polishing composition of any one of embodiments 1 to 17, wherein the pH of the polishing composition is at least 2.5, or at least 3.0, at least 3.5, at least 4.0, at least 4.5, at least 5.0, or at least 5.5.

[0065] Embodiment 19. The polishing composition according to any one of embodiments 1 to 18, wherein the pH of the polishing composition is 11 or less, or 9 or less, or 7 or less, or 6.5 or less, or 6 or less, or 5.5 or less, or 5 or less.

[0066] Embodiment 20. The polishing composition according to embodiment 18 or 19, wherein the pH is in the range of 3 to 5.8.

[0067] Embodiment 21. The polishing composition of any one of embodiments 1 to 20, which is essentially free of aminosilane compounds.

[0068] Embodiment 22. The polishing composition of any one of embodiments 1 to 21, which is essentially free of phosphonic acid.

[0069] Embodiment 23. The polishing composition of any one of embodiments 1 to 22, wherein the oxidizing agent comprises hydroxylamine and at least one additional oxidizing agent.

[0070] Embodiment 24. The polishing composition of embodiment 23, wherein the at least one additional oxidizing agent is selected from potassium persulfate, ammonium persulfate, periodic acid, permanganate, Ce(IV) nitrate, or any combination thereof.

[0071] Embodiment 25. The polishing composition of any one of embodiments 1 to 24, wherein the oxidizing agent consists essentially of hydroxylamine.

[0072] Embodiment 26. The polishing composition of any one of embodiments 1 to 25, comprising hydroxylamine in an amount of 0.5 wt% to 3.0 wt%, zirconia particles in an amount of 3 wt% to 8 wt%, and water in an amount of at least 90 wt%, based on the total weight of the polishing composition.

[0073] Embodiment 27. The polishing composition of any one of embodiments 1 to 26, wherein the zirconia-containing abrasive particles contain Cl-containing species in an amount of at least 1 ppm and no more than 3000 ppm.

[0074] Embodiment 28. A combination product comprising a first polishing composition and a second polishing composition, wherein the first polishing composition comprises abrasive particles comprising zirconia and an oxidizing agent comprising hydroxylamine, and the second polishing composition comprises abrasive particles comprising zirconia and an oxidizing agent comprising hydroxylamine, and wherein the weight percent ratio of hydroxylamine of the first polishing composition to the second polishing composition is at least 5:1, or at least 8:1, or at least 10:1.

[0075] Embodiment 29. The combination product of embodiment 28, wherein the amount of hydroxylamine in the first polishing composition is at least 1.0 wt % and not more than 20 wt %, and the amount of hydroxylamine in the second polishing composition is at least 0.05 wt % and not more than 0.8 wt %, based on the total weight of the first polishing composition.

[0076] Embodiment 30. The combination product of any one of embodiments 28 or 29, wherein the first polishing composition is the polishing composition of any one of embodiments 1-27.

[0077] Embodiment 31. The combination product of any one of embodiments 28-30, wherein the first polishing composition and the second polishing composition comprise the same amount of zirconia particles.

[0078] Embodiment 32. A combination product according to any one of embodiments 28 to 31, wherein the average particle size (D50) ratio ZP1:ZP2 of the zirconia particles of the first polishing composition (ZP1) to the zirconia particles of the second polishing composition (ZP2) can be 1:1.1 or less, or 1:1.3 or less, or 1:1.5 or less, or 1:1.7 or less, or 1:1.8 or less.

[0079] Embodiment 33. The combination product of any one of embodiments 28-32, wherein the first polishing composition has a copper to silicon nitride (Cu:SiN) polishing selectivity of at least 2.5:1, or at least 3:1, or at least 3.5:1, or at least 4:1, and the second polishing composition has a Cu:SiN polishing selectivity of 1:15 or less, or 1:20 or less, or 1:25 or less, or 1:30 or less.

[0080] Embodiment 34. A method of polishing a substrate, comprising, in the order mentioned, polishing the substrate with a first polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, wherein the amount of hydroxylamine is at least 1.0 wt % based on the total weight of the first polishing composition; and polishing the substrate with a second polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, wherein the amount of hydroxylamine is at least 0.05 wt % and not more than 0.8 wt % based on the total weight of the second polishing composition.

[0081] Embodiment 35. The method of embodiment 34, wherein the substrate is a patterned wafer.

[0082] Embodiment 36. The method of embodiment 35, wherein the patterned wafer comprises copper pillars, a silicon nitride layer, and a silicon dioxide layer.

[0083] Embodiment 37. The method of any one of embodiments 34 to 36, wherein polishing of the substrate is adapted such that the copper material removal rate (MMR) during polishing of the substrate with the first polishing composition is at least 3500 Å / min, or at least 3800 Å / min, or at least 4000 Å / min, or at least 4200 Å / min.

[0084] Embodiment 38. The method of any one of embodiments 34 to 37, wherein the first polishing composition has a copper to silicon nitride (Cu:SiN) polishing selectivity of at least 2.5:1, or at least 3:1, or at least 3.5:1, or at least 4:1, and the second polishing composition has a Cu:SiN polishing selectivity of 1:15 or less, or 1:20 or less, or 1:25 or less, or 1:30 or less.

[0085] Embodiment 39. The method of any one of embodiments 34 to 38, wherein the substrate is a patterned wafer containing copper pillars, and the copper dishing value Cud after polishing the substrate with the first polishing composition and the second polishing composition can be 200 Å or less, or 150 Å or less, or 100 Å or less, or 80 Å or less, or 60 Å or less. [Example]

[0086] The following non-limiting examples illustrate the present invention.

[0087] Example 1 polishing composition A first polishing composition (S1-1) was prepared by combining 5 wt. % zirconia particles having an average particle size of 100 nm, 1.5 wt. % hydroxylamine, and 0.01 wt. % benzotriazole in deionized water. The pH was adjusted to pH 5.50 with a KOH solution.

[0088] Additionally, comparative compositions were prepared that further contained 0.03 wt% 3-aminopropyltrimethoxysilane (C1), 0.01 wt% (aminomethyl)phosphonic acid (C2), and both 0.03 wt% (3-aminopropyl)trimethoxysilane and 0.01 wt% (aminomethyl)phosphonic acid (C3). Compositions C1, C2, and C3 further contained 0.5 wt% glycine. A summary of the polishing compositions is shown in Table 1 below.

[0089] [Table 1]

[0090] Polishing test. Polishing tests were conducted to evaluate the polishing efficiency of the compositions summarized in Table 1.

[0091] The polishing tests evaluated a) copper removal rate, b) silicon nitride (SiN) removal rate, and c) silicon dioxide (SiO2) removal rate.

[0092] A precise description of the abrasion tests performed is provided below. A summary of the abrasion results is given in Table 2.

[0093] [Table 2]

[0094] Surprisingly, composition S1-1 was observed to have a much higher copper removal rate and sensitivity to copper compared to silicon nitride and silicon dioxide than polishing compositions C1, C2, and C3.

[0095] Copper removal rate / silicon nitride removal rate / and silicon dioxide removal rate testing As used herein, the following description of measuring copper removal rate, silicon nitride removal rate, and silicon dioxide removal rate also defines the conditions of the "copper polishing test," "silicon nitride polishing test," and "silicon dioxide polishing test."

[0096] All polishing experiments were performed using an IPEC 472 machine manufactured by IPEC / Westech Systems Inc. as the polishing tool. The polishing pad was a poromeric polyurethane Politex Reg II manufactured by DuPont.

[0097] A 150 mm diameter wafer (Lot #GM080520-2 from Advantive Technologies) with a 1.5 micron thick upper Cu film and a 0.7 mm base Si layer below the Cu film was used as the polishing substrate for the copper polishing tests.

[0098] To measure the silicon nitride removal rate, a 150 mm diameter wafer with a 2.0 μm thick upper silicon nitride (SiN) layer was used with a 0.7 mm Si base (lot #GM051721-2 from Advantive Technologies) below the SiN layer.

[0099] Additionally, to measure the silicon dioxide removal rate, a 150 mm diameter TEOS wafer (Lot #GM112921-3) from Advantive Technologies was used, which had a 2.0 μm thick silicon dioxide film on top and a 0.7 mm Si layer below the silicon dioxide film.

[0100] The process parameters for conducting the polishing experiments were the same as those for measuring the copper removal rate, silicon nitride removal rate, and silicon dioxide removal rate and are summarized in Table 3.

[0101] [Table 3]

[0102] The pad temperature during the polishing process was maintained at 22-25° C. After processing, the wafers were cleaned with cleanroom wipes and deionized water, and then dried with compressed air.

[0103] The material removal rate (MRR) was determined by the change in wafer weight before and after polishing. The average material removal rate per minute was calculated by dividing the change in wafer weight before and after polishing by the time spent polishing (i.e., 1 minute). The wafer weight was measured using a benchtop balance.

[0104] Example 2 Two polishing compositions (S2 and S3) were prepared in the same manner as composition S1 in Example 1, except that sample S3 further contained 0.5 wt. % glycine, while sample S2 was the same as sample S1. Polishing efficiency tests for a) copper removal rate, b) silicon nitride (SiN) removal rate, and c) silicon dioxide (SiO) removal rate were also performed as described in Example 1.

[0105] As shown in Table 4, both compositions S2 and S3 had high copper removal rates, but the removal rates for SiN and SiO2 were much lower, similar to the results for sample S1 in Example 1. Furthermore, it can be seen that although the copper removal rate was slightly lower when glycine was added (sample S3), sample S3 had a higher selectivity for copper to SiN and SiO2 (5.66 / 0.94 / 1.0) than sample S2 (4.58 / 1.05 / 1.0).

[0106] [Table 4]

[0107] Example 3 Combination Products A combination product for a two-step polishing process was prepared by creating a first polishing composition for the first polishing step and a second polishing composition for the second polishing step.

[0108] As the first polishing composition, composition S1-1 of Example 1 was used.

[0109] A second polishing composition (S1-2) was developed containing a lower amount of hydroxylamine, and the zirconia particles had a larger average particle size of 180 nm, but the weight percent of zirconia particles was the same as S1-1 (5 wt%). The components of the first and second polishing compositions are summarized in Table 5.

[0110] [Table 5]

[0111] To evaluate the polishing efficiency of the second polishing composition, the same type of experiment as that of composition S1-1 in Example 1 was carried out to determine the copper removal rate, silicon nitride removal rate, and silicon dioxide removal rate. A summary of the results for the second polishing composition is shown in Table 5. It can be seen that the second polishing composition was particularly effective in polishing silicon dioxide and then silicon nitride, but the copper removal rate was very low.

[0112] [Table 6]

[0113] Example 4 A method for performing a two-step polishing process on a patterned wafer using a combination product.

[0114] The polishing experiment was performed by polishing a patterned wafer. The patterned wafer contained isolated copper pillars surrounded by a dielectric layer (as shown in Figure 1B). The dielectric layer of the patterned wafer included a silicon dioxide layer (made with TEOS) and a silicon nitride layer. The goal of polishing was to efficiently remove the copper protruding portion of the copper pillar so that the remaining copper pillar was flush with the surrounding dielectric layer while avoiding copper dishing.

[0115] The polishing compositions used in the first and second polishing steps are summarized in Table 6 below.

[0116] [Table 7]

[0117] Additionally, polishing preferably reduces the thickness of the outer layer of the dielectric layer (silicon dioxide layer) by approximately 5000 Å.

[0118] The polishing process parameters for both polishing stages were the same as those summarized in Table 3 above.

[0119] The first polishing step is highly efficient by removing the protruding portions of the copper pillars. After the second polishing step, the copper dishing value is less than 100 Å. Furthermore, the silicon dioxide layer is reduced by a thickness of at least 5000 Å but not more than 10000 Å.

[0120] Example 5 A stability test was performed on a slurry composition containing zirconia particles and hydroxylamine (Sample S1) compared to a slurry composition in which 1.5 wt% of the hydroxylamine was replaced with 1.5 wt% of hydrogen peroxide (Sample C5). All other components of Sample C5 were the same as those of Sample S1, including the pH.

[0121] For the stability test, the change in the amount of oxidizer was measured over a 7-day period at a temperature of 22° C. As summarized in Table 8, it was observed that the slurry composition containing hydrogen peroxide (Sample C5) had already lost approximately 68 percent of its hydrogen peroxide content just a few hours after the first day of slurry composition preparation. In contrast, the amount of hydroxylamine in Sample S1 remained stable for up to 7 days.

[0122] [Table 8]

[0123] As used herein, the stability factor represents the number of days at 22° C. until the amount of oxidizer is reduced by at least 10% by weight based on the original amount of oxidizer in the polishing composition.

[0124] In certain embodiments, the stability factor (SF) of the polishing composition of the present disclosure can be at least 10, at least 20, or at least 30.

[0125] The polishing compositions of the present disclosure can have the advantage of maintaining their polishing efficiency over extended periods of time.

[0126] In the foregoing specification, the concepts have been described with reference to specific embodiments. However, those skilled in the art will recognize that various modifications and changes can be made without departing from the scope of the invention as set forth in the following claims. Therefore, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present invention.

Claims

1. A polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, the polishing composition being designed to polish copper substrates at an average material removal rate (MMR) of at least 3500 Å / min according to a copper polishing test.

2. A polishing composition comprising abrasive particles comprising zirconia, an oxidizing agent comprising hydroxylamine, and water, the polishing composition having a stability factor (SF) of at least 7.

3. The copper to silicon dioxide (Cu:SiO ２ 3. The polishing composition of claim 1, wherein the polishing selectivity of the composition to the polishing agent is at least 2.5:

1.

4. The Cu:SiO ２ 4. The polishing composition of claim 3, wherein the polishing selectivity is at least 3.5:

1.

5. 3. The polishing composition of claim 1, wherein the abrasive particle material comprises at least 80% by weight of zirconia.

6. 3. The polishing composition of claim 1, wherein the abrasive particles have an average (D50) particle size of at least 30 nm and no more than 500 nm.

7. 3. The polishing composition of claim 1, wherein the amount of hydroxylamine is at least 0.1 wt. % and no more than 10 wt. %, based on the total weight of the polishing composition.

8. 3. The polishing composition of claim 1, wherein the amount of the abrasive particles is at least 1 wt. % and not more than 10 wt. % based on the total weight of the polishing composition.

9. 3. The polishing composition of claim 1, wherein the polishing composition has a copper to silicon nitride (Cu:SiN) selectivity of at least 2.5:

1.

10. The polishing composition of claim 1 or 2, wherein the oxidizing agent consists essentially of hydroxylamine.

11. 3. The polishing composition of claim 1, comprising hydroxylamine in an amount of 0.5 wt % to 3.0 wt %, zirconia particles in an amount of 3 wt % to 8 wt %, and water in an amount of at least 90 wt %, based on the total weight of the polishing composition.

12. A combination product comprising a first polishing composition and a second polishing composition, The first polishing composition comprises the polishing composition of claim 1 ; the second polishing composition comprises abrasive particles containing zirconia and an oxidizing agent containing hydroxylamine; the ratio of the amount of hydroxylamine in the first polishing composition to the amount of hydroxylamine in the second polishing composition by weight percent hydroxylamine is at least 5:

1.

13. 13. The combination product of claim 12, wherein the amount of the hydroxylamine in the first polishing composition is at least 1.0 wt % and no more than 10 wt %, based on the total weight of the first polishing composition, and the amount of the hydroxylamine in the second polishing composition is at least 0.05 wt % and no more than 0.8 wt %, based on the total weight of the second polishing composition.

14. 14. The combination product of claim 12 or 13, wherein the first polishing composition has a copper to silicon nitride (Cu:SiN) polishing selectivity of at least 2.5:1, and the second polishing composition has a Cu:SiN polishing selectivity of 1:15 or less.

15. A method for polishing a substrate, comprising polishing the substrate with the polishing composition of claim 1 or 2, wherein the substrate is a patterned wafer, and the patterned wafer comprises copper pillars, a silicon nitride layer, and a silicon dioxide layer.

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