WO2009070967A1 - A chemical-mechanical polishing liquid - Google Patents

Abstract

A chemical-mechanical polishing liquid is disclosed, which comprises water, silica doped by metal and one or more kinds of the following rate-accelerators: organic acid, fluoride, ammonia, quaternary amine salts and the derivatives thereof. The polishing liquid has higher polishing rate for TEOS, higher selection ratio of removal rate for TEOS to one or more kinds material of SiN, BD, SiC and SiON. The chemical-mechanical polishing liquid still attains higher polishing rate for TEOS and better controlling ability for defect in the case of the lower content of abrasive. So the cost is extremely reduced.

Description

 Chemical mechanical polishing liquid

 The present invention relates to a chemical mechanical polishing liquid in a semiconductor manufacturing process. technical background

In the fabrication of integrated circuits, a plurality of dielectric layers including multiple trenches are formed on a semiconductor silicon wafer. The trenches filled with metal wires are arranged in a dielectric layer to form a circuit interconnection pattern. The arrangement of the patterns usually has a damascene structure and a double Heavy metal inlay structure. These damascene structures first cover the dielectric layer with a barrier layer and then cover the barrier layer with metal. These metals need to be at least filled with trenches to form circuit interconnections. As the device size of integrated circuits shrinks and the number of wiring layers increases, copper has become a wire material for deep submicron integrated circuits because it has better electromigration resistance and higher electrical conductivity than aluminum. The barrier layer is mainly made of tantalum or tantalum nitride to prevent copper from diffusing to the adjacent dielectric layer. Chemical mechanical polishing (CMP) is used to planarize the surface of the chip during the fabrication of the chip. These planarized chip surfaces facilitate the production of multilayer integrated circuits and prevent distortion caused by coating the dielectric layer on uneven surfaces. The copper CMP process is usually divided into two steps: The first step is to quickly remove the interconnected metal copper with a specially designed polishing solution; the second step is to remove the barrier layer and a small amount of dielectric layer with a specially designed polishing solution to provide a flat polishing. surface. In order to achieve the effect of flattening the polished surface, in the second polishing process of copper CMP, the polishing liquid usually needs to have a specific selectivity, and the barrier layer and part of the dielectric layer are removed without causing copper as an interconnecting wire. Excessive depression. In the case of low-k materials, there may be one, two or three layers between the barrier layer and the low-k dielectric layer, and the top cover layer may be used for topography correction, while the bottom cover layer It is used as a polish stop layer to protect the underlying low-k dielectric layer from chemical and mechanical damage. The top cover layer may be TEOS or silicon nitride (SiN), and the lower cover layer may be TEOS, silicon carbide (SiC), silicon oxynitride (SiON), silicon oxynitride (SiCN), SiN or low-k dielectric layer itself. . Generally, a low-k dielectric CDO (carbon doped oxide) is used as a termination layer. In some circuit designs, the TEOS layer needs to be selectively removed, while at the same time minimizing other overlay layers. However, in other circuit designs, it is necessary to completely remove the cover layer and stop on the low-k dielectric layer. Therefore, in the design of CMP polishing solution, it is necessary to obtain suitable polishing rates of TEOS, SiN, SiC, SiON. SiCN and CDO and the selection ratio therebetween, thereby meeting various requirements of circuit design.

The polishing mechanism of the CMP polishing liquid on the semiconductor device is as follows: First, the composition and electrochemical characteristics of the surface of the polishing substrate are changed by chemical action, and then the surface of the substrate which has been changed is removed by mechanical grinding. During the polishing process of the interconnected metal copper, the surface of the metallic copper is first oxidized by the oxidizing agent, and then the complexing agent in the polishing liquid is adsorbed on the surface of the oxidized copper, and a complex is formed, and finally the oxide layer of the copper and The complex is removed by the abrasive. However, since the TEOS layer (silica) is chemically inert and cannot be oxidized and complexed by chemical agents, the current polishing solution mainly improves the polishing rate of the polishing solution to the TEOS layer in two ways: (1) The polishing fluid has a higher abrasive content and generally has an abrasive content of more than 10 wt. The TEOS layer is removed by mechanical grinding of the intensive polishing liquid, for example, patent US 7253111. However, higher polishing abrasives are likely to cause mechanical damage to the surface of the polished substrate; (2) The pH of the polishing solution is higher, in an alkaline environment (pH = 10 to 11.5), the -OH group in the polishing solution is in TEOS. More -SiOH groups are formed on the surface of the substrate, and the polishing abrasive and TEOS are strengthened. The chemical action of the surface of the layer, for example, patent US7276180. However, in an alkaline environment, other metal ions and abrasive particles are easily adsorbed on the surface of the substrate and are difficult to remove, thereby forming more surface contamination.

Summary of invention

The technical problem to be solved by the present invention is to overcome the requirements of the prior art method in order to satisfy the requirement that the TEOS needs to have a high removal rate and a suitable selection ratio with other materials in the barrier polishing stage of the chemical mechanical polishing process of Cu. Increase the abrasive content or pH easily caused by surface scratches, particle residual defects, and provide a polishing rate with a higher TEOS, higher TEOS for one or more of SiN, BD, SiC and SiON A chemical mechanical polishing liquid having a better surface morphology and a better removal rate of the material.

 The chemical mechanical polishing liquid of the present invention contains water, and further contains one or more of silica of a catastrophic metal and a rate promoter: an organic acid, a fluoride, an aqueous ammonia, and a quaternary ammonium salt and a derivative thereof. The use of the metal doped silica in combination with the rate enhancer allows the polishing fluid of the present invention to have a higher dielectric (TEOS) polishing rate.

 Wherein the metal doped silica is a silicon dioxide in which a metal element is introduced in a skeleton structure. The introduction of metal ions in the framework structure of silica is to enhance the strength and stability of the silica. The metal is preferably aluminum, zirconium, hafnium, gold, silver, iron, chromium or molybdenum, more preferably aluminum. The metal doped silica preferably has a particle diameter of 20 80 nm. The amount of the metal-doped silica is preferably from 1 to 20% by mass, more preferably from 3-15% by mass, most preferably from 3 to 10% by mass.

Wherein, the organic acid is preferably oxalic acid, 2-phosphonic acid butane-1, 2, 4-tricarboxylic acid, 2-hydroxyphosphine. One or more of acylacetic acid, aminotrimethylenephosphonic acid and tartaric acid; the fluoride is preferably one or more of hydrogen fluoride, ammonium fluoride, ammonium fluorosilicate and ammonium fluoroborate; The quaternary ammonium salt is preferably one or more of tetrabutylammonium hydroxide, tetramethylammonium hydroxide and tetrabutylammonium fluoroborate. The rate promoter is preferably used in an amount of from 0.05 to 1% by mass, more preferably from 0.1 to 0.6% by mass. The rate promoter of the present invention can form a hydrogen bond with a metal doped silica abrasive, or form a hydrogen bond with a polishing substrate, or simultaneously with a metal doped silica abrasive and polishing base. Hydrogen bonds are formed between the materials. The solution containing only the rate promoter has only a weak polishing effect on the polishing substrate, and the addition of the silica-based abrasive of the doped metal can significantly increase the polishing rate of the polishing solution to TEOS.

 The pH of the polishing liquid of the present invention is preferably from 2 to 5.

 The chemical mechanical polishing liquid of the present invention may further be conventional chemical additives such as corrosion inhibitors, oxidizing agents, complexing agents, and surfactants.

The polishing liquid of the present invention can be obtained by simply mixing and mixing the above components, and then adjusting to a suitable pH value using a pH adjuster. _{The P} H regulator may be selected from conventional pH adjusting agents in the art, such as potassium hydroxide, aqueous ammonia, and nitric acid. In the present invention, the reagents and raw materials used are commercially available.

The positive progress of the present invention is that the chemical mechanical polishing liquid of the present invention is suitable for polishing insulating materials such as silicon dioxide, carburized silicon dioxide, silicon nitride, silicon carbide and silicon oxynitride, and has a high TEOS polishing. Rate, higher TEOS selectivity ratio for one or more of SiN, BD, SiC, and SiON, lower copper removal rate. The chemical mechanical polishing liquid of the invention can achieve a higher polishing rate of TEOS in the case of a lower abrasive content, such as an abrasive content of 1.2 to 9%, and has better defect control ability and greatly reduces The cost. DRAWINGS

 Figure 1 is a comparison of polishing rates for Polishing of TEOS, BD, SiN, SiON, and SiC with Polish 1 and Comparative Slurry 1~6.

 Fig. 2 is a comparison of polishing rates for polishing Cu by the polishing liquid 9 and the comparative polishing liquid 7. Fig. 3 is a comparison of the polishing rates of polishing of TEOS, BD, SiN, SiON and SiC by the polishing liquid 10 13 and the comparative polishing liquid 2.

 Fig. 4 is a comparison of polishing rates of polishing of TEOS, BD, SiN, SiON and SiC by polishing liquids 14 to 18 and comparative polishing liquid 2.

 Fig. 5 is a comparison of polishing rates of polishing of TEOS, BD, SiN, SiON and SiC by the polishing liquid 19 21 and the comparative polishing liquid 2.

 Figure 6 is a comparison of polishing rates for polishing TEOS, BD, SiN, SiON, and SiC with polishing liquids 22 to 27.

 Figure 7 is a comparison of polishing rates for polishing TEOS, BD, SiN, SiON, and SiC with 28~30 polishing solution.

 Figure 8 is a comparison of polishing rates for polishing TEOS, BD, SiN, SiON, and SiC with polishing fluids 31~36.

 Figure 9 is a comparison of polishing rates for polishing TEOS, BD, SiN, SiON, and SiC with polishing solutions 37 to 39.

Fig. 10 is a comparison of polishing rates of polishing of TEOS, BD and Cu by polishing liquids 40 to 49. Figure 11 is a SEM scan of the surface of the chip after polishing the structured chip with the polishing liquid 47. Summary of the invention

 The invention is further illustrated by the following examples, but is not intended to limit the invention. In the following examples, the percentages of the contents are all by mass.

Example 1 Polishing rate of various polishing substrates by silica, yttrium aluminum silica and alumina-coated silica particles

 Slurry 1: Aldo-doped silica (45nm) 10%, HF 0.05%, TBAH 0.3%, pH=3 o Polishing solution 2: Zirconium doped silica (45nm) 10%, HF 0.05%, TBAH 0.3 %, pH=3 o Polishing solution 3: fused silica (45nm) 10%, HF 0.05%, TBAH 0.3%, pH=3 o Polishing solution 4: gold doping: silicon dioxide (45nm) 10%, HF 0.05%, TBAH 0.3%, pH=3 c Polishing solution 5: Silver-doped silica (45nm) 10%, HF 0.05%, TBAH 0.3%, pH=3 o Polishing solution 6: Iron-doped silica (45nm 10%, HF 0.05%, TBAH 0.3%, pH=3 o Polishing solution 7: chromium doping: silicon dioxide (45nm) 10%, HF 0.05%, TBAH 0.3%, pH=3 o Polishing solution 8: Molybdenum doping : silica (45 nm) 10%, HF 0.05%, TBAH 0.3%, pH=3. Comparative polishing solution 1: HF 0.05%, tetrabutylammonium hydroxide (TBAH) 0.3%, pH=3. Comparative Polishing Solution 2: Aluminum-doped silica (45 nm) 10%, pH=3.

 Comparative polishing solution 3: Silica (35 nm) 10%, pH=3.

 Comparative polishing solution 4: Silica (35 nm) 10%, HF 0.05%, TBAH 0.3%, pH=3. Comparative Polishing Solution 5: Silica-coated silica (30 nm) 10%, pH=3.

 Comparative Polishing Solution 6: Silica-coated silica (30 nm) 10%, HF 0.05%, TBAH 0.3%, pH=3.

TEOS, BD, SiN, SiON, and SiC were polished using polishing liquid 1 and comparative polishing liquids 1 to 6. Polishing conditions: 2.0 psi under pressure, Politex polishing cloth, polishing disc speed 70 rpm, polishing The liquid flow rate is 100 ml/min, and the polishing machine Logitec PM5. The polishing rate for each material is shown in Figure 1. It is shown in Fig. 1 that only the polishing liquid 1 containing aluminum-doped silica and rate promoters HF and TBAH has a higher polishing rate of TEOS, and lower BD, SiN and compared with the comparative polishing liquids 1 to 6. Polishing rate of SiC material. The combination of Si0 ₂ and alumina-coated silica particles with chemical components does not achieve this effect. It can be inferred from the structure of the aluminum-doped silica that the silica doped with other metals can also have a similar effect when combined with the above rate promoter.

Example 2 Polishing Rate of Cu Polished Substrate by Polishing Solution Containing Aluminum-Doped Silica and Tetrabutylammonium Hydroxide

 Polishing solution 9: aluminum-doped silica (45 nm) 6%, TBAH 0.3%, BTA 0.15%, pH=3.0. Comparative Polishing Solution 7: Aluminum-doped silica (45 nm) 6%, BTA 0.15%, pH = 3.0.

 Polishing conditions: downforce 1.5 psi, polishing cloth Politex, polishing disc speed 70 rpm, polishing fluid flow rate 100 ml/min, polishing machine Logitec PM5. The polishing rate for Cu is shown in Figure 2.

 It is shown by Fig. 2 that the polishing liquid 7 introduced with the rate promoter TBAH has a lower Cu polishing rate than the comparative polishing liquid 7. In combination with the results of Example 1, after the introduction of the rate promoter TBAH, the TEOS polishing rate was increased to lower the polishing rate of Cu, thereby imparting a stronger planar correction effect on the surface of the structured chip.

Example 3 Polishing rate of various polishing substrates by a polishing solution containing a rate promoter and aluminum-doped silica

 Polishing solution 10: aluminum-doped silica (45 nm) 10%, TBAH 0.3%, pH=3.

 Polishing solution 11 : Aluminum-doped silica (45 nm) 10%, tetramethylammonium hydroxide (TMAH) 0.3%, pH=3 o

Polishing solution 12: aluminum-doped silicon dioxide (45 nm) 10%, ammonia water 0.3%, pEK3. Polishing solution 13: aluminum-doped silica (45 nm) 10%, ammonium fluoride 0.3%, pH=3.

 The above polishing liquid was used to polish TEOS, BD, SiN, SiON and SiC. Polishing conditions: 2.0 psi under pressure, polishing cloth Politex, polishing disc speed 70 rpm, polishing fluid flow rate 100 ml/min, polishing machine Logitec PM5. The polishing rate for each material is shown in Figure 3.

 Figure 3 shows that the combination of the above rate promoter and aluminum-doped silica increases the polishing rate of the TEOS to the polishing solution and has a higher TEOS to one or more of SiN, BD, SiC and SiON. The choice is better than that.

Example 4 Polishing rate of various polishing substrates containing organic acid, aluminum-doped silica. Polishing solution 14: Aluminum-doped silica (45 nm) 10%, oxalic acid 0.3%, pH=3.

 Polishing solution 15: Aluminum-doped silica (45nm) 10%, 2-phosphonic acid butane -1, 2, 4-tricarboxylic acid

0.3%, pH=3.

Polishing solution 16: aluminum-doped silica (45 nm) 10%, 2-hydroxyphosphonoacetic acid 0.3%, pH=3. Polishing solution 17: aluminum-doped silica (45 nm) 10%, aminotrimethylenephosphonic acid 0.3%, pH=3. Polishing solution 18: aluminum-doped silica (45 nm) 10%, tartaric acid (TA) 0.3%, pH=3. The above polishing liquid was used to polish TEOS, BD, SiN, SiON and SiC. Polishing conditions: 2.0 psi under pressure, Politex polishing cloth, polishing plate rotation speed 70 rpm, polishing liquid flow rate 100 ml/min, polishing machine Logite _C PM5. The polishing rate for each material is shown in Figure 4.

 Figure 4 shows that the combination of the above rate promoter and aluminum-doped silica can increase the polishing rate of the polishing solution to TEOS, especially with oxalic acid, and has a higher TEOS to SiN.

The selection ratio of one or more materials in BD, SiC, and SiON.

Example 5 Polishing Rate of Fluoride-Containing, Aluminum-Doped Silica-Based Polishing Solution for Various Polishing Substrates The polishing liquid 19: aluminum-doped silica (45 nm) 10%, hydrogen fluoride 0.3%, pH=3. Polishing solution 20: aluminum-doped silica (45 nm) 10%, ammonium fluorosilicate 0.3%, pH=3. Polishing solution 21: aluminum-doped silica (45 nm) 10%, ammonium fluoroborate 0.3%, pH=3. The above polishing liquid was used to polish TEOS, BD, SiN, SiON and SiC. Polishing conditions: 2.0 psi under pressure, Politex polishing cloth, 70 rpm polishing disc speed, 100 ml/min polishing fluid flow rate, and Logitec PM5 polishing machine. The polishing rate for each material is shown in Figure 5.

 Figure 5 shows that the combination of the above rate promoter and aluminum-doped silica increases the polishing rate of the TEOS to the polishing solution and has a higher TEOS to one or more of SiN, BD, SiC and SiON. The choice is better than that.

Example 6 Polishing Rate of Various Polished Substrates Containing Different Contents of Aluminum-Doped Silica-Based Polishing Solution 22: Aluminum-doped silica (45 nm) 1%, HF 0.05 °/. , TBAH 0.3%, pH=3. Polishing solution 23: aluminized silica (45 nm) 3%, HF 0.05%, TBAH 0.3%, pH=3. Polishing solution 24: aluminum-doped silica (45 nm) 6%, HF 0.05%, TBAH 0.3%, pH=3. Polishing solution 25: aluminum-doped silica (45 nm) 10%, HF 0.05%, TBAH 0.3%, pH=3. Polishing solution 26: aluminum-doped silica (45 nm) 15%, HF 0.05%, TBAH 0.3%, pH=3. Polishing solution 27: aluminum-doped silica (45 nm) 20%, HF 0.05%, TBAH 0.3%, pH=3. TE Polishing TEOS, BD, SiN, SiON, and SiC with the above polishing solution. Polishing conditions - 2.0 psi under pressure, polishing cloth Politex, polishing disc speed 70 rpm, polishing fluid flow rate 100 ml/min, polishing machine Logitec PM5. The polishing rate for each material is shown in Fig. 6.

 Fig. 6 shows that the amount of the aluminum-doped silica is preferably from 1% to 20%, more preferably from 3 to 15%, most preferably from 3 to 10%.

Example 7 Polishing Rate of Various Aluminized Silica-Containing Polishing Solutions for Various Polishing Substrates Polishing Solution 28: Aluminum-doped Silica (25 nm) 6%, HF 0.05%, TBAH 0.3%, pH= 3. Polishing solution 29: smear aluminum silica (45 hm) 6%, HF 0.05%, TBAH O.3%, pH=3. Polishing solution 30: aluminum-doped silica (80 nm) 6%, HF 0.05%, TBAH O.3%, pH=3. The above polishing liquid was used to polish TEOS, BD, SiN, SiON and SiC. Polishing conditions: 2.0 psi under pressure, Politex polishing cloth, 70 rpm polishing disc speed, 100 ml/min polishing fluid flow rate, and Logitec PM5 polishing machine. The polishing rate for each material is shown in Figure 7.

 Fig. 7 shows that the particle diameter of the aluminum oxide is preferably in the range of 20 to 80 nm.

 Example 8 Polishing solution containing various amounts of rate-increasing agent polishing rate for various polishing substrates Polishing solution 31 : Aluminium doped: silica (45 nm) 6%, TBAH 0.02%, pH=3 o Polishing solution 32 : Blending: Silica (45nm) 6%, TBAH 0.05%, pH=3 o Polishing Solution 33: Miscellaneous Aluminum: Silicon Dioxide (45nm) 6%, TBAH 0.1%, pH=3 o Polishing Solution 34: Blending Aluminum: Silica (45nm) 6%, TBAH 0.3%, pH=3 o Polishing solution 35: Aluminium doping: silica (45nm) 6%, TBAH 0.6%, pH=3 o Polishing solution 36: Aluminizing: Silica (45nm) 6%, TBAH 1%, pH=3 o

 The above polishing liquid was used to polish TEOS, BD, SiN, SiON and SiC. Polishing conditions: 2.0 psi under pressure, polishing cloth Politex, polishing disc speed 70 rpm, polishing fluid flow rate 100 ml/min, polishing machine Logitec PM5. The polishing rate for each material is shown in Fig. 8.

 Figure 8 shows that the rate promoter is preferably used in an amount of from 0.05 to 1% by weight, more preferably from 0.1 to 0.6% by weight.

Example 9 Polishing Rate of Various Polishing Substrates by Different pH Polishing Solutions

 Polishing solution 37: Aluminum-doped silica (45 nm) 6%, TBAH 0.1%, pH=2.

 Polishing solution 38: Miscellaneous aluminum silica (45nm) 6%, TBAH 0.1%, pH=3.

Polishing solution 39: aluminum-doped silica (45 nm) 6%, TBAH 0.1%, pH=5. The above polishing liquid was used to polish TEOS, BD, SiN, SiON and SiC. Polishing conditions: 2.0 psi under pressure, Politex polishing cloth, 70 rpm polishing disc speed, 100 ml/min polishing fluid flow rate, and Logitec PM5 polishing machine. The polishing rate for each material is shown in Figure 9.

 Fig. 9 shows that the pH of the polishing liquid of the present invention is preferably from 2 to 5.

 Example 10 Polishing Rate of Various Polished Substrates by Polishing Solution Containing Other Additives

 Polishing solution 40: Miscellaneous aluminum silica (45 nm) 10%, hydrofluoric acid 0.027%, tetrabutylammonium hydroxide 0.3%, benzotriazole 0.15%, pH=2.6.

Polishing solution 41: aluminum-doped silicon dioxide (45 nm) 10%, hydrofluoric acid 0.027%, tetrabutylammonium hydroxide 0.3%, 2-phosphonic acid butane-1, 2, 4-tricarboxylic acid 0.1%,

 Polishing solution 42: aluminum-doped silica (45 nm) 10%, hydrofluoric acid 0.027%, tetrabutylammonium hydroxide 0.3%, ammonium polyacrylate 0.1%, pH=2.6.

 Polishing solution 43: aluminum-doped silica (45 nm) 1.2%, hydrofluoric acid 0.003%, tetrabutylammonium hydroxide 0.033%, benzotriazole 0.1%, 2-phosphonium bromide-1, 2, 4-tricarboxylate Acid 0.044%, ammonium polyacrylate 0.01%, pH = 2.6.

 Polishing solution 44: aluminum-doped silica (45 nm) 1.64%, hydrofluoric acid 0.0045%, tetrabutylammonium hydroxide 0.05%, benzotriazole 0.1%, 2-phosphonium bromide-1, 2, 4-tricarboxylate Acid 0.067%, ammonium polyacrylate 0.01%, pH = 2.6.

 Polishing solution 45: aluminum-doped silica (45nm) 2.00%, hydrofluoric acid 0.006%, tetrabutylammonium hydroxide 0.067%, benzotriazole 0.1%, 2-phosphonate butane-1, 2, 4-tricarboxylate Acid 0.089%, ammonium polyacrylate 0.01%, pH = 2.6.

Polishing solution 46: aluminum-doped silica (45 nm) 3.0%, hydrofluoric acid 0.009%, tetrabutylammonium hydroxide 0.10%, benzotriazole 0.1%, 2-phosphonate butane-1, 2, 4-tricarboxylate Acid 0.13%, polypropylene Ammonium acetate 0.01%,

 Polishing solution 47: Miscellaneous aluminum silica (45nm) 6.0%, hydrofluoric acid 0.018%, tetrabutylammonium hydroxide 0.2%, benzotriazole 0.1%, 2-phosphonium bromide-1, 2, 4-tricarboxylate Acid 0.2%, ammonium polyacrylate 0.01%, pH = 2.6.

 Polishing solution 48: aluminum-doped silica (45 nm) 9.0%, hydrofluoric acid 0.027%, tetrabutylammonium hydroxide 0.3%, benzotriazole 0.1%, 2-phosphonium bromide-1, 2, 4-tricarboxylate Acid 0.2%, polyacrylic acid continued 0.01%, pH = 2.6.

 Polishing solution 49: aluminum-doped silica (45nm) 18%, hydrofluoric acid 0.054%, tetrabutylammonium hydroxide 0.6%, benzotriazole 0.2%, 2-phosphonate butane-1, 2, 4-tricarboxylate Acid 0.4%, polyacrylic acid iron 0.01%, pH = 2.6.

 TE Polishing TEOS.BD and Cu with the above polishing solution. Polishing conditions: lower pressure 1.5 psi, polishing cloth Politex, polishing plate speed 70 rpm, polishing liquid flow rate 100 ml/min, polishing machine Logitec PM5. The polishing rate for each material is shown in Fig. 10.

 Figure 10 shows that both the polishing liquids 40 to 49 have a higher TEOS polishing rate and a lower BD removal rate, and the polishing liquids 40, 43 to 49 all have a lower Cu polishing rate.

 The polishing chip 47 is used to polish the chip with structure, and the effect is as shown in Fig. 11. The surface of the obtained chip is free from scratches, chemical corrosion and contamination.

Claims

Rights request  A chemical mechanical polishing liquid comprising water, characterized by further comprising: one or more of a metal-doped silica and a rate promoter: an organic acid, a fluoride, an ammonia, and a quaternary ammonium Salt and its derivatives.  The chemical mechanical polishing liquid according to claim 1, wherein the metal is aluminum, zirconium, hafnium, gold, silver, iron, chromium or molybdenum.  The chemical mechanical polishing liquid according to claim 1, wherein the metal-doped silica has a particle diameter of 20 to 80 nm.  The chemical mechanical polishing liquid according to claim 1, wherein the metal-doped silica is used in an amount of from 1 to 20% by mass.  The chemical mechanical polishing liquid according to claim 4, wherein the metal-doped silica is used in an amount of from 3 to 10% by mass.  The chemical mechanical polishing liquid according to claim 1, wherein the organic acid is selected from the group consisting of oxalic acid, butane-1, 2, 4-tricarboxylic acid, 2-hydroxyphosphonoacetic acid. One or more of aminotrimethylenephosphonic acid and tartaric acid; the fluoride is selected from one or more of hydrogen fluoride, ammonium fluoride, ammonium fluorosilicate and ammonium fluoroborate; The ammonium salt is selected from one or more of tetrabutylammonium hydroxide, tetramethylammonium hydroxide, and tetrabutylammonium fluoroborate.  The chemical mechanical polishing liquid according to claim 1, wherein the rate promoter is used in an amount of 0.05 to 1% by mass.  The chemical mechanical polishing liquid according to claim 7, wherein the rate promoter is used in an amount of 0.1 to 0.6% by mass. The chemical mechanical polishing liquid according to claim 1, wherein: said chemical The mechanical polishing solution has a pH of 2 to 5.  The chemical mechanical polishing liquid according to claim 1, wherein the chemical mechanical polishing liquid further contains one or more of a corrosion inhibitor, an oxidizing agent, a complexing agent, and a surfactant.