Chemical mechanical polishing composition and use thereof

Abstract

The present invention provides a chemical mechanical polishing composition, comprising: abrasive particles, a catalyst, a promoter, a polybasic acid, and water. A chemical mechanical polishing solution of the present invention can effectively remove silicon boride under acidic conditions, thereby adjusting polishing selectivity of the polishing solution to different materials.

Description

A chemical mechanical polishing composition and its use Technical Field

[0001] The present invention relates to the field of chemical mechanical polishing, in particular to a chemical mechanical polishing liquid and application thereof. Background Art

[0002] The rapid development of modern chip technology has greatly promoted the miniaturization of integrated circuit components. To ensure the proper distribution and efficient operation of circuit components at the nanoscale, the wafer surface must also be flattened to a corresponding level. Currently, the most effective method to achieve this goal is chemical mechanical polishing (CMP).

[0003] A semiconductor wafer typically includes a substrate, such as silicon or gallium arsenide, on which a plurality of transistors have been formed. The transistors are chemically and physically connected to the substrate by patterning regions in the substrate and layers on the substrate. The transistors and layers are separated by an interlayer dielectric (ILD) primarily comprising some form of silicon dioxide (SiO2). The transistors are interconnected using what are known as multi-level interconnects. Typical multi-level interconnects include stacked thin films composed of one or more of the following materials: titanium (Ti), titanium nitride (TiN), tantalum (Ta), aluminum-copper (Al-Cu), aluminum-silicon (Al-Si), copper (Cu), tungsten (W), doped polysilicon (poly-Si), and various combinations thereof. In addition, transistors or groups of transistors are typically isolated from each other by using trenches filled with insulating materials such as silicon dioxide, silicon nitride, or polysilicon.

[0004] Chemical mechanical polishing involves both chemical and mechanical action. Typically, a wafer is mounted on a polishing head, with its front surface in contact with the polishing pad in the CMP equipment. Under pressure, the polishing head moves linearly across the polishing pad or rotates in the same direction as the polishing table. Simultaneously, a polishing composition ("slurry") is injected between the wafer and the polishing pad at a constant flow rate. Centrifugal action spreads the slurry onto the polishing pad. Thus, through the combined chemical and mechanical action, the wafer surface is polished and globally planarized.

[0005] With the continued advancement and development of semiconductor device structures and functions, simple polycrystalline silicon structures are no longer able to meet these specific requirements. It is necessary to dope single-crystalline silicon with elements such as boron, phosphorus, and carbon to modify the chemical and physical properties of polycrystalline silicon to meet these requirements. While many known CMP slurry compositions are suitable for polishing polycrystalline silicon, no research has been conducted on CMP polishing compositions for boron-doped polycrystalline silicon. Summary of the Invention

[0006] In order to overcome the above technical defects, the object of the present invention is to provide a chemical mechanical polishing solution capable of removing silicon boride under acidic conditions.

[0007] Specifically, the present invention discloses a chemical mechanical polishing composition, comprising: abrasive particles, a catalyst, an accelerator, a polyacid and water.

[0008] Preferably, the abrasive particles are selected from one or more of aluminum oxide, cerium oxide, zirconium oxide, titanium oxide or silicon dioxide;

[0009] The mass percentage concentration of the abrasive particles is 0.1 wt% to 30 wt%.

[0010] Preferably, the abrasive particles are silicon oxide particles;

[0011] The mass percentage concentration of the abrasive particles is 0.5 wt % to 20 wt %.

[0012] Preferably, the catalyst is selected from one or more of alkali metal salts, alkaline earth metal salts and ammonium salts;

[0013] The mass percentage concentration of the catalyst is 0.001 wt% to 1 wt%.

[0014] Preferably, the alkali metal salt is selected from one or more of sodium salt and potassium salt;

[0015] The alkaline earth metal salt is selected from one or more of magnesium salts and calcium salts;

[0016] The mass percentage concentration of the catalyst is 0.01 wt% to 0.5 wt%.

[0017] Preferably, the accelerator is one or more of polyols and polyamide compounds;

[0018] The mass percentage concentration of the accelerator is 0.1 wt% to 10 wt%.

[0019] Preferably, the polyol is one or more selected from ethylene glycol, glycerol, pentaerythritol, trimethylolethane, xylitol, sorbitol, polyethylene glycol;

[0020] The mass percentage concentration of the accelerator is 0.1 wt% to 5 wt%.

[0021] Preferably, the polyacid is selected from one or more of oxalic acid, malonic acid, succinic acid, glutaric acid, lactic acid, succinic acid, and citric acid;

[0022] The mass percentage concentration of the polyacid is 0.01 wt % to 1 wt %.

[0023] Preferably, the mass percentage concentration of the polyacid is 0.01 wt% to 0.5 wt%.

[0024] Preferably, it further contains a pH regulator selected from one or more of nitric acid, sulfuric acid, phosphoric acid, sodium hydroxide, potassium hydroxide, and ammonia water.

[0025] Preferably, the pH value of the chemical mechanical polishing composition is 2-7.

[0026] The present invention also discloses a use of any of the above chemical mechanical polishing compositions for polishing silicon boride.

[0027] The chemical mechanical polishing liquid of the present invention can significantly remove silicon boride under acidic conditions, thereby adjusting the polishing selectivity of the polishing liquid for different materials. DETAILED DESCRIPTION

[0028] The advantages of the present invention are further described below with reference to specific embodiments.

[0029] Specific Examples and Comparisons: According to the formulation given in Table 1, all components were dissolved and mixed uniformly, and the weight percentage was adjusted to 100% with water. The pH was adjusted to the desired value using a pH adjuster. The abrasive particles were silicon dioxide, and the polyacid was citric acid. The percentages in the concentrations described in the examples refer to weight concentrations.

[0030] Table 1 Components and contents of chemical mechanical polishing liquids of Examples 1-15 and Comparative Examples 1-5

[0031] Further characterization of the properties of the chemical mechanical polishing solution in the embodiment of the present invention was carried out by using the polishing solution in the embodiment and the comparative example.

[0032] Polishing conditions: 2.0 psi pressure, 93 / 87 rpm polishing disc and head speeds, IC1000 polishing pad, 300 mL / min polishing fluid flow rate, LK polishing machine, and 1 minute polishing time. The polishing rates of SiB and oxide were measured using a non-metallic film thickness gauge, as shown in Table 2.

[0033] Table 2 Polishing test results of chemical mechanical polishing solutions of Examples 1-15 and Comparative Examples 1-5

[0034] Comparative Examples 1-5 show that adding a promoter under acidic conditions can significantly increase the removal rate of borosilicate.

[0035] By comparing Examples 1, 2, 4, 8, and 9 with Comparative Examples 1-5, it can be seen that the removal rate of silicon boride can be further increased by adding a suitable catalyst while adding the promoter.

[0036] It can be seen from Examples 1-15 that by properly adjusting the types and concentrations of the catalyst and the promoter, different selectivities of the removal rates of silicon boride and silicon oxide can be obtained.

[0037] Comparing Example 1 with Comparative Examples 6 and 7, it can be seen that using metals other than alkaline earth metals or alkali metals, such as iron or aluminum, does not achieve a sufficient SiB removal rate. Comparing Example 1 with Comparative Examples 8 and 9, it can be seen that using monohydric alcohols, such as ethanol or propanol, also does not achieve a fast SiB removal rate.

[0038] In summary, the method proposed in this patent can significantly remove silicon boride under acidic conditions, thereby adjusting the selectivity of different materials.

[0039] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A chemical mechanical polishing composition, characterized in that, Comprising: Abrasive particles, a catalyst, an accelerator, a polybasic acid, and water.

2. The chemical mechanical polishing composition according to claim 1, wherein The abrasive particles are selected from one or more of alumina, cerium oxide, zirconium oxide, titanium oxide, or silica; The mass percentage concentration of the abrasive particles is 0.1 wt% to 30 wt%.

3. The chemical mechanical polishing composition according to claim 2, wherein The abrasive particles are silica particles; The mass percentage concentration of the abrasive particles is 0.5 wt% to 20 wt%.

4. The chemical mechanical polishing composition according to claim 1, wherein The catalyst is selected from one or more of alkali metal salts and alkaline earth metal salts; The mass percentage concentration of the catalyst is 0.001 wt% to 1 wt%.

5. The chemical mechanical polishing composition according to claim 4, wherein The alkali metal salts are selected from one or more of sodium salts and potassium salts; The alkaline earth metal salts are selected from one or more of magnesium salts and calcium salts; The mass percentage concentration of the catalyst is 0.01 wt% to 0.5 wt%.

6. The chemical mechanical polishing composition according to claim 1, wherein The accelerator is one or more polyols; The mass percentage concentration of the accelerator is 0.1 wt% to 10 wt%.

7. The chemical mechanical polishing composition according to claim 6, wherein The polyols are selected from one or more of ethylene glycol, glycerol, pentaerythritol, trimethylolethane, xylitol, sorbitol, polyethylene glycol; The mass percentage concentration of the accelerator is 0.1 wt% to 5 wt%.

8. The chemical mechanical polishing composition according to claim 1, wherein The polybasic acid is selected from one or more of oxalic acid, malonic acid, succinic acid, glutaric acid, lactic acid, succinic acid, citric acid; The mass percentage concentration of the polybasic acid is 0.01 wt% to 1 wt%.

9. The chemical mechanical polishing composition according to claim 1, wherein The mass percentage concentration of the polybasic acid is 0.01 wt% to 0.5 wt%.

10. The chemical mechanical polishing composition according to claim 1, wherein It further contains a pH regulator, which is selected from one or more of nitric acid, sulfuric acid, phosphoric acid, sodium hydroxide, potassium hydroxide, and ammonia water.

11. The chemical mechanical polishing composition according to claim 1, wherein The pH value of the chemical mechanical polishing composition is 2 to 7.

12. A use of the chemical mechanical polishing composition according to any one of claims 1-11 for polishing boronized silicon.

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