Chemical mechanical polishing slurry

Abstract

The present invention provides a chemical mechanical polishing slurry, comprising: silicon dioxide abrasive particles, a carboxyl-containing compound, and a polyamino acid compound. The chemical mechanical polishing slurry of the present invention has a relatively high silicon nitride removal rate and an extremely low tungsten removal rate.

Description

A chemical mechanical polishing fluid Technical Field

[0001] This invention relates to a chemical mechanical polishing slurry, and more particularly to a chemical mechanical polishing slurry having a high silicon nitride removal rate and an extremely low tungsten removal rate. Background Technology

[0002] The integrated circuit (IC) manufacturing industry has experienced exponential growth over the past few decades. With the development of ICs, functional density (i.e., the number of interconnect devices per wafer area) has increased while feature size has decreased, leading to the introduction of embedded memory technology and high-k metal gate (HKMG) technology. Embedded memory technology integrates memory devices and logic devices on the same semiconductor wafer. This memory device supports the operation of the logic device and improves performance compared to using separate wafers for different types of devices. High-k metal gate (HKMG) technology is the fabrication of semiconductor devices using metal gate electrodes and a high-k metal gate dielectric layer. During chip manufacturing, charge signals control the conduction of field-effect transistors (FETs) through the gate, and the quality of the dielectric film on the gate has a significant impact on the FET's performance. In the past, silicon dioxide was commonly used as the gate dielectric film, but with the shrinking of processes and the need for higher performance, silicon dioxide has become very thin. However, this material can cause leakage current, which leads to thermal effects in the silicon channels, thus limiting the speed, power consumption, and heat management of modern chips. To reduce leakage current, improve energy consumption, and enhance performance, metallic conductor materials such as tungsten, aluminum, and tungsten-palladium alloys are introduced. In some manufacturing processes, insulating materials such as silicon nitride are also incorporated. To improve electrical performance, the chemical mechanical polishing process must remove the insulating material while minimizing the impact on the thickness of the metallic conductor material.

[0003] Existing technology CN116875194A discloses the use of specific rate inhibitor molecules to stop the chemical mechanical polishing of tungsten on the barrier layer. The disadvantage is that it has a high tungsten polishing rate and a low barrier layer polishing rate. CN114686109A discloses low tungsten static corrosion, providing a high tungsten polishing rate and a medium silicon oxide polishing rate, but it does not address the barrier layer polishing rate and has a high polishing rate. CN118271971A discloses that by using two types of abrasive particles in combination, the chemical mechanical polishing slurry has good stability and can simultaneously perform high-speed chemical mechanical polishing on materials such as tungsten and silicon nitride. The disadvantage is that the polishing rates of both tungsten and silicon nitride are high and there is no selectivity.

[0004] This invention provides a chemical mechanical polishing slurry with a high silicon nitride removal rate and an extremely low tungsten removal rate, which can be applied to the polishing process of high dielectric constant gate processes. Summary of the Invention

[0005] This invention discloses a chemical mechanical polishing fluid, comprising: silica abrasive particles, one or more of a pyridine compound, piperidine compound, pyrrolidine compound or pyrrole compound containing one or more carboxyl groups, and a polyamino acid compound.

[0006] Preferably, the pyridine compound, piperidine compound, pyrrolidine compound, or pyrrole compound containing one or more carboxyl groups is selected from one or more of 2-carboxypyridine, 3-carboxypyridine, 4-carboxypyridine, 2,3-dicarboxypyridine, 2,4-dicarboxypyridine, 2,6-dicarboxypyridine, 3,5-dicarboxypyridine, 2-carboxypiperidine, 3-carboxypiperidine, 4-carboxypiperidine, 2,3-dicarboxypiperidine, 2,4-dicarboxypiperidine, 2,6-dicarboxypiperidine, 3,5-dicarboxypiperidine, 2-carboxypyrrolidine, 3-carboxypyrrolidine, 2,4-dicarboxypyrrolidine, 2,5-dicarboxypyrrolidine, 2-carboxypyrrole, 3-carboxypyrrole, 2,5-dicarboxypyrrole, and 3,4-dicarboxypyridine.

[0007] Preferably, the polyamino acid compound is selected from polyglutamic acid, polyaspartic acid, polylysine, polyleucine, polyglycine, polyhistidine, polyarginine, polyalanine, polyvaline, polyproline, polytryptophan, polytyrosine, polyphenylalanine, polyserine, and polythreonine.

[0008] Preferably, the concentration of the silica abrasive particles is 0.5 wt% to 8 wt%.

[0009] Preferably, the concentration of the silica abrasive particles is 1% to 5 wt%.

[0010] Preferably, the concentration of the pyridine compound, piperidine compound, pyrrolidine compound, or pyrrole compound containing one or more carboxyl groups is 0.01 wt% to 1 wt%.

[0011] Preferably, the concentration of the pyridine compound, piperidine compound, pyrrolidine compound, or pyrrole compound containing one or more carboxyl groups is 0.01 wt% to 0.5 wt%.

[0012] Preferably, the content of the polyamino acid compound is 0.01wt%-1wt%.

[0013] Preferably, the content of the polyamino acid compound is 0.01wt%-0.5wt%.

[0014] Preferably, the pH value of the chemical mechanical polishing solution is 2-6.

[0015] Preferably, the chemical mechanical polishing fluid may further include additives such as pH adjusters and bactericides.

[0016] This invention provides a chemical mechanical polishing (CMP) slurry with a high silicon nitride removal rate and an extremely low tungsten removal rate. It utilizes one or more of pyridine, piperidine, pyrrolidine, or pyrrole compounds containing one or more carboxyl groups to increase the SiN polishing rate, while simultaneously using a polyamino acid compound to suppress the W polishing rate. The CMP slurry of this invention simultaneously improves the SiN polishing rate and suppresses the W polishing rate, exhibiting a high SiN / W selectivity ratio. The CMP slurry disclosed in this invention can be applied to high-dielectric-constant gate process polishing. Detailed Implementation

[0017] The chemical mechanical polishing composition of the present invention will be described in detail below through specific embodiments to provide a better understanding of the present invention, but the following embodiments do not limit the scope of the present invention.

[0018] In the specific embodiments and comparative examples, all components were dissolved and mixed evenly according to the formulations given in Table 1, and water was added to bring the mass percentage to 100%. The pH value was adjusted using a pH adjuster.

[0019] The concentrations mentioned in the examples all refer to mass percentage concentrations.

[0020] Table 1 Chemical mechanical polishing slurries of Examples 1-16 and Comparative Examples 1-4

[0021] Polishing was performed using the polishing slurry formulated according to Table 1 under the following conditions. Specific polishing conditions: Reflexion LK polishing machine, IC1010 polishing pad, 300mm wafer, polishing pressure 1.5psi, polishing disc speed 93 rpm, polishing head speed 87 rpm, polishing slurry flow rate 300ml / min, and polishing time 1min.

[0022] The results of Comparative Example 1 show that polishing with only SiO2 abrasive particles results in a very low polishing speed for silicon nitride, indicating an inverse selectivity between silicon nitride and tungsten. The results of Comparative Example 4, compared to Comparative Examples 2 and 3, show that the carboxypyridine compound selected in this invention significantly improves the silicon nitride removal speed compared to other carboxylic acids and heterocyclic acids. The results of Example 1 and Comparative Example 4 show that the addition of polyamino acid compounds greatly reduces the tungsten removal rate and significantly improves the silicon nitride / tungsten selectivity ratio. This invention utilizes pyridine compounds, piperidine compounds, pyrrolidine compounds, or pyrrole compounds with one or more carboxyl groups to increase the silicon nitride removal rate and uses polyamino acid compounds to suppress the tungsten removal rate. This significantly increases the silicon nitride / tungsten selectivity ratio, minimizing the impact on the tungsten thickness on the substrate surface during polishing and ensuring electrical performance.

[0023] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications 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 shall still fall within the scope of the technical solution of the present invention.

Claims

1. A chemical mechanical polishing slurry, characterized in that, include: Silica abrasive particles, containing one or more of the following: pyridine compounds, piperidine compounds, pyrrolidine compounds, or pyrrole compounds, or polyamino acid compounds.

2. The chemical mechanical polishing slurry as described in claim 1, characterized in that, The pyridine compound, piperidine compound, pyrrolidine compound, or pyrrole compound containing one or more carboxyl groups is selected from one or more of 2-carboxypyridine, 3-carboxypyridine, 4-carboxypyridine, 2,3-dicarboxypyridine, 2,4-dicarboxypyridine, 2,6-dicarboxypyridine, 3,5-dicarboxypyridine, 2-carboxypiperidine, 3-carboxypiperidine, 4-carboxypiperidine, 2,3-dicarboxypiperidine, 2,4-dicarboxypiperidine, 2,6-dicarboxypiperidine, 3,5-dicarboxypiperidine, 2-carboxypyrrolidine, 3-carboxypyrrolidine, 2,4-dicarboxypyrrolidine, 2,5-dicarboxypyrrolidine, 2-carboxypyrrole, 3-carboxypyrrole, 2,5-dicarboxypyrrole, and 3,4-dicarboxypyridine.

3. The chemical mechanical polishing slurry as described in claim 1, characterized in that, The polyamino acid compound is selected from polyglutamic acid, polyaspartic acid, polylysine, polyleucine, polyglycine, polyhistidine, polyarginine, polyalanine, polyvaline, polyproline, polytryptophan, polytyrosine, polyphenylalanine, polyserine, and polythreonine.

4. The chemical mechanical polishing slurry as described in claim 1, characterized in that, The concentration of the silica abrasive particles is 0.5wt% to 8wt%.

5. The chemical mechanical polishing slurry as described in claim 4, characterized in that, The concentration of the silica abrasive particles is 1% to 5 wt%.

6. The chemical mechanical polishing slurry as described in claim 1, characterized in that, The concentration of the pyridine compound, piperidine compound, pyrrolidine compound, or pyrrole compound containing one or more carboxyl groups is 0.01 wt% to 1 wt%.

7. The chemical mechanical polishing slurry as described in claim 6, characterized in that, The concentration of the pyridine compound, piperidine compound, pyrrolidine compound, or pyrrole compound containing one or more carboxyl groups is 0.01 wt% to 0.5 wt%.

8. The chemical mechanical polishing slurry as described in claim 1, characterized in that, The content of the polyamino acid compound is 0.01wt%-1wt%.

9. The chemical mechanical polishing slurry as described in claim 8, characterized in that, The content of the polyamino acid compound is 0.01wt%-0.5wt%.

10. The chemical mechanical polishing slurry according to any one of claims 1-9, characterized in that, The pH value of the chemical mechanical polishing fluid is 2-6.

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