Chemical and mechanical grinding fluids

Abstract

The present invention relates to a chemical mechanical polishing slurry (polishing slurry) for polishing amorphous carbon materials. The chemical mechanical polishing slurry contains abrasive particles, a compound containing a carboxyl group, and a compound containing two or more hydroxyl groups. Preferably, the abrasive particles are silica with a particle size of 20 to 120 nm, and the content of the abrasive particles is 0.1 to 5 mass %, the content of the compound containing a carboxyl group is 0.01 to 0.5 mass %, and the content of the compound containing two or more hydroxyl groups is 0.05 to 3 mass %. The chemical mechanical polishing slurry of the present invention has a high removal rate for amorphous carbon materials and has good market prospects.

Description

[Technical Field]

[0001] The present invention relates to the field of chemical mechanical polishing, and more particularly to a chemical mechanical polishing liquid (polishing slurry). [Background technology]

[0002] Amorphous carbon films, also known as diamond-like carbon films, have attracted considerable attention due to their excellent properties, such as high hardness, high strength, high thermal conductivity, high resistivity, high radiation resistance, high chemical stability, low friction coefficient, and good transmittance in the infrared optical wavelength range. They have enormous potential for application in fields such as high-density integrated electronic devices that require high temperature, high frequency, high power, and radiation resistance.

[0003] As semiconductor processes become increasingly sophisticated, chip microfabrication technology requires ever-finer patterning, and lithography laser wavelengths are gradually shortening with process improvements. While photoresist films are typically thinned to control pattern resolution, excessively thin photoresist films etch before the underlying material, resulting in pattern distortion. Therefore, a hard mask film must be formed on the underlying material in addition to the photoresist pattern. Traditionally, silica and silicon nitride were often used as hard masks to ensure processing margins during the etching process. However, as process miniaturization continues, the hard mask thickness requirements are becoming smaller. To achieve high resolution and reduce material necking and footing, amorphous carbon films, which have higher chemical stability and less diffuse reflection, are now commonly used as hard masks.

[0004] Amorphous carbon films can be formed by well-known chemical vapor deposition (CVD) and physical vapor deposition (PVD) methods. PVD methods, such as sputtering, require directional deposition of amorphous carbon films, requiring measures such as rotating the substrate or placing multiple targets within the apparatus to form uniform amorphous carbon films. Such amorphous carbon film formation equipment is complex and expensive, and forming amorphous carbon films can be difficult depending on the substrate shape. On the other hand, CVD methods form amorphous carbon films using reactive gases, which makes the equipment simple and inexpensive. Therefore, plasma CVD is currently the most commonly used technology, specifically using hydrocarbons with benzene rings or multiple double bonds, such as naphthalene, benzene, and toluene, as reactive gases. However, in processes with a microstructure of 50 nm or less, the problem of residual bubble-like or droplet-like carbon particles remaining during the transfer process of amorphous carbon layers formed by CVD processes has become a significant issue. In addition, by selecting an appropriate deposition technique and changing the deposition parameters, it is possible to obtain C sp 2 and sp 3 The mixing ratio can be controlled, and the film properties can be further adjusted.

[0005] Therefore, in order to improve the lithography accuracy in the semiconductor device manufacturing process, the interlayer flatness in each process is an extremely important factor. As described in Chinese patent application (publication) CN109623581A, amorphous carbon materials are very stable at room temperature and are resistant to chemical reactions. 3The higher the content of cerium oxide, the higher the Mohs hardness, which makes planarization difficult and increases processing time. This patent improves the removal rate of carbon materials by combining a pre-processing process of rough polishing and etching. In Korean patent application (publication) KR20200057566A, adding compounds such as imino acid or formic acid to cerium oxide abrasive grains effectively removes amorphous carbon films, but removing residues such as cerium oxide generated during polishing poses another challenge. Furthermore, Chinese patent application (publication) CN102464944A uses a large amount of strong oxidizing agent, but the removal rate of carbon materials is low and does not meet the requirements of semiconductor processes.

[0006] Thus, in order to provide a high-quality surface to the amorphous carbon material film on the chip, a polishing composition that can achieve a high polishing rate and has excellent surface quality (e.g., a small number of scratches) is required. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Chinese patent application (published) CN109623581A [Patent Document 2] Korean patent application (publication) KR20200057566A [Patent Document 3] Chinese patent application (published) CN102464944A Summary of the Invention [Means for solving the problem]

[0008] The present invention provides a chemical mechanical polishing solution that improves the polishing rate of amorphous carbon materials. The present invention provides a chemical mechanical polishing liquid for polishing amorphous carbon materials, the polishing liquid comprising abrasive particles, a compound containing a carboxyl group, and a compound containing two or more hydroxyl groups.

[0009] Preferably, the abrasive particles are silica, and the particle diameter of the abrasive particles is 20 to 120 nm. Preferably, the mass percentage content of the abrasive particles is 0.1 to 5%. Preferably, the mass percentage of the abrasive particles is 0.1 to 2%.

[0010] Preferably, the compound containing a hydroxyl group is one or more compounds selected from pyridine compounds, piperidine compounds, pyrrolidine compounds, pyrrole compounds, and derivatives thereof.

[0011] Preferably, the compound containing a hydroxyl group is 2-carboxylpyridine, 3-carboxylpyridine, 4-carboxylpyridine, 2,4-dicarboxylpyridine, 2-methyl-4-carboxylpyridine, 2,6-dicarboxylpyridine, 6-amino-2-dicarboxylpyridine, 3,5-dicarboxylpyridine, 2-carboxylpiperidine, 3-carboxylpiperidine, 4-carboxylpiperidine, 2,3-dicarboxylpiperidine, 2,4-dicarboxylpyridine, A polishing liquid characterized by containing one or more compounds selected from the group consisting of carboxylpiperidine, 2,6-dicarboxylpiperidine, 3,5-dicarboxylpiperidine, 1-methyl-piperidine-4-carboxylic acid, 2-carboxylpyrrolidine, 3-carboxylpyrrolidine, 2,4-dicarboxylpyrrolidine, 2,5-dicarboxylpyrrolidine, 2-carboxylpyrrole, 3-carboxylpyrrole, 2,5-dicarboxylpyrrole, and 3,4-dicarboxylpyrrole.

[0012] Preferably, the mass percentage content of the compound containing a hydroxyl group is 0.01 to 0.5%. Preferably, the mass percentage content of the compound containing a hydroxyl group is 0.01 to 0.2%.

[0013] Preferably, the polishing liquid is characterized in that the compound containing two or more hydroxyl groups is one or more selected from pentaerythritol, ethylene glycol, 1,2-propylene glycol, 2-methylpropanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, trimethylolpropane, glycerin, xylitol, glucose, ascorbic acid, sorbitol, sucrose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, and carboxymethylcellulose.

[0014] Preferably, the polishing liquid is characterized in that the content of the compound containing two or more hydroxyl groups is 0.05 to 3% by mass percentage. Preferably, the polishing liquid is characterized in that the content of the compound containing two or more hydroxyl groups is 0.1 to 1% by mass percentage.

[0015] Preferably, the chemical mechanical polishing liquid has a pH value of 2 to 6.

[0016] The chemical mechanical polishing liquid of the present invention may contain additives commonly used in the art, such as a pH adjuster and a disinfectant. The chemical mechanical polishing solution of the present invention can be prepared in a concentrated form, and when used, it is diluted with ion-exchanged water to within the concentration range of the present invention. Another aspect of the present invention provides use of any of the above chemical mechanical polishing liquids for polishing an amorphous carbon material. [Effects of the Invention]

[0017] The chemical mechanical polishing solution of the present invention has a high removal rate for amorphous carbon materials, does not contain an oxidizing agent, thereby reducing production costs, is easy to use, and does not require rough polishing or etching as wafer pretreatment, and therefore has excellent market prospects. DETAILED DESCRIPTION OF THE INVENTION

[0018] The advantages of the present invention will be further illustrated below with reference to specific examples.

[0019] Table 1 shows the components and their contents (mass concentrations) of Examples 1 to 19 of the chemical mechanical polishing solution of the present invention. All components are dissolved and mixed uniformly according to the formulation in the table, and water is added to make the mass percentage 100%. The pH value of the polishing solution can be adjusted to the desired pH value using a pH adjuster. The pH adjuster may be any pH adjuster commonly used in the art.

[0020] Table 1: Composition and content of chemical mechanical polishing solutions of Comparative Examples 1-9 and Examples 1-19 [Table 1] JPEG2025539661000002.jpg247169JPEG2025539661000003.jpg246170JPEG2025539661000004.jpg145169

[0021] To demonstrate the polishing performance of the above chemical mechanical polishing solutions, we further conducted polishing rate tests. The specific polishing conditions were as follows: Reflexion LK polishing machine, IC1010 polishing pad, 300 mm wafer, polishing pressure 1.0 psi, polishing disk rotation speed 93 rpm, polishing head rotation speed 87 rpm, polishing solution flow rate 300 ml / min, and polishing time 1 minute. The carbon material removal rate for each polishing solution was measured and is listed in Table 2.

[0022] Table 2: Polishing rates of amorphous carbon materials using chemical mechanical polishing solutions of Comparative Examples 1-9 and Examples 1-19 [Table 2] JPEG2025539661000006.jpg173103

[0023] As is clear from the test results in Table 2, Comparative Examples 1-2 show that polishing using only pure SiO2 hardly resulted in any significant amorphous carbon removal rate. Comparative Examples 3 and 4-5 show that adding either a carboxyl group-containing compound alone or an alcohol containing two or more hydroxyl groups alone improved the amorphous carbon removal rate. Comparing the results of the Examples and Comparative Examples 4-5, the simultaneous addition of a carboxyl group-containing compound and a polyol (a compound containing two or more hydroxyl groups) significantly increased the amorphous carbon removal rate. Comparing Comparative Examples 6-7 and 8-9 with the Examples reveals that the pH range of the polishing solution of the present invention is appropriate for a pH of 2 to 6. Furthermore, comparing Comparative Examples 6-7 with the Examples confirms that the polishing solution of the present invention, despite not containing an oxidizing agent, exhibited a higher removal rate for carbon materials than when an oxidizing agent was added alone to the abrasive particles.

[0024] From the above results, it was demonstrated that the present invention can significantly improve the removal rate of amorphous carbon materials by adding a carboxyl group-containing compound and a polyol to the polishing liquid.

[0025] Although specific examples of the present invention have been described in detail, these are merely examples and are not intended to limit the technical scope of the present invention. Any equivalent modifications or substitutions made by a person skilled in the art that do not deviate from the spirit of the present invention are all considered to be within the scope of the present invention.

Claims

1. A chemical mechanical polishing solution for polishing an amorphous carbon material, comprising: A chemical mechanical polishing liquid comprising abrasive particles, a compound containing a carboxyl group, and a compound containing two or more hydroxyl groups.

2. 2. The chemical mechanical polishing solution according to claim 1, A chemical mechanical polishing solution, wherein the abrasive particles are silica and have a particle size of 20 to 120 nm.

3. 2. The chemical mechanical polishing solution according to claim 1, A chemical mechanical polishing solution characterized in that the mass percentage content of the abrasive particles is 0.1 to 5%.

4. 4. The chemical mechanical polishing solution according to claim 3, A chemical mechanical polishing solution characterized in that the mass percentage of the abrasive particles is 0.1 to 2%.

5. 2. The chemical mechanical polishing solution according to claim 1, The chemical mechanical polishing liquid is characterized in that the compound containing a carboxyl group is one or more compounds selected from the group consisting of pyridine compounds, piperidine compounds, pyrrolidine compounds, pyrrole compounds, and derivatives thereof.

6. 6. The chemical mechanical polishing solution according to claim 5, The compound containing a carboxyl group is 2-carboxypyridine, 3-carboxypyridine, 4-carboxypyridine, 2,4-dicarboxypyridine, 2-methyl-4-carboxypyridine, 2,6-dicarboxypyridine, 6-amino-2-dicarboxypyridine, 3,5-dicarboxypyridine, 2-carboxypiperidine, 3-carboxypiperidine, 4-carboxypiperidine, 2,3-dicarboxypiperidine, 2,4-dicarboxy 1. A chemical mechanical polishing solution comprising one or more compounds selected from the group consisting of piperidine, 2,6-dicarboxylpiperidine, 3,5-dicarboxylpiperidine, 1-methyl-piperidine-4-carboxylic acid, 2-carboxylpyrrolidine, 3-carboxylpyrrolidine, 2,4-dicarboxylpyrrolidine, 2,5-dicarboxylpyrrolidine, 2-carboxylpyrrole, 3-carboxylpyrrole, 2,5-dicarboxylpyrrole, and 3,4-dicarboxylpyrrole.

7. 2. The chemical mechanical polishing solution according to claim 1, The chemical mechanical polishing solution is characterized in that the mass percentage content of the compound containing a carboxyl group is 0.01 to 0.5%.

8. 8. The chemical mechanical polishing solution according to claim 7, The chemical mechanical polishing solution is characterized in that the mass percentage content of the compound containing a carboxyl group is 0.01 to 0.2%.

9. 2. The chemical mechanical polishing solution according to claim 1, the compound containing two or more hydroxyl groups is one or more selected from the group consisting of pentaerythritol, ethylene glycol, 1,2-propylene glycol, 2-methylpropanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, trimethylolpropane, glycerin, xylitol, glucose, ascorbic acid, sorbitol, sucrose, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylcellulose, and carboxymethylcellulose.

10. 2. The chemical mechanical polishing solution according to claim 1, A chemical mechanical polishing solution characterized in that the mass percentage content of the compound containing two or more hydroxyl groups is 0.05 to 3%.

11. 11. The chemical mechanical polishing liquid according to claim 10, A chemical mechanical polishing solution characterized in that the mass percentage content of the compound containing two or more hydroxyl groups is 0.1 to 1%.

12. The chemical mechanical polishing liquid according to any one of claims 1 to 11, The chemical mechanical polishing solution has a pH value of 2 to 6.

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