CN112646550B

CN112646550B - Diamond grinding fluid for wafer substrate slice

Info

Publication number: CN112646550B
Application number: CN202011548272.7A
Authority: CN
Inventors: 侯军; 王凯丽
Original assignee: Jiangsu Austrian Mstar Technology Ltd
Current assignee: Jiangsu Austrian Mstar Technology Ltd
Priority date: 2020-12-23
Filing date: 2020-12-23
Publication date: 2022-03-18
Anticipated expiration: 2040-12-23
Also published as: CN112646550A

Abstract

A diamond grinding fluid for a wafer substrate slice belongs to the technical field of fine chemical engineering. The addition of the alcohol ether organic solvent in the grinding fluid reduces the surface tension of the grinding fluid and increases the wetting and penetrating capacity. The molecular structure of the multifunctional metal ion trapping agent contains amide functional group, and the amide functional group is connected with an oxygen atom. The synergistic effect of the metal ion trapping agent and the organic solvent can obviously reduce the adsorption force of the grinding scraps on the surface and the edge of the wafer, and the wafer is easy to wash, so that the grinding scraps are prevented from being brought into a wax removal groove. And the diamond micro powder is uniformly dispersed by adopting a high-performance dispersing agent, so that the grinding fluid has good dispersion stability.

Description

Diamond grinding fluid for wafer substrate slice

Technical Field

The invention relates to the field of grinding fluid, in particular to diamond grinding fluid easy to clean after grinding, and belongs to the field of fine chemical engineering.

Background

The diamond grinding fluid is prepared by dispersing abrasive particles in a medium, is a grinding product with excellent chemical and mechanical properties, and can be used for grinding and polishing silicon wafers, engineering ceramics, compound crystals, precise optical devices, liquid crystal panels, gems, metal workpieces and the like.

After the polishing and lapping steps in the wafer substrate process, it is necessary to clean the residues of the abrasive particles, the organic substances, the metal oxides, and the like. The cleaning effect has an important influence on the back-end process, so that the cleaning agent has higher requirements on the cleaning agent after grinding and also provides new requirements on the easy cleaning capability of the grinding fluid. For example, after the sapphire substrate sheet is polished by copper polishing, the surface of the wafer may have abrasive dust residues, and these residues need to be primarily cleaned by deionized water (especially, the adhesive wax on the edge of the sheet is more likely to absorb the abrasive dust, etc.) to obtain a sapphire wafer meeting the quality requirement, and then the sapphire wafer can be further placed into a wax removal groove for cleaning. If the abrasive dust is not easy to be washed by water in the step, the abrasive dust can be brought into a wax removing groove, and the pollution to the electrode is caused.

At present, the commonly used diamond grinding fluid usually uses mixed alkane solvents such as white oil, kerosene and the like, and has the advantages of high removal rate, low cost and the like, but the disc surface of the grinding fluid is not easy to clean, and the treatment cost of the abrasive dust waste liquid is high; in addition, aqueous grinding fluid such as ethylene glycol, ethanol, propylene glycol, glycerol and the like can be used, the disc surface of the grinding fluid is easy to clean, the waste liquid of the abrasive dust is easy to treat, the environment is friendly and the like, but the edge of the grinding fluid sheet is easy to adsorb the abrasive dust and other dirt, is not easy to clean, is easy to be brought into a wax removing groove, causes electrode pollution, influences the LED quality and the like.

Therefore, it is still a subject to be studied how to improve the cleaning ability of the surface of the substrate sheet and to significantly reduce the defects on the surface of the chip while polishing the substrate sheet at a high speed.

The invention content is as follows:

aiming at the defects of the prior art, the invention provides the diamond grinding fluid which is easy to clean after polishing, and the probability that grinding scraps are brought into a paraffin removal groove can be obviously reduced.

The technical scheme of the application is as follows: a diamond grinding fluid comprises the following specific components in percentage by weight: 0.5 to 5 percent of diamond micro powder; 0.1-5% of surfactant; 0.1-5% of metal ion trapping agent; 0.1 to 10 percent of dispersant; 15-70% of a lubricant; 20-60% of alcohol ether organic solvent.

The diamond micro powder is non-agglomerated powder, and the granularity is 2-10 um.

The metal ion scavenger is glycine, lysine, amino trimethylene phosphonic Acid (ATMP), triethylene tetramethylene diamine tetra methylene phosphonic acid (EDTMPA), and ethylenediamine diphenyl sodium acetate (EDDHA-Na), preferably amino trimethylene phosphonic acid or ethylenediamine diphenyl sodium acetate;

the dispersing agent is polyacrylate, polycarboxylate, block phosphate polymer, preferably polyacrylate or ammonium polyacrylate salt.

The surfactant is polyoxyethylene alkylamine, polyoxyethylene alkylolamide, polyacetylene alcohol or fatty alcohol polyether, preferably polyacetylene alcohol;

the lubricant is one or two of ethylene glycol, polyethylene glycol, propylene glycol, diethylene glycol and triethylene glycol, and preferably ethylene glycol.

The alcohol ether organic solvent is one or two of tripropylene glycol methyl ether, propylene glycol methyl ether, diethylene glycol ethyl ether and acetone glycerol, preferably diethylene glycol ethyl ether or tripropylene glycol methyl ether.

The invention has the beneficial effects that: the addition of the alcohol ether organic solvent reduces the surface tension of the grinding fluid and increases the wetting and penetrating capacity. The multifunctional metal ion trapping agent has a molecular structure containing amide functional group, and the amide functional group is connected with an oxygen atom. The metal ion trapping agent has the advantages of large molecular weight, strong dispersibility and strong trapping capability on metal ions. The synergistic effect of the metal ion trapping agent and the organic solvent can obviously reduce the adsorption force of the grinding scraps on the surface and the edge of the wafer, and the wafer is easy to wash, so that the grinding scraps are prevented from being brought into a wax removal groove. And the diamond micro powder is uniformly dispersed by adopting a high-performance dispersing agent, so that the grinding fluid has good dispersion stability.

Drawings

FIG. 1 is a graph showing the polishing effect of the polishing liquid of comparative example 1 on sapphire.

FIG. 2 is a graph showing the polishing effect of the polishing liquid of example 10 on sapphire.

FIG. 3 is a graph showing the polishing effect of the polishing liquid of example 2 on sapphire.

Detailed Description

The present invention will be further described with reference to the following embodiments.

Example 1

The diamond grinding fluid of the embodiment comprises the following components in parts by weight: 0.5% of diamond micropowder, 4% of dispersing agent, 0.1% of metal ion trapping agent, 0.1% of surfactant, 70% of lubricant and 27.3% of organic solvent. The pH adjuster was triethanolamine, and the pH of the diamond polishing solution for sapphire polishing in this example was 7.5.

TABLE 1 compositions and mass contents of polishing solutions of examples 1-15 and comparative examples

The raw materials in the examples of the present application were all purchased commercially. Such as dow chemistry, tikahm, etc.

The analytical test method in the examples of the present application is as follows:

polishing and grinding the sapphire substrate by using the diamond grinding fluid; simultaneously, the wafer after polishing the grinding fluid is cleaned by deionized water, and the easy cleaning degree of the abrasive dust on the surface and the edge of the wafer is observed:

equipment: grinding machine

Polishing the main disc: copper disc with disc diameter of about 60cm and rotation speed of 80rpm

Polishing head: three polishing heads, each polishing head fixes the sapphire sheet on the ceramic disc through a ceramic correction ring

Pressure: 15 kg/head

Flow rate of polishing solution: 3ml/min

Temperature: 20-30 ℃ and starting a circulating water cooler

Diluting and proportioning: use of stock solution

Polishing time length: 10-15min

Table two: under the same conditions, the polishing rates and the crystal face cleanliness after grinding water for examples 2 and 10 and the conventional sapphire grinding liquid purchased from the market are shown in the following table.

Comparative example 1: the formula of the grinding fluid without alcohol ether solvent and ion catcher comprises 0.5 percent of diamond micropowder, 4 percent of polyacrylate, 0.1 percent of polyacetylene alcohol and 95.4 percent of ethylene glycol.

Comparative example 2: the formula of the grinding fluid without the ion scavenger is as follows: according to parts by weight, 0.5% of diamond micropowder, 4% of polyacrylate, 0.1% of polyacetylene alcohol, 70% of ethylene glycol and the balance of organic solvent tripropylene glycol methyl ether.

Comparison of the data in table two with the effects in fig. 1, 2 and 3 shows that, compared with commercially available aqueous sapphire polishing solutions, the surface tension of the polishing solution is reduced and the cleaning capability of deionized water is initially improved in the embodiment of the present invention after the organic solvent is added; the added metal ion trapping agent is combined, and the chelating and dispersing effects are utilized, so that the adsorption of residues is reduced, and the cleaning capability is improved again. The synergistic effect of the two greatly reduces the adsorption of the wafer surface to the residues while ensuring the removal rate, improves the cleaning capacity of the deionized water and greatly reduces the residues brought into the dewaxing groove.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. A diamond grinding fluid for a wafer substrate slice is characterized by comprising the following components in percentage by mass:

0.5 to 5 percent of diamond micro powder;

0.1-5% of surfactant;

0.1-5% of metal ion trapping agent;

0.1 to 10 percent of dispersant;

15-70% of a lubricant;

20-60% of alcohol ether organic solvent;

the diamond micro powder is non-agglomerated powder, and the granularity is 2-10 microns;

the metal ion trapping agent is one or more of glycine, lysine, amino trimethylene phosphonic acid, triethylene tetramethlene diamine tetramethylene phosphonic acid and ethylenediamine dipheny phenyl sodium acetate;

the dispersing agent is polyacrylate, polycarboxylate and block phosphate polymer;

the surfactant is polyoxyethylene alkylamine, polyoxyethylene alkylolamide, polyacetylene alcohol or fatty alcohol polyether;

the lubricant is one or two of ethylene glycol, polyethylene glycol, propylene glycol, diethylene glycol and triethylene glycol;

the alcohol ether organic solvent is one or two of tripropylene glycol methyl ether, propylene glycol methyl ether, diethylene glycol ethyl ether and acetone glycerol.

2. A diamond abrasive liquid for wafer substrate sheets according to claim 1, wherein: the metal ion trapping agent is amino trimethylene phosphonic acid or ethylenediamine diphthalic sodium acetate.

3. A diamond abrasive liquid for wafer substrate sheets according to claim 1, wherein: the dispersant is polyacrylate or ammonium polyacrylate salt.

4. A diamond abrasive liquid for wafer substrate sheets according to claim 1, wherein: the surfactant is a polyacetylene alcohol.

5. A diamond abrasive liquid for wafer substrate sheets according to claim 1, wherein: the lubricant is ethylene glycol.

6. A diamond abrasive liquid for wafer substrate sheets according to claim 1, wherein: the alcohol ether organic solvent is diethylene glycol ethyl ether or tripropylene glycol methyl ether.