Heavily doped monocrystalline silicon wafer corrosion technique by alkali corrosion before acid corrosion

A single crystal silicon wafer, acid etching technology, applied in the direction of post-processing, crystal growth, post-processing details, etc., can solve problems such as not meeting customer requirements

Inactive Publication Date: 2011-04-20
TIANJIN ZHONGHUAN ADVANCED MATERIAL TECH
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  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Can not meet customer requirements

Method used

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Embodiment

[0012] Example: 6-inch heavily doped monocrystalline silicon wafer, resistivity 0.0004-0.0037Ω.㎝, silicon wafer TTV<1 before etching, removal amount required to remove 60um / both sides. The specific etching process steps are as follows:

[0013] 1) Configure alkali corrosion solution, first pour solid potassium hydroxide into the alkali corrosion tank, and then inject pure water into the tank to prepare solid potassium hydroxide: water = 30%: 70% aqueous solution;

[0014] 2) Raise the temperature of the alkali etching machine to 84°C;

[0015] 3) Put the silicon wafer to be processed into the alkali etching machine and start etching; the etching time is 7min12s; the removal amount of alkali etching is about 20μm;

[0016] 4) After the alkali etching is finished, take out the silicon wafer and put it into a water truck; clean the monocrystalline silicon wafer after alkali etching, and then dry it;

[0017] 5) Pour the cleaned etched monocrystalline silicon wafer into the acid...

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PUM

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Abstract

The invention relates to a heavily doped monocrystalline silicon wafer corrosion technique by alkali corrosion before acid corrosion. The corrosion technique comprises the following steps: carrying out alkali corrosion on the monocrystalline silicon wafer by using a 30% potassium hydroxide aqueous solution at 84 DEG C for 7 minutes 12 seconds, wherein the removal amount of the alkali corrosion is about 20 mu m; washing the monocrystalline silicon wafer subject to alkali corrosion, and carrying out centrifugal drying; and carrying out acid corrosion by using an acid corrosion solution at 28 DEG C for 14 seconds, wherein the acid corrosion solution comprises 15-25% of hydrofluoric acid, 25-30% of nitric acid and 50-60% of acetic acid, and the removal amount of the acid corrosion is about 10 mu m. By utilizing the technique, the heavily doped monocrystalline silicon wafer with satisfactory surface can be produced, and the total thickness variation (TTV) added value of the heavily doped monocrystalline silicon wafer is less than 2.5 mu m; and the qualification rate of the product is higher than 98%, thus the market demands for low-TTV heavily doped monocrystalline silicon wafer can be satisfied, and the technique provided by the invention can be dominating in the market.

Description

technical field [0001] The invention relates to a production method of a single crystal silicon wafer, in particular to an etching process in which a heavily doped single crystal silicon wafer is first etched with alkali and then etched with acid. Background technique [0002] The main processing flow of polished silicon wafers includes single crystal growth→rolling→slicing→chamfering→grinding→etching→polishing→cleaning→packaging, etc. Among them, corrosion is an important production process. Its function is to remove the mechanical stress damage layer with a certain depth formed on the surface of the silicon single crystal silicon wafer after mechanical processing such as slicing and grinding due to the stress generated by mechanical processing. The usual method is to use an acid etching solution or alkali etching solution at a certain concentration and a certain temperature to chemically react with the single crystal silicon wafer, so as to achieve the purpose of removing ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C30B33/10C23F1/24C23F1/40H01L21/02
Inventor 张俊生罗翀张晋英刘沛然王国瑞
Owner TIANJIN ZHONGHUAN ADVANCED MATERIAL TECH
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