Etching Liquid for Controlling Silicon Wafer Surface Shape

Abstract

A method for manufacturing a silicon wafer includes a planarizing process 13 for polishing or lapping the upperside and lowerside surfaces of a thin disk-shaped silicon wafer obtained by slicing a silicon single crystal ingot, an etching process for dipping the silicon wafer into the etching liquid wherein silica powder is dispersed uniformly in an alkali aqueous solution, thereby etching the upperside and lowerside surfaces of the silicon wafer, and a both-side simultaneous polishing process 16 for polishing the upperside and lowerside surfaces of the etched silicon wafer simultaneously or a one-side polishing process for polishing the upperside and lowerside surfaces of the etched silicon wafer one after another, in this order.

1 . An etching liquid for controlling a silicon wafer surface shape, wherein silica powder is dispersed uniformly in an alkali aqueous solution.  
   
   
       2 . The etching liquid of  claim 1 , wherein 
 the alkali aqueous solution is a 40 to 50 weight % sodium hydroxide aqueous solution, and    the addition rate of the silica powder to be added to the alkali aqueous solution is 1 to 100 g/L to the sodium hydroxide.    
   
   
       3 . The etching liquid of  claim 1 , wherein the average particle diameter of the silica powder is 50 to 5000 nm.  
   
   
       4 . (canceled)  
   
   
       5 . (canceled)  
   
   
       6 . The etching liquid of  claim 2  wherein the average particle diameter of the silica powder is from 500 nm (0.5 μm) to 3000 nm (3 μm).