Process for cleaning a semiconductor wafer

Abstract

Semiconductor wafers are cleaned by forming a first liquid film on a surface of the semiconductor wafer to be cleaned, the first liquid film containing hydrogen fluoride and ozone; replacing the first liquid film with a second aqueous liquid film which contains hydrogen fluoride and ozone, the concentration of hydrogen fluoride in the second liquid film being lower than in the first liquid film; and removing the second liquid film.

1 . A process for cleaning a semiconductor wafer surface, comprising forming a first aqueous liquid film on the surface, the first liquid film containing hydrogen fluoride and ozone; replacing the first liquid film with a second aqueous liquid film which contains hydrogen fluoride and ozone, the concentration of hydrogen fluoride in the second liquid film being lower than in the first liquid film; and removing the second liquid film. 
   
   
       2 . The process of  claim 1 , wherein no more than 120 s elapse from formation of the first liquid film until removal of the second liquid film. 
   
   
       3 . The process of  claim 1 , wherein no more than 60 s elapse from formation of the first liquid film until replacement of the first liquid film with the second liquid film. 
   
   
       4 . The process of  claim 1 , wherein the concentration of hydrogen fluoride in the first liquid film is from 0.1 to 10 wt %. 
   
   
       5 . The process of  claim 2 , wherein the concentration of hydrogen fluoride in the first liquid film is from 0.1 to 10 wt %. 
   
   
       6 . The process of  claim 1 , wherein the concentration of hydrogen fluoride in the second liquid film is from 0.001 to 0.1 wt %. 
   
   
       7 . The process of  claim 2 , wherein the concentration of hydrogen fluoride in the second liquid film is from 0.001 to 0.1 wt %. 
   
   
       8 . The process of  claim 4 , wherein the concentration of hydrogen fluoride in the second liquid film is from 0.001 to 0.1 wt %. 
   
   
       9 . The process of  claim 1 , wherein the first liquid film is replaced with the second liquid film through displacement of the first liquid film by the second liquid film, and the surface remains constantly wetted with liquid during the replacement. 
   
   
       10 . The process of  claim 1 , wherein the semiconductor wafer is rotated with a rotational speed in the range of from 100 to 2000 rpm during cleaning. 
   
   
       11 . The process of  claim 1 , wherein the first or second liquid film, or both liquid films, contain HCl in a concentration of from 0.2 to 2.0 wt %. 
   
   
       12 . The process of  claim 2 , wherein the first or second liquid film, or both liquid films, contain HCl in a concentration of from 0.2 to 2.0 wt %. 
   
   
       13 . The process of  claim 4 , wherein the first or second liquid film, or both liquid films, contain HCl in a concentration of from 0.2 to 2.0 wt %. 
   
   
       14 . The process of  claim 6 , wherein the first or second liquid film, or both liquid films, contain HCl in a concentration of from 0.2 to 2.0 wt %. 
   
   
       15 . The process of  claim 1 , wherein the second liquid film is displaced by ultrapure water, ultrapure water containing ozone, SC1 solution or dilute hydrochloric acid.