| 摘要 |
PURPOSE:To enable to form a thin Si oxide film of clean and favorable quality on the surface of an Si substrate by a method wherein in the middle to wash the Si substrate in a boiling solution containing a hydrogen peroxide solution, gas containing ozone is introduced into the solution thereof. CONSTITUTION:Aqueous ammonia and a hydrogen peroxide solution are mixed, and when Si wafers are washed in the boiling solution thereof, Si oxide films are removed, and contaminating impurities existing on the films thereof are also removed. At this case, contaminating impurities existing on the interface between the Si oxide films and the Si substrates are partially left, and adheres again newly. At this time, an ozone feed tube 50 furnished with small holes is provided at the bottom of a washing tank 40, and after the Si wafers 60 put on a supporting base 70 are washed for the prescribed hours according to the mixed liquid 80 of aqueous ammonia, the hydrogen peroxide solution and water, oxygen gas containing ozone is supplied in succession, and washing is continued. Accordingly, contaminating impurities hardly exist on the interfaces between the Si oxide films and the Si substrates. Moreover, it is also favorable to use the mixed liquid of hydrochloric acid, hydrogen peroxide and water, or the mixed liquid of sulfuric acid and a hydrogen peroxide solution as the solution thereof. |
