Patent ID: 8865509
Filing Date: 2014-10-21
Classification: H01L,Y02E

Abstract:
1. A cleaning method of a silicon substrate comprising: a first step of etching a surface of a silicon substrate by a metal-ion-containing mixed aqueous solution of an oxidizing agent and hydrofluoric acid, and of forming a porous layer on the surface of the silicon substrate; a second step of etching the porous layer by mixed acid mainly containing hydrofluoric acid and nitric acid, and of forming texture on the surface of the silicon substrate; a third step of etching the surface of the silicon substrate on which the texture is formed by an alkaline chemical solution; and a fourth step of treating the silicon substrate etched by the alkaline chemical solution with ozone-containing water, of generating an air bubble within the pore formed in the silicon substrate, and of removing metal and organic impurities from within the pore.