SOI SUBSTRATE MANUFACTURING METHOD

摘要

PURPOSE: A silicon-on-insulator(SOI) substrate manufacturing method is provided to obtain the even silicon active layer by preventing the dishing phenomenon generated when polishing the silicon. CONSTITUTION: The both SOI substrate and device separating film manufacturing method comprises the steps of: forming a field oxidizing film on a first semiconductor substrate(21) by the partial oxidizing process; forming an impurity doping layer in the first semiconductor substrate(21); forming an insulating film(25) flatten on the whole surface of the substrate(21); binding a second semiconductor substrate(26) on the surface of the insulating film(25); primary polishing the rear face of the first semiconductor substrate(21) to the upper area of the impurity doping layer; flatting by wetting etching the rear face of the first semiconductor substrate(21) by using the impurity doping layer as an etching stop layer; and secondarily polishing the rear face of the first semiconductor substrate(21) until the insulating film(25) is exposed.