FABRICATION METHOD OF SILICON ON INSULATOR WAFER

摘要

PURPOSE: A fabrication method of a silicon on insulator(SOI) wafer is to properly control the concentration of impurities doped into the wafer, thereby allowing the silicon wafer to have good characteristic. CONSTITUTION: A fabrication method of a SOI wafer comprises the steps of: providing a first silicon substrate(10) and a second silicon substrate(20) both made of bulk type; forming a thermal oxide on one sided surface of the first silicon substrate; forming a first boron ion-doped layer at a first depth from the one sided surface of the second silicon substrate and a second boron ion-doped layer at a second depth lower than the first depth; contacting the thermal oxide with the one-sided surface of the second silicon substrate; polishing the other sided surface of the second silicon substrate by a selected thickness; etching the polished other sided surface of the second silicon substrate by a predetermined thickness to a portion adjacent to the first boron-doped layer; etching a portion of the other sided surface of the second silicon substrate including the first boron-doped layer using the second boron-doped layer as an etch stopper; polishing a portion of the other sided surface of the second silicon substrate including the second boron-doped layer to form a silicon layer(20a); and thermally oxidizing the silicon layer.