PROCESS FOR MANUFACTURE OF BONDED WAFER

摘要

A process for the manufacture of a bonded wafer comprising the steps of: forming a oxide film on the surface of at least one of a base wafer and a bond wafer, intimately contacting the base wafer with the bond wafer through the oxide film; thermally treating the resulting product in an oxidative atmosphere to bond the base wafer and the bond wafer; grinding the rim of the bond wafer to a desired thickness to remove the rim; removing the unbonded area in the rim of the bond wafer by etching; and thinning the bond wafer to a desired thickness, the etching being performed using a mixed acid 30°C or lower which comprises at least hydrofluoric acid, nitric acid and acetic acid. In the process, the unbonded area in the rim of the bond wafer is etched and a bonded wafer can be manufatured at a high ratio of etch rate selectivity (R_Si/R_SiO2) of Si to SiO₂ without causing no metal contamination.