PROCESS FOR MANUFACTURE OF BONDED WAFER

摘要

The present invention provides a method for manufacturing a bonded wafer comprising steps of forming an oxide film on at least a surface of a base wafer or a surface of a bond wafer; bringing the base wafer and the bond wafer into close contact via the oxide film; subjecting these wafers to a heat treatment under an oxidizing atmosphere to bond the wafers together; grinding and removing the outer periphery of the bond wafer so that the outer periphery has a predetermined thickness; subsequently removing an unbonded portion of the outer periphery of the bond wafer by etching; and then thinning the bond wafer so that the bond wafer has a desired thickness, wherein the etching is conducted by using a mixed acid at 30°C or less at least comprising hydrofluoric acid, nitric acid, and acetic acid. Thus there is provided a method for manufacturing a bonded wafer by which unbonded portions of the outer periphery of the bond wafer are removed with a high selectivity ratio (R Si /R SiO2 ) without causing metallic contamination.