Patent ID: 7960225

Claim:
A method of controlling film thinning of a semiconductor wafer for a solid-state image sensing device, comprising: forming the solid-state image sensing device in a surface layer of the semiconductor wafer; bonding, thereafter, a support substrate to a surface of the semiconductor wafer to make a bonded wafer; grinding, after the bonding, the semiconductor wafer from a rear surface side of the semiconductor wafer while leaving a semiconductor wafer layer on the solid-state image sensing device; mirror-finishing, after the grinding, the ground surface of the semiconductor wafer layer by one of polishing and etching; measuring thickness extending from the mirror-finished surface of the semiconductor wafer layer to the solid-state image sensing device, and obtaining residual thickness data; and plasma etching, based on the residual thickness data, the semiconductor wafer layer from the mirror-finished surface of the semiconductor wafer layer until a predetermined thickness is reached by controlling the plasma etching amount.