MANUFACTURE OF BONDED DIELECTRIC ISOLATION SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To manufacture a bonded dielectric isolation substrate, without uselessly consuming element-forming regions and make uniform the Si island depth distribution between wafers and in a wafer plane. SOLUTION: The surface of an Si wafer A for an active layer is etched through a mask 21 to form flat-bottom recesses 24 for forming scribe lines and V-grooves 25 for forming dielectric isolation grooves. An insulation film 26 and polysilicon layer 27 are formed and planarized. A wafer B for a support substrate is laminated and heat treated to form a bonded substrate C. An Si substrate 101 at the active layer is ground and polished. The flat bottoms of the recesses 24 serve for polishing stoppers. The area of the recesses 24 is set to 0.2-40% of the Si substrate entire surface. If less than 0.2%, they do not function as a polishing stopper and if exceeding 40%, the chip area is too small, resulting in reduction of the manufacturing efficiency.