Patent ID: 9741603
Date: 2017-08-22
CPC Classifications: H01L

Claim:
1. A method for producing a hybrid substrate comprising the steps of: furnishing an SOI substrate which is obtained by stacking a first silicon oxide layer and a silicon active layer in this order on a silicon substrate such that a terrace portion not including the silicon active layer is left on an outer peripheral portion of the silicon substrate surface, forming a second silicon oxide layer on the silicon active layer surface of the SOI substrate, bonding the SOI substrate to a support substrate having a different coefficient of thermal expansion from the SOI substrate, wherein the bonding is performed at a temperature of 100° C. to less than 250° C., with the second silicon oxide layer interposed therebetween, to form a bonded substrate, wherein the terrace portion of the SOI substrate and the support substrate are not directly contacted with each other, subjecting the bonded substrate to a combination of a consolidation heat treatment for increasing the bond strength between the SOI substrate and the support substrate and a grinding/thinning treatment of thinning the whole silicon substrate by grinding, the combination being repeated at least twice under the conditions that the temperature of a first consolidation heat treatment is equal to or higher than the bonding temperature, the silicon substrate after a first grinding/thinning treatment has a thickness of 130 μm at the thinnest, the temperature of a final consolidation heat treatment is 200° C. to less than 250° C., the silicon substrate after a final grinding/thinning treatment has a thickness of 60 μm at the thinnest, etching away the thinned silicon substrate until the first silicon oxide layer is exposed, and etching away the bare first silicon oxide film, yielding a hybrid substrate in which the silicon active layer is disposed on the support substrate via the silicon oxide layer, wherein in the combination of the consolidation heat treatment and the grinding/thinning treatment, the consolidation heat treatment and the grinding/thinning treatment are conducted in this order.