Method of manufacturing semiconductor bonded substrate

摘要

The most distinctive feature of the present invention lies in that a warp and crystal defects can be prevented from occurring and a processing margin for forming an isolation groove can be improved in an intelligent power device including a power element section and an IC control section within one chip. A bonded wafer is obtained by bonding an active-layer substrate and a supporting substrate with an epitaxially grown silicon layer interposed therebetween so as to cover an oxide film selectively formed at the interface of the active-layer substrate. Isolation trenches are then formed in the bonded wafer to such a depth as to reach the oxide film from the element forming surface of the active-layer substrate. Thus, an IC controller is formed within a dielectric isolation region surrounded with the isolation trenches and the oxide film and accordingly the IC controller can effectively be isolated by a dielectric.