Semiconductor substrate and method of manufacturing the same

Abstract From the Canadian patent

To provide a manufacturing method excellent in controllability, productivity and economics of a high-quality SOI wafer, and a wafer manufactured by that method, in the wafer manufactured by bonding after, bonding, separation is made on an interface of a high porosity layer in a porous region including a low porosity layer and the high porosity layer in a surface formed on a main surface side of a first Si substrate 2 to transfer a non-porous layer onto a second substrate. After separation at the high porosity layer a residual, low porosity thin layer is made non-porous by a smoothing process such as hydrogen annealing without using selective etching.