초록 ▼

A manufacturing method excellent in controllability, productivity and economics of a high-quality SOI wafer and a wafer manufactured by that method are provided. After wafer bonding, separation is made on an interface of a high porosity layer in a porous region including a low porosity layer and the

A manufacturing method excellent in controllability, productivity and economics of a high-quality SOI wafer and a wafer manufactured by that method are provided. After wafer 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.

대표청구항 ▼

[ What is claimed is:] [1.] A method of manufacturing a semiconductor substrate comprising the steps of:preparing a first substrate having a porous region including at least two layers different in porosity and a non-porous layer formed on said porous region;bonding a surface of said non-porous laye

[ What is claimed is:] [1.] A method of manufacturing a semiconductor substrate comprising the steps of:preparing a first substrate having a porous region including at least two layers different in porosity and a non-porous layer formed on said porous region;bonding a surface of said non-porous layer of said first substrate to a surface of a second substrate;separating said first and second substrates from each other to transfer said non-porous layer to said second substrate; andremoving the residual portion of the porous region remaining on a separation surface of said second substrate or making the residual portion non-porous to smooth said separation surface;wherein the step of preparing said first substrate comprises a step of forming a first porous layer of 1 .mu.m or less thickness, a second porous layer adjacent to said first porous layer and high in porosity, and said non-porous layer adjacent to said first porous layer.