Patent ID: 7592208

Claim:
A method for manufacturing a semiconductor substrate, comprising: forming a first semiconductor layer on a semiconductor base material; forming a second semiconductor layer on the first semiconductor layer, the second semiconductor layer having an etching selectivity larger than that of the first semiconductor layer; forming, at the second semiconductor layer and the first semiconductor layer in the vicinity of an element region, at least three or more hole portions for exposing the semiconductor base material; forming, on the semiconductor base material, a supporting body for supporting the second semiconductor layer on the semiconductor base material so that the hole portions are filled and the second semiconductor layer is covered; etching the supporting body at regions other than predetermined regions including the hole portions and the element region to form an aperture plane in the supporting body, the aperture plane exposes a part of an end section of the first semiconductor layer; etching the first semiconductor layer via the aperture plane to form a hollow section between the second semiconductor layer of the element region and the semiconductor base material; and forming an insulation film in the hollow section, wherein the forming the hole portions is performed so that at least two or more the hole portions are formed in one direction of the element region and at least one or more the hole portion(s) is/are formed in the other direction crossing the one direction of the element region.