摘要 |
A method for manufacturing a semiconductor device includes: forming a first semiconductor layer and a second semiconductor layer sequentially on a semiconductor substrate; forming a first groove penetrating the first semiconductor layer and the second semiconductor layer by partially etching the first semiconductor layer and the second semiconductor layer; forming a support covering the second semiconductor layer from inside of the first groove to a surface of the second semiconductor layer so as to support the second semiconductor layer; etching a sidewall formed in the first groove of the support so as to render the sidewall thin; forming a second groove exposing the first semiconductor layer by sequentially etching a part of the second semiconductor layer and a part of the first semiconductor layer; forming a cavity between the semiconductor substrate and the second semiconductor layer by etching the first semiconductor layer through the second groove under an etching condition in which the first semiconductor layer is more easily etched than the second semiconductor layer; and forming a buried oxide film by thermally oxidizing an upper surface of the semiconductor substrate and a lower surface of the second semiconductor layer that are facing inside of the cavity.
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