| 摘要 |
PROBLEM TO BE SOLVED: To form a plurality of porous layers in on single crystalline substrate effectively by forming a plurality of two kinds of single crystalline semiconductors on a single crystalline substrate by an epitaxial method alternately, and forming a low porous degree layer and a high porous degree layer on a surface and a second layer from the surface, respectively. SOLUTION: Two kinds of single crystalline semiconductor layers 1 to 4 or more of impurities of different kinds and concentrations are made to grow at least on one surface of a single crystalline substrate 10 alternately by an epitaxial method. The layer 1 of a surface and the second layer 2 from the surface of the single crystalline semiconductor layers 1 to 4 are formed porous to a low porous degree layer 11 and a high porous degree layer 12 each. A non-porous single crystalline layer 5 is formed on a surface, the surface is subjected to thermal oxidation, and an SiO2 layer 6 is formed. After the SiO2 layer 6 and a supporting substrate 7 are laminated, they are separated in the high porous degree layer 12 and/or in a boundary with a layer adjacent to the high porous degree layer 12. The non-porous singled crystalline layer 5 is separately grown on the supporting substrate 7 in this way.
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