METHOD FOR MANUFACTURING SEMICONDUCTOR SUBSTRATE, AND THE SEMICONDUCTOR SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a method for uniformly controlling the concentration of impurity in a second epitaxially grown layer 105, that is formed on a first semiconductor substrate 101 which is doped with impurities in high concentra tion. SOLUTION: The method includes the steps: a first semiconductor substrate 101 is prepared (a). A porous layer 102 is formed on the surface of the first semiconductor layer 101 (b); a non-porous single crystal silicon layer 103 is formed on the porous layer 102 (c). A back seal layer 104 is formed on the rear surface of the first semiconductor substrate 101 (d); the epitaxially grown layer 105 is formed on the non-porous single-crystal silicon layer 103 (e); a second semiconductor substrate 106 is adhered to the epitaxially grown layer 105 with an insulation layer 107 in between (f); the porous layer 102 is exposed; the remaining unwanted porous layer 102 is removed (g); and the surface of the non-porous single-crystal silicon layer 103 is smoothened (i).