Patent ID: 6987072

Claim:
A method for fabricating a semiconductor crystal comprising in this order: a first step for forming a semiconductor crystal layer that contains lattice carbon atoms at some of its lattice positions, at least one Group IV element other than carbon at other lattice positions, and interstitial carbon atoms on a substrate; a second step for adding an impurity to the semiconductor crystal layer that is capable of reacting with carbon; and a third step for removing the interstitial carbon atoms selectively by reacting the interstitial carbon atoms with the impurity; the semiconductor crystal layer being formed by growing crystals using a source gas containing carbon and at least one Group IV element other than carbon on the substrate; the source gas being a C source gas and a Si source gas and/or Ge source gas; and the C source gas containing at least one member selected from the group consisting of CH 4 , C 2 H 6 , SiH 3 CH 3 , and alcohol; the Si source gas containing at least one member selected from the group consisting of SiH 4 , Si 2 H 6 , and SiH 2 Cl 2 ; and the Ge source gas containing at least one of GeH 4 and C(GeH 3 ) 4 .