A substrate with a second semiconductor layer and a second mask film
formed thereon is subjected to a heat treatment in an oxidizing
atmosphere. Thus, second oxidized regions are formed through oxidization
of the second semiconductor layer in regions of the second semiconductor
layer that are not covered by the second mask film. At the same time, a
second base layer is formed in each region that is interposed by the
second oxidized regions. Then, the second mask film is removed, and a
third semiconductor layer is selectively grown on the surface of the
second base layer that is exposed between the second oxidized regions so
as to cover the second oxidized regions, after which the first oxidized
regions and the second oxidized regions covering the entire upper surface
of the substrate are removed.