Method for fabricating a semiconductor substrate

A method for fabricating a heteroepitaxial semiconductor substrate used as a substrate of a compound semiconductor device, said heteroepitaxial semiconductor substrate comprising a substrate of a first semiconductor material and an epitaxial layer of a second semiconductor material grown heteroepitaxially on said substrate of said first semiconductor material, said method comprising steps of:

• growing the epitaxial layer on the substrate of the first semiconductor material heteroepitaxially to form a heteroepitaxial semiconductor substrate body;
• depositing a stress inducing layer on a top surface of the epitaxial layer so as to induce a stress of at least 1.7.times.10.sup.8 dyn/cm.sup.2 in the epitaxial layer;
• applying a cyclic annealing process to the heteroepitaxial semiconductor substrate body for repeatedly and alternately holding the heteroepitaxial semiconductor substrate body including the stress inducing layer deposited on the epitaxial layer at a first temperature and at a second temperature lower than the first temperature while applying said stress to the epitaxial layer by the stress inducing layer;
• and
• removing the stress inducing layer from the epitaxial layer after the step of applying the cyclic annealing is completed.