Heteroepitaxy of GaAs on Si: The effect of i n s i t u thermal annealing under AsH3

Abstract
This letter shows that an in situ thermal annealing step in AsH3/H2 during the metalorganic vapor phase epitaxy of GaAs on Si(001) improves the crystalline quality. The dislocation density is reduced (below 107 cm2) without affecting the Si diffusion across the heterointerface or the strain level in the epilayer. The nature of the various near‐band‐gap recombinations present in the unannealed and annealed samples is discussed in light of selective photoluminescence experiments.