Micro-Raman characterization of GaAs/Si with atomic layer epitaxy grown predeposition layers

The growth of good optical quality GaAs layers on Si is reported using a thin nucleation layer grown by atomic layer epitaxy (ALE) technique in an MOCVD reactor. The GaAs/Si heteroepitaxial layers grown by this method are characterized by micro-Raman and photoluminescenec techniques and are compared to that grown by other two-step growth processes. It is found that the ALE assisted growth of GaAs/Si results in low density of antiphase domains and. electron-traps as compared to the two-step growth, which leads to high minority carrier lifetimes so essential for device fabrications.