Si Surface Cleaning and Epitaxial Growth of GaAs on Si by Electron Cyclotron Resonance Plasma‐Excited Molecular‐Beam‐Epitaxy at Low Temperatures

Si surface cleaning prior to growth and successive epitaxial growth of on Si were carried out at low temperatures by ECR plasma‐excited MBE. The oxide on Si surface was removed quite effectively by hydrogen plasma exposure even at temperatures as low as 400°C. was epitaxially grown on Si at temperatures as low as 400°C using plasma and metallic Ga. At 500°C and above, single‐domain was grown on double‐domain Si without using a two‐step growth method. A SIMS profile revealed that no pile‐up of either carbon or oxygen at the hetero‐interface treated by hydrogen plasma exposure at 630°C, which indicates a much cleaner interface in comparison with that of typical MOCVD‐grown on Si heat‐treated at 1000°C. Insertion of a buffer layer grown at lower temperature with higher microwave power is effective for reducing stress without decreasing crystal quality. Using this technique, 6.6 μm thick was grown at 630°C without introducing any cracks. Estimated stress of this layer is and double‐crystal x‐ray diffraction measurement has shown the FWHM of (400) peak to be 190 arcsec.