GaAs Epilayer Growth on Si(100) Substrates Cleaned by As/Ga Beam and Its RHEED Patterns

Abstract

The GaAs epitaxial layers were grown on Si(100) substrates by molecular beam epitaxy(MBE) using the two-step method. The Si(100) substrates were cleaned with different surface cleaning method of vacuum heating, As-beam, and Ga-beam at the substrate temperature of 800 o C. Growth temperature and thickness of the GaAs epitaxial layer were 800 o C and 1 µm, respectively. The surface structure and epitaxial growth were observed by reflection high-energy electron diffraction(RHEED) and scanning electron microscope(SEM). Just surface structure of the Si(100) substrate cleaned by Ga-beam at 800 o C shows double domain (2 × 1). RHEED patterns of the GaAs epitaxial layers grown on Si(100) substrates with cleaning method of vacuum heating, As-beam, and Ga-beam show spot-like, (2 × 4) with spot, and clear (2 × 4). From SEM, it is found that the GaAs epitaxial layers grown on Si(100) substrates with Ga-beam cleaning has a high quality.