Elemental vapor transport epitaxy of II-VI semiconductors

Abstract

Molecular beam epitaxy (MBE) is an advanced deposition technique known to produce high quality semiconductor films and structures. While great progress has been achieved in recent years, MBE still suffers from problems with elemental flux control which include: flux instabilities, long respoNSe times, significant transients, and difficulty of scaling to large area depositions. The elemental vapor transport epitaxy (EVTE) technique was formulated to resolve several problems typically accompanying conventional MBE. In EVTE, the vapor sources feed through regulating valves into a common flux distribution manifold that is located below the inverted wafer. We previously reported the EVTE growth of GaAs without gallium source related oval defects. In this paper, we report on EVTE deposition of the ZnSe, ZnTe, CdSe, CdTe, and ZnTe-ZnSe on GaAs (100) substrates. We have achieved selenium elemental flux control with respoNSe times less than one second and deposited films thickness uniformity ± 1.8% over a 2.0″substrate. Elemental vapor transport epitaxy grown materials show good surface morphology and stoichiometry, sharp interface, and low outdiffusion from the substrate. X-ray analysis showed crystallinity (FWHM = 95 arcsec) of the ZnSe films.