ELEMENTAL VAPOR TRANSPORT EPITAXY OF II-VI SEMICONDUCTORS

Molecular beam epitaxy (MBE) is an advanced deposition technique known to produce high quality semiconductor films and structures. While gre at 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 scali ng to large area depositions. The elemental vapor transport epitaxy (E VTE) technique was formulated to resolve several problems typically ac companying conventional MBE. In EVTE, the vapor sources feed through r egulating valves into a common flux distribution manifold that is loca ted below the inverted wafer. We previously reported the EVTE growth o f 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 co ntrol with response times less than one second and deposited films thi ckness uniformity +/- 1.8% over a 2.0'' substrate. Elemental vapor tra nsport epitaxy grown materials show good surface morphology and stoich iometry, sharp interface, and low outdiffusion from the substrate. X-r ay analysis showed crystallinity (FWHM = 95 arcsec) of the ZnSe films.