Investigation of the Electrical and Optical Properties of Junctions in Vapor-Deposited Compound Semiconductors

摘要

Germanium was epitaxially deposited on gallium arsenide by means of the hydrogen reduction of GeCl4. Above 800C, germanium reacted with the GaAs seed to form a black powder. Proper deposition was observed below about 750C. Nonetheless, cross doping of the Ge layer by gallium was observed even at deposition temperatures as low as 670C; the heterojunctions showed tunnel diode characteristics. Deliberately doped junctions of p-Ge on n-GaAs showed the I-V characteristics of Ge junctions, while the photovoltaic response was that of a GaAs junction. The voltage sign of the response was that of normal p-n junctions. An apparatus is described for the epitaxial deposition of GaAs. AsCl3 was flowed over hot gallium metal and GaAs deposited downstream at a lower temperature. The conditions for the preparation of high-purity, smooth layers are described, and doping techniques are given. Epitaxial lasers were made by the deposition of zinc-doped epitaxial layers on n-type GaAs substrates. (Author)