Unintentional dopants incorporated in GaAs layers grown by molecular beam epitaxy

Abstract

Motivated by the stringent material requirements that low noise FET’s place upon underlying buffer layers, the electrical properties of unintentionally doped layers of GaAs grown by MBE have been investigated. A relatively shallow acceptor (0.027 eV) with a room temperature concentration of 2×1014 cm−3 is generally characteristic of undoped material presently grown by a number of laboratories involved in MBE. During experimental investigations, undesirable system configurations leading to higher background doping levels were identified. These configurations include BeO/Ta film substrate heaters (n?6×1016 cm−3), fused quartz/Ta film substrate heaters (n?2×1015 cm−3) and hot stainless steel fixtures illuminated by the Ga oven (p?1016 cm−3).

Optical and Electrical Characterization of Chemical Defects in GaAs Layers Grown by MBE

“…Coloration occurs anodically by electron extraction accompanied either by H + extraction (3) or OH-insertion (4). For display applications we have prepared AIROF's on transparent, electronically conducting substrates by complete anodization of a previously evaporated thin film of Ir (5). We have reported the fabrication and performance of a solid-state cell utilizing such a display electrode (6).…”

A miniature single element effusion cell for the vacuum deposition of transition-metal and rare-earth elements

“…diam wire had too little resistance and, subsequently, required as much as 400-450 W of power for routine operation. It is generally desirable to limit the contact area of the heating element with the BN sleeve in order to minimize the contamination of the effused beam by B and N. 10 However, we have found that the benefits of good thermal contact between Ta and the BN, together with generous radiation shielding, lowers the operational temperature of the cell to allow evaporation of the charge without the disassociation of BN.…”