New MBE (Molecular Beam Epitaxy) Buffer Used to Eliminate Backgating in GaAs MESFETs

摘要

A new buffer layer has been developed that eliminates backgating between MESFET's fabricated in active layers grown upon it. The new buffer is grown by molecular beam epitaxy (MBE) at low substrate temperatures (150-300 C) using Ga and As4 beam fluxes. It is highly resistive, optically inactive, and crystalline, and high-quality GaAs active layers can be grown on top of the new buffer. MESFET's fabricated in active layers grown on top of this new buffer show improved output resistance and breakdown voltages; the dc and Rf characteristics are otherwise comparable to MESFET's fabricated by alternative means and with other buffer layers.