Reliability of Implant-Isolation Regions in Highly-Doped GaAs-Based Structures

Abstract

ABSTRACTHighly-doped n-type (2 × 1019 cm−3) and p-type (7 × 1019 cm−3) GaAs layers were implanted with multiple energy F+ or H+ ions and subsequently annealed at ∼550°C to produce high resistance regions. The resistance of these layers at 200°C was monitored as a function of time and showed no changes for periods of several months. This is in contrast to some previously reported data, which showed complete loss of isolation after a period of several days in proton-implanted n+ GaAs. Here, we show that isolation of heavily-doped near-surface regions by protons requires implantation through cap layers which place the peak of the nuclear stopping profile at the GaAs surface. The application of these results to isolation of thick, multilayer heterostructure devices is discussed and SIMS and TEM data are used to illustrate the redistribution of the implanted ions and the defects they create, respectively.