Abstract
Contamination, Oxidization and radiation damage are induced on GaAs surface by Reactive Ion Etching (RIE) using a O2-discharge of 13.56 MHz in a parallel plate reactor. This formation depends on several RIE conditions, such as r.f power (which is equivalent to cathode-accelerated voltage) and etching time. The increase in schottky junction leakage current and the decrease in the schottky barrier height are caused by the induced damage which extends to an over 0.2μm depth from the surface. The damage thus induced compensates more than 1×1016cm-3 carrier concentration in GaAs. As a result, d.c characteristics of MESFET, such as Idss, gm and Vp decrease.
It has been confirmed that several methods, such as the protection of the GaAs surface by the SiO2 layer, wet etching of GaAs surface and thermal annealing after dry etching under low cathode accelerated voltage condition, are useful techniques for surface treatment in the fabrication of GaAs MESFET without damage influence.
