一、引言无论在低噪声领域还是在大功率工作方面,都已确立了 GaAs MES FET 的地位,从而开展了许多可靠性的探讨。已报道了铝栅金属化系统的退化机理,并且提出了用耐熔金属系统作为更可靠的替代。同时,由于在以合金再生长为基础的欧姆接触中,如Au-Ge/Ni 中,存在着讨厌的缓慢互扩散,也研究了替代的金属化系统和欧姆接触工艺。例如,为了改善扩散型欧姆接触的表面均匀性和外形,Anderson 等在 GaAs 上生长外延 Ge I. INTRODUCTION The GaAs MES FET has been established in both low-noise and high-power applications and many reliability studies have been conducted. Degradation mechanisms of aluminum grid metallization systems have been reported, and refractory metal systems have been proposed as more reliable alternatives. At the same time, there is an annoying slow interdiffusion in ohmic contacts based on alloy regrowth, such as Au-Ge / Ni, as well as alternative metallization systems and ohmic contact processes. For example, in order to improve the surface uniformity and shape of diffused ohmic contacts, Anderson et al. Grew epitaxial Ge on GaAs