Comparison of GaAs Metallization Systems for High Temperature Applications

Abstract

ABSTRACTTransition metal-germanide/silicide based ohmic contact systems to n-type GaAs have been studied using current-voltage (I-V) and transmission line measurements (TLM). The effects of substituting various metals from groups IVB and VIB into the metallization stack have been compared, as well as the effects of using germanium or silicon. Rapid Thermal Annealing (RTA) was used to facilitate the reactions. Titanium and molybdenum were shown to be more effective metallizations than chromium, even though chromium readily forms a silicide or germanide. Germanium has been found to produce an ohmic contact of low resistivity, while metallization with silicon alone does not show ohmic behavior.