The investigation of failure mechanism of n-GaN/Ti/Al/Ni/Au ohmic contact by novel TLM

摘要

Based on traditional transmission line method (TLM), an improved method was used to investigate the failure mechanism of n-GaN/Ti/Al/Ni/Au ohmic contact under high-current density (105 A/cm2). A novel structure is proposed and fabricated. The degradation of the ohmic contact was studied by the novel structure. According to analyzing the energy spectrum of the sample before and after degradation, it is concluded that Aluminium diffusion is the main factor that destroyed the good ohmic contact.