Investigation of NiSi Contacts on n-Type Gallium Nitride Using Low-Temperature Annealing

Nickel silicide (NiSi) contacts were employed to obtain contacts with excellent surface roughness characteristics on n-type gallium nitride under low-temperature annealing conditions. Raman spectroscopy and atomic force microscopy were used to analyze the surface properties and confirm the formation of NiSi contacts. Transmission line method measurements and two-terminal measurements were conducted to reveal the ohmic characteristics of the NiSi contacts. The mechanism behind the ohmic behavior of the NiSi electrodes was also explored, with the results indicating that Si doping plays a crucial role. Overall, this study suggests that using silicide-based contacts allows for the formation of low-roughness contacts at low temperatures.