Effects of Metal Work Function and Operating Temperatures on the Electrical Properties of Contacts to n-type GaN

The electrical properties of various metal contacts on n-type GaN at high and low doping concentration (5*10
¹⁸
cm
^-3
and 1*10
¹⁵
cm
^-3
) were simulated to determine the underlying trend between the metallic contact work function and the resultant Schottky barrier height between the metal and the GaN material. Pt, Ni, Pd, Au, Co, Cu and Ag metals having different work functions were investigated. Operating temperatures of structures were varied between 200 K and 400 K. It is found that the turn-on voltage for the diode is dependent on the value of work function for each metal used in the simulation process. Effective change in the current was obtained at different operating temperatures for all metals used at both doping concentrations.