Ohmic Contacts on p-Type GaN

Ohmic contact is one of the fundamental requirements for GaN detectors with high performance.But Ohmic contacts on p-type GaN with low specific contact resistance are more difficult to realize than those on n-type GaN.In this paper,research about Ohmic contacts on p-type GaN is reported.With Au and Cr/Au deposited on p-type GaN materials and appropriate annealing process,good Ohmic contacts have been obtained.Specific contact resistances of the Au/p-GaN and Cr/Au/p-type GaN structures are 7.88×10~(-2)Ω·cm~2 and 1.94×10~(-2)Ω·cm~2 respectively.