Formation of local p⁺ region in ZnSe by Cu₃Ge contact

Cu₃Ge/Pt/Au has been deposited onto the surface of p-ZnSe, n⁺-ZnSe and n-ZnSe. It was found that the observed Cu₃Ge/p-ZnSe ohmic behaviour is due mainly to hole tunnelling through the metal/semiconductor interface. A p⁺-n junction-like I-V characteristic for Cu₃Ge/n-ZnSe was also observed. Furthermore, a negative differential resistance with a peak-to-valley ratio of approximately 6 was observed under forward bias when Cu₃Ge was deposited onto n⁺-ZnSe. These observations all suggest that Cu₃Ge can form a local p⁺ region on the ZnSe surface.