Enhancement of p-type doping of ZnSe using a modified (N+Te)delta-doping technique

Delta doping techniques have been investigated to enhance the p-type doping of ZnSe. Tellurium was used as a codopant for improving the nitrogen dopin g efficiency. The net acceptor concentration (N-A-N-D) increased to 1.5x10( 18) cm(-3) using single delta doping of N and Te (N+Te), while it was limit ed to 8x10(17) cm(-3) by delta doping of N alone. A promising approach was developed in which three consecutive delta-doped layers of N+Te were deposi ted for each delta-doping cycle. An enhancement in the (N-A-N-D) level to 6 x10(18) cm(-3) has been achieved in ZnSe using this technique. The resultan t layer has an average ZnTe content of only about 3%. This doping method sh ows potential for obtaining highly p-type doped ohmic contact layers withou t introducing significant lattice mismatch to ZnSe. Low-temperature photolu minescence spectra reveal some Te-related emissions. (C) 2000 American Inst itute of Physics. [S0003-6951(00)00816-0].