Codoping characteristics of Zn with Mg in GaN

The doping characteristics of Mg-Zn codoped GaN films grown by metalorganic chemical vapor deposition are investigated. By means of the concept of Mg-Zn codoping technique, we have grown p-GaN showing a low electrical resistivity (0.72 Omega cm) and a high hole concentration (8.5x10(17) cm(-3)) without structural degradation of the film. It is thought that the codoping of Zn atoms with Mg raises the Mg activation ratio by reducing the hydrogen solubility in p-GaN. In addition, the measured specific contact resistance of Mg-Zn codoped GaN film is 5.0x10(-4) Omega cm(2), which is one order of magnitude lower than that of Mg doped only GaN film (1.9x10(-3) Omega cm(2)). (C) 2000 American Institute of Physics. [S0003-6951(00)02234-8].