We report the realization of p-type behavior in ZnO thin films, which are p
repared by codoping method using Ga (donor) and N (acceptor) as the dopants
. Especially using active N formed by passing N2O gas through an electron c
yclotron resonance (ECR) plasma source is quite effective for the acceptor
doping. We have observed a room temperature resistivity of 2 Omega cm and a
hole concentration of 4 x 10(19) cm(-3). These values are enough high for
practical applications in various oxide electronic devices.