Fabrication of the low-resistive p-type ZnO by codoping method

We have demonstrated the possibility of growing p-type ZnO films by a pulsed laser deposition technique combined with plasma gas source. The p-type ZnO film has been fabricated by passing N₂O gas through an electron cyclotron resonance (ECR) or RF plasma source. N₂O gas is effective to prevent "O" vacancy from occurring and introduce "N" as an acceptor, at the same time. With Ga and N codoping technique, we have observed a room temperature resistivity of 0.5 Ñ cm and a carrier concentration of 5 × 10¹⁹ cm^-3 in ZnO film on glass substrate. Two-step growth, with a thin ZnO template layer formed at high temperature, is quite effective to realize a well crystallized growth at low temperature. The observed p-type ZnO films will open the door for practical applications in various oxide electronic devices.