Effects of substrate temperature on the electrical and the optical properties of n-type ZnO/p-type 4H-SiC

We investigated the effect of the substrate temperature on the electrical and the optical properties of ZnO/4H-SiC structures. The n-type ZnO layer was grown on p-type 4H-SiC substrate by pulsed laser deposition to form p-n hetero-junction diode structure. The n-type ZnO thin films were deposited by pulsed laser deposition at different temperatures of 200, 400, and 600 degrees C, respectively. It was shown from transmission line method (TLM) and auger electron spectroscopy (AES) data that the sheet resistance of ZnO on SiC was increased from similar to 760 Omega/square to similar to 4000 Omega/square as the deposition temperature increases and the oxygen outdiffusion decreases. The I-V characteristics with and without illumination have also been studied.