Annealing-dependent electrical properties of Ga-doped ZnO film on silicon carbide.

The effect of substrate temperature and thermal annealing on the structural, electrical, and optical properties of Ga-doped zinc oxide (GZO) thin films were examined for use as transparent electrodes on silicon carbide (SiC). The variation of these properties is thought to be related to the presence and stability of Ga3+ ions substituted into Zn2+ sites and adsorbed oxygen ions in GZO thin films, as well as the interfacial thickness of GZO/SiC. GZO thin film deposited at 400 degrees C without annealing has the lowest resistivity of - 1.96 x 10(-4) Ω x cm, which increased after annealing. The photosensitivity of GZO/SiC was increased with increased substrate temperature (from 1.51 to 6.87%) and after annealing (from 2.78 to 8.67%). These results were clarified by comparatively analyzing the chemical composition ratio of oxygen in the GZO thin films and the interfacial thickness between GZO/SiC.