利用銅膜和氧化鋁(Al2O3)基板直接反應生成CuAlO2薄膜的研究

Abstract

Transparent conducting oxide (TCO) materials have great potential for the semiconductor industry, such as light emitting devices or solar cells. Because of the general characteristic in the electronic structure of oxides, there are few studies about p-type TCO’s. CuAlO2 is one of the p-type TCO materials. From other studies, most methods of making CuAlO2 thin films needed mixed target or more than one targets. The films’ properties are 0.01 Ω-cm~10 Ω-cm in resistivity, 50％ ~ 80％ of visible light transmittance, and poly-crystalline. Our goal is to synthesize single crystalline CuAlO2 thin films with high visible transmittance, and low resistivity by a simple synthetic route. Transparent conducting thin films of CuAlO2 were prepared by RF sputtering of a pure copper target on c-face sapphire substrates. The sputtering was performed in ~ 60 mtorr of Ar atmosphere and the substrate temperature was in the range of 300 K to 600 K. After deposition, the substrate temperature was raised to above 1000 K and the films were annealed in O2 atmosphere (100 ~ 760 torr). The X-ray diffraction (XRD) patterns of the films showed the peaks which could be assigned with those of the crystalline CuAlO2, and the structure is single crystalline.