为了更好实现ZnO材料在光电器件方面的应用,研究了Ag/Au和n-ZnO薄膜的欧姆接触。通过半导体特性分析系统测出欧姆接触的I-V特性曲线和采用挖补圆盘法测试了欧姆接触的接触电阻率,研究了退火温度对接触特性的影响。利用俄歇电子能谱(AES)研究了欧姆接触的微观结构,比较了不同的金属电极的反射特性。结果表明,Ag(50nm)/Au(100nm)和n-ZnO薄膜的欧姆接触在退火温度为500℃时最好,欧姆接触电阻率仅为5.2×10-4Ω·cm-2,且其反射特性比其它金属电极好。
In order to realize the ZnO materials better in the application of the photoelectric devices, this paper studies the Ag/Au ohmic contact to n-ZnO thin films. Semiconductor characteristic analysis system is used to measure the I-V characteristic curve. Dig disc method is used to test the ohmic contact resistance rate. They reflect the influence of annealing temperature on the contact characteristics. Auger electron spectroscopy (AES) is used to study the microscopic structure of ohmic contact finally. The results show that Ag (50 nm)/Au (100 nm) ohmic contact to n-ZnO thin film is the best when annealing tem- perature is 500 ℃. The as-deposited Ag/Au scheme shows a specific contact resistivity of 2.3 × 10-2 Ω · cm-2. And the lowest specific contact resistivity is 5.2 × 10-4 Ω · cm-2. The specific contact resis- tivity shows a decreasing tendency with the annealing temperature up to 500 ℃. However, for the sample annealed above 600 ℃, the I-V curves reveal the characteristics of local bending,which shows rectifica- tion trends. Interface diffusions and reactions induced by annealing treatment are found to be responsible for the decrease of ohmic contact resistivity and the rectification trends. The reflection of Ag/Au charac- teristic is better than that with other metal depositions.