Preparation And Electrical Characterization Of LiMgZnO Thin Film Transistors

Transparent thin film transistor (TFT) is one of field effect transistors, which is widely applied to the industry of flat panel display and transparent circui. With the development of large size liquid crystal display and active matrix organic light emitting diode, silicon-based TFT can not meet the requirenment of its industry application. The major reason is that the mobility of silicon-based TFT is too slow (<1cm2/V s) and it is sensitive to visible light. Metal oxide TFT, especially ZnO-based TFT, becomes the desirable substitute for silicon-based TFT because of its high mobility and low cost. However, metal oxide TFT are also experiencing some troubles. For example, metal oxide TFT performance is not stable and its mobility is not high enough, which metal oxide TFT its next development. In ordor to improve the mobility of metal oxide TFT, LiMgZnO-TFT was fabricated. The details are as follows:(1)Firstly, we studied on the influence of annealing temperature on the characteristics of LiMgZnO-TFT, and found that the optimized annealing temperature is800℃. We got the mobility of3.03cm2/V s, the threshold voltage of17V, the on/off ratio of4.1E+06;(2)After the optimized annealing temperature, we still studied on the influence of channel condition on the characteristics of LiMgZnO-TFT. We got the optimizedl channel length, namely50um. We got the mobility of10.83cm2/V s, the threshold voltage of-18V, the on/off ratio of9.49E+06;(3)What’s more, we studied on the influence of active layer thickness on the characteristics of LiMgZnO-TFT, and found when active layer thickness is35nm, the TFT performance is best. We got the mobility of10.83cm2/V s, the threshold voltage of-18V, the on/off ratio of9.49E+06;(4)Lastly, we studied on the influence of02flow on the characteristics of LiMgZnO-TFT. We got the optimized O2flow, namely3SCCM. We got the mobility of12.8cm2/V s, the threshold voltage of-15V, the on/off ratio of2.41E+07.