底栅和顶栅结构全透明氧化锌薄膜晶体管的制备

报道了制备在50mm石英玻璃衬底上的透明氧化锌薄膜晶体管(ZnO-TFT),采用了底栅和顶栅两种结构进行比较.ZnO沟道层由射频磁控溅射方法制备,SiO2薄膜作为栅绝缘层.结果发现底栅结构的ZnO-TFT具有较好的电学性质,该器件工作在n沟道增强模式,具有较好的夹断效应和饱和特性,其场效应迁移率、阈值电压和电流开关比分别为18.4cm2/(V·s),-0.5V和104.顶栅结构的ZnO-TFT则工作在n沟道耗尽模式,没有明显的饱和特征.不同结构ZnO-TFT电学性质的差别可能是由于不同的ZnO/SiO2界面特性所致.两种结构的ZnO-TFT在可见光波段都有很高的光学透过率.

Fabrication of Bottom-Gate and Top-Gate Transparent ZnO Thin Film Transistors

Transparent zinc oxide thin film transistors (ZnO-TFTs) with bottom-gate and top-gate structures were con-structed on 50mm silica glass substrates. The ZnO films were deposited by RF magnetron sputtering and SiO2 films servedas the gate insulator layer. We found that the ZnO-TFTs with bottom-gate structure have better electrical performancethan those with top-gate structure. The bottom-gate ZnO-TFTs operate as an n-channel enhancement mode,which haveclear pinch off and saturation characteristics. The field effect mobility, threshold voltage, and the current on/off rationel depletion mode operation and no saturation characteristics were detected. The electrical difference of the devices maybe due to the different character of the interface between the channel and insulator layers. The two transistors types havehigh transparency in the visible light region.