TFT有源层刻蚀均一性和电学性质的研究

Analysis of etching uniformity of active layers and electrical characteristics of thin film transistor electrode

对TFT制作工艺中,TFT有源层刻蚀均一性与电学性质进行分析研究。通过扫描电子显微镜,电学测试设备对样品进行分析。结果显示沟道有源层的刻蚀功率,气体比例及刻蚀压强对有源层的刻蚀均一性都有较大影响,并会影响TFT电学特性的均一性。通过适当降低刻蚀功率及反应气体SF6/Cl2的比例,同时,降低反应压强,可以改善有源层刻蚀的均一性。从而,TFT电学特性的均匀性得到优化。

Active layers（a-Si） were etched by enhance cathode couple plasma（ECCP） and used as electronic channels in the thin film transistors. The uniformity of active layers and electrical characteristics were studied. The obtained samples were characterized by scanning electron microscopy （SEM） and electronic parameter measurement. The etching power, gas ratio and etching pressure played an important role in uniformity of active layers, which can cause the issue about TFT electrical characteristics. The uniformity of active layers can be improved by reduced the ratio about etching power ratio （source power/bias power） and reaction gas ratio （SF6/C12）, meanwhile, reaction pressure was also reduced. Therefore, the uniformity of TFT electrical charaeteristics can also be improved.