α—Si TFT矩阵等离子体刻蚀技术的研究

STUDY OF THE PLASMA ETCHING TECHNIQUES OF AMORPHOUS SILICON THIN FILM TRANSISTOR ACTIVE MATRIX

本文介绍了α-Si TFT有源矩阵的CF_4等离子体刻蚀技术。分析了CF_4等离子体刻蚀α-Si:H和α-SiN_x的机理,对α-Si TFT的有源层与绝缘层之间刻蚀选择性和均匀性进行了研究,讨论了等离子体刻蚀速率与射频功率、反应室压力及衬底温度的依赖关系。根据实验结果总结了CF_4等离子体刻蚀速率随射频功率、反应室压力和衬底温度的增加而增大的规律,通过控制合适的工艺条件,成功地实现了选择性刻蚀并改善了刻蚀的均匀性。

The CF4 plasma etching (PE) techniques required for the fabrication of amorphous silicon (a-Si) thin film transistor (TFT) active matrix are introduced. The fundamentals of plasma etching of a-Si:H and a-SiNz are analysed. The etching selectivity and uniformity between the active and insulating layers of a-Si TFT have been investigated. The relations of plasma etching rate with rf power, chamber pressure and substrate temperature have been discussed. Experimental results show that the CF4 plasma etching rate would increase with the increase of rf power, chamber pressure and substrate temperature. Selective etching can be realized by controlling suitable process conditions and the etching uniformity is improved also.