过孔的不同干法刻蚀工艺对TFT-LCD性能的影响研究

为了改善过孔的干法刻蚀中刻蚀率的不同导致SD线和P-Si接触面积不一致的问题,同时解决ELA工艺导致PSi表面突起而造成SD与P-Si点状接触的问题,探究了过孔的不同干法刻蚀工艺对TFT-LCD性能的影响,从中找出最佳的过孔干法刻蚀工艺。利用京东方产线设备制备了两种不同的LTPS阵列样品,样品一的过孔工艺采用传统的底部接触方式,样品二采用新的侧面接触方式,样品一和样品二其余的工艺过程一致。实验结果表明:多点的U-I曲线由发散变为集聚,电子迁移率有所提高;SEM数据表明采用侧面接触方式能够完全将P-Si刻穿。采用侧面接触方式能够明显的解决干法刻蚀中刻蚀率的不同导致SD线和P-Si接触面积不一致的问题,同时避免了ELA工艺导致P-Si表面突起而造成SD与P-Si点状接触的问题,电学性能有所改善,同时减少了工艺时间,提高了产能。

Influence of different dry etching process of contact hole on TFT-LCD performance

In order to overcome the inconsistent contact area between SD line and P-Si caused by the difference of etching rate in via hole dry etching technology, as well as to solve the point contact between SD line and P-Si made by P-Si surface convex during the ELA process, we explored the influence of various via hole dry etching technology upon the property of TFT-LCD, so as to find the optimal via hole dry etching technology.Two different samples of LTPS array were prepared by using BOE production line equipment, wherein the sample 1 was prepared by adopting conventional Just Contact Method, while the sample 2 was prepared by adopting a new type of Side Contact Method. Besides the differences of contacting methods, there is no other differences of technological processes during making these two samples.The experimental results show that the multipoint U-I curve changes from a divergent curve to a concentration curve, and electron mobility increases in some degree. In addition, the SEM data show that the P-Si can be cut through completely by Side Contact Method. Side Contact Method is able to overcome the inconsistent contact area between SD line and P-Si caused by the difference of etching rate of via hole dry etching technology, as well as to solve the point contact between SD line and P-Si made by P-Si surface convex during the ELA process,so that the TFT-LCD electrical performance can be improved. In addition, the Side Contact Method can reduce the process time, and improve the productivity.