LCoS芯片p-n结光生电流理论分析  

Theoretical Analysis of Photogenerated Leakage Current of p-n Junctions in LCoS

作　　者：欧毅[1] 李大勇[1] 刘明[1] 

机构地区：[1]中国科学院微电子研究所纳米加工与新器件集成技术实验室,北京100029

出　　处：《液晶与显示》2006年第1期24-28,共5页Chinese Journal of Liquid Crystals and Displays

基　　金：国家"973"计划资助项目(No.2003CB314703;No.2003CB314704)

摘　　要：LCoS中像素有源驱动电路受到光照后会在p-n结上产生光生漏电流,而光生漏电流的产生会引起LCoS的图像对比度退化,直接影响其成像质量。从光学和半导体器件物理两方面出发,分析了光生漏电流的产生机理,指出了影响漏电流大小的主要因素是入射光功率和挡光层的厚度。以Al膜作为挡光层材料,实际测量了不同厚度Al膜在可见光范围内的反射率,并在测量数据的基础上分别计算了不同情况下的光生电流的大小。当Al膜厚度为50nm时,光生电流最大仅为5.15×10-10A,可以抑制光生漏电流的产生,满足了LCoS的实际使用时的要求。When CMOS driver circuit is illuminated by a light, the photogenerated leakage current in the p-n junction is produced, this current reduces the image quality by attenuating the contrast of the LCoS image. This paper analyzes the producing of the photogenerated leakage current based on the optics and the semiconductor theory, indicats that the primary factors are the light source power and the thickness of the protection shield. Using the Al film as the protection shield, the reflection in the visible range at different Al thickness is measured,and the value of the photogenerated leakage current is calculated. When the thickness of Al is 50 nm, the maximum value of the photogenerated leakage current is only 5.15×10^-10A,which can meet the LCoS application requirement.

关 键 词：LCOS P-N结 光生漏电流 挡光层 

分 类 号：TN141.9[电子电信—物理电子学]