TFT-LCD器件Al电极TFT特性研究

TFT character of Al electrode in TFT-LCD

本文对Mo/Al/Mo作为TFT-LCD器件源/漏极的TFT特性进行了研究。与单层Mo相比,存在沟道界面粗糙,I_(off)偏大问题,通过优化膜层结构,改善界面状态,得到了平整的沟道界面和良好的TFT特性。增加Bottom Mo的厚度,可以有效减少Al的渗透,防止Al-Si化合物的形成,得到界面平整的沟道;N^+刻蚀后SF6处理对特性影响不大,增加刻蚀时间可以使I_(on)和I_(off)同时降低;PVX沉积前处理气体N_2+NH_3与H_2区别不大,都可以减少沟道缺陷,而增加H_2处理时间会增强等离子的轰击作用,减少了沟道表面Al-Si化合物,但处理时间过长可能会使沟道缺陷增加;采用bottom Mo加厚,N^+刻蚀以及PVX沉积前处理等最优条件,可以得到沟道界面良好,TFT特性与单层Mo相当的TFT器件。

TFT character of the Mo/A1/Mo as TFT-LCD source/drain was studied. Compared with the single Mo, the channel interface was rougher and Ioff was larger. Through the optimization of the structure of membrane layer and the interface state, good TFT character and smooth channel interface were received. Increasing the thickness of bottom Mo could effectively reduce the penetration of Al, and prevent the formation of Al-Si compounds to get the smooth channel interface. SF6 treatment after N＋ etching had no influence on properties, while Ion and loff were all reduced with increasing of the etching time. The treatment gas H2 before PVX deposition the same as N2 ＋ NH3 could reduce the channel defects. The plasma bombardment effect was enhanced and A1-Si compounds on the surface of the channel were reduced when the H2 processing time was increased, but the processing time was not too long to increase channel defect. Using the best condition of bottom Mo thickening, the N＋ etch time increasing and the plasma treatment before PVX deposition, the good channel interface could be obtained and TFT character was as well as that of single Mo.