Degradation mechanisms for polycrystalline silicon thin-film transistors with a grain boundary in the channel under negative gate bias stress  

作　　者：Dongli Zhang Mingxiang Wang Huaisheng Wang 张冬利;王明湘;王槐生(School of Electronic and Information Engineering,Soochow University,Suzhou 215006,China)

机构地区：[1]School of Electronic and Information Engineering,Soochow University,Suzhou 215006,China

出　　处：《Chinese Physics B》2022年第12期599-604,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.61971299 and 61974101);the Natural Science Foundation of Jiangsu Province of China(Grant No.BK20201201);the Fund from Suzhou Science and Technology Bureau(Grant No.SYG201933);the Fund from the State Key Laboratory of ASIC and System,Fudan University(Grant No.2021KF005)

摘　　要：The negative gate bias stress(NBS)reliability of n-type polycrystalline silicon(poly-Si)thin-film transistors(TFTs)with a distinct defective grain boundary(GB)in the channel is investigated.Results show that conventional NBS degradation with negative shift of the transfer curves is absent.The on-state current is decreased,but the subthreshold characteristics are not affected.The gate bias dependence of the drain leakage current at V_(ds)of 5.0 V is suppressed,whereas the drain leakage current at V_(ds)of 0.1 V exhibits obvious gate bias dependence.As confirmed via TCAD simulation,the corresponding mechanisms are proposed to be trap state generation in the GB region,positive-charge local formation in the gate oxide near the source and drain,and trap state introduction in the gate oxide.

关 键 词：negative bias stress POLY-SI thin-film transistor grain boundary 

分 类 号：TQ127.2[化学工程—无机化工] TB383.2[一般工业技术—材料科学与工程] TN321.5[电子电信—物理电子学]