Contact resistance asymmetry of amorphous indium–gallium–zinc–oxide thin-film transistors by scanning Kelvin probe microscopy
Wu Chen-Fei1, 2, Chen Yun-Feng1, 2, Lu Hai1, 2, †, , Huang Xiao-Ming3, Ren Fang-Fang1, 2, Chen Dun-Jun1, 2, Zhang Rong1, 2, Zheng You-Dou1, 2
       

(a1) and (a2) Surface potential VSP profiles near the edge of electrodes of the a-IGZO TFT. The shaded regions depict the topographic edges of the S/D electrodes. The voltage drops at drain and source contacts are highlighted. (b) Channel, source, and drain resistance as a function of gate bias voltage of the TFT.