Influence of Channel Thickness Variation on Temperature and Bias Induced Stress Instability of Amorphous SiInZnO Thin Film Transistors

TFTs (thin film transistors) were fabricated using a-SIZO (amorphous silicon-indium-zinc-oxide) channel by RF(radio frequency) magnetron sputtering at room temperature. We report the influence of various channel thicknesson the electrical performances of a-SIZO TFTs and their stability, using TS (temperature stress) and NBTS (negativebias temperature stress). Channel thickness was controlled by changing the deposition time. As the channel thicknessincreased, the threshold voltage (VTH) of a-SIZO changed to the negative direction, from 1.3 to -2.4 V. This is mainly dueto the increase of carrier concentration. During TS and NBTS, the threshold voltage shift (ΔΔVTH) increased steadily,with increasing channel thickness. These results can be explained by the total trap density (NT) increase due to theincrease of bulk trap density (NBulk) in a-SIZO channel layer. KCI Citation Count: 6