P‐7.14: Adjustment of etch performance and Vth by Mo thickness of Mo‐Al‐Mo gate electrode in ADS Pro TFT

The regulation of FICD and profile angle without changing the etchant is successfully realized by adjusting the top Mo and bottom Mo thicknesses of Mo/Al/Mo electrodes. The trends of FICD and profile angle are explained in terms of galvanic effects. Meanwhile, the effects of FICD and profile angle on Vth and its stability are explored. When the top Mo thickness increases, profile angle decreases gradually. The bottom Mo thickness increases, and both profile angle and FICD then decrease. Profile angle decreases, the exposed area of Al sidewall in electrode increases, and the sidewall Al diffuses to the GI to form a P‐type electric dipole, resulting in an increase in Vth as well as Vth shift under PBTPS. When the gate FICD decreases, the electrode shading effect is weakened, the amorphous silicon is illuminated by light to induce the SW effect, and the negative Vth shift under NBTPS is partially counteracted, and the degree of the negative Vth shift thus decreases.