Effect of Light Shielding Metal on the Performance of a-IGZO TFTs with a Self-Aligned Top-Gate Structure

摘要

The electrical characteristics of self-aligned top-gate IGZO TFTs with a different light shielding metal (SM) layer design is investigated and compared in this paper. It is found that the TFT with floating SM has best stability regardless the SM induced barrier lower. However, SM connected to drain has a worst stability, off state current, initial threshold voltage (Vth) and serious kink-effect. Achievements can be attained by connecting SM to gate or source electrode for better input, output characteristics and stability especially to gate electrode for best gate controllability.