Improving the electrical stability of a-IGZO TFT through gate surround structures

Abstract

This paper delves into a structural modification of dual-gate oxide thin film transistor (TFT). Diverging from the conventional dual-gate TFT structure, the authors’ approach connects the bottom and top gate electrodes, effectively enveloping all four sides of the a-IGZO channel. This shielding configuration ensures stable operation, even under light illumination. Moreover, capitalizing on the stability under light conditions, the authors observed a remarkable threefold improvement in the mobility of the fabricated TFT with this proposed structure, resulting in a substantial 156% increase in current. Furthermore, in the negative bias illumination stress test, the proposed TFT exhibited minimal fluctuations when compared to its single-gate counterpart, further underscoring its exceptional and robust performance.