Asymmetric staggered electrode for oxide thin film transistors

Abstract

Asymmetric staggered electrode (ASE) structure with Zn-based oxide channel layer has been implemented to improve the performance and the stability without passivation. Compared with both top-electrode and bottom-electrode structures, improvement has been observed since ASE-TFT was less affected by channel surface and interface interferences, which were main degradation factors in oxide TFTs, due to different current-path. The ASE-TFT showed device performance with sub-threshold swing (S.S) of 0.72 V, field-effect mobility (µFE) of 12.3 cm2 V−1 s−1, and on-to-off current ratio larger than 1x108. These improvements are mainly due to the formation of the current-path from edge of top-source to edge of bottom-drain which can avoid current scattering and charge trapping.