Influence of mechanical bending strain on bias-stress stability of flexible top-gate p-type SnO TFTs
Journal
Proceedings of SPIE - The International Society for Optical Engineering
Journal Volume
11304
Date Issued
2020
Author(s)
Abstract
In this paper, flexible coplanar top-gate p-type SnO TFTs are demonstrated. The TFT performance was optimized by adjusting the post-deposition annealing temperature of the SnO channel. The on/off current ratio of the TFT first improves and then degrades as the channel annealing temperature increases. With an optimized annealing temperature of 175C, the flexible SnO TFT exhibits a field-effect mobility of 0.71 cm2/V-s, threshold voltage of 5.2 V, subthreshold swing of 1.6 V/decade, and on/off current ratio of 1.6 x 103. The gate-bias stress stability of the optimized TFT was then investigated. When the TFT is at flat state, the threshold voltage shifts after bias-stressed at +10 V and -10 V for 10000 s are 0.2 V and nearly 0 V, respectively. The electrical stability degrades slightly when the TFT is subjected to both mechanical tensile and compressive strains. At a compressive strain of 0.25%, the threshold voltage shifts increase to 0.8 V and -0.3 V for positive and negative bias stress, respectively. At a tensile strain of 0.25%, the corresponding values are 0.7 V and -0.2 V. Compared with unpassivated bottom-gate SnO TFTs, the gate-bias stress stability is greatly improved.
SDGs
Type
conference paper