Effects of Mechanical Stress on Flexible Dual-Gate a-InGaZnO Thin-Film Transistors

The effects of mechanical tensile and compressive stress on dual-gate amorphous InGaZnO thin-film transistors (a-IGZO TFTs) on a flexible substrate were investigated. Both the tensile and compressive stresses led to increases in free electrons and deep states in a-IGZO. Strong tensile stress tends to form more deep defects than compressive stress, resulting in severe deterioration in performance. Small compressive stress seems to repair defects in the relatively poor quality etch-stop layer (ESL), resulting in increased mobility in the top-gate-controlled performance.