Tensile Stress Effect on Performance of a-IGZO TFTs With Source/Drain Offsets

We report the effect of repeated tensile bending stress on the electrical performance of amorphous-indium–gallium–zinc-oxide (a-IGZO) thin-film transis- tors (TFTs) with source/drain offset. The tensile strain induces the negative transfer shift for the conventional TFTs, but the ON-current ( ${I}_{ \mathrm{\scriptscriptstyle ON}}$ ) increases significantly for the offset TFTs with negligible change in threshold voltage ( ${V}_{\textsf {TH}}$ ). The experimental results can be fitted well with technology computer aided design simulation by the generation of donor-like states in the bending region of the a-IGZO semiconductor. The degraded TFT performance can be completely recovered by thermal annealing at 250 °C for 1 h, confirming the generation of the donor-like metastable defects, oxygen vacancies.