通过掺杂钽改善p型SnOx薄膜晶体管的电学性能和边缘效应

In this work,the incorporation of tantalum(Ta)into p-type metal-oxide(SnOx)semiconductor film is investigated to improve the electrical characteristics and suppress the fringe effect of thin film transistors(TFTs).The Ta-doped SnOx(SnOx:Ta)film is deposited by radio-frequency(RF)magnetron sputtering with a Sn:Ta(3 at.%)target and thermally annealed at 270 ℃ for 30 min.Here,we observe that the SnOx:Ta film presents increased crystallinity,reduced defect density(3.25×1012 cm-2·eV-1),and widened bandgap(1.98 eV),in comparison with the undoped SnOx film.As a result,the SnOx:Ta TFTs exhibit a lower off-state current(Ioff),an improved on/off current ratio(2.17×104),a remarkably decreased subthreshold swing(SS)by 41%,and enhanced device stability.Additionally,by introducing Ta dopants,the fringe effect as well as the impact of channel width-to-length ratio(W/L)on electrical performances of the p-type oxide TFTs can be effectively suppressed.These results shall contribute to further exploration and development of p-type SnOx TFTs.