High mobility thin film transistors with indium oxide/gallium oxide bi-layer structures

摘要

We investigate the transport properties of thin-film transistors using indium oxide (In_2O_3)/gallium oxide (Ga_2O_3) bi-layer stacks as the channel material. At low gate bias, we observe the transistor field-effect mobility increases with the film resistivity to μfe = 51.3 cm~2/Vs and ON/OFF current ratio to 10~8 due to combinatorial layer thickness modulation. With the Ga_2O_3 layer thickness ratio increase to R=14.35%, these observations are accompanied with one-order-of-magnitude reduction in the transistor subthreshold swing to 0.38 V/decade and suggest a trap-limited conduction mechanism upon which the reduced scattering centers due to annihilation of subgap states improve the device electric characteristics without post-growth annealing.