Polycrystalline In-Ga-O semiconductor for high-performance thin-film transistor

摘要

We have developed a high mobility oxide semiconductor using a polycrystalline In-Ga-O (IGO) as a channel material. The IGO thin-film transistor (TFT) showed a field-effect mobility of 39.1 cm²V⁻¹ s⁻¹, a threshold voltage of 1.4 V, and a subthreshold gate voltage swing of 0.12 V/decade. The polycrystalline IGO thin film showed the cubic bixbyite structure of In2O3 without an obvious preferred orientation. The average grain size of polycrystalline IGO was about 10 μm. The high mobility of IGO TFT is related to the In2O3 crystalline phase and large grain size of the IGO film. The potential barrier height at grain boundary of the polycrystalline IGO was lower than 20 meV