Preparation of P-Type SnO TFTs and their Electrical Performance

P-type SnO thin films and thin-film transistors (TFTs) were prepared by DC magnetron sputtering combined with photoresist lithography at room temperature.The key technological issues in the preparation process of DC magnetic sputtering are comprehensively studied.It is found that p-type SnO thin-film transistors with a high on-off ratio can be obtained by pre-sputtering for 5 min,oxygen ratio of 13%,growth pressure of 0.96 Pa,and annealing at 200℃for 1.5 h.The on-off ratio is 6.2×10³,and the subthreshold swing is 9.96 V·dec^-1.By prolonging the annealing time (2 h),the mobility of the linear region can be greatly increased to 1.61 cm²·V^-1·S^-1,and the subthreshold swing only increases by 0.54 V·dec^-1.By extending the pre-sputtering time to 8 min,it is found that the carrier mobility of the p-type SnO thin-film transistor is greatly improved,and the mobility in linear region and saturation region of the device is 5.25 and 0.43 cm²·V^-1·S^-1.