Bottom-Gate Thin-Film Transistors Based on GaN Active Channel Layer

GaN thin films were utilized as an active channel layer to produce bottom-gate n-type thin-film transistors (TFTs). The GaN thin films with wurtzite structure were deposited by the reactive dc magnetron sputtering technique using liquid gallium target. The resulting GaN TFTs exhibit good electrical performance, including a field-effect mobility of 5 $\hbox {cm}^{2}/\hbox {V}\cdot\hbox {s}$ , a threshold voltage of 11.5 V, an on/off current ratio of $\hbox {6} \times \hbox {10}^{6}$ , and a subthreshold swing of 0.4 V/dec. The reported GaN TFTs have great potential in the application of next-generation flat-panel display.