High-Performance a-InGaZnO Thin-Film Transistors with Extremely Low Thermal Budget by Using a Hydrogen-Rich Al(2)O(3) Dielectric

Electrical characteristics of amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) are compared by using O(2) plasma-enhanced atomic layer deposition Al(2)O(3) dielectrics at different temperatures. High-performance a-IGZO TFTs are demonstrated successfully with an Al(2)O(3) dielectric deposited at room temperature, which exhibit a high field-effect mobility of 19.5 cm(2) V(− 1) s(− 1), a small subthreshold swing of 160 mV/dec, a low threshold voltage of 0.1 V, a large on/off current ratio of 4.5 × 10(8), and superior negative and positive gate bias stabilities. This is attributed to the hydrogen-rich Al(2)O(3) dielectric deposited at room temperature in comparison with higher deposition temperatures, thus efficiently passivating the interfacial states of a-IGZO/Al(2)O(3) and the oxygen vacancies and improving conductivity of the a-IGZO channel by generating additional electrons because of enhanced hydrogen doping during sputtering of IGZO. Such an extremely low thermal budget for high-performance a-IGZO TFTs is very attractive for flexible electronic application.