The threshold voltage instability (Vth) in indium-gallium-zinc oxide thin film transistor was investigated with disparate SiNx gate insulators under bias-temperature-illumination stress. As SiNx film stress became more tensile, the negative shift in Vth decreased significantly from -14.34 to -6.37 V. The compressive films exhibit a nitrogen-rich phase, higher hydrogen contents, and higher N-H bonds than tensile films. This suggests that the higher N-H related traps may play a dominant role in the degradation of the devices, which may provide and/or generate charge trapping sites in interfaces and/or SiNx insulators. It is anticipated that the appropriate optimization of gate insulator properties will help to improve device reliability.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)