Degradation caused by Joule heating of transparent amorphous oxide semiconductor thin-film transistors (TFTs) is an important issue for display technology. Deep understanding of the mechanism of self-heating degradation generated by driving pulse voltage will pave the way for the development of highly reliable flexible displays. In this work, by using a pseudo interval measurement method, we examined the relationship of the highest and the lowest heating temperature in pulse 1 cycle and frequency. These self-heating converged to a constant temperature under pulse voltage applied at 1 kHz. Moreover, the long-term reliability under positive-bias stress voltage at 1 kHz of low converged temperature condition was improved relative to that of the stress voltage at 10 Hz of dynamic temperature change condition. We discussed the degradation mechanism of oxide TFTs generated by pulse voltage, and clarified that the degradation was accelerated by thermionic emission which occurred at low frequency.
The existence of hot carriers in an oxide thin-film transistor was confirmed by using an emission analysis technique. It has been clarified that degradation due to hot carriers causes degradation phenomena such as a decrease in on-current without shift in threshold voltage, which has not been seen so far, in high-mobility device. Moreover, it was confirmed by photo emission analysis that the main degradation factor was hot carriers against dynamic stress in which a pulse voltage was applied to the gate.
Degradation by Joule heating of amorphous metal oxide thin-film transistors is one of the important issues for realizing next-generation displays. To clarify the self-heating degradation mechanism, it is indispensable to analyze the detailed temperature change of TFTs. In this study, we proposed a technique to suppress deterioration caused by self-heating in terms of driving methods, and investigated relation on the temperature change in the degradation mechanism caused by self-heating.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.