Self-Heating Stress-Induced Severe Humps in Transfer Characteristics of Amorphous InGaZnO Thin-Film Transistors

P‐1.5: Dynamic Current Stress‐Induced Instabilities of a‐InGaZnO TFTs

“…The saturation-regime DCS was then investigated with a constant VD of 40 V and VG pulse ranging fro m 0 to 30 V. As shown in Fig. 4, the transfer curves under the saturation-regime DCS exhibit the negative s hift with slight SS deterioration, similar to the Stage-II SH degradation [8] in Fig. 2.…”

“…Considering the power during VG peak is higher than the reported SH-triggering power [7], both channe l donors and defects are most plausibly generated by the SH effect. As clarified in our previous work [8], the SHE effect can turn the deep-state oxygen vacancy (Vo) defect into shallow-donor Vo, as illustrated in Fig. 3(a).…”

Fluorination-mitigated high-current degradation of amorphous InGaZnO thin-film transistors

“…Moreover, the power of Stage-Ⅱ exceeds 15 mW, higher than the required SH-activated power [8] . Such SH-induced channel carriers are often ascribed to the heat-driven external dopants (e.g., hydrogen) from the doped S/D [9,15] or the thermal induction of shallow-donor defects from deep states (e.g., oxygen vacancy V O ) [10,22] . Considering the n + a-IGZO S/D in this work is formed by Ar plasma rather than doped with external donors, the SH effect in Stage-Ⅱ most plausibly turns the deep-state Vo into the shallow-donor Vo in the a-IGZO chan- nel [10,14] , as illustrated in Fig.…”

“…Besides the superior switching characteristics, the high-current driving capability of AOS TFTs is increasingly demanded by advanced applications, such as the gate driver on the array (GOA), electroluminescence, and micro-LED displays [5−7] . So far, the AOS TFTs under high current stresses (HCSs) have encountered complicated severe degradation behaviors, such as threshold voltage (V th ) shift [8] , abnormal hump [9,10] , subthreshold swing (SS) deterioration [11] , and even hard breakdown [12] .…”

“…The self-heating (SH) effect is considered to be the main cause of HCS degradations, since the HCS-induced Joule heat can easily elevate the temperature of the AOS channel with poor thermal conductivity [13] . The underlying mechanism is often ascribed to SH-induced external and internal defects, such as hydrogen and oxygen vacancies [9,14] . To suppress the SH degradations, the device architectures have been adjusted to enhance the heat dissipation [15,16] .…”