Tsai Y.-S.Chen J.-Z.JIAN-ZHANG CHEN2019-09-262019-09-26201200189383https://scholars.lib.ntu.edu.tw/handle/123456789/425242This paper investigates the positive gate-bias temperature stability of RF-sputtered bottom-gate Mg 0.05Zn 0.95O active-layer thin-film transistors (TFTs) annealed at 200 ¢XC for 5 h and 350 ¢XC for 30 min. Although the TFT devices initially exhibited similar electrical characteristics, the TFTs annealed at 350 ¢XC demonstrated stability characteristics superior to those annealed at 200 ¢XC. This result is due to the improved crystallinity and more stable phase with greater proportion of Zn replaced by Mg in the ZnO crystals. The results also reveal a hump shape in the subthreshold region of the transfer characteristics, which is induced by the positive gate-bias stress at elevated temperatures. The hump phenomenon was suppressed in the TFT annealed at 350 ¢XC. The hump disappeared shortly after removing the positive gate bias, suggesting that this phenomenon was meta-stable and resulted from gate-bias-induced electric field. One possible mechanism responsible for the hump formation in the transfer curve is the gate-field-induced back-channel parasitic transistor. Alternatively, this hump phenomenon might have been due to the creation of meta-stable vacancies in which the neutral defects were thermally excited and released electrons into the active layer to form a leakage path when the TFTs were subjected to gate-bias stress at elevated temperatures. ? 2006 IEEE.Gate-bias stabilityMgOMgZnOoxide thin-film transistors (TFTs)thermal stabilityjournal article10.1109/TED.2011.21722122-s2.0-84855449286https://www2.scopus.com/inward/record.uri?eid=2-s2.0-84855449286&doi=10.1109%2fTED.2011.2172212&partnerID=40&md5=018f18b5afac99f77ff5ec49d5e7f303