Date

Place

[P2-20]
14:00 ~ 15:30
Title:Simple Method for Stable In-Ga-Zn-O Thin-Film Transistors by Vertically Controlling the Oxygen Vacancy
Yeong-gyu Kim, Seokhyun Yoon, Seonghwan Hong, and Hyun Jae Kim (Yonsei Univ., Korea)
Abstract: Control of the oxygen vacancy in active layer is important to facilitate high performance and stable oxide TFTs. In this study, we changed the oxygen partial pressure during sputtering to control the oxygen vacancy in active layer vertically. We fabricated two types of TFTs: one was fabricated with only 0% oxygen partial pressure (sample A) and the other was fabricated with 0% oxygen partial pressure for front channel and 5% oxygen partial pressure for back channel (sample B). The field-effect mobility of the sample A and sample B was 8.89 and 8.35 cm2/Vs, respectively. Sample B had little degradation on electrical performance compared with sample A. To investigate the stability of these TFTs, we conducted 100 times consecutive transfer characteristic measurements. The transfer curves shifted to positive direction on both TFTs as the number of measurements was increased. This behavior was attributed to the trapping of charges at active layer and near the interface between active channel and gate dielectric layer. Vth shift of the sample A and sample B after 100 times measurement were 2.97 and 1.34 V, respectively. The enhancement of consecutive measurement stability came from the low oxygen vacancy in back channel of sample B TFT.
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