Date

Place

[41-4]
10:15 ~ 10:30
Title:Beneficial Effect of Hydrogen in Aluminum Oxide Deposited by Atomic Layer Deposition Method on Electrical Properties of IGZO Thin Film Transistor
Yunyong Nam (KAIST, Korea), Hee-Ok Kim, Sung Haeng Cho, Chi-Sun Hwang (ETRI, Korea), Taeho Kim, Sanghun Jeon (Korea Univ., Korea), and Sang-Hee Ko Park (KAIST, Korea)
Abstract: We present the role of hydrogen in aluminium oxide (Al2O3) gate dielectric in?a-InGaZnO (IGZO) thin film transistor (TFT). In comparison to?a-IGZO TFT with low temperature (150oC) Al2O3?gate insulator,?a-InGaZnO devices with high temperature (250-300oC) Al2O3?exhibit poor transistor characteristics such as low mobility, high subthreshold slope and huge hysteresis. Through DC and short pulsed I-V measurements, it is revealed that the degradation of transistor performance stems from charging and discharging phenomenon of the interface traps located in between?a-IGZO semiconductor and Al2O3?gate insulator. We found that low temperature Al2O3?ALD film contains higher density of hydrogen atoms than high deposition temperature counterparts. It is suggested that high concentration hydrogen atoms can passivate charge trapping sites in the interface and the bulk, resulting in excellent transistor characteristics. These results provide that hydrogen could serve a beneficial effect on defect passivation for oxide TFTs.
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