| 학회 | 한국재료학회 |
| 학술대회 | 2020년 가을 (11/18 ~ 11/20, 휘닉스 제주 섭지코지) |
| 권호 | 26권 1호 |
| 발표분야 | G. 나노/박막 재료 분과 |
| 제목 | Electrical Properties of a sol-gel based IGZO Transistor Integrated with Plasma Treated Al2O3 Dielectric |
| 초록 | InGaZnO (IGZO) metal-oxide thin film transistors with high-k dielectric, which is based on sol-gel processing, have highly taken attention for next generation display gadgets due to their high optical transparency, low power consumption, and low fabrication cost. However, the goal to further improved electrical performance of sol-gel based IGZO transistor has remained challenging. In this study, we investigated the influence on electrical properties and bias stability of IGZO transistor by CF4 and Ar plasma treatment onto the surface of Al2O3 dielectric integrated with IGZO transistor. The average on-current (Ion) and field effect mobility (μFE) of plasma-treated dielectric samples increased compared to bare dielectric without treatment. More specifically, in the case of Ar plasma treatment, average hysteresis window (ΔVth) increased from 1.48 V to 2.39 V, and slightly increased to 1.73 V on CF4 plasma treatment. The plasma treatment onto Al2O3 dielectric induced average threshold voltage (Vth) shifting to positive direction. Compared to bare transistor, electrical bias stability of the treated devices was also enhanced. To understand more deeply, we fabricated Al2O3 capacitor having the metal-oxide-semiconductor structure. The average capacitance increased on Ar plasma treated Al2O3 but decreased on CF4 plasma treated compared to bare. The threshold voltage of the capacitor after plasma treatment moved to negative direction and hysteresis window of plasma treated Al2O3 was even wider than the bare, which is intimately correlated with electrical performance of sol-gel IGZO transistor. It is note that variation on dielectric relaxation was relieved after plasma treatment. These phenomena might be due to the surface modification of chemical states on Al2O3 dielectric layers, which was confirmed by x-ray photoelectron microscopy, and fermi energy modulation in band gap of IGZO channel. This simple surface modification method would pave a road toward improvement of electrical properties of IGZO transistor. Furthermore, the concept would be applicable method for other semiconducting transparent oxide materials. |
| 저자 | 오세영, 박우진, 박희정, 조병진 |
| 소속 | 충북대 |
| 키워드 | <P>sol-gel IGZO; IGZO transistor; high-k dielectric; ALD Al<SUB>2</SUB>O<SUB>3</SUB>; plasma treatment</P> |
