| 학회 | 한국재료학회 |
| 학술대회 | 2015년 봄 (05/14 ~ 05/15, 구미코) |
| 권호 | 21권 1호 |
| 발표분야 | A. 전자/반도체 재료 |
| 제목 | InGaZnO Photo-Transistors for Fast Recover and Low Consumption Power |
| 초록 | Amorphous oxide semiconductors (AOSs) represented by amorphous-indium-gallium-zinc-oxide (a-IGZO), have attracted attention due to their high mobility, low processing temperature and good uniformity over large area. Taking these advantages, AOSs can be used as active-layers of thin film transistors (TFTs), sensors, or flexible electronics, etc. Recently, AOS-based photo-transistors have been attracted much attention due to their high sensitivity to light. However, AOS photo-transistors usually shows non-ignorable long-term recovery after turning light off due to persistent photo-current originating from lattice relaxation and excitation of electron carriers by light. It has been known that positive gate bias stress applied to AOS TFTs can cause electron carrier trapping in acceptor-like subgap defects, resulting in a reduction of electron carriers in the AOS active-layer and positive shift of threshold voltage. Considering this role of positive gate bias stress, the long-term recovery of AOS photo-transistor can possibly be overcome by just using +3V gate bias pulse to artificially suppress the persistent photo-current. In addition, this photo-transistor operated at +1 voltage lower than other studies. In this work, molybdenum as a gate electrode was deposited by direct current (DC) magnetron sputtering. Al2O3 dielectric layer was deposited at relatively low temperature by atomic layer deposition with trimethylaluminium (TMA) and water (H2O) sources. A-IGZO films as active-layers were grown by radio frequency (RF) magnetron sputtering. The active-layers were patterned by photolithography and wet-etching process. Finally, source/drain electrodes were formed with Mo/Cu bi-layers by DC sputtering and defined via lift-off process. In order to investigate the photo-response of the fabricated IGZO TFTs and the effect of positive gate bias stress on the photo-response, curret-voltage (I-V) measurements were carried out with/without positive gate bias pulses under monochromatic lights with various wavelengths. |
| 저자 | 김예균1, 윤명구2, 도현우1, 조형균2 |
| 소속 | 1성균관대, 2신소재공학부 |
| 키워드 | IGZO TFTs; IGZO photo-transistors |
