AVS 60th International Symposium and Exhibition
    Electronic Materials and Processing Thursday Sessions
       Session EM-ThP

Paper EM-ThP7
Investigation of Dual-Active-Layered Zinc–Tin–Oxide/Indium–Gallium–Zinc–Oxide Thin-Film Transistors with the Durability of the Chemical Damage

Thursday, October 31, 2013, 6:00 pm, Room Hall B

Session: Electronic Materials and Processing Poster Session
Presenter: C.H. Kim, Yonsei University, Republic of Korea
Authors: C.H. Kim, Yonsei University, Republic of Korea
H.J. Kim, Yonsei University, Republic of Korea
Correspondent: Click to Email
Amorphous–indium–gallium–zinc–oxide (a-IGZO) as channel materials of thin-film transistors (TFTs) has attracted attention as alternative of amorphous silicon (a-Si) for the backplanes of next-generation active-matrix organic light-emitting diode (AMOLED) displays and active-matrix liquid-crystal displays (AMLCDs) due to advantages such as high field-effect mobility, flexibility, good uniformity, transparency in visible light, and low temperature process. However, IGZO thin film has an activated chemical reaction in the bulk of wet etchants for patterning source/drain (S/D) electrodes. Therefore, the process using IGZO film as a channel layer should adopt the protection layer (mainly insulator), that is high cost process due to accessional lithography process and causes a large parasitic capacitance due to the misalignment margin among the gate, the protection layer, and the S/D. So as to improve the above disadvantages, we applied Zn–Sn–O (ZTO) to the protection layer. ZTO has higher chemical stability than IGZO owing to its SnO2 content, and provides very lower contact resistance compared to that of insulator due to the semiconductor property. The dual-active-layered IGZO/ZTO (DALZI) has the IGZO layer under ZTO layer, which is the protection layer that shied IGZO layer from damage by the aluminum etchant. The DALZI TFT was successfully shielded by ZTO layer during soaking in aluminum etchant, whereas the IGZO TFT was readily damaged or removed. As the above reason, the electrical performance of the DALZI TFT could be preserved after exposure to aluminum etchant compared with that of the IGZO TFT. Hence, the DALZI structure could grant IGZO-based oxide semiconductor the first option for next-generation active-matrix switch device due to low cost.