Transport property improvements of amorphous In-Zn-O transistors with printed Cu contacts via rapid temperature annealing

Publication date: Available online 20 February 2016
Source:Thin Solid Films
Author(s): Ju Yeon Won, Young Hun Han, Hyun Ju Seol, Ki June Lee, Rino Choi, Jae Kyeong Jeong
The device performance of amorphous In-Zn-O (a-IZO) thin-film transistors (TFTs) with printed Cu contacts was significantly improved by the insertion of a diffusion barrier Ta layer and rapid thermal process (RTP) annealing. Furnace-annealed a-IZO TFTs with Cu/Ta contacts exhibited mobility values of 21.3 cm²/Vs, subthreshold gate swing (SS) values of 1.9 V/decade, and I ON/OFF of ~10⁶. In contrast, the SS, mobility, and I ON/OFF ratio of RTP-annealed a-IZO TFTs with Cu/Ta contacts were 30.6 cm²/Vs, 0.68 V/decade, and 3 × 10⁷, respectively. We attributed the performance improvement of devices with Cu/Ta contacts to the suppression of Cu in-diffusion within the a-IZO channel due to the rapid heating associated with RTP annealing.