Kim Min Seong, Kim Hyung Tae, Yoo Hyukjoon, Choi Dong Hyun, Park Jeong Woo, Kim Tae Sang, Lim Jun Hyung, Kim Hyun Jae
School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
Process Research Team, Display Research Center, Samsung Display, 1 Samsung-ro, Giheung-gu, Yongin-si, Gyeonggi-do 17113, Republic of Korea.
ACS Appl Mater Interfaces. 2021 Jul 14;13(27):31816-31824. doi: 10.1021/acsami.1c05565. Epub 2021 Jun 28.
In this study, the oxygen scavenger layer (OSL) is proposed as a back channel in the bilayer channel to enhance both the electrical characteristics and stability of an amorphous indium-gallium-zinc oxide thin-film transistor (a-IGZO TFT) and also to enable its fabrication at low temperature. The OSL is a hafnium (Hf)-doped a-IGZO channel layer deposited by radio-frequency magnetron cosputtering. Amorphous IGZO TFTs with the OSL, even if annealed at a low temperature (200 °C), exhibited improved electrical characteristics and stability under positive bias temperature stress (PBTS) compared to those without the OSL, specifically in terms of field-effect mobility (31.08 vs 9.25 cm/V s), on/off current ratio (1.73 × 10 vs 8.68 × 10), and subthreshold swing (0.32 vs 0.43 V/decade). The threshold voltage shift under PBTS at 50 °C for 10,000 s decreased from 9.22 to 2.31 V. These enhancements are attributed to Hf in the OSL, which absorbs oxygen ions from the a-IGZO front channel near the interface between a-IGZO and the OSL.
在本研究中，提出将氧清除层（OSL）作为双层沟道中的背沟道，以增强非晶铟镓锌氧化物薄膜晶体管（a-IGZO TFT）的电学特性和稳定性，并实现其低温制造。OSL是通过射频磁控共溅射沉积的掺铪（Hf）的a-IGZO沟道层。具有OSL的非晶IGZO TFT，即使在低温（200°C）下退火，与没有OSL的相比，在正偏压温度应力（PBTS）下也表现出改善的电学特性和稳定性，特别是在场效应迁移率（31.08对9.25 cm²/V s）、开/关电流比（1.73×10⁷对8.68×10⁶）和亚阈值摆幅（0.32对0.43 V/十倍频程）方面。在50°C下10000 s的PBTS下阈值电压偏移从9.22 V降至2.31V。这些增强归因于OSL中的Hf，它从a-IGZO与OSL界面附近的a-IGZO前沟道吸收氧离子。
