Teflon/SiO2 Bilayer Passivation for Improving the Electrical Reliability of Oxide TFTs Fabricated Using a New Two-Photomask Self-Alignment Process

Materials

Ching-Lin Fan³  Ming-Chi Shang³  Bo-Jyun Li³  Yu-Zuo Lin⁴  Shea-Jue Wang²  Win-Der Lee¹  Bohr-Ran Hung³ 

[1] Department of Electrical Engineering, Lee-Ming Institute of Technology, New Taipei City 243, Taiwan; E-Mail:;Institute of Materials Science and Engineering, National Taipei University of Technology, Taipei 106, Taiwan; E-Mail:;Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, 43 Section 4, Keelung Road, Taipei 106, Taiwan; E-Mails:;Department of Electronic Engineering, National Taiwan University of Science and Technology, 43 Section 4, Keelung Road, Taipei 106, Taiwan; E-Mail:

关键词: indium gallium zinc oxide (IGZO);    thin film transistors (TFTs);    passivation layer;    Teflon;    SiO₂;   

DOI  :  10.3390/ma8041704

来源: mdpi

【 摘 要 】

This study proposes a two-photomask process for fabricating amorphous indium–gallium–zinc oxide (a-IGZO) thin-film transistors (TFTs) that exhibit a self-aligned structure. The fabricated TFTs, which lack etching-stop (ES) layers, have undamaged a-IGZO active layers that facilitate superior performance. In addition, we demonstrate a bilayer passivation method that uses a polytetrafluoroethylene (Teflon) and SiO₂ combination layer for improving the electrical reliability of the fabricated TFTs. Teflon was deposited as a buffer layer through thermal evaporation. The Teflon layer exhibited favorable compatibility with the underlying IGZO channel layer and effectively protected the a-IGZO TFTs from plasma damage during SiO₂ deposition, resulting in a negligible initial performance drop in the a-IGZO TFTs. Compared with passivation-free a-IGZO TFTs, passivated TFTs exhibited superior stability even after 168 h of aging under ambient air at 95% relative humidity.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.