Environmentally and Electrically Stable Sol-Gel-Deposited SnO2 Thin-Film Transistors with Controlled Passivation Layer Diffusion Penetration Depth That Minimizes Mobility Degradation

Won-Yong Lee; Do Won Kim; Hyeon Joong Kim; Kyoungdu Kim; Sin-Hyung Lee; Jin-Hyuk Bae; In-Man Kang; Kwangeun Kim; Jaewon Jang

doi:10.1021/acsami.1c23955

Environmentally and Electrically Stable Sol-Gel-Deposited SnO₂ Thin-Film Transistors with Controlled Passivation Layer Diffusion Penetration Depth That Minimizes Mobility Degradation

ACS Appl Mater Interfaces. 2022 Mar 2;14(8):10558-10565. doi: 10.1021/acsami.1c23955. Epub 2022 Feb 17.

Authors

Won-Yong Lee¹, Do Won Kim¹, Hyeon Joong Kim¹, Kyoungdu Kim¹, Sin-Hyung Lee^{1

2}, Jin-Hyuk Bae^{1

2}, In-Man Kang^{1

2}, Kwangeun Kim³, Jaewon Jang^{1

2}

Affiliations

¹ School of Electronic and Electrical Engineering, Kyungpook National University, Daegu 41566, Korea.
² School of Electronics Engineering, Kyungpook National University, Daegu 41566, Korea.
³ School of Electronics and Information Engineering, Korea Aerospace University, Goyang 10540, Korea.

PMID: 35175718
DOI: 10.1021/acsami.1c23955

Abstract

This study examines the effect of the annealing time of the Y₂O₃ passivation layer on the electrical performances and bias stabilities of sol-gel-deposited SnO₂ thin-film transistors (TFTs). The environmental stabilities of SnO₂ TFTs were examined. After optimizing the Y₂O₃ passivation layers in SnO₂ TFTs, the field-effect mobility was 7.59 cm²/V•s, the V_TH was 9.16 V, the subthreshold swing (SS) was 0.88 V/decade, and the on/off-current ratio was approximately 1 × 10⁸. V_TH shifts were only -0.18 and +0.06 V under negative and positive bias stresses, respectively. The SnO₂ channel layer thickness and oxygen-vacancy concentration in SnO₂, which determine the carrier concentration, were successfully tuned by controlling the annealing time of the Y₂O₃ passivation layers. An extremely thin Y₂O₃ passivation layer effectively blocked external molecules, thus affecting the device performance. The electrical performance was maximized in SnO₂ TFTs using a 15 min-annealed Y₂O₃ passivation layer. In this TFT, the field-effect mobility was maximally retained and the bias and environmental stabilities were sustained over 90 days of air exposure.

Keywords: SnO2; Y2O3; diffusion; passivation; stability; thin-film transistors.