Wu CH, Mohanty SK, Huang BW, Chang KM, Wang SJ, Ma KJ. High-mobility and low subthreshold swing amorphous InGaZnO thin-film transistors by
in situH
2plasma and neutral oxygen beam irradiation treatment.
NANOTECHNOLOGY 2023;
34:175202. [PMID:
36696686 DOI:
10.1088/1361-6528/acb5f9]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/25/2023] [Indexed: 06/17/2023]
Abstract
In this work, staggered bottom-gate structure amorphous In-Ga-Zn-O (a-IGZO) thin film transistors (TFTs) with high-k ZrO2gate dielectric were fabricated using low-cost atmospheric pressure-plasma enhanced chemical vapor deposition (AP-PECVD) within situhydrogenation to modulate the carrier concentration and improve interface quality. Subsequently, a neutral oxygen beam irradiation (NOBI) technique is applied, demonstrating that a suitable NOBI treatment could successfully enhance electrical characteristics by reducing native defect states and minimize the trap density in the back channel. A reverse retrograde channel (RRGC) with ultra-high/low carrier concentration is also formed to prevent undesired off-state leakage current and achieve a very low subthreshold swing. The resulting a-IGZO TFTs exhibit excellent electrical characteristics, including a low subthreshold swing of 72 mV dec-1and high field-effect mobility of 35 cm2V-1s-1, due to conduction path passivation and stronger carrier confinement in the RRGC. The UV-vis spectroscopy shows optical transmittance above 90% in the visible range of the electromagnetic spectrum. The study confirms the H2plasma with NOBI-treated a-IGZO/ZrO2TFT is a promising candidate for transparent electronic device applications.
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