Kim, Taikyu Ryu, Seung Ho Jeon, Jihoon Kim, Taeseok Baek, In-Hwan Kim, Seong Keun 2025-03-24T01:00:29Z 2025-03-24T01:00:29Z 2025-03-19 2025-01 0003-6951 https://pubs.kist.re.kr/handle/201004/152107 This study presents considerable improvements in the electrical characteristics of atomic-layer-deposited 3-nm-thick In2O3 thin-film transistors (TFTs), which were achieved by introducing a 2-nm-thick amorphous Al2O3 interfacial layer to passivate the surface of a polycrystalline HfO2 gate dielectric. The resulting devices exhibited exceptional electrical characteristics, including an ultrahigh field-effect mobility (mu(FE)) of approximately 147.5 +/- 16.6 cm(2)/V s, subthreshold swing of 103.7 +/- 9.1 mV/dec, and threshold voltage (V-TH) of 0.5 +/- 0.1 V. These enhancement-mode devices represent increases of more than threefold in mu(FE) compared to devices without an amorphous passivation layer. This is despite all the fabrication processes being identical, except for the introduction of the Al2O3 interfacial layer. This improvement can be primarily attributed to the reduced electron scattering through suppressed remote Coulomb interactions. Furthermore, the In2O3 TFTs exhibited enhanced operational stability, showing minimal V-TH shifts of 0.15 and -0.01 V under positive and negative bias-stress conditions, respectively. The findings of this study emphasize the critical role of the surface passivation of polycrystalline HfO2 dielectrics in improving the electrical performance of ultrathin In2O3 TFTs. English American Institute of Physics Ultrahigh field-effect mobility of 147.5 cm2/Vs in ultrathin In2O3 transistors via passivating the surface of polycrystalline HfO2 gate dielectrics Article 10.1063/5.0240110 1 Applied Physics Letters, v.126, no.3 Applied Physics Letters 126 3 N scie scopus 001408675900018 2-s2.0-85216107279 Physics, Applied Physics Article THIN-FILM TRANSISTORS OXIDE MOSFETS