Article
Engineering, Electrical & Electronic
Wei Zhong, Liangyun Kang, Sunbin Deng, Lei Lu, Ruohe Yao, Linfeng Lan, Hoi Sing Kwok, Rongsheng Chen
Summary: The study found that ITZO thin-film transistors with a scandium oxide (Sc2O3) passivation layer showed excellent electrical performance and stability, especially under negative bias temperature stress and positive bias temperature stress. In contrast, devices with an aluminum oxide (Al2O3) passivation layer exhibited poorer stability.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Kaizhen Han, Subhranu Samanta, Shengqiang Xu, Ying Wu, Xiao Gong
Summary: The study found that by reducing the equivalent oxide thickness, a temperature-independent mu(eff) can be achieved in the high field or high carrier concentration regime, while a strong temperature dependency is observed in the low field or low carrier concentration regime. Additionally, the relationship between EOT scaling and the gate bias voltage at which E-F equals to E-M was studied, revealing that α-IGZO TFTs can achieve high performance in low-power applications.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Fei Shan, Jae-Yun Lee, Hao-Zhou Sun, Han-Lin Zhao, Xiao-Lin Wang, Sung-Jin Kim
Summary: This study investigates a method for radio frequency oxygen plasma treatment of IZO films, showing that this posttreatment technology can improve the mobility and stability of IZO thin-film transistors. The process involves spin coating and thermal annealing to form the active layers, followed by O-2 plasma posttreatment to create a multistacked architecture triggered by O-2. The plasma-treated TFT devices exhibit improved electrical characteristics compared to untreated samples.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Yan-Kui Liang, Jing-Wei Lin, Li-Chi Peng, Yi Miao Hua, Tsung-Te Chou, Chi-Chung Kei, Chun-Chieh Lu, Huai-Ying Huang, Sai Hooi Yeong, Yu-Ming Lin, Po-Tsun Liu, Edward-Yi Chang, Chun-Hsiung Lin
Summary: In this article, enhancement-mode thin-film transistors (TFTs) with ultrathin (approximately 3 nm) amorphous indium-zinc oxide (a-IZO) channel derived from atomic layer deposition (ALD) were demonstrated. The ALD-deposited IZO channel TFT showed improved device characteristics compared to thicker IZO channels. It exhibited high field-effect channel mobility, low subthreshold gate swing, high Ion/Ioff current ratio, and stable threshold voltages after positive and negative bias stress tests.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Ritwik Vatsyayan, Shadi A. Dayeh
Summary: We present a new physics-based model for dual-gate a-IGZO TFTs, which was fine-tuned through experimental implementation and benchtop characterization. The model accurately captures the various operating regimes and characteristics of the TFTs, including ambipolar subthreshold currents, graded interbias-regime current changes, threshold and flat-band voltages, interface trap density, gate leakage currents, noise, and small signal parameters. We validated the model's performance by designing and fabricating a two-stage common source amplifier circuit, which exhibited excellent agreement between measured and simulated gain and phase performance over a wide frequency range.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Cheol Hee Choi, Taikyu Kim, Min Jae Kim, Seong Hun Yoon, Jae Kyeong Jeong
Summary: This article investigates the stability mechanism of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) with a natural length of around 8 nm, focusing on the point defects in hafnium oxide (HfO2) gate dielectric. The point defects in HfO2 respond to external stresses, such as electric field and temperature, with oxygen vacancies and positively charged defects causing abnormal negative shifts in threshold voltage under positive gate bias temperature stress (PBTS). The insertion of a 0.7-nm-thick ultrathin SiO2 interlayer between a-IGZO and optimized HfO2 further enhances device performance and stability.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Xiaoyu Lin, Qian Xin, Jaekyun Kim, Jidong Jin, Jiawei Zhang, Aimin Song
Summary: In this study, ultrathin AlxOy films used as gate dielectrics in thin-film transistors (TFTs) were prepared through an anodization process in aqueous and organic electrolytes. The effects of anodization electrolyte on the surface morphologies and electrical properties of AlxOy films were investigated through a series of anodization voltages. By using these anodized AlxOy films as gate dielectrics, 1-V indium-gallium-zinc-oxide (IGZO) TFTs were fabricated. The electrical characteristics of the IGZO TFTs with AlxOy films prepared in organic electrolyte showed enhancement compared to those with AlxOy films prepared in aqueous electrolyte, possibly due to the introduction of more carbon species in the anodized dielectric films. This work offers a method to further improve the properties of ultrathin anodized dielectrics and demonstrates the potential of using anodization for large-area low-power electronics in the future.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Weijie Ye, Yuan Liu, Bingqi Wang, Junkai Huang, Xiaoming Xiong, Wanling Deng
Summary: An improved model is developed to characterize the low-frequency noise (LFN) properties of amorphous indium-zinc-oxide thin-film transistors (a-IZO TFTs) in this article. The model considers both the oxide traps in the gate insulator and the discrete trap centers in the active-layer film, accurately describing the excess noise in the subthreshold and above-threshold regions. The model has been validated and successfully applied to a-IZO TFTs with different tail-state densities.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Hyunhee Kim, Taegyu Kim, Youngjin Kang, Seoung-Pil Jeon, Jiwan Kim, Jaehyun Kim, Sung Kyu Park, Yong-Hoon Kim
Summary: Researchers have successfully demonstrated sub-volt operating metal-oxide thin-film transistors using high-k gadolinium-doped hafnium oxide films. The Gd doping significantly improved the leakage current characteristics compared to undoped HfO2 films, making the high-k HGO film a promising candidate for low-power consumption sub-volt operating TFTs.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
I. Sak Lee, Joohye Jung, Dong Hyun Choi, Sujin Jung, Kyungmoon Kwak, Hyun Jae Kim
Summary: A homojunction-structured oxide phototransistor based on mechano-chemically treated IGZO absorption layer exhibited outstanding optoelectronic characteristics and sensitivity, making it suitable for optical sensor applications.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Engineering, Electrical & Electronic
Jeongho Lee, Jidong Jin, Seohyun Maeng, Gisang Choi, Hayoung Kim, Jaekyun Kim
Summary: This study investigates the performance of indium tin zinc oxide (ITZO) thin-film transistors (TFTs) with different channel structures. The results show that bilayer-channel ITZO TFTs exhibit enhanced electrical performance and bias stress stability compared to single-channel ITZO TFTs. The electrical properties of the bilayer-channel films can be fine-tuned by adjusting their oxygen stoichiometry using an oxygen-compensated capping layer.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Subhranu Samanta, Kaizhen Han, Chen Sun, Chengkuan Wang, Annie Kumar, Aaron Voon-Yew Thean, Xiao Gong
Summary: The study found that in the sub-10-nm regime, TFT devices with a channel thickness of 3.6 nm can achieve low subthreshold swing and the highest effective mobility. The effective mobility does not degrade significantly as the alpha-IGZO thickness is reduced from 6 to 3.6 nm.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Wensi Cai, Haiyun Li, Zhigang Zang
Summary: The study showed that IZO films annealed at 350 degrees Celsius exhibit the best performance, and with the use of a thin AlxOy layer as the gate dielectric, high-performance IZO TFTs were demonstrated. These devices have a high current on/off ratio, high mobility, and are close to the theoretical limit of subthreshold swing.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Guangan Yang, Hao Tian, Zuoxu Yu, Tingrui Huang, Yong Xu, Huabin Sun, Weifeng Sun, Wangran Wu
Summary: This work demonstrates 400-V amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) with a drift region doped by hydrogen near the drain side. By optimizing the length of the drift region and the hydrogen flow rate, the breakdown voltage and output current are improved, along with enhanced carrier concentration. The proposed 400-V a-IGZO TFTs exhibit an excellent tradeoff relationship between on-resistance and breakdown voltage.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Li Zhu, Yongli He, Chunsheng Chen, Xiangjing Wang, Ying Zhu, Yixin Zhu, Huiwu Mao, Changjin Wan, Qing Wan
Summary: A high-performance transparent amorphous indium gallium zinc oxide thin-film transistor (a-IGZO TFT) gated by ALD-deposited HfAlOx was reported in this study. After an optimization process, the device showed significantly reduced trap density and good stability.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
