Floating gate effect in amorphous InGaZnO thin-film transistor

被引:5
|
作者
Qin Ting [1 ]
Huang Sheng-Xiang [1 ]
Liao Cong-Wei [1 ]
Yu Tian-Bao [1 ]
Luo Heng [1 ]
Liu Sheng [1 ]
Deng Lian-Wen [1 ]
机构
[1] Cent S Univ, Sch Phys & Elect, Changsha 410083, Hunan, Peoples R China
基金
中国国家自然科学基金;
关键词
InGaZnO; floating gate; thin film transistors; device model; TFTS;
D O I
10.7498/aps.67.20172325
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
In recent years, considerable attention has been paid to amorphous indium gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs) for high performance flat panel display, such as liquid-crystal displays (LCDs), active-matrix organic light-emitting diode (AMOLED) display and flexible display. This is because IGZO TFTs are more suitable for pixels and circuit integrations on display panel than the conventional silicon-based devices. The merits of IGZO TFT technology include high mobility, decent reliability, low manufacturing cost, and excellent uniformity over large fabrication area. However, it was reported that the electrical characteristics of IGZO TFT are susceptible to shift after electrical aging measurement under illumination, which is caused by the activation of trapped electrons from sub-gap states to conducting states. Therefore, it is necessary to introduce light shielding layer to suppress the electrical characteristic shift under illumination aging measurements. Lim et al. demonstrated the characteristics of IGZO TFT with additional light shielding metal layer, and proved that the threshold voltage of TFT can be tuned linearly by adjusting the biasing voltage of the light shielding metal. Taking advantage of this tunable threshold voltage, AMOLED pixel circuit with a threshold voltage shift compensation function can be implemented. However, drawback of this method lies in the adding of additional biasing line, which increases the circuit area and restricts the integration of high-resolution pixel circuits. Thus, Zan et al. proposed adopting floating (unbiased) light shielding metal layer to improve the characteristics of device. However, Zeng et al. demonstrated the abnormal output characteristics of the IGZO TFT, as it cannot be saturated due to the introduction of floating light shielding metal layer. It seems that the IGZO TFT with floating metal is different from the conventional double-gate or single gate structure. To date, the current conducting mechanism of IGZO TFT with floating metal has not been discussed yet. In this paper, the distribution of electrical potential in the IGZO TFT with a cross sectional view is thoroughly analyzed. It is confirmed that the abnormal output characteristic of IGZO TFT is caused by the capacitive coupling between the floating gate and the drain electrode of the transistor. On the basis of the voltage distribution relationship between the equivalent capacitances, a threshold-voltage-dependent current-voltage model is proposed. The simulated results by technology computer-aided design tool and those by the proposed model are in good agreement with each other. Therefore, the mechanism of floating gate effect for IGZO TFT is comprehensively demonstrated. The illustrated conducting mechanism and the proposed current-voltage model are helpful in developing the device and process of IGZO TFT with novel structure.
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页数:7
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共 24 条
  • [1] Amorphous In-Ga-Zn-O Dual-Gate TFTs: Current-Voltage Characteristics and Electrical Stress Instabilities
    Abe, Katsumi
    Takahashi, Kenji
    Sato, Ayumu
    Kumomi, Hideya
    Nomura, Kenji
    Kamiya, Toshio
    Kanicki, Jerzy
    Hosono, Hideo
    [J]. IEEE TRANSACTIONS ON ELECTRON DEVICES, 2012, 59 (07) : 1928 - 1935
  • [2] Oxide-TFT technologies for next-generation AMOLED displays
    Arai, Toshiaki
    [J]. JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 2012, 20 (03) : 156 - 161
  • [3] Modeling of currentuvoltage characteristics for double-gate a-IGZO TFTs and its application to AMLCDs
    Baek, Gwanghyeon
    Kanicki, Jerzy
    [J]. JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY, 2012, 20 (05) : 237 - 244
  • [4] Light-induced instability of an InGaZnO thin film transistor with and without SiOx passivation layer formed by plasma-enhanced-chemical-vapor-deposition
    Chen, Te-Chih
    Chang, Ting-Chang
    Hsieh, Tien-Yu
    Tsai, Chih-Tsung
    Chen, Shih-Ching
    Lin, Chia-Sheng
    Hung, Ming-Chin
    Tu, Chun-Hao
    Chang, Jiun-Jye
    Chen, Po-Lun
    [J]. APPLIED PHYSICS LETTERS, 2010, 97 (19)
  • [5] Light-Enhanced Bias Stress Effect on Amorphous In-Ga-Zn-O Thin-film Transistor with Lights of Varying Colors
    Chen, Wei-Tsung
    Hsueh, Hsiu-Wen
    Zan, Hsiao-Wen
    Tsai, Chuang-Chuang
    [J]. ELECTROCHEMICAL AND SOLID STATE LETTERS, 2011, 14 (07) : H297 - H299
  • [6] A Novel a-InGaZnO TFT Pixel Circuit for AMOLED Display With the Enhanced Reliability and Aperture Ratio
    Kim, Yeonkyung
    Kim, Yongchan
    Lee, Hojin
    [J]. JOURNAL OF DISPLAY TECHNOLOGY, 2014, 10 (01): : 80 - 83
  • [7] Stability of low temperature and transparent amorphous InGaZnO thin film transistor under illumination
    Li Xi-Feng
    Xin En-Long
    Shi Ji-Feng
    Chen Long-Long
    Li Chun-Ya
    Zhang Jian-Hua
    [J]. ACTA PHYSICA SINICA, 2013, 62 (10)
  • [8] Double gate GaInZnO thin film transistors
    Lim, Hyuck
    Yin, Huaxiang
    Park, Jin-Seong
    Song, Ihun
    Kim, Changjung
    Park, JaeChul
    Kim, Sunil
    Kim, Sang-Wook
    Lee, Chang Bum
    Kim, Yong C.
    Park, Young Soo
    Kang, Donghun
    [J]. APPLIED PHYSICS LETTERS, 2008, 93 (06)
  • [9] Solution-processed lithium-doped zinc oxide thin-film transistors at low temperatures between 100 and 300 °C
    Liu, Fangmei
    Qian, Chuan
    Sun, Jia
    Liu, Peng
    Huang, Yulan
    Gao, Yongli
    Yang, Junliang
    [J]. APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 2016, 122 (04):
  • [10] Improved performance of the amorphous indium-gallium-zinc oxide thin film transistor with Cu-Mo source/drain electrode
    Ning Hong-Long
    Hu Shi-Ben
    Zhu Feng
    Yao Ri-Hui
    Xu Miao
    Zou Jian-Hua
    Tao Hong
    Xu Rui-Xia
    Xu Hua
    Wang Lei
    Lan Lin-Feng
    Peng Jun-Biao
    [J]. ACTA PHYSICA SINICA, 2015, 64 (12)