具有臨界電壓補償功能雙閘極IGZO TFT電路之研究

Study on the Dual Gate IGZO TFT Circuits with Threshold Voltage Compensation Function

盧冠銘(Kuan-Ming Lu)

指導教授 ： 戴亞翔

國立交通大學/電機學院/顯示科技研究所/碩士(2011年)

https://doi.org/10.6842/NCTU.2011.00242

摘要

非晶矽IGZO薄膜電晶體 (IGZO TFTs) 備受關注，因為它有幾個優點，如高載子遷移率，高透明度，製程溫度低，均勻性好。然而，臨界電壓 (Vth) 的不穩定，限制了IGZO 在電路上的應用。最近，雙閘極IGZO TFT被提出具有較好的元件特性和較穩定的臨界電壓，它的結構分別在底部和頂部各有一個閘極。
在正常的底部閘極 (bottom-gate) 的操作下，雙閘極IGZO薄膜電晶體的臨界電壓可透過頂部閘極 (top-gate) 來操控。基於這個現象，我們提出了透過頂部閘極的操作來補償臨界電壓的變異的新概念。在本篇論文中，將此新概念應用到數位緩衝器(digital buffer) 和有機發光二極體(OLED) 的畫素電路中，利用實驗的方式來驗証這個新概念。

關鍵字

雙閘極IGZO TFT ； 臨界電壓補償電路 ； 主動式矩陣有機發光二極體

並列摘要

Amorphous InGaZnO4 (IGZO) thin film transistor (TFT) has drawn great attention because it has several merits such as high mobility, high transparency, low processing temperature, and potentially good uniformity. However, the threshold voltage (Vth) instability IGZO TFT can limits its applications in the circuits. Recently, the dual-gate IGZO TFT with two gates on the bottom and the top was proposed to have better device performance and better stability of Vth after voltage stress.
The threshold voltage of the TFT using the bottom-gate in its normal operation can be controlled by the top-gate. Based on this phenomenon, a new concept of using the top-gate to compensate threshold voltage variation is proposed. In this thesis, this new concept of Vth compensation is demonstrated experimentally in digital buffer and pixel circuits of active-matrix organic light-emitting diode (AMOLED).

並列關鍵字

dual-gate IGZO TFT ； threshold voltage compensation circuit ； active matrix organic light-emitting diode

參考文獻

[1] Joon Chul Goh, Hoon Ju Chung, Jin Jang, and Chul Hi Han, “A New Pixel Circuit for Active Matrix Organic Light Emitting Diodes”, IEEE Electron Device Lett, VOL. 23, pp. 544-546, NO. 9, SEPTEMBER 2002

[2] Roger G. Stewart, “Active Matrix OLED Pixel Design”, SID Symposium Digest of Technical Papers, May 2010, Volume 41, Issue 1, pp. 790-793

[3] Jae Hoon Lee, Ji Hoon Kim, and Min Koo Han, “A New a-Si:H TFT Pixel Circuit Compensating the Threshold Voltage Shift of a-Si:H TFT and OLED for Active Matrix OLED”, IEEE ELECTRON DEVICE LETTERS, VOL. 26, p.897-899, NO. 12, DECEMBER 2005

[4] Young Ju Park*, Myoung Hoon Jung, Sang Ho Park, and Ohyun Kim, “Voltage-Programming-Based Pixel Circuit to Compensate for Threshold Voltage and Mobility Using Natural Capacitance of Organic Light-Emitting Diode”, Japanese Journal of Applied Physics 49 (2010) 03CD01

[5] Seung Min Lee, Chang Il Ryoo, Jae Wook Park, “Control of Threshold Voltage in Back Channel Etch Type Amorphous Indium Gallium Zinc Oxide Thin Film Transistors”, SID Symposium Digest of Technical Papers, May 2011, Volume 42, Issue 1, pp. 104-106