使用雙閘極IGZO電晶體之新型電路

Abstract

最近，雙閘極 (DG) 非晶矽IGZO薄膜電晶體(TFT)被提出有比單閘極薄膜電晶體更好的特性和穩定性，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薄膜電晶體的汲極電流可透過頂部閘極(top-gate)來控制。這現象使得電路設計更有彈性。在本篇論文中，我們回顧以前各種雙閘極電晶體電路的設計概念。此外，對於新的雙閘極電晶體電路開發更提出補償和回饋的新設計概念。補償的概念應用在主動矩陣有機發光二極體(AMOLED)和主動畫素感測器(APS)中，利用頂部的閘極來補償臨界電壓 (Vth) 的變異。此外，也提出來使用回饋概念的逆變器和差動放大器並且用實驗加以驗證。期望能以提出的電路作為出發點發展出更多的雙閘極薄膜電晶體電路。

Recently, the dual-gate (DG) amorphous InGaZnO4 (IGZO) thin film transistors (TFTs) with two gates at the bottom and on the top was proposed to have better performance and stability than single-gate TFT. The drain current of TFT using the bottom gate in its primary operation can be controlled by top gate. This phenomenon provides great flexibility for the circuit design. In this thesis, various circuits of DG TFT are reviewed in categories of design concept. Furthermore, the new design concepts of compensation and feedback are proposed for the development of new DG TFT circuits. The circuits of active-matrix organic light-emitting diode (AMOLED) and active pixel sensor (APS) using the top gate to compensate threshold voltage (Vth) variation are proposed to demonstrate the concept of compensation. Moreover, the inverter and differential amplifier circuits using the concept of feedback are also proposed and experimentally verified. It is expected that more DG TFT circuits are to be developed with the proposed circuits as the starting point.