低溫多晶矽薄膜電晶體直流模型與小訊號模型

Abstract

低溫多晶矽(Low Temperature Poly-Silicon，LTPS)已經變成一種應用在主動矩陣液晶顯示器和主動矩陣有機發光顯示器上TFT的標準製程。想要達到有效的電路模擬，發展正確的模型為必然的趨勢。為了能模擬大數量的矩陣圖素和積體驅動電路，模型必須夠簡單以允許大規模資料的電路模擬。 我們的直流模型適用於N型和P型通道LTPS TFT。模型建立在物理基礎上，也提出了幾個重要的物理參數用來解釋物理現象對汲極電流的影響，這些參數和元件結構和製程有關。直流模型包含了所有的操作區：線性區、飽和區、Kink區。模型中也考慮了溫度及通道長度對電流的影響。 本論文也包含了電晶體的小訊號模型。我們利用Cold-FET 高頻量測方法，萃取電晶體外部寄生元件參數；再經由矩陣轉換求得內部本質元件參數；最後建立電晶體小訊號等效模型。

Low-temperature poly-silicon (LTPS) is becoming a standard technology for the fabrication of thin-film transistors (TFTs) used in active matrix liquid crystal displays and in active matrix organic light emissive displays. In order to be able to simulate large number of matrix pixels or integrated drivers, this model is simple enough to allow simulator convergence. A analytical model for the DC characteristics of both n- and p-channel LTPS TFT is described. Our approach results in a physically based model with some parameters, which are related to the device structure and fabrication process. The DC model describes all regimes of operation: linear, saturation, and Kink. The effects of temperature and channel length are also included in our model. This thesis also contains the small-signal modeling. This method consists in a direct determination of all the FET parasitic elements. The knowledge of these parasitic element values allows us to determine the intrinsic parameters after a few simple matrix manipulations. Then all the extrinsic and intrinsic components are determined.