The Development of a-Si:H TFT Model And Display Driver Circuit Design

• Main Authors: Ren-Zheng Xiao, 蕭仁政
• Other Authors: Wen-Yaw Chung
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/16115577665655406247

碩士 === 中原大學 === 電子工程研究所 === 94 === ABSTRACT Active matrix organic light emitting diodes (AMOLEDs) have gained a much interesting focus in the world wide. The LTPS are widely fabricated technologies on AMOLED, but a-Si:H thin film transistors still have own stable and high yield fabrication processes. To develop a-Si:H TFTs drivers for the applications of AMOLED panels are still rival commodities.The RPI model is unable to extract parameters of Vt and Rds precisely, which results in the variation changes on simulations of device driving currents. We bring up different kinds of procedures and a better method of extracting parameters on Vt and Rds. According to the improved extracting parameter method, the ring oscillator is approved.Experimental results the DC model RMS(Root Mean-Square Error) error is smaller than 5% , AC model RMS error is smaller than 3% base on the ring oscillator. This thesis present the development of display gate driver circuit design with ELDO and measure AMOLED pixel circuit.To use and design bootstrapped n-type inverter to compensate the Vt shift. Furthermore, the threshold voltage and subthreshold swing shift of a-Si:H TFT under DC operation is discussed and measured.DC voltage stress causes a constant Vt shift ,but subthreshold swing isn’t change much.Finally,we invertigate the leakage current and driving with different device structures are discussed.The a-Si island is completely shielded by the gate electrode exhibits higher leakage current.The structure of single gate dual channel a-Si:H TFT exhibits higher driving current.