Yuichi Masutani

1.8-inch poly-Si TFT-LCDs with novel TFT structure and storage capacitance arrangement

We have fabricated 1.8-inch and 86,400-pixel poly-Si TFT-LCDs with a novel TFT structure and a storage capacitance (Cst) arrangement. The TFTs have a self-aligned offset structure which is made by a simple process without using an additional mask. With this structure, we have reduced the OFF current, and hence, attained a high ON/OFF current ratio of 107. A novel Cst line arrangement called modified Cst on gate was adopted. Gate lines and Cst lines are arranged alternatively, and the (n-1)-th Cst line is connected to the n-th gate line at the lines end. The Cst line works as redundancy of the gate line. Consequently, we have obtained TFT arrays with no line-defects (240 gate lines). By using these techniques, we have succeeded in fabricating a high-performance 1.8-inch poly-Si TFT-LCD panel for a projection TV.