<title>Polycrystalline thin-film transistors on plastic substrates</title>

Abstract

Flat panel displays made on plastic substrates are envisioned for use in certain commercial and military systems because they are more rugged and lightweight than displays made on glass substrates. High information content can be attained for such displays using an active matrix array of thin film transistors (TFTs) for the pixels and high current TFTs for the drivers. In this work the fabrication of high performance polysilicon TFTs on flexible plastic substrates is presented along with corresponding electrical characteristics. Plastic substrates pose severe temperature constraints on the fabrication process. To overcome electrical characteristics. Plastic substrates pose sever temperature constraints on the fabrication process. To overcome these constraints, our group at LLNL has used low temperature silicon, oxide, and aluminum thin film deposition steps and pulsed excimer laser processing to perform the TFT channel crystallization and the source/drain doping. Sheet resistance values below 1k(Omega) /$DAL are obtained using our laser doping technique for 900 angstrom thick polysilicon films. Our n-channel polysilicon TFT electrical performance on plastic shows mobilities up to 50 cm2/V-sec and ON current to OFF current ratios of up to 1 X 106 for gate voltages from -1 to +35 V.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.