Effect of Gate Insulator on Amorphous Silicon Thin Film Transistor Performance (Korea-Japan Joint Symtosium on Information Display)

抄録

Amorphous silicon (a-Si) thin film transistors (TFTs) have become the dominant technology for driving active matrix liquid crystal displays. Gate insulator quallty is one of the most important issues in determining TFT performance. We have performed a detailed study on various insulators used in amorphous silicon TFT displays. Properties of various PECVD silicon nitrides and silicon dioxide will be discussed based on electrical and mechanical measurements and with regard to their influence on TFT processing and performance. Transistors fabricated with various insulators were characterized by measuring mobility, threshold voltage and transfer characteristics. TFTs with optimum gate dielectrics have been fabricated with threshold voltage ≈ 2.0 V, field-effect mobility > 1.0 cm^2/vs and ON/OFF ratio of over 10^7.