Tri-layer a-Si:H TFTs on polymeric substrates

Large area electronic applications such as active matrix flat panel displays currently use glass as substrate material. Glass substrates are available with large area, low cost, and with flat and smooth surfaces that simplify device processing. Glass is also heavy and fragile, however, and alternatives are of interest. Using a mountant technique, we have fabricated hydrogenated amorphous silicon thin film transistors (a-Si:H TFTs) on both colored and nearly colorless polyimide substrates with performance nearly identical to devices fabricated on glass substrates. These results indicate that with suitable thermal engineering, a-Si:H devices and circuits can be fabricated on polymeric substrates using nearly standard processing.