AIR-GAP AMORPHOUS-SILICON THIN-FILM TRANSISTORS

Top gate and bottom gate amorphous silicon thin film transistors where the dielectric has been replaced by an air gap have been fabricated o n glass substrates using surface micromachining techniques. Bridges we re formed by using low density silicon nitride as a sacrificial layer. In bottom grate structures the bridge material was amorphous silicon and in top gate structures it was highly doped n(+) microcrystalline s ilicon. The first working devices show transistor behavior with field effect mobilities between 0.1 and 0.5 cm(2) V-1 s(-1). (C) 1998 Americ an Institute of Physics.