Fully self-aligned amorphous-silicon mos transistors

Fully self-aligned amorphous-silicon MOS transistors have been proposed and fabricated for the first time. All positions, i.e., an active region, source and drain region, contact holes and metal electrodes are determined by only one photo-mask for the top silicon-nitride layer of a multi-layer structure deposited successively on a glass substrate. The total number of photolithographic steps is 6. On-off current ratio and the maximum field-effect mobility of the fabricated transistor are 10⁵ and 0.25 cm²/Vs, respectively.