True Direct Ohmic Contact to Hydrogenated Amorphous Silicon
Original Publication Date: 1987-Nov-01
Included in the Prior Art Database: 2005-Feb-02
A technique is described whereby low resistance contact to hydrogenated amorphous silicon is achieved through the use of YxGdy alloys without the need of a heavily doped (n+-type) layer at the metal/a-Si:H interface. Such low resistance/direct ohmic simplifies the fabrication process of various a-Si:H devices, such as thin film transistors, Schottky diodes, p-i-n junctions, etc. True direct ohmic, non-rectifying or low resistance contact to undoped and n-type doped hydrogenated amorphous silicon films has been achieved by using YxGdy alloys without n+-type layers at the metal/a-Si:H interface. The electron concentration is increased in the region near the YxGdy/a-Si:H interface and the highest resistivity region is the bulk semiconductor (a-Si:H) region.