Thin-film switching device having chlorine-containing active region and methods of fabrication therefor

摘要

A thin-film switching device includes an active region including noncrystalline silicon, e.g., hydrogenated amorphous silicon, which includes chlorine distributed in a manner which produces a predetermined photoconductivity and a predetermined field-effect mobility in the active region. Preferably, the active region includes a plurality of hydrogenated amorphous silicon layers, at least one of which includes chlorine. In one embodiment, the plurality of hydrogenated amorphous silicon layers includes a hydrogenated amorphous silicon layer including between 0.1 ppm and 106 ppm chlorine. In another embodiment, the plurality of hydrogenated amorphous silicon layers includes a first hydrogenated amorphous silicon layer having a first chlorine concentration and a second hydrogenated amorphous silicon layer having a second chlorine concentration less than the first chlorine concentration. The first hydrogenated amorphous silicon layer includes 1 ppm to 105 ppm chlorine, and the second hydrogenated amorphous silicon layer includes less than 104 ppm chlorine. Related fabrication methods are also discussed.