Hydrogenated amorphous silicon germanium black-matrix material for active-matrix liquid-crystal displays

Integration of the black matrix (BM) in active-matrix liquid-crystal displays (AMLCDs) into the TFT array is desirable to improve display performance. This requires a black-matrix material that is both an optical absorber and an electrical insulator. Amorphous silicon germanium (a-SiGe:H) is a candidate material for this application. When deposited by magnetron sputtering, a-SiGe:H can have both high optical density and high electrical resistivity. Compared to organic materials considered for black-matrix integration, a-SiGe:H offers higher optical density at a given film thickness, more-flexible processing, and better process compatibility with AMLCD fabrication.