Optical barrier and methods for forming the optical barrier without etching a transparent layer below the optical barrier

摘要

An optical barrier made of tungsten (W) or titanium-tungsten (TiW). A layer of the optical barrier material is deposited over a transparent layer such as indium tin oxide (ITO). The optical barrier material is then patterned using photolithography processing steps and a dry etchant. The patterned optical barrier material acts as a light-shielding layer over a light-sensing device to form a dark reference device or dark pixel.