Plasma etching of polycrystalline silicon films using chlorine based mixtures for fabrication of infrared sensors and MOS gates

Image sensors based on active pixel sensor (APS) and fabricated employing a simple MOS technology are used in a fast growing number of applications. Large feature size is used to offer high photodetection sensitivity and low cost. This kind of sensors became very popular since the beginning of 90´s. Here, for devices fabrication, plasma etching of Si with chlorine containing gas mixtures is employed which provides anisotropic etch with vertical walls, high uniformity and well controlled etch rate.