US Patent 11404461 Anti-reflective layers in semiconductor devices

A Complementary Metal Oxide Semiconductor, CMOS, device for radiation detection. The CMOS device includes a semiconductor diffusion layer having a photodetector region for receiving incident light, and a polysilicon layer having a patterned structure in a region at least partially overlapping the photodetector region. The structure includes a plurality of features being perforations extending through the polysilicon layer or columns of polysilicon, wherein the perforations are filled with, or the columns are surrounded by, a dielectric material.