US Patent 10157946 Method for forming CMOS image sensor structure

A semiconductor device is operated for sensing incident light and includes a substrate, a device layer, a semiconductor layer and a color filter layer. The device layer is disposed on the substrate and includes light-sensing regions. The semiconductor layer overlies the device layer and has a first surface and a second surface opposite to the first surface. The first surface is adjacent to the device layer. The semiconductor layer includes microstructures on the second surface. The color filter layer is disposed on the second surface of the semiconductor layer.