A semiconductor device contains a photodiode formed in a substrate of the semiconductor device. At a top surface of the substrate, over the photodiode, a surface grating of periodic field oxide in a periodic configuration and/or gate structures in a periodic configuration is formed. The field oxide may be formed using an STI process or a LOCOS process. A semiconductor device with a surface grating including both field oxide and gate structures has the gate structures over the semiconductor substrate, between the field oxide. The surface grating has a pitch length up to 3 microns. The surface grating covers at least half of the photodiode.