Abstract: The body of a PIN photodiode is of a silicon semiconductor material. The PIN photodiode has a large area incident surface on which light impinges and is operated at high voltages. In the fabrication of a PIN photodiode, as described, a high concentration of N-type dopant is deposited on the body. It has been discovered that if a phosphorus silicate glass, as a source of N-type dopant, is in contact with a surface of the PIN photodiode body in a high temperature ambient and for an extended period of time, lattice damage on the surface of the silicon body results. These lattice defects are responsible for premature voltage breakdown in the device. In a first method of fabrication of PIN photodiode devices the phosphorus silicate glass is on the silicon surface for about 12 minutes after which it is removed and then any phosphorus atoms in the surface of the body are diffused into the body.