Radiation damage in InGaAs photodiodes by 1 MeV fast neutrons

Irradiation damage in In_0.53Ga_0.47As p-i-n photodiodes by 1 MeV fast neutrons has been studied as a function of fluence for the first time, and the results are discussed in this paper. The degradation of the electrical and optical performance of diodes increases with increasing fluence. The induced lattice defects in the In_0.53Ga_0.47As epitaxial layers and the InP substrate are studied by Deep Level Transient Spectroscopy (DLTS) methods. In the In_0.53Ga_0.47As epitaxial layers, hole and electron capture levels are induced by irradiation. The influence of the type of radiation source on the device degradation is then discussed by comparison to 1 MeV electrons with respect to the numbers of knock-on atoms and the nonionizing energy loss (NIEL). The radiation source dependence of performance degradation is attributed to the difference of mass between the two irradiating particles and the probability of nuclear collision for the formation of lattice defects.