Electrophysical Parameters of PIN Photodiodes Irradiated with ⁶⁰Co γ-Quanta

Abstract

The results of studies of the changes in the electrophysical parameters of PIN photodiodes made on monocrystalline silicon wafers of the p-type of conductivity of orientation (100) with ρ = 1000 Ohm cm, when irradiated with γ-quanta from a ⁶⁰Co source, are presented. It is established that as a result of the irradiation of the PIN photodiodes doses up to 2 × 10¹⁵ quanta/cm² results in an increase in the reverse dark current by more than an order of magnitude. However, the shape of the curve of the dependence of the current on the applied reverse voltage of irradiated PIN photodiodes does not change qualitatively, just as for the original devices, there are three regions with different dependencies of the current on voltage—sublinear, superlinear, and linear—caused by different mechanisms of the generation-recombination processes in the depletion region of the p–n transition. The main reason for the increase in the reverse current of PIN photodiodes as a result of the irradiation of γ-quanta is the formation of the generation-recombination centers of radiation origin due to the condensation of the primary radiation defects (vacancies and/or self-interstitial atoms) on the technological residual structural defects formed both during the growth of silicon single crystals and during subsequent high-temperature treatments during the formation of devices.