Analysis of the Effect of Radiation Defects by Low-energy Protons on Electrophysical Properties of Silicon N+ -P-P+Structure

Abstract

Nowadays, radiation engineering is a promising direction in the creation of semiconductor devices. The proton irradiation is used to controllably change the optical, electrical, recombination, mechanical and structural properties of the semiconductors. Low-energy protons make it possible to purposefully change material properties near the surface where the n+ -p junction is located. In this paper, the impact of low-energy protons on the electro physical parameters of n+ -p-p+ silicon photoelectric converters (SPC) is analyzed. The current-voltage characteristics and switching time of these SPCs are measured. The switching time is determined using rectangular bipolar voltage pulses with an amplitude of 10 mV, a frequency of 200 kHz, or a frequency of 1 MHz. A theoretical and experimental analysis of the obtained results is performed. The comparison of experimental data with the results of calculations shows that protons with an energy of 180 keV and a dose of 1015 cm–2 create two regions in the space charge region of the n+ -p junction with different switching times of 4.2 × 10–7 s and 5.5 × 10–8 s. SPC frequency characteristics have been improved by reducing the effective lifetime by 5-10 times. This effect can be used to create high-speed photodiodes with an operating modulation frequency of 18 MHz.