AbstractA comparative study of the effect of pulsed γ-neutron irradiation on the photosensitivity spectra of Si p – n photodiodes with active layers based on self-assembled GeSi nanoisland arrays and Ge epitaxial layers is performed. The irradiation of photodiodes with GeSi nanoislands is found to not lead to photosensitivity degradation in the spectral region of interband optical absorption in nanoislands (wavelength range of 1.1–1.7 μm). At the same time, a steady decrease in the intrinsic photosensitivity of Si and the photosensitivity of photodiodes based on Ge epitaxial layers with an increase in irradiation dose is observed. This effect is attributed to the accumulation of radiation-induced defects in the Si matrix and deep in Ge epitaxial layers, respectively.

A comparative study of the effect of pulsed γ-neutron irradiation on the photosensitivity spectra of Si p–n photodiodes with active layers based on self-assembled GeSi nanoisland arrays and Ge epitaxial layers is performed. The irradiation of photodiodes with GeSi nanoislands is found to not lead to photosensitivity degradation in the spectral region of interband optical absorption in nanoislands (wavelength range of 1.1–1.7 μm). At the same time, a steady decrease in the intrinsic photosensitivity of Si and the photosensitivity of photodiodes based on Ge epitaxial layers with an increase in irradiation dose is observed. This effect is attributed to the accumulation of radiation-induced defects in the Si matrix and deep in Ge epitaxial layers, respectively.

3D Monte-Carlo algorithm and computer code have been developed that allows choosing and optimizing the conditions of ion irradiation needed for the adequate ion-beam simulation of radiation damage under fast neutron irradiation. It is established that, by the proper selection of energy and dose of Si+ ions, it is possible to reproduce well the effect of irradiation with fission neutrons of subsurface and buried layers of silicon or Si-based 2D and 3D-heterostructures. The results can be used for testing the radiation hardness of silicon-based electronic and optoelectronic device structures.

The effect of neutron radiation on the electroluminescence of the Si p-i-n diode containing a multilayered Ge/Si heterostructure with self-assembled nanoislands is studied. In comparison with bulk Si, the diodes containing Ge(Si) nanoislands exhibit a higher radiation hardness of the electroluminescence signal, which is attributed to spatial localization of charge carriers in the Ge/Si nanostructures. The spatial localization of charge carriers impedes their diffusion to radiation defects followed by nonradiative recombination at the defects. The results show the possibilities of using Ge/Si heterostructures with self-assembled nanoislands for the development of optoelectronic devices resistant to radiation.

A comparative study has been carried out of the radiation exposure influence on the surface morphology of siliconon-insulator and silicon-on-sapphire device structures. Before the exposure to radiation, the surface morphology of silicon films had a block nature with very much pronounced mosaic structure and average roughness of about 25 nm. Electron and X-ray radiation led to distinct relief smoothing of silicon film surface of SOI and SOS structures resulting in a more uniform nature of the surface microrelief. Thus, the radiation exposure made it possible to modify the surface morphology of silicon heterostructures.

There is described the possibility to use a special optical system based on using a powerful semiconductor continuous wave laser as a power source.