​ Abstract: Radiation degradation during γ-irradiation of discrete low-power thyristors, both control (Si) and investigated SiGe-fabricated, is a complex nonlinear process that is individual for each device. It is possible to distinguish three γ-irradiation ranges, in which the degradation of the average holding current for control and investigated thyristors proceeds in different ways. For Dγ ≈ 1·10 ¹ …1·10 ² mSv there is a decrease in Ih(Dγ) for control Si devices, possibly connected with the "low-dose effect" for SiGe devices, there is an increase in the holding current, therefore, no "low dose effect". Range Dγ ≈ 1·10 ² …1·10 ⁴ mSv can be considered as an area of unstable operation of the control thyristors in the γ-radiation field, devices made with SiGe are sufficiently more stable. For Dγ ≥ 1·10 ⁴ mSv there is an expected increase in Ih(Dγ) for Si thyristors, devices, manufactured with SiGe continue to be more stable. When Dγ ≈ 1·10 ¹ …1·10 ⁴ mSv use of SiGe makes it possible to increase the average interval radiation resistance of thyristors by approximately 7 %, and in the range of Dγ ≈ 1·10 ⁴ …1·10 ⁶ mSv ≈ up to 12 %.

Keywords: Individual nonlinear process, Discrete low-power thyristor, Radiation degradation, Average interval radiation resistance, SiGe.

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