Fig 1.
NIEL values for the proton, neutron and electron irradiation of silicon.
This plot confirms that the NIEL values calculated using the PHITS model were in good agreement with the data obtained from the SR-calculator [12].
Fig 2.
Defect production efficiencies as functions of the cascade damage energy for SiC, GaAs, GaN and InAs.
The surviving probabilities of defects for the arsenic compounds GaAs and InAs evidently increase along with the damage energy and this increase is nonlinear over the energy range from 1 to 20 keV.
Table 1.
Material constants used for the calculation of damage production.
Ed values for SiC [16], GaAs [17], GaN [18] and InAs [19] were obtained from the literature.
Fig 3.
Particle energy spectra of radiation sources for a low-Earth orbit (left) and for deep space (right). The GCR and TP fluxes are included in low-Earth orbit and the GCR fluxes are included in deep space. Note that electrons in space-based radiation are ignored in the current version of PHITS.
Fig 4.
Calculated DDD geometry for a semiconductor exposed to cosmic rays as determined in the PHITS code.
In this diagram, space-based radiation is emitted from the surface of the sphere towards the center. The device comprises a glass cover made of SiO2, a semiconductor and an aluminum plate. The thickness of the glass cover was varied from 0 to 800 μm.
Fig 5.
NIELeff and NIELconv values for the proton and neutron irradiation of semiconductors as calculated using the PHITS code.
Fig 6.
Recoil energy spectra produced by the reaction of 10−11 MeV neutrons incident on 14N atoms.
Fig 7.
NIELeff / NIELconv ratios for semiconductors in response to proton and neutron irradiation.
Fig 8.
DDDeff and DDDconv values for low-Earth orbit and deep space.
Fig 9.
DDDeff / DDDconv ratios for low-Earth orbit and deep space for SiC, InAs, GaAs and GaN.
Table 2.
DDDeff, DDDconv and DDDeff / DDDconv for SiC, InAs, GaAs and GaN exposed to cosmic rays in low-Earth orbit and deep space.
Fig 10.
DDDeff values for InAs in a low-Earth orbit as a function of the thickness of a glass cover.
A glass cover with a thickness of approximately 200 μm is sufficient to decrease the effect of low-energy protons and so reduce displacement damage in semiconductors.