Suppression of irradiation effects in gold-doped silicon detectors

Abstract

Two sets of silicon detectors were irradiated with 1 MeV neutrons to different fluences and then characterized. The first batch were ordinary p - i - n photodiodes fabricated from high-resistivity silicon, while the second batch were gold-doped power diodes fabricated from silicon material initially of low resistivity . The increase in reverse leakage current after irradiation was found to be more in the former case than in the latter. The fluence dependence of the capacitance was much more pronounced in the p - i - n diodes than in the gold-doped diodes. Furthermore, photo current generation by optical means was less in the gold doped devices. All these results suggest that gold doping in silicon somewhat suppresses the effects of neutron irradiation.

Differences in Calibration Factors of a Neutron Diode Dosimeter at Different Facilities

“…In addition, because the external voltage applied to a PIN diode is expressed as a proportional relationship like Equation (2) [3], [4], neutron fluence in the above Equation (1) is inversely proportional to the charge of carrier lifetime in the device. The applied voltage is inversely proportional to the carrier lifetime from the relation of diffusion length and Equation (2).…”

Radiation Response of Forward Biased Float Zone and Magnetic Czochralski Silicon Detectors of Different Geometry for 1-MeV Neutron Equivalent Fluence Monitoring

“…Therefore a maximum range of few has been evaluated. At such high fluences one can consider that for these types of detectors the relaxation regime [20]- [27] is already established (as for the BPW34FS diode, see [2]), since the modification of the curve shape indicates that the device becomes ohmic-like. This effect can also be observed for thicker detectors as it is illustrated in the next sections.…”

Depth Analysis of Crystalline Silicon Used for Radiation-Hard Detectors

“…In order to improve the properties of the devices, the silicon material can be doped with metals such as gold, platinum, erbium, or niobium [4][5][6][7][8][9][10][11]. These metals are responsible for a change in material behaviour from lifetime to relaxation [9][10][11].…”

“…These metals are responsible for a change in material behaviour from lifetime to relaxation [9][10][11]. In relaxation material, τ D τ 0 while in lifetime material, τ D τ 0 [12][13][14][15].…”

“…Here, τ D is the dielectric relaxation time and τ 0 is the minority carrier recombination lifetime [12][13][14][15]. In relaxation material the effects of radiation are suppressed [5,9] such that the damage is minimal. In this case the Fermi level of the material is not affected by any incident radiation [16].…”