Effects of Damage by 0.8 MeV - 5.0 MeV Protons in Silicon Surface-Barrier Detectors

Changes in the performance of silicon surface-barrier detectors after irradiation with protons at energies between 0.80 MeV and 5.00 MeV have been investigated for fluences up to 1017 protons cm-2. Irradiations of the front, surface-barrier contacts and the rear, ohmic contacts of these transmission detectors were performed. In general, the detector current and noise increased with fluence. When the rear, ohmic contact was irradiated with protons which stopped within the detector, the changes in the current and noise after irradiation were several orders of magnitude smaller than after a similar irradiation of the front contact. For protons with energies greater than about 1 MeV, the detector capacitance decreased at low reverse biases and increased at high biases with increasing fluence. The results indicate that a significant reduction in the increase of detector current and noise can be obtained if the density of radiation-produced defects in the region of the junction is minimized.