Accession Number:

AD0643268

Title:

RADIATION EFFECTS IN SILICON AND GERMANIUM.

Descriptive Note:

Final rept.,

Corporate Author:

NORTRONICS NEWBURY PARK CALIF APPLIED RESEARCH DEPT

Personal Author(s):

Report Date:

1966-11-01

Pagination or Media Count:

155.0

Abstract:

Measurements indicate that oxygen concentration does not affect lifetime degradation in neutron-irradiated silicon. Type and amount of dopant is also unimportant in n-type material and plays only a limited role in p-type silicon with resistivities less than approximately 5 ohm-cm. The dependence of lifetime on both carrier concentration and temperature indicates that simple recombination theory is not followed alternate possibilities for explaining the results are proposed. Carrier concentration and mobility in neutron-irradiated silicon are more seriously affected by oxygen, dopant, and possibly other factors, especially in n-type material. The dominance of the disordered region in recombination is indicated in several ways, including behavior of short-term annealing. Measurement of the dependence of lifetime on injection level has proved very effective in obtaining recombination level parameters. The dominant recombination level at low excitation in both neutron- and gamma-irradiated germanium has been found to be E sub r - E sub v 0.34 eV with almost no dependence on dopant. Evidently the effective energy level position of the recombination center is unaffected by the disordered region. A second level at E sub c - E sub r approximately 0.2 eV is required to explain the dependence of lifetime on injection level at high excitation. Comparison with measurements of the temperature dependence of lifetime indicates a temperature variation of electron capture probability. Author

Subject Categories:

  • Radioactivity, Radioactive Wastes and Fission Products
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE