EFFECTS OF ELECTRON BOMBARDMENT ON GERMANIUM (in Japanese)
Two studies of radiation effects on germanium were done. First, the effects of 1-Mev electron bombardment on conductivity of about 10 ohm-cm n-type, 1.8 ohm-cm p-type, and CO ohm-cm undoped thin germanium single crystals were investigated. The observed initial carrier removal rates were 0.12 cm/sup -1/ for n-type Ge and 0.43 cm/sup -1/ for p-type Ge. For undoped-Ge, the increment of carriers was observed. If this increment was due to holes, the rate was 6.0046 cm/sup -1/ and agreed with the rate of the introduction of holes in n-type samples. The number of the displaced atoms was calculated by the use of the model of Seltz and Koehler, and the energy level scheme of the radiation-induced defects was estimated. The levels consisted of an electron trap 0.11 ev below the conduction band, a hole trap 0.10 ev above the valence band, and an acceptor level 0.29 ev above the valence hand. Second, the change of electric conductivity of n-type germanium single crystals with a local irradiation by 4.2- Mev electrons and its isothermal annealing were studied. Sb-doped 2 to 3 ohm-cm and undoped about 20 ohm-cm specimens, 0.4 to 0.5 mm thick, were bombarded at about --180 deg C and heated at 78 deg C or 150 deg C. A linear accelerator provided bombarding electrons, about 4 x 10 /sup 15//cm/sup 2/. The conductivity of the doped sample at the exposed region showed an ordinary change with integrated flux, but at the unexposed region, it decreased after a small increment. The rate of annealing of the locally irradlated region of samples was larger than that of the uniformily irradiated region. This phenomenon was predominant in the outer area of the exposure. Application of an electric field of about 10 volts/cm seemed to affect the changes at both regions. From these results, it was concluded that some of the radiation-induced defects were mobile in the crystal over a long range. (JAIF)
- Research Organization:
- Government Industrial Research Inst., Nagoya
- NSA Number:
- NSA-17-030129
- OSTI ID:
- 4698650
- Journal Information:
- Proc. Japan Conf. Radioisotopes, Vol. Vol: 5th, No. 3; Other Information: Orig. Receipt Date: 31-DEC-63
- Country of Publication:
- Country unknown/Code not available
- Language:
- Japanese
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