Migration energy for the silicon self-interstitial

The generation of vacancy-related point defects in low dose 1.3 MeV proton irradiated high purity silicon has been investigated. The dose rate was varied to give a total dose of 5x10(9) cm(-2) at irradiation temperatures from 70 to 295 K. The inverse dose rate effect, i.e., a decrease in the production of room temperature stable vacancy related defects for increasing dose rates, is also shown to be thermally activated and involve long range migration of the silicon self-interstitial. The inverse dose rate effect is utilized to obtain a value of 0.065+/-0.015 eV for the migration energy of the Si interstitial at room temperature and below. This is an experimental estimate of the interstitial migration energy and the low value suggests that ionization enhanced diffusion is important for the motion of Si interstitials. (C) 1999 American Institute of Physics. [S0021-8979(99)08713-7].