Study of the Anisotropy of Radiation Damage Rates in n-Type Silicon

Abstract

Consideration of the factors influencing electron radiation damage has led to the development of a computer program to predict damage rates as a function of electron beam energy and crystal orientation with respect to the beam. Experimental results using low-energy electrons (in the range 100–400 keV) are presented, which show the carrier removal rate as a function of sample orientation and electron beam energy. These measurements supplement the earlier results of Haddad and Banbury. Comparison of the calculated and experimental results enables us to make suggestions about the form of the displacement energy as a function of direction in the crystal, and to determine an effective threshold energy of 22 eV. Our model of the displacement-energy profile is justified in a simple manner from crystallographic considerations.