Ion Bombardment of Silicon

Abstract

When silicon plates were bombarded with protons of energies about 100 kV, the infrared absorption spectrum above 1.1 μ showed chromatic fringes corresponding approximately to the range of the protons. The fringes did not begin to disappear on annealing until the plates were heated to over 1100°C. The effect appears to be caused by a reflecting layer involving trapped hydrogen. After long irradiation, small flatbottomed pits were found of about the depth of the range. The effect could also be produced with helium ions on silicon. No effect was found with germanium.