A method for investigation of light-element distribution in the surface layers of semiconductors and dielectrics

The density profiles of light elements (hydrogen, carbon, oxygen) in the surface layers of solids have been investigated by analysing the spectra of recoils from elastic scattering knocked out of the lattice by heavier projectiles. The method and its implementation with heavy-ion beams from a cyclotron are described. Various limiting factors in the depth resolution of the method are analysed. Particular attention is given to the effect of surface roughness. The application of the method to investigation of the density profile of hydrogen, carbon and oxygen in semiconducting and dielectric compounds (a-Si:H, a-Si1-xGex:H, a-Si1-xCx:H, Al2O3 and Ta2O5) is described.