The origin of non‐Gaussian profiles in phosphorus‐implanted silicon

The origin of the tail on the distribution of phosphorus atoms implanted into misaligned silicon crystals has been established by measuring the number of phosphorus atoms transmitted through thin silicon crystals during implantation. Experiments on 〈110〉 and 〈100〉 crystals show that the tail is due entirely to atoms which are scattered into channels. The preparation of crystals 0.4–0.8 μm thick from epitaxial layers by selective electrochemical etching and ion beam thinning is described and the measurement of their thickness by backscattering techniques is discussed. It is suggested that the tails on the profiles of other dopants in silicon are also due to atoms which have entered channels in the crystals.