The Dependence of Extinction Distance on Deviation from the Bragg Condition in Silicon

The dependence of the (111) and (220) extinction distances in silicon on deviation from the exact Bragg condition has been investigated. The results obtained for the (220) reflection show good agreement with both the two‐beam and multi‐beam dynamical theories. For the (111) reflection, however, the results are in poor agreement with the two‐beam theory and in only partial agreement with the multi‐beam theory. The agreement with the multi‐beam theory is improved when electron scattering factors obtained from recent X‐ray measurements are employed in the multi‐beam calculations.