Measurement of small elastic strains in silicon using electron channeling patterns

Abstract

A silicon single-crystal slab 0.15 mm in thickness was bent to produce small, nonuniform surface strains of the order of 0.2%. The electron channeling patterns were observed in a JSM 840 SEM (scanning electron microscope) at an accelerating voltage close to 25 kV. Proper choice of the triangles formed by intersecting channeling lines of zero-order and of higher-order Laue zones allows one to measure the changes in their dimensions caused by imposed strain. It was estimated that the lower limit of detectable elastic strain is close to 0.1%. The possibilities of using this method for estimation of the average elastic strains in thin epitaxial layers are discussed.