Characterization of strain in crystal bilayers using ion-channeling patterns

This paper describes the experimental and theoretical simulation, the observation and the quantification of strain present in crystal bilayers using ion-channeling patterns produced-by a focused 3 MeV proton beam. The dechanneling effects of strain are first experimentally simulated using different rotation angles between two individual, 0.3-mu m-thick, [100] silicon crystals. The patterns produced when both crystals are aligned close to the [100] axis, with a small rotation angle at the interface, are considered in detail using Monte Carlo computer simulations. Previously unobserved effects occurring in channeling patterns are discussed and general conditions under which different behavior is observed are described. Channeling patterns recorded through a thinned Si0.85Ge0.15/Si crystal bilayer are then used to characterize the interface rotation angle dong several off-normal axes.