PRECISION, ACCURACY AND RESOLUTION OF STRAIN MEASUREMENT WITH ELECTRON MICRO-DIFFRACTION. J.M. Zuo, Dept. of Physics and Astronomy, Arizona State University, Tempe, AZ 85287

Electron microdiffraction formed with a convergent beam is capable of probing crystalline strain filed associated with mismatching interfaces and grain boundaries in nanometer resolutions. The diffraction pattern formed with diskes containes both low order structure factor and lattice parameter information. However, application of electron microdiffraction is complicated by the dynamic effects or multiple scattering in electron diffraction. It has been shown that under weak scattering conditions in a off zone axis orientation the position of high order zone lines (HOLZ) (similar to the Kossel lines in x-ray) can be approximated kinematically. In cases where the choice of diffraction condition is limited by the nature of strain field, for example, edge on orientation in the case of interface, effects of dynamic scattering in the HOLZ line positions need to be estimated and taken into considerations in the simulation. Examples in and off zone axis cases will be given together with the practical applications in semiconductor interfaces. A simple practical procedures in diamond and zincblende structures will also be described. The recent developement of 25 micron pixel imaging plates for electrons makes it possible to record whole electron diffraction with sufficient resolution digitally. The pixel registry of imaging plates plus the intensity data make it possible to analyse the whole pattern geometry with sufficient accuracy. Its benefit for the strain measurement will be discussed together with other possibilities with this new detector.