Investigation of III-V Superlattices and Heterostructures by Convergent-BeamElectron Diffraction

摘要

The Convergent Beam Electron Diffraction (CBED) technique is developed and usedfor the evaluation of III-V semiconductors (with emphasis on GaAs/AlAs superlattices and GaInAsP heterostructures). The theory of CBED computation is outlined. Particular attention is given to the investigation of GaAs/AlAs multilayers. The fine structure of the First Order Laue Zone (FOLZ) reflections in CBED patterns of GaInAsP heterostructures is investigated. By using many beam dynamical calculations, the features in FOLZ reflections are explained. The effect of various parameters on the fine features in FOLZ discs is discussed and values of some parameters are estimated from the CBED patterns. The effect of illumination coherence as a first step to future CBED work is considered.