Electron beam induced x-ray emission: An in situ probe for composition determination during molecular beam epitaxy growth

An in situ, x-ray emission measurement technique is developed. This technique is demonstrated to measure composition at the monolayer level for the InGaAs/GaAs heterojunction system. This electron beam induced x-ray emission technique is a powerful method for in situ compositional analysis during molecular beam epitaxy (MBE) growth. Unlike the reflection high-energy electron diffraction (RHEED) method, this electron beam stimulated x-ray emission technique affords a new method for the real-time monitoring of the elemental composition while the sample is rotating during growth. The technique exhibits long term reproducibility, and in addition, compares reasonably well with RHEED. Well-characterized standards are required for quantitative analysis of the composition, and knowledge about the electron sampling trajectories is required for accurate elemental analysis at the monolayer level.