Reflection high-energy electron diffraction:

Reflection high-energy electron diffraction (RHEED) is another type of diffraction technique used to characterize the surface of crystalline materials.

• RHEED systems gather information only from the surface layer of the sample and hence quite useful to monitor the growth condition of the materials at different stages:
    ☆ Substrate thermal cleaning monitoring
    ☆ Controlling initial growth stage
    ☆ Monitoring surface structure and growth dynamics
    ☆ Growth rate measurement

• The small incident angle makes it sensitive to the structure of top monolayers.

RHEED: Principle of operation:

• RHEED is typically based on the reflection of electrons with high kinetic energy (~ 5 - 100 keV) and low impact angle (< 5°) from the surface of a solid.