• Effusion cells
• Components
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• Water Cooling Systems
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• Beam Flux Monitor
• Transfer Systems
• Manipulators
• Heaters
• Substrate Holders
• RHEED Systems
• RHEED Screens
• RHEED Software
• MBE Software
• Power Supplies
• Bake Unit
• UHV-Systems
• LT-STM-System
• Catalogue

The CreaTec reflection high-energy electron diffraction (RHEED) system HP-4 is widely used as an in-situ characterization tool in molecular beam epitaxy (MBE) due to its compatibility with the growth process. Its main application is the determination of growth rates and the study of growth dynamics through RHEED intensity oscillations.

The electron gun is designed to deliver a very high quality beam under realistic MBE conditions. This is achieved by several beam alignments that can be adjusted while the gun is operating. The position of the electron beam source can be varied to center the brightest spot of the filament on the optical axis. The first set of deflection plates then eliminates any deviation of the beam direction. And finally, the aperture manipulator allows the exact alignment of the electron beam with the axis of the magnetic lens for minimum aperrations. Selectable apertures reduce the beam diameter and divergence, while the electron source is operated at its optimum for minimum energy spread. This results in superior FWHM and transfer width of the diffraction pattern. Electrostatic deflection is used throughout for maximum stability and minimum beam distortion. The internal electromagnetic shielding greatly reduces the influence of stray fields, the most importent noise source in RHEED experiments.

• LaB6 cathode
• Differential pumping
• Higher precision
• Internal 16 bit DAC control of gun parameters with PC interface