RHEED Screens Print E-mail

 

A standard RHEED screen configuration is based on a RHEED screen (phosphorus coated lead glass disk), a RHEED screen holder (for mounting) and a standard UHV window. Optionally, a shutter is available to protect the RHEED screen in case of using agressive gases during the deposition process.

Features:

RHEED screen:

  • The viewing screen utilizes a short persistence (P43) zinc sulfide (Cu activated) phosphor coating on a lead glass, mounted on a standard viewport
  • For electrostatic discharge either an indiumtinoxid (ITO) or an aluminium (Al) coating is used to ensure good electrical conductivity and prevent charging. Especially the Al film prevents stray light from inside the chamber from affecting the RHEED image and enhances the contrast
  • Lead glass is required to absorb the X-rays generated when the high energy electrons strike the screen
  • 6" or 8" CF mounting

RHEED screen holder:

  • The RSH - RHEED screen holder is designed for fast and easy mounting and exchange of RHEED screens. The special shape of the screen holder allows the possibility to mount a RHEED screen on a UHV window without further modifications.
  • The design of the stainless steel mounting brackets also guarantees a reliable electrical and mechanical connection to the system ground.

rsh.jpg

RHEED screen shutter:

  • Rotary-actuated shutter assembly to protect RHEED screen from depositing materials
  • 90° swing type shutter, cover >80° of viewport window
  • 6" or 8" CF mounting

window-shutter.gif

Applications:

RHEED screens are mainly used within MBE and PLD deposition system where single crystalline layers are prepared. From RHEED oscillations the growth rate can be precisely determined as well as lattice mismatches in heteroepitaxial systems.

Product description:

RHEED screens are used to display RHEED patterns (see picture on the righthand side) obtained from the diffraction process initiated by electrons hitting a single crystalline substrate under crazing angle with high kinetic energy. Fluorescence effects in a thin phosphorus layer make each spot visible. By using a video camera system the RHEED data can be recorded and evaluated (SAFIRE) accordingly. Depending on the material system used in the preparation chamber indiumtinoxid (ITO) or aluminium (Al) coated screens are used. The RHEED screen is an essential part of a complete RHEED system.
rheed-screen.jpg

 

 
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