|
OMICRON Product Line
FOCUS Photoemission Electron Microscopes (PEEM)
The PEEM essentially consists of an imaging electrostatic lens system and a UV light source
for the creation of photoelectrons via photoemission. The photoelectrons emitted from the surface are imaged onto a channelplate for amplification and finally onto a fluorescent screen
for direct inspection or observation using a CCD camera. In contrast to an SEM, the PEEM does not use a scanned probe beam, but the sample surface is uniformly illuminated by, e.g.,
UV light or X-rays. This way beam induced damage of delicate surfaces is avoided. The magnified image of the surface can be observed directly and in real-time (even video
frequency, if the photon intensity is sufficient) on the fluorescent screen.
With respect to it’s parallel image acquisition, the basic principle of operation is similar to an
optical microscope. However, since electrons are used for imaging the resolution is no longer limited by the wavelength of the photon beam. Instead, a high electrostatic field between the
sample and the objective lens accelerates the electrons released to energies of typically 10 to 15 keV. Thus a lateral resolution of up to 20 nm can be gained.
Applications
This product is part of the OMICRON Product Line
|
