The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

SCEM Projects

The Scanning Confocal Electron Microscope
US. Patent # 6,548,810

Filed August 1, 2001
Issued April 15, 2003

In today's technologically driven society, many important electronic, magnetic, and photonic devices are being manufactured at a continuously decreasing scale. To maximize component density and further decrease size, such devices also are being fabricated as multi-layered , partially metallized structures. A well known example is the microelectronic or device/ integrated circuit, which can have from one to five or more layers in a structure that may be only 2-10 microns thick. Within the individual layers of this device, important features can range in size from about 100 micrometers to 10's of nanometers. This regime of materials, thickness and resolution is beyond reach of conventional optical microscopy, but is critically important to the materials science, microelectronics and the new emerging nanoscience communities.

The Scanning Confocal Electron Microscope (SCEM), is an electron-optical implementation of the Scanning Confocal Optical Microscope (SCOM) which permits the observation and characterization of sub-surface structures of thick, optically opaque materials. The device merges the concept of confocal imaging with the ease of use of the Scanning Electron Microscope (SEM), the penetration ability of the scanning, transmission and x-ray microscopes, and achieves unprecedented resolutions in optically dense materials. It provides both large fields of view as well as a nanometer scale spatial resolution. Under appropriate conditions depth slicing through the specimen is possible. The SCEM can function as much as 100 times faster than the STXM, yet can be constructed for only a fraction of the cost.