Development of a Local Electrode Atom Probe

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9703932 Kelly This award provides partial support for a development program to build and test an new analytical instrument, a local electrode atom probe (LEAP). This instrument will use very high electric fields applied to a surface to field evaporate atoms and accelerate them toward an imaging detector. The atom type is determined by time-of-flight mass spectrometry for each atom. A three-dimensional image which is made up of the atom positions and identities is then reconstructed from the data. Unlike prior instruments of this genre, the LEAP will have the capability to obtain these images from planar samples. It will also be able to record the data orders of magnitude faster than previous instruments. This higher speed and planar specimen geometry will make the LEAP technique able to tackle new problems which have previously been out of reach. It is expected that this LEAP will be able to do many of the jobs that previously would have been done with a secondary ion mass spectrometer (SIMS) and it will do them with atomic-scale spatial resolution. The specimen geometry for this microscope is such that it is realistic to fabricate and analyze specimens from whole classes of materials which have been off-limits in the past. Semiconductors, insulators, thin film structures on planar substrates, and even microelectronic devices are examples. A couple of intractable problems in the microelectronics industry are specifically targeted in this project because of their technological and economic significance and because they will serve as prime illustrations of the power of the technique. Successful analysis of these materials problems is a goal of this program. The combination of these capabilities will produce a technological breakthrough in materials characterization. ***