Facilities

LEAP 4000 HR

The LEAP 4000 HR (Local Electrode Atom Probe) was originally developed by IMAGO (now a part of CAMECA) in Madison, USA.The LEAP provides a local electrode with a diameter of 25 microns, which allows the analysis of smaller samples, especially micro tips on coupons. Nevertheless it is still possible to analyze wire shaped samples.

Due to the local electrode design the LEAP is best suited for analysis of micro tip coupons. Such coupons are typically a doped Silicon substrate with several small needles on top of it. These needles can be either substrates for deposition of multilayer structures or posts for samples prepared by the Focused Ion Beam (FIB) with the "lift out"-technique. The Local Electrode bears one huge disadvantage, though. It has to be renewed frequently because it is damaged by larger chunks from the tips which are ripped off because of specimen failure.

The device can be operated either in voltage or in laser pulse mode. For laser mode a pulsed picosecond UV unit is available.

The integrated reflectron increases the mass resolution, but has a negative impact on the detection efficiency. Furthermore the spatial resolution is typically lower than in  the LAWATAP. When an extremely high resolution or a high detection efficiency is required, the LAWATAP is the better choice.

An advantage over the LAWATAP is the larger field of view. This results in much larger volumes to be available for analysis. The number of detected atoms in a measurement is typically one order of magnitude larger than at the LAWATAP. It is thus best suited for analysis of concentration gradients.

For more information visit the website of the manufacturer: http://www.cameca.fr/instruments-for-research/atom-probe.aspx


The LEAP 4000 HR