Solarus 950 Owner’s Manual and User’s Guide
1
Gatan Advanced Plasma System
Owner’s Manual and User’s Guide
Overview
Optimal imaging and microanalysis in electron microscopy requires a clean, well-
prepared specimen. This is especially important for FEG TEM, because specimen
contamination rates tend to increase as probe size decreases and beam current
density increases. The high performance now possible with the FESEM under-
scores the need for eliminating hydrocarbon contamination, especially for those
applications involving low voltage, high-resolution operation.
An RF-generated gas plasma cleaning process, originating within the semi-
conductor industry for wafer cleaning, has been known and available for some
time. A version of this technique was adapted for EM applications by Nestor
Zaluzek at Argonne National Laboratory and University of Chicago (US Patent
5,510,624, dated April 23, 1996).
The Solarus Advanced Plasma System expands this process to a new level.
Solarus is a low power hydrogen and oxygen radical generator producing glow-
discharge plasma within the generator housing. The hydrogen and oxygen radicals
disperse from the generator by convection, passing over and around the specimen/
specimen holder tip to clean hydrocarbons from the surfaces. The process pro-
duces H
2
O, CO
2
, and CO gases that are pumped away by the vacuum system.
Solarus incorporates a multi-stage diaphragm pump backing a turbomolecular
drag pump to assure fast, reliable pumping. The pump package enables pump and
vent cycles of less than two minutes. With cleaning times of 1-2 minutes, the full
Solarus 950 cleaning cycle takes less than four minutes.
