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Surface Analysis

Scienta ESCA-300

The Scienta ESCA 300 is generally regarded as one of the best XPS instruments in operation today. A combination of design factors permit data to be obtained from samples rapidly without sacrificing energy resolution. A basic summary of the instrument is provided below. A more detailed description of the Lehigh Scienta ESCA300 together with some examples of work done on the instrument can be found here:

Basic facts

X-ray source: Monochromatic Al Ka x-rays generated from a rotating anode which can operate at power levels of up to 7.5 kW. The monochromator consists of seven crystals mounted on three Rowland circles. The x-ray spot is a line >5mm long and >1mm wide.

Energy analyzer: High resolution 300 mm mean radius hemispherical electrostatic analyzer designed for high throughput with small solid angle acceptance for enhanced angle resolved XPS capabilities.

Detector: Multi channel microchannel plate-CCD camera combination.

Charge compensation: Non-line-of sight monochomatic low energy electron flood gun

Sample stage and manipulation: 5 axis computer controlled precision manipulator. Sample heating to >600°C and sample cooling to -100°C.

Sample analyses: Multiple sample analysis and unattended operation are available by programming the sample positions and analysis sequences. This can include full sets of angle resolved analyses. Sputter depth profiling is also possible. After suitable training, investigators may operate the instrument and analyze their samples, or, if more convenient, the samples can be sent to Lehigh for analysis.

Analyzed area: The nominal analyzed area is rectangular with approximate dimensions of 4 mm x 0.2 mm for a total area of about 0.8 mm&sup2. The size of the analyzed area can be adjusted electronically and mechanically. The minimum practical area for routine sample analysis is about 0.5 mm x 0.1 mm.

In situ sample preparation: The sample chamber and/or attached chambers provide the ability to heat specimens to >1000°C without the use of electron bombardment, expose surfaces to various vacuum compatible reactant gases, deposit thin films from a precision Knudsen cell and monitor the thickness with a crystal monitor, monitor the vacuum with an RGA, fracture brittle samples in situ, sputter clean surfaces, and scrape surfaces in UHV. The sample entry chamber, which can have base pressures in the low 10 -8 torr range, can be used to carry out experiments at temperatures >400°C at pressures ranging from 10 -8 to 700 torr.

Sample types: Virtually any material with outgassing rates that allow the pumps to maintain pressures of 10 -7 torr or lower can be analyzed. In the past, this has included a number of unusual materials including fabrics, skin, and hair.

Data analysis: DOS based or Windows based software is available free-of-charge to carry out the data analysis. Either program can be used to export the data as text files that can be imported into other data analysis software. Data can be taken at Lehigh and e-mailed to the user if desired.

Scope of effort: Most work is done on a sample by sample basis at an hourly or daily rate. Small projects that may take a few days to a few weeks of instrument time are also welcomed. The cost of this approach is taken on a case by case basis. Within limits, it may be possible to accommodate modifications to the instrument which will allow specific experiments to be carried out in situ.

Inquiries regarding technical aspects of the instrument, availability of instrument time and the extent to which changes can be made to accommodate special experimental needs should be directed to:
Dr. Alfred Miller
(610)758-3563 or (610)758-3603
acm0@lehigh.edu

Inquiries regarding pricing should be directed to:
Gene Lucadamo
(610) 758-4855
eal7@lehigh.edu