Scientific instrument calls for special positioning stage
East Grinstead based Thermo VG Scientific has added the Theta Probe to
its portfolio of special scientific research and measuring instruments.
The machine directs a beam of X-rays to a 300mm diameter sample target
(semiconductor material, for example), and from the energy of emitted
photoelectrons is able to analyse surface impurities and layer thickness,
without destroying the sample. previous machines were only able to
analyse up to 70mm diameter samples.
Key to the process is the machine’s ability to position samples with
great precision for accurate surface analysis. This is achieved by a
multi-axis stage with X, Y and Z axes supplied by Heason Technologies.
The X and Y axes are used to position samples for sequential zone
analysis, while the Z axis aids focusing to compensate for sample
thickness.
Special features of the stage include its ability to operate in an
ultra-high vacuum (UHV) environment (1 x 10 -10 Torr) and the use of high
precision piezo ceramic motors with low magnetic characteristics.
Non-contact linear encoders provide a resolution of 0.1micrometre and all
mechanical parts are UHV rated to eliminate outgassing.