Photoelectron emission
(PEEM) is a potentially powerful technique for real-time, sub-micron
imaging of organic, metal and semiconductor electronic devices.
It is non-intrusive with broad imaging capabilities, but application
has been limited due to lack of understanding of imaging contrast
mechanisms. More refined control of sample positioning was necessary
to further understanding of some of these mechanisms
We are using a newly developed* 5-axis nonmagnetic
in-vacuum stage for micron-scale positioning of samples we investigate
with PEEM. This compact in-vacuum system has eliminated vibration
problems, while the piezo-driven motors give consistent, repeatable
control of sample position with linear step size 1µm and an
angular step of 1/360°.
For example, precise measurements of angle with respect
to the microscope axis are now possible. Below are shown images
demonstrating the strong effect of small variations in the angular
orientation of the sample with respect to the normal. The 16 µm
wide raised lines on this titanium sample are 1/2 µm tall.
The sample is tilted 1/3° with respect to the PEEM axis in the
left and right images; the bright edge is tipped toward the microscope.
The center image shows the sample oriented normal to the PEEM.
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