Lake Shore Cryotronics CRX-6.5K, Руководство пользователя

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22 CHAPTER 2: System Overview
Model CRX-6.5K Probe Station
FIGURE 2-17 compares the resolution of the two microscopes under similar
conditions in a TTPX probe station. Although the Zoom 160 image has visibly more
resolution in this comparison, it is important to note that these results are difficult to
duplicate during actual measurements. Factors such as the sample surface texture
and normal levels of room vibration can quickly degrade the resolution of the Zoom
160 to match that of the Zoom 70.
2.3.6.2 Lighting Types
There are two types of lights available for each microscope, coaxial and ring. The
primary difference between the two is in the way light is reflected off of the sample
surface into the microscope.
The coaxial light configuration guides light from the light source along the same path
(coaxially) with the light returning from the sample. This allows the vision system to
image very highly reflective samples such as those patterned on polished silicon.
FIGURE 2-18 (left) is an image of four gold circles (10 µm to 100 µm in diameter)
patterned on a highly reflective surface illuminated with a coaxial light. Although the
image appears relatively flat and has modest contrast, it is more than adequate for
properly landing probes. FIGURE 2-18 (right) is an image of the same sample
illuminated with a ring light. The image is darker and even lower in contrast because
nearly all of the light is cleanly reflected away from the microscope. It would be
difficult to properly land a probe using this image.
FIGURE 2-17 Left: Best case resolution (approximately 2 μm) obtained with Zoom 160 and coaxial light on a TTPX probe station; Right:
Typical resolution (approximately 3 μm) obtained with Zoom 70 and coaxial light on a TTPX probe station
FIGURE 2-18 Left: Highly reflective surface through a Zoom 70 with a coaxial light;
Right: Highly reflective surface through a Zoom 70 with a ring light