Wednesday, May 08, 2024
Debugging: 10x10 grid of 20nm squares
Scrappy innit? I could tell from the microscope that the probe was tracing out a square, however point contact is a bit patchy - don't expect to see individual 20μm squares as this is a rigid chonky tip.
As this was scanned in both X and Y, we can pretty clearly see that the probe is too high in the top right corner of the image. Rough sums as follows:
Height of stage: 75mm
Travel from centre to endstop: 2mm
Therefore Pythagoras tells us 0.025mm height variation on the flexure stage.
We're moving 0.2mm here, so we'd expect a height variation of roughly 2.5μm, which feels about right. A few more test patterns required, and a way of actually making sure I'm properly centred to get some consistency. Perhaps a pattern of groups of concentric squares varying in height?
