Dim. Edge scanner calibration - max accuracy in Normal- & SmallScan-mode

MilanP posted on Thu, Mar 30 2017 11:44 AM

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Dim. Edge scanner calibration - max accuracy in Normal- & SmallScan-mode

Hello,

I have a document entitled "DIMENSION EDGE INSTALLATION AND TEST PROCEDURE", in which there is a procedure how to properly calibrate a Dimension Edge AFM microscope. The last step of a calibration is to manually edit the "SGSCANNER.SYS" file (Step 4.6). According to this document, I should calculate LowGain values from HighGain values and replace them. This is the part I have a problem with. The formula is simple. I should take appropriate voltage from HighGain section and multiply it with (2.5/11), where 2.5 is the total range in z-direction in Small Scan mode and 11 is the total range in Normal mode. The problem is that, when I switch to Small Scan mode and use this calibration file with new calculated LowGain values, the total range in z-direction will be 11.2 um (from -5.6 to 5.6 um). The total range should, however, be 2.5 um in this mode, as I used this value in my calculation and according to the document this is the value I should use for LowGain section.

Another thing is that in Step 4.6 of this document there is an example showing how to calculate the values for the LowGain section. According to this example I should replace old value of the voltage for LowGainNonlinearized section (16.5759) with newly calculated one (4.0972). The calculated value (4.0972) is much smaller than the one it replaces (16.5759). This looks a bit suspicious. Is the formula correct?

The Dimension Edge microscope has no official manual. There is just a help file in the NanoDrive software. In the help, there is a chapter about calibration, but there is no information that I should make changes to the "SGSCANNER.SYS", or how to calibrate the Small Scan mode. I tried to switch to Small Scan mode make the calibration of the microscope in there by following the help file and then switch to Normal Mode and make the calibration again, but I came across another problem. When I restarted the microscope, and loaded the Small Scan mode using new calibration file, the head was not using the whole range of 20x20um^2 in XY direction, but just a small fraction of it (namely 5x5um^2).

Here are my questions:

What is a proper way to calibrate the Dimension Edge microscope and to be accurate as much as possible in the Normal mode as well as in the Small Scan mode?

(In my opinion the proper way of calibrating the microscope in Small Scan mode would be to obtain an image from small area of a calibration grating (~ 15x15um^2) in this mode and use the maximum image resolution available (1024x1024px). And in Normal Mode, I should scan the largest area of a grating (100x100um^2) at maximum resolution, I guess.).

Furthermore, what is the entire range of Dimension Edge piezo in z- and xy-direction? I mean the range I should set in SGSCANNER.SYS for HighGain and LowGain section.
 
Thank you

Best regards,
Milan

Details of my setup:
The model of my microscope is: Dimension Edge.
I am using the calibration grating which was delivered with the microscope, model VGRP-15M, Pitch Size = 10um, Depth = 180nm (unknown accuracy).
I have also the TGXYZ01 grating from MicroMasch that is accurate in z-direction (accuracy = 0.4 nm) and the TDG01 grating from NT-MDT that is accurate in XY direction (accuracy = 1 nm).
I am calibrating the microscope in tapping mode, mostly with TESPA probes.
NanoDrive: v8.01 (R1.65039)