user manual

6.4.5
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(3) Carrying out Calibration
(a) With the CD measurement function of the SEM main unit, set a sample for calibration
into the SEM and set the instrument conditions to those actually used for
measurement.
Since the value of working distance is calculated from the focused objective lens
current, adjusting the focus causes a variation in the working distance value. Select a
working distance value in the WORKING DISTANCE block of the Operation panel -
Cond tab and then, adjust the Z axis of the specimen stage to obtain a focus. After
obtaining a coarse focus with the stage Z control, carry out fine focusing in the usual
procedure. Finally set magnification again, because focusing operation will cause a
small fraction to magnification value eve if it is not shown in the magnification
indication. It may cause discrepancy with measurement condition.
NOTICE: If the focus varies significantly, the objective lens yoke is affected by magnetic
hysteresis and causes a reduction in measurement reproducibility.
After a large change in the focus, click the DeGauss button on the Setup dialog
window - Optics tab to eliminate the effect of hysteresis, then adjust the focus and
astigmatism correction again.
You can use F2 key as the hot-key for degaussing.
Fig. 6.4-17 DeGauss Button
(b) Set the desired visual field and magnification for the observed SEM image, then set
the Run button to Freeze or use the Capture button to freeze the image.
DeGauss button