Biomedical Engineering Reference
In-Depth Information
• Atomically flat sample: A highly polished sample that
is contamination-free
(A silicon wafer, or cleaved mica or HOPG works well).
• Angled sample holder: A small sample holder that can hold a sample at 7
8
.
B1
xy specifications
B1.1 Scan range
An image of a standard test pattern with a known pitch is acquired. The pitch is measured
from this image, ideally by averaging over a large number of cells. The scan range can be
calculated by multiplying the number of cells viewed in a line profile by the pitch. See
Figure B1.
B1.2 xy measurement accuracy
This test is designed to verify that xy measurements derived from the AFM are accurate. It
also determines if they are the same across different parts of the scan range (i.e. the x and y
linearity). Using the same image measured in Section B1.1, the pitch is measured at
several locations on the sample. The standard deviation of the measurements is calculated,
as well as the maximum error. See Figure B2.
B2
z specifications
B2.1
z range
Using a sample holder that applies a known angle between the sample's surface and
the scanner x-y axis, the xy test pattern is scanned. The number of features in the
image is counted, and from this, the z range of the scanner is calculated as shown in
Figure B3.
Fig. B1. Measurement of pitch with a typical X-Y calibration specimen.
 
Search WWH ::




Custom Search