Total Thickness Variation
(TTV): The absolute difference between the thickest
and thinnest points.
how concave or convex the deformation of the median surface
of the wafer at the center point, independent of any thickness
Warp: The difference
between the maximum and minimum values of the median surface
from an established reference plane.
Global Total Indicated
Reading (GTIR): The maximum peak-to-valley deviation
of a wafer surface as measured from a specified reference plane.
Site Total Indicated
Reading (STIR): Site by site measurement of the flatness
of a wafer.
Measurement of difficulty that charged carriers have in moving
through the wafer.
The longest flat on the wafer. Usually to orient the wafer on
the process equipment.
The shorter flat on the wafer. Used to identify the type and
orientation of the wafer.
Unwanted impurities on the surface of the wafer. Common term
for particles is Light Point Defect (LPD's). Measured by the
total number of particles across the entire surface of the wafer
greater than a certain size.