Bruker DektakXT, User Manual

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2-2 System Overview
HOW THE SYSTEM WORKS
The DektakXT system takes measurements electromechanically by moving a diamond-tipped stylus
over the sample surface according to a user-programmed scan length, speed, and stylus force. The
stylus is linked to a Linear Variable Differential Transformer (LDVT), which produces and processes
electrical signals that correspond to surface variations of the sample. After being converted to digital
format, these surface variations are stored for display and analysis.
The Vision64 application calculates and displays the results of user-selected analytical functions for
measuring surface texture and other parameters to characterize the profile data. For example, the Ra
(average roughness) analytical function—the most commonly used international parameter of
roughness—calculates the arithmetic average deviation from the mean line within the assessment
length.
If there is an active database, selected analytical functions are logged to it during each
measurement.
STAGE CONFIGURATIONS
The DektakXT stylus surface profiler comes in the following stage configurations:
•
The standard 2-D DektakXT system , which includes a two-axis, manual sample-positioning
stage with 101.6 x 101.6 mm (4 x 4 inches) of X-Y translation, manual leveling, two-point
programmable or cursor software leveling, and manual theta rotation (see
Figure 2-2 ). This
standard stage accommodates samples up to 50 mm (1.9 inches) thick and performs long scans
of 55 mm (2.16 inches). It provides
±
50.8 mm (2 inches) of X-Y translation as well as manual
theta positioning (see Figure 2-3 ). The standard system is available with 50 mm (1.97 inch), 100
mm (3.94 inch), and 150 mm (5.90 inch) wafer alignment pins, along with one of the following
sample fixtures (chucks):
•
101 mm (4-inch) square base platform with no vacuum capability
•
Ceramic vacuum
•
Dedicated photo voltaic vacuum
Figure 2-2: Standard Manual Sample-Positioning Stage with Square Base Platform Fixture