Instruction manual

Interleave Scanning and LiftMode
Interleave Mode Description
Rev. B MultiMode SPM Instruction Manual 219
12.2 Interleave Mode Description
Enabling Interleave changes the scan pattern of the tip relative to the imaged area. With Interleave
mode disabled, the tip scans back and forth in the fast scan direction while slowly moving in the
orthogonal direction as shown on the left of Figure 12.2a. This is the standard scan pattern of the
NanoScope III.
Figure 12.2a X-Y Scan Pattern
With Interleave mode enabled, the system first performs a standard trace and retrace with the Main
Feedback Controls in effect. The tip moves at half the normal rate in the slow scan direction. As
shown on the right of Figure 12.2a, an additional trace and retrace are then performed with the
Interleave Feedback Controls enacted. The frame rate halves because twice as many scan lines are
performed for the same scan rate.
Four modes are possible for Interleave scan: Interleave, Linear, Retrace Lift and Lift. With
Interleave selected, the feedback remains on during the Interleave pass with the values under
Interleave Feedback Controls (Setpoint, Gains, etc.) in effect. In Lift mode, the feedback is instead
turned off, and the tip lifted off the surface and scanned at a user-selected height. Topography data
recorded during the main pass is used to keep the tip a constant distance from the surface during the
interleave trace and retrace. In Linear mode, the tip is lifted above the surface to the specified
height using the median value of the main scan line as the reference for the lift height. If there are
any features taller than the lift height you entered, the system will lift the tip over those features
rather than crashing the tip. In Retrace Lift the tip is on the surface during the main scan, and lifts
during the retrace scan line.
INTERLEAVE
trace and retrace
With INTERLEAVE enabled scanner executes
trace/retrace pairs, alternately performing a
MAIN pair, then an INTERLEAVED pair.
Vertical Scan speed is 1/2 normal rate with
twice the number of lines.
INTERLEAVE
ENABLED
four Main and four Interleave
scan lines shown
INTERLEAVE
DISABLED
(standard)
four scan lines
(trace/retrace pairs)
shown
slow scan
direction
fast scan
direction
MAIN trace
and retrace