Instruction manual

Force Imaging
Force Modulation with ‘Negative LiftMode’
214 MultiMode SPM Instruction Manual Rev. B
11.7.2 Obtain a TappingMode Image
While negative LiftMode force modulation data is imaged using Channel 2, height data is obtained
using TappingMode on Channel 1. You must obtain a satisfactory TappingMode image to generate
good data.
1. Verify that the Interleave mode parameter on the Interleave Controls panel is Disabled.
2. Verify that the AFM mode parameter in the Other Controls panel is set to Tapping.
3. Select Realtime > View > Sweep > Cantilever or the Cantilever Tune icon. Enter a
main controls Start frequency value of 5kHz and End frequency value of 100kHz for
FESP tips.
4. Set Target Amplitude to 1-2V, and click the Auto Tune button, or tune manually.
5. Click the Interleave Controls button to verify that the bimorph drive parameters are correct.
6. Exit the Cantilever Tune dialog box.
7. Verify that all Scan controls and Feedback Controls parameters are set for obtaining a
TappingMode image.
8. Set the Channel 1 panel Data type parameter to Height.
9. Set the Line direction to Retrace and enter an appropriate Data Scale value for your
sample.
10. Engage the tip on the surface and obtain a good TappingMode image.
11.7.3 Obtain a Negative LiftMode Force Modulation Image
1. Set the Data type parameter in the Channel 2 panel to Amplitude. Set the Line direction
parameter to Retrace.
2. Switch the Interleave mode parameter in the Interleave Controls panel to Lift. Negative
LiftMode imaging is now in effect.
3. Using the left arrow key, optimize the negative LiftMode image by slowly decreasing the
Lift scan height parameter in the Interleave Controls panel from zero until you reach the
surface. In most cases, you should not go below -60.0nm.
Note: This is sometimes best performed while in Realtime > View > Scope
Mode.When the interleaved scan is enabled, the tip’s TappingMode height
above the sample reduces by the Lift scan height amount. This places the
oscillating tip in contact with the sample as surface features are profiled. The
contrast between light and dark reveals areas of high and low elasticity, with the
dark area indicating harder material and the lighter areas indicating softer
material.