Bruker 004-130-000 User manual

Document Revision History: SPM Training Notebook
Revision Date Section(s) Affected Reference Approval
Rev. F 01/28/2011 Re-branded R.Wishengrad
Rev. E 10/27/2003 Content and Format Update N/A C. Kowalski
Rev. D 08/05/2003 Overall Content and Format Update N/A L. Burrows
Rev. C 07/30/2003 Content Update N/A L. Burrows
Rev. B 08/01/1998 Format Update N/A C. Fitzgerald
Rev. A 05/09/1997 Initial Release N/A J. Thornton
Copyright © 2003, 2011 Bruker Corporation
All rights reserved.
SPM Training Notebook
004-130-000 (standard)
004-130-100 (cleanroom)

Notices: The information in this document is subject to change without notice. NO WARRANTY OF ANY KIND IS MADE WITH REGARD TO
THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE. No liability is assumed for errors contained herein or for incidental or consequential damages in connection with the
furnishing, performance, or use of this material. This document contains proprietary information which is protected by copyright. No part of this
document may be photocopied, reproduced, or translated into another language without prior written consent.
Copyright: Copyright © 2003, 2011 Bruker Corporation. All rights reserved.
Trademark Acknowledgments: The following are registered trademarks of Bruker Corporation. All other trademarks are the property of their
respective owners.
Product Names:
NanoScope®
MultiMode™
Dimension™
BioScope™
Atomic Force Profiler™ (AFP™)
Dektak®
Software Modes:
TappingMode™
Tapping™
TappingMode+™
LiftMode™
AutoTune™
TurboScan™
Fast HSG™
PhaseImaging™
DekMap 2™
HyperScan™
StepFinder™
SoftScan™
Hardware Designs:
TrakScan™
StiffStage™
Hardware Options:
TipX®
Signal Access Module™ and SAM™
Extender™
TipView™
Interleave™
LookAhead™
Quadrex™
Software Options:
NanoScript™
Navigator™
FeatureFind™
Miscellaneous:
NanoProbe®

Rev. F SPM Training Notebook 1
Table of Contents
1.0 History and Definitions in SPMs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.3 Other forms of SPM: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.0 Scanning Tunneling Microscope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.0 Contact Mode AFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.0 TappingMode AFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.0 Non-contact Mode AFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
6.0 Advantages and Disadvantages of Contact Mode AFM, TappingMode AFM,
and Non-contact Mode AFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.1 Contact Mode AFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.2 TappingMode AFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6.3 Non-contact Mode AFM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.0 Piezoelectric Scanners: How They Work. . . . . . . . . . . . . . . . . . . . . . . . . 14
8.0 Piezoelectric Scanners: Hysteresis and Aging. . . . . . . . . . . . . . . . . . . . . 16
8.1 Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
8.2 Aging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
9.0 Piezoelectric Scanners: Creep and Bow. . . . . . . . . . . . . . . . . . . . . . . . . . 19
9.1 Creep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
9.2 Bow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
10.0 Probes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10.1 Silicon Nitride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
10.2 Silicon. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
11.0 Types of SPM Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11.1 Contact Mode Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11.2 TappingMode Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
11.3 Probes for Other SPM Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
12.0 Atomic Force Microscopy- “Beam Deflection” Detection . . . . . . . . . . 25

2 SPM Training Notebook Rev. F
13.0 SPM Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
14.0 Abbreviated Instructions for Dimension Series AFMs. . . . . . . . . . . . . 29
14.1 Mode of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
14.2 Align the Laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
14.3 Adjust the Photodetector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
14.4 Locate Tip. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
14.5 Focus Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
14.6 Cantilever Tune (TappingMode Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
14.7 Set Initial Scan Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
14.8 Engage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
14.9 Adjust Scan Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
14.10 Set Desired Scan Size, Scan Angle, and Offsets . . . . . . . . . . . . . . . . . . . . . 31
15.0 Abbreviated Instructions for the MultiMode AFM. . . . . . . . . . . . . . . . 32
15.1 Mode of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
15.2 Mount Probe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
15.3 Select Scanner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
15.4 Mount Sample . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
15.5 Place Optical Head on Scanner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
15.6 Align Laser and Tip-Sample Approach (2 Methods) . . . . . . . . . . . . . . . . . . . 33
15.7 Adjust Photodiode Signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
15.8 Cantilever Tune (TappingMode Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
15.9 Set Initial Scan Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
15.10 Engage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
15.11 Adjust Scan Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
15.12 Set Desired Scan Size, Scan Angle, and Offsets . . . . . . . . . . . . . . . . . . . . . 35
16.0 Realtime Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
16.1 Setpoint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
16.2 Integral Gain. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
16.3 Scan Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
16.4 Other Important Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
17.0 Force Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
18.0 Offline Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
18.1 File Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
18.2 Image Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
18.3 Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
19.0 Tip Shape Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
19.1 Resolution Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
20.0 Typical Image Artifacts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
21.0 Calibration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

Rev. F Scanning Probe Microscope Training Notebook 1
SPM Training Notebook
This Notebook is intended to be used as an introduction by the first-time user of Bruker NanoScope
Scanning Probe Microscopes (SPM). For further information, please consult the Command
Reference Manual and/or the appropriate NanoScope manual.
Specifically, this manual covers the following:
•History and Definitions in SPMs: Page 3
•Scanning Tunneling Microscope: Page 5
•Contact Mode AFM: Page 8
•TappingMode AFM: Page 10
•Non-contact Mode AFM: Page 11
•Advantages and Disadvantages of Contact Mode AFM, TappingMode AFM, and
Non-contact Mode AFM: Page 12
•Piezoelectric Scanners: How They Work: Page 14
•Piezoelectric Scanners: Hysteresis and Aging: Page 16
•Piezoelectric Scanners: Creep and Bow: Page 19
•Probes: Page 21
•Types of SPM Probes: Page 23
•Atomic Force Microscopy- “Beam Deflection” Detection: Page 25
•SPM Configurations: Page 26
•Abbreviated Instructions for Dimension Series AFMs: Page 29
•Abbreviated Instructions for the MultiMode AFM: Page 32
•Realtime Operation: Page 36
•Force Curves: Page 42

2 Scanning Probe Microscope Training Notebook Rev. F
•Offline Operation: Page 44
•Tip Shape Issues: Page 53
•Typical Image Artifacts: Page 58
•Calibration: Page 62

History and Definitions in SPMs
Rev. F Scanning Probe Microscope Training Notebook 3
1.0 History and Definitions in SPMs
1.1 History
Scanning Tunneling Microscope (STM)
• Developed in 1982 by Binning, Rohrer, Gerber, and Weibel at IBM in Zurich, Switzerland.
• Binning and Rohrer won the Nobel Prize in Physics for this invention in 1986.
Atomic Force Microscope (AFM)
• Developed in 1986 by Binning, Quate, and Gerber as a collaboration between IBM and Stanford
University.
1.2 Definitions
Scanning Probe Microscopy (SPM): Consists of a family of microscopy forms where a sharp probe is
scanned across a surface and probe/sample interaction is monitored.
The two primary forms of SPM:
1. Scanning Tunneling Microscopy (STM)
2. Atomic Force Microscopy (AFM) (also called Scanning Force Microscopy (SFM)
• There are 3 primary modes of AFM:
• Contact Mode AFM
• Non-contact Mode AFM
• TappingMode AFM

History and Definitions in SPMs
4 Scanning Probe Microscope Training Notebook Rev. F
1.3 Other forms of SPM:
Lateral Force Microscopy (LFM)
Force Modulation Microscopy
Magnetic Force Microscopy (MFM)
Electric Force Microscopy (EFM)
Surface Potential Microscopy
Phase Imaging
Force Volume
Electrochemical STM & AFM (ECM)
Scanning Capacitance Microscopy (SCM)
Scanning Thermal Microscopy (SThM)
Near-field Scanning Optical Microscopy (NSOM or SNOM)
Scanning Spreading Resistance (SSRM)
Tunneling AFM (TUNA)
Conductive AFM (CAFM)
NanoIndentation
Torsional Resonance Mode (TR Mode)
NanoLithography / NanoManipulation
SECPM

Scanning Tunneling Microscope
Rev. F Scanning Probe Microscope Training Notebook 5
2.0 Scanning Tunneling Microscope
Basic SPM Components

Scanning Tunneling Microscope
6 Scanning Probe Microscope Training Notebook Rev. F
Figure 2.0a Feedback Loop Maintains Constant Tunneling Current
STM is based on the fact that the tunneling current between a conductive tip and sample is
exponentially dependent on their separation.
This can be represented by the equation: I ~ Ve -cd
• I = Tunneling current
• V = Bias voltage between tip and sample
•c=constant
• d = tip-sample separation distance
As the tip scans the sample surface, it encounters sample features of different heights, resulting in
an exponential change in the tunneling current.
A feedback loop is used to maintain a constant tunneling current during scanning by vertically
moving the scanner at each (x,y) data point until a “setpoint” current is reached.
The vertical position of the scanner at each (x,y) data point is stored by the computer to form the
topographic image of the sample surface.
This technique is typically limited to conductive and semiconducting surfaces

Scanning Tunneling Microscope
Rev. F Scanning Probe Microscope Training Notebook 7
2.1 Applications
• Atomic resolution imaging (STM is the only technique which detects atomic-scale
defects)
• Electrochemical STM
• Scanning Tunneling Spectroscopy
• Low-current imaging of poorly conductive samples

Contact Mode AFM
8 Scanning Probe Microscope Training Notebook Rev. F
3.0 Contact Mode AFM
Figure 3.0a Feedback Loop Maintains Constant Cantilever Deflection
Contact mode AFM operates by scanning a tip attached to the end of a cantilever across the sample
surface while monitoring the change in cantilever deflection with a split photodiode detector. The
tip contacts the surface through the adsorbed fluid layer on the sample surface.
A feedback loop maintains a constant deflection between the cantilever and the sample by
vertically moving the scanner at each (x,y) data point to maintain a “setpoint” deflection. By
maintaining a constant cantilever deflection, the force between the tip and the sample remains
constant.

Contact Mode AFM
Rev. F Scanning Probe Microscope Training Notebook 9
The force is calculated from Hooke's Law: where:
•F=Force
• k = spring constant
• x = cantilever deflection.
Force constants usually range from 0.01 to 1.0 N/m, resulting in forces ranging from nN to µN in an
ambient atmosphere.
The distance the scanner moves vertically at each (x,y) data point is stored by the computer to form
the topographic image of the sample surface.
Operation can take place in ambient and liquid environments.
Fkx–=

TappingMode AFM
10 Scanning Probe Microscope Training Notebook Rev. F
4.0 TappingMode AFM
Figure 4.0a Feedback Loop Electronics
TappingMode AFM operates by scanning a tip attached to the end of an oscillating cantilever
across the sample surface.
The cantilever is oscillated at or slightly below its resonance frequency with an amplitude ranging
typically from 20nm to 100nm. The tip lightly “taps” on the sample surface during scanning,
contacting the surface at the bottom of its swing.
The feedback loop maintains a constant oscillation amplitude by maintaining a constant RMS of
the oscillation signal acquired by the split photodiode detector.
The vertical position of the scanner at each (x,y) data point in order to maintain a constant
“setpoint” amplitude is stored by the computer to form the topographic image of the sample
surface. By maintaining a constant oscillation amplitude, a constant tip-sample interaction is
maintained during imaging.
Operation can take place in ambient and liquid environments. In liquid, the oscillation need not be
at the cantilever resonance.
When imaging in air, the typical amplitude of the oscillation allows the tip to contact the surface
through the adsorbed fluid layer without getting stuck.

Non-contact Mode AFM
Rev. F Scanning Probe Microscope Training Notebook 11
5.0 Non-contact Mode AFM
Figure 5.0a Feedback Loop Maintains Constant Oscillation Amplitude or Frequency
The cantilever is oscillated at a frequency which is slightly above the cantilever’s resonance
frequency typically with an amplitude of a few nanometers (<10nm), in order to obtain an AC
signal from the cantilever.
The tip does not contact the sample surface, but oscillates above the adsorbed fluid layer on the
surface during scanning
The cantilever's resonant frequency is decreased by the van der Waals forces, which extend from
1nm to 10nm above the adsorbed fluid layer, and by other long range forces which extend above the
surface. The decrease in resonant frequency causes the amplitude of oscillation to decrease.
The feedback loop maintains a constant oscillation amplitude or frequency by vertically moving the
scanner at each (x,y) data point until a “setpoint” amplitude or frequency is reached.
The distance the scanner moves vertically at each (x,y) data point is stored by the computer to form
the topographic image of the sample surface.

Advantages and Disadvantages of Contact Mode AFM, TappingMode AFM, and Non-contact Mode AFM
12 Scanning Probe Microscope Training Notebook Rev. F
6.0 Advantages and Disadvantages of Contact Mode AFM,
TappingMode AFM, and Non-contact Mode AFM
6.1 Contact Mode AFM
Advantages:
• High scan speeds (throughput).
• Contact mode AFM is the only AFM technique which can obtain “atomic resolution”
images.
• Rough samples with extreme changes in vertical topography can sometimes be scanned
more easily in contact mode.
Disadvantages:
• Lateral (shear) forces can distort features in the image.
• The forces normal to the tip-sample interaction can be high in air due to capillary forces
from the adsorbed fluid layer on the sample surface.
• The combination of lateral forces and high normal forces can result in reduced spatial
resolution and may damage soft samples (i.e., biological samples, polymers, silicon)
due to scraping between the tip and sample.
6.2 TappingMode AFM
Advantages:
• Higher lateral resolution on most samples (1nm to 5nm).
• Lower forces and less damage to soft samples imaged in air.
• Lateral forces are virtually eliminated, so there is no scraping.
Disadvantages:
• Slightly slower scan speed than contact mode AFM.

Advantages and Disadvantages of Contact Mode AFM, TappingMode AFM, and Non-contact Mode AFM
Rev. F Scanning Probe Microscope Training Notebook 13
6.3 Non-contact Mode AFM
Advantage:
• No force exerted on the sample surface.
Disadvantages:
• Lower lateral resolution, limited by the tip-sample separation.
• Slower scan speed than TappingMode and Contact Mode to avoid contacting the
adsorbed fluid layer which results in the tip getting stuck.
• Non-contact usually only works on extremely hydrophobic samples, where the adsorbed
fluid layer is at a minimum. If the fluid layer is too thick, the tip becomes trapped in the
adsorbed fluid layer causing unstable feedback and scraping of the sample.
Note: Due to these disadvantages, applications for non-contact mode AFM imaging
have been limited.

Piezoelectric Scanners: How They Work
14 Scanning Probe Microscope Training Notebook Rev. F
7.0 Piezoelectric Scanners: How They Work
SPM scanners are made from piezoelectric material, which expands and contracts proportionally to
an applied voltage.
Whether they elongate or contract depends upon the polarity of the voltage applied. All DI scanners
have AC voltage ranges of +220V to -220V for each scan axis.
Figure 7.0a The effect of applied voltage on piezoelectric materials.
The scanner is constructed by combining independently operated piezo electrodes for X, Y, & Z
into a single tube, forming a scanner which can manipulate samples and probes with extreme
precision in 3 dimensions.
In some models (e.g. MultiMode SPM) the scanner tube moves the sample relative to the stationary
tip. In other models (e.g., STM, Dimension Series and BioScope SPM’s) the sample is stationary
while the scanner moves the tip.
Figure 7.0b Typical scanner piezo tube and X-Y-Z configurations. AC Signals applied to conductive areas of
the tube create piezo movement along the three major axes
AC voltages applied to the different electrodes of the piezoelectric scanner produce a scanning
raster motion in X and Y. There are two segments of the piezoelectric crystal for X (X & X) and Y
(Y & Y).
0 V
+ V
- V
No applied voltage
Extended
Contracted
Electrode
Z
Y
Y
XX X
X
Y
Y
Z
Metal
Electrode
Piezoelectric
Material
GND

Piezoelectric Scanners: How They Work
Rev. F Scanning Probe Microscope Training Notebook 15
Figure 7.0c Waveforms applied to the piezo electrodes during a raster scan with the X axis designated as the
fast axis (Scan Angle = 0°)
+V
-V
0
X
+V
-V
0
X
+V
-V
0
Ytt
+V
-V
0
Yt
t
z
X AXIS
Y AXIS
1416 -410
Schematic of piezo movement during a raster scan.
Voltage applied to the X- and Y-axes produce the
scan pattern.

Piezoelectric Scanners: Hysteresis and Aging
16 Scanning Probe Microscope Training Notebook Rev. F
8.0 Piezoelectric Scanners: Hysteresis and Aging
8.1 Hysteresis
Because of differences in the material properties and dimensions of each piezoelectric element,
each scanner responds differently to an applied voltage. This response is conveniently measured in
terms of sensitivity, a ratio of piezo movement-to-piezo voltage, i.e., how far the piezo extends or
contracts per applied volt.
Sensitivity is not a linear relationship with respect to scan size. Because piezo scanners exhibit
more sensitivity (i.e., more movement per volt) at the end of a scan line than at the beginning, the
relationship of movement vs. applied voltage is nonlinear. This causes the forward and reverse scan
directions to behave differently and display hysteresis between the two scan directions.
Figure 8.1a Effect of Nonlinearity and Hystersis
The effect of nonlinearity and hysteresis can be seen from the curve above (see Figure 8.1a). As the
piezo extends and retracts throughout its full range, it moves less per applied volt at the beginning
of the extension than near the end. The same is true when the piezo is retracting - the piezo moves
less per applied volt at the beginning of its extension than near the end.
Nonlinearity and hysteresis can cause feature distortion in SPM images if not properly corrected.
Examples of these effects on AFM images are shown below with the DI-supplied 10 µm pitch
calibration grating. The depth of each square is 200nm. Please refer to the standard for step height
information.