Chapter 8.14
DI AFM Nanoscope Dimension
3100:
Atomic Force Microscope
(afm2)
1.0
Title, Ownership & Training
Digital Instruments Nanoscope 3100 atomic force
microscope. This tool belongs to the
research group of Professor Jeffrey Bokor, and is administered directly by
students in his and Professor V. Subramanian’s group. All users must first be cleared by Professor Bokor, pass a
written test, and an oral test that certify not only the knowledge but also the
proficiency of the operator. It is
obligatory that the potential user undergo a significant amount of hands-on
training, and gain a solid understanding of the equipment before taking the
qualification tests.
2.0
Purpose
This manual describes basic operation of tapping mode
surface contour measurements.
3.0
Scope
3.1 Overview / Application
The
DI-3100 is an Atomic Force Microscope particularly suited for handling
semiconductor wafers and die for device microscopy. It is capable of various
Scanning Probe Microscopy techniques including Contact, Tapping, Scanning
Tunneling and Lateral Force Modes, although Contact and Tapping Modes are the
most prevalently used on the DI-3100. Both Contact and Tapping Mode are well
suited for topographical imaging of surfaces, with vertical resolution ranging
from one micron down to sub nanometer scales. All of these techniques share a
common approach where a motor controlling a mechanical tip is placed in a
feedback loop as the tip is scanned across a surface. The mechanism upon which
the feedback is based is the predominant difference between the modes. Surface
imaging and analytical studies of roughness are common uses for this tool.
3.2 Sample
Preparation / User Policy
3.2.1 The
DI-3100 has a vacuum chuck that can hold 4" and 6" wafers. The switch
for the vacuum is on the upper right hand side. The vacuum is weak however and
will not hold smaller pieces. For smaller individual samples a magnetic sample
holder (located on the AFM bench) is available. The magnetic sample holder adds
significant height to the sample with respect to the chuck and added caution is
required when translating the stage near the SPM. For non-magnetic samples,
double-sided adhesive (also located on the AFM bench) tabs can be used to stick
samples to the chuck. Be aware that the adhesive contaminates mounted samples
and should only be used for end-of-process samples. Users can also have custom
sample holders machined for use with this tool. Minimal force is needed to keep
samples in place.
3.2.2 The
materials policy for imaging is fairly broad. Most materials related to
semiconductor fabrication are allowed in this tool, including gold,
photoresist, parylene, copper, etc. If a user feels he/she has a non-standard
material, please check with a superuser first.
3.2.3 Samples to
be imaged must be relatively planar to avoid having the scan head crash into
features on sample. The scan head nominally focuses approximately one
millimeter off of the substrate, with the cantilever tilted slightly down.
Hence, vertical features or any tilt on the order of one millimeter needs to be
handled with caution. Users may use their own judgment if they believe areas of
the sample may be safely imaged without endangering the scanner. However,
excessive tall vertical features that cannot be easily navigated around should
not be imaged on this device. Once the sample is navigated to a safe area for
engaging (landing) the cantilever however, the topographical features to be
imaged must have nominal roughness on the order of one micron or less. Although
millimeter tilt or features are tolerable on the sample itself, the area to be
imaged must not have any topography higher than approximately one micron.
Rough topography on the order of microns can break the cantilever while
scanning, but millimeter scaled features may damage the scan head (which is NOT
replaceable). Reread this section after studying Section 9.0 of this
manual if necessary. The sample requirements here differentiate between
topography encountered while translating the stage to an imaging location
(before the scanner is engaged), and topography encountered during an actual
scan (after the scanner is engaged).
3.2.4 A default
tip is NOT loaded in the scan head. All users must supply their own tips.
3.2.5 All users
must use latex gloves while touching any component of the AFM, and must leave
the chuck clean. However due to the various materials imaged (e.g. gold,
photoresist), wafers imaged by the AFM are no longer VLSI-clean. If there are
special needs, please consult staff.
3.2.6 The scan
head used can image a maximum field of approximately 100 µm x 100 µm. If a
larger lateral displacement is required, use other Microlab tools (e.g. ASIQ,
Dektak).
3.2.7 Both
tapping mode and contact mode are commonly used. Other modes are possible on the DI-3100, however users are
required to discuss these with superusers.
4.0
Applicable Documents
4.1
After becoming familiar with the aspects covered in this
overview of the AFM, it is recommended that users look over the Scanning
Probe Microscopy Training Notebook provided by Digital Instruments. This
provides some additional information on some of the data analysis and
modification tools described above as well as tips on imaging techniques and
artifacts. The section on Imaging Artifacts at the end is
particularly recommended. A copy of this training manual is located next to the
AFM.
4.2
Advance users of the DI-3100 are also encouraged to utilize
the Command Reference Manual provided by Digital
Instruments. This manual is available upon request.
5.0
Definitions and Process
Terminology
5.1 TAPPING MODE
Tapping
Mode is the most common imaging technique used with the DI-3100. This mode
operates by scanning a tip attached to the end of an oscillating cantilever
across the sample surface. The amplitude of oscillation ranges from 20 nm to
100 nm, with the frequency near the resonant peak of the cantilever. The tip
lightly 'taps' the surface, altering the oscillatory motion as the scanner
moves across the surface. By adjusting the vertical position of the scanner to
maintain a constant RMS signal of oscillation, a surface is imaged. The
oscillation is measured by a laser positioned by the user to reflect signal
into a photodiode detector)
Advantages
5.1.1
Higher lateral resolution on most samples (1 nm to 5 nm)
5.1.2
Lower forces and less damage to soft samples imaged in air
5.1.3
Lateral forces are virtually eliminated, so there is no
scraping
Disadvantages
5.1.4
Slightly lower scan speed than contact mode AFM
5.1.5
For tapping mode, use an etched single crystal silicon probe
tip (TESP/RTESP). This probe is a silverish color and is available in the
Microlab for check out. (See Section 9.0 for probe tip policies). Standard
TESP/RTESP tips have a resonant frequency ~300 kHz and have cantilevers 125 µm
long.
6.0
Safety
Large
voltages (upwards of +/- 220V) are applied in order to actuate the piezo. While these voltages nodes are shielded from
human contact, care must be exercised, especially if they are accessed through
the break-out box.
7.0
Statistical/Process Data
8.0
Available Process, Gases, Process
Notes
9.1
Tip Mounting
If you need to load a new tip:
9.1.1 Open the
hood to the AFM and tighten (turn
clockwise) the knob attached to the dovetail. This lifts the SPM slightly
so that it can be removed. Unplug the cord and gently slide the SPM out of the
dovetail and place it on the workbench.
9.1.2 Remove the
Cantilever Holder from the SPM and place it onto the cylindrical tip mounter.
9.1.3 Pull the
metal spring back, load tip using the etched guides and replace spring. Check
that tip is mounted firmly and is secure. Use sharp tweezers when handling the
tip, and only touch the probe by the side edges.
9.1.4 Replace
the Cantilever Holder. DO NOT APPLY
TWISTING MOTIONS when placing the cantilever holder onto the head. Doing so will DAMAGE THE PIEZO SCANNER. The piezo scanner is made of a half-cylinder
of piezo crystal, which is extremely fragile and expensive to replace or
repair. Place the SPM into dovetail. Gently
loosen knob to allow the SPM to fall
into place. Reconnect the cord.
9.2
System Startup
9.2.1 You must
follow the following procedures exactly.
Without starting the nanoscope software first, random voltages (which
maybe very large) will be applied to the piezo scanner, causing possible
damage.
9.2.2 Enable the
DI-3100 on the wand.
9.2.3 Start Nanoscope
software (icon on desktop).
9.2.4 Turn on
the microscope controller and facilities.
9.2.5 Under the DI
menu, select Microscope Select and choose Quadrexed3100.
(A DI Multimode AFM shares this controller and software and may have been setup
prior).
9.2.6 Verify at
the bottom Status Bar that TappingAFM Mode is displayed.
9.3
Align the Laser to the Tip
9.3.1 While
looking at the trace of the laser beam, turn the upper knob at the top of the
SPM clockwise until the intensity of the trace just becomes very dim (start
with the laser trace towards the left). This means the laser has just hit the
substrate off of which the 125 µm cantilever is mounted. Turn the upper knob
<1/4 turn counter-clockwise to bring the laser just off the substrate.
9.3.2 By turning
the lower knob in either direction (the laser trace should move towards and
away from you), find the point at which the laser is just shadowed by the
cantilever. It should only require less than 1/8 turn to move on and off the
cantilever; if it requires more than this, the laser is most likely hitting the
substrate and you need to back off slightly.
9.3.3 Check the
viewport on the side of the SPM to confirm the laser is approximately aligned
to the cantilever with the red dot centered.
9.3.4 Move the
laser with the upper knob until the laser is approximately at the end of the
cantilever. Adjust either knob in small increments to maximize the Laser
Sum Signal, as displayed on the right monitor.
9.4
Adjust the Photodetector
9.4.1 Use the
two knobs located at the left of the SPM to adjust the photodetector.
9.4.2 Look at
the laser signal on the right monitor and try to center the red dot at the
center of the cross.
9.4.3 Try to get
~0V vertical deflection.
9.4.4 Sum should
be ~2 (or slightly less).
9.5
Align the Microscope to the Tip
9.5.1 Select Stage
→ Locate
Tip from the top menu.
You should do locate tip before focus surface. Doing it the other way risks crashing the tip.
9.5.2 The tip
will move up and down before stopping to help you find it. Zoom out if
necessary. There needs to be reflective light to adequately see the tip: Use
the chuck if necessary. To move chuck, use the Focus Surface
instructions that follow.
9.5.3 Use the
two knobs at the left of the optical objective on the camera to center the
cantilever under the cross hairs.
9.5.4 Use the
trackball to focus on the tip as best as possible (requires holding down the
left Focus button on trackball).
9.5.5 If you
cannot find the tip when zoomed in, it may be too far from the surface to
reflect light. Use “focus surface” to
lower the head slightly and try again.
9.6
Focus on the surface of the sample
9.6.1 Load your
sample. Use the chuck and vacuum, magnetic sample holder studs, or provided
double sided adhesive to fix your sample onto the chuck. (Note: The
travel on the chuck is limited so keep your sample on the upper half of the
chuck if possible. The chuck can also be manually rotated if necessary.)
9.6.2 Select Stage
→ Focus
Surface from the top menu.
9.6.3 Check
visually to ensure that there is enough clearance such that the sample can move
under the SPM with adequate clearance. There is no
interlock or detection mechanism preventing users from crashing their samples
into the SPM, so make conservative estimates. If there is not enough
clearance, hold down on the Focus button on the trackball, and push the
ball upwards; this lifts the SPM.
9.6.4 Use the
trackball to move the wafer under the SPM (note the top of the trackball orients
towards the back of the DI-3100).
9.6.5 Follow
instructions on screen to focus on the surface of your sample. Watch
both the monitor and the SPM itself when focusing; it is possible to crash the
head into the sample when trying to focus and this will damage the tip AND SPM.
The SPM should be at least 2 mm above the surface (although you will need to be
closer than 5 mm) to focus.
9.6.6 Tips
9.6.6.1 Use the Lock
button in any mode to lock in your fastest movement on the trackball.
9.6.6.2 Always Zoom
Out before trying rough focusing.
9.6.6.3 It is
typically easiest to focus on the edge of a wafer (especially if the features
on your wafer are small) as this provides a guaranteed 500 µm of relief that is
relatively easy to find.
9.6.6.4 Focus
Surface is one of the few modes that allow you to move the chuck. You can do
this step before Locate Tip, as that typically also requires the chuck
to be under the SPM.
9.6.6.5 Instructions
for available functions of the trackball are displayed in the Focus Surface
window. This is also true for other modes such as Locate Tip.
9.6.7 After
rough focus, find the features to be imaged, zoom in and refocus. Center
desired feature in view.
Note: Users must always
both Locate Tip AND Focus Surface (zoomed fully in) for every new sample that
is loaded. Whenever moving to new sections of a sample, the user must also
repeat Focus Surface, even if there is no specific topography to be imaged. The
DI-3100 calculates the difference in working distance between the tip and the
surface in order to estimate how far it must lower the SPM head.
9.7
Tuning the Cantilever
9.7.1 Select View
→
Cantilever Tune from the top menu (or click the tuning fork icon).
9.7.2 Check that
Auto Tune Controls has a frequency sweep from 100 kHz to
500 kHz, with a Target Amplitude of 2 - 3 V. Rough surfaces may do better with
a Target Amplitude set at 0.5 - 1 V.
9.7.3 Click on
the Auto Tune button.
9.7.4 A classic
resonant peak curve should appear with a resonant frequency around 300 kHz. (A
frequency outside of 220 - 320 kHz warrants a tip change.) Note the
software picks a frequency slightly below the resonant peak to account for
damping that occurs when the tip approaches a surface.
9.7.5 Return to
Image mode.
9.8
Set Initial Scan Parameters
9.8.1 In the
Scan Controls panel, set the initial scan parameters to a conservative setting.
A good start is a Scan Size of 1 µm, X and Y Offsets of 0, a Scan Angle of 0,
and a Scan Rate of 2 Hz.
9.8.2 In the
Feedback Controls panel, set Integral Gain to 0.5, and Proportional Gain to
0.7.
9.8.3 Channel 1
is typically set to collect Height data, while Channel 2 collects Phase data.
Line Direction should be set to Trace, Real Time Plane Fit should be Line, and
Offline Plane Fit to None. Both High and Low Pass Filters should be Off. Other
types of data collection can be selected if desired for either channel,
although only two channels can be saved at once.
9.9
Engaging the Surface
9.9.1 Select Motor
→ Engage from the
top menu (or click on the green down arrow Engage icon) to engage the
tip (the motor value located at the bottom of the monitor displays the number
of microns the motor has moved down from its original position).
9.9.2 Wait until
the tip engages the surface.
9.9.3 Once
contact with the wafer surface occurs, go to View → Scope Mode (Or click
the Scope Mode icon. This will show the Scope Trace on the right
monitor allowing you to view the trace and retrace of the sample.
9.9.3.1
Go to Motor/Withdraw then go to Stage/Focus
Surface.
9.9.3.2
Using the roller, manually move the SPM 50-100 µm more
negative.
9.9.3.3
Repeat "Engage" until motor no longer
fails.
9.9.3.4
Go to Motor/Withdraw 2 - 3 times.
9.9.3.5
Using the roller, manually move the SPM 50 - 100 µm more
positive.
9.9.3.6
Repeat "Engage" until motor no longer
fails.
9.10 Z-Offset
9.10.1
In the “scope mode”, the
right-hand side of the screen shows the “Z-Offset Voltage”. This is voltage applied to the piezo to
maintain constant oscillation amplitude.
If it is substantially different from zero, go to Motor → Step Motor
and click on “tip up” or “tip down” to bring the Z-Offset to about zero. Doing so will avoid applying a large,
sustained voltage to the piezo. Large
applied voltages tend to depole the piezoelectric material and cause it to lose
its sensitivity permanently.
9.11 Scanning
Technique
9.11.1 Go to View
→ Scope
Mode (or click on the Scope Mode icon).
9.11.2 Check to
see if Trace and Retrace are tracking each other well (i.e. look similar). If
they are tracking, the lines should look the same, but they will not
necessarily overlap each other, either horizontally or vertically. It may help
here to disable the Slow Scan Axis, forcing the SPM to image the same line over
and over.
9.11.3
If tracking well (tip is scanning on the sample
surface)
9.11.3.1 Click on
Setpoint and use right arrow key to gradually increase the Setpoint value,
until the tip lifts off the surface (at this point the Trace and Retrace will
no longer track each other).
9.11.3.2 Next,
decrease the Setpoint with the left arrow key until the Trace and Retrace
follow each other again.
9.11.3.3 Decrease
the Setpoint 1 - 2 arrow clicks more to ensure that the tip will continue to
track the surface. Occasionally the tip will lift off of the surface during a
scan and the setpoint will need to be re-lowered.
9.11.3.4 If
necessary, increase the Integral Gain until the tracking between Trace and
Retrace lines is optimal. Over increasing the Integral Gain will result in
noise showing up on top of the signal. Proportional Gain should also be
adjusted in the same direction as Integral Gain, remaining 30 - 100% higher in
value. Integral Gain is a high frequency parameter, while Proportional Gain is
a low frequency parameter. Both modulate the response time of the applied
feedback.
9.11.3.5 Go to View
→ Image Mode (or click on the
Image Mode icon) to view the image.
9.11.4
If not tracking well
9.11.4.1 Adjust the
Scan Rate, Gains, and/or Setpoint to improve the tracking. Using the arrow keys
(left/right) increments each parameter by a recommended amount. Wait 1 - 3 scanlines
after each adjustment to allow the SPM to settle.
9.11.4.2 Scan Rates
and Setpoints depend significantly upon the type of sample being imaged.
Recommended scan rates are 2 Hz for scan sizes 1 - 3 µm, 1 Hz for 5 - 10 µm,
and 1.0 - 0.1 Hz for larger scans. Samples
with larger steps typically need slower scan speeds. Decreasing the Setpoint
increases the amplitude of oscillation of the cantilever, although too high a
value may lead to distorted images and damage of soft films. Increasing the
Integral and Proportional Gain can also improve tracking by decrease the
response time of the feedback loop.
9.11.4.3 If there
is noise riding on top of image signal (i.e. signal oscillation not the
same in the trace and retrace directions), decreasing the Gain may help.
9.11.5
Tips
9.11.5.1 Scan Size,
Scan Angle, and other parameters can be modified after features are located.
9.11.5.2 Decreasing
Samples per Line and the Resolution of the scan can speed up rough scans to
allow the user to locate small features by producing a quick rough image.
9.11.5.3 In Image
Mode, Offset and Zoom In/Out can be used to reposition the
cantilever within the current scan window without manually typing in x/y
offsets (click on execute after placing a cursor or box). Such repositioning
however is only accurate within microns of displacement and may not work well
with small scans.
9.11.5.4 After a
large displacement by the scanner (including forcing the SPM to the top or
bottom of a scan), there may be significant 'creep' distortion observed in the
scanned image. This should fade with time, and image capture can begin after
the creep has settled. For large displacements, it may take more than 1 scan
for the creep to completely settle out.
9.11.5.5 Remember
that the scan rate needs to be adjusted when scan sizes are enlarged.
9.11.5.6 Typical
tapping mode tips are anisotropic in shape and can give higher resolution
imaging depending on scan angle. Consult either the DI website or user manuals
for more information (this typically only an issue for very thin imaging).
9.11.5.7 Further
advice and more advance image adjustment techniques are available in DI-3100
manuals that are available upon request from the superuser (Section 5.0).
Note: The piezo
crystal that is utilized by the SPM is subject to stress and wear, especially
with the application of large DC offsets. After the SPM head is engaged, it
relies upon the piezo crystal for lateral displacement (i.e. X Offset and Y
Offset); hence large (> ~20 µm) displacements in the scanning field tend to
stress the crystal more than average and are to be avoided if possible. Large
scans have the same effect, and since large scans often required a slow Scan
Rate (and hence long scan time), they tend to particularly stress the piezo. If
step heights are the main function for such sweeps, use of either of the
Microlab profilometers (asiq/Dektak) is recommended instead.
9.12 Image
Capture
9.12.1
In Image Mode, image captures consist of raw
data from the AFM, yielding all possible information. In Scope Mode
the image capture grabs a screen shot of the scope output and is not as useful.
Remember to be in Image Mode when capturing
images.
9.12.2 Select Capture
→ Capture
Filename to set the file name. (Use the extension .001 for
the first file of a series. The software will then increment each subsequent
capture to 002, 003 and so on.
9.12.3 Make sure
the hood is closed while capturing the image to prevent optical noise from
disturbing the photodetector.
9.12.4 Select Capture
→ Capture (or click
on the Eye Icon) to begin capture. At the bottom of the screen,
the Capture bar should say either Capture: On or Capture:Next.
Capture:On means the capture has begun and will end when the scan
reaches the opposite end of the screen. Changing any essential control
parameters will halt the scan and require you to start the scan over. Capture:Next
means the image capture will begin after the scanner reaches the top or bottom
of the screen. You can force the scanner to go to the top or bottom by using
the respective icon. When the capture is done, Capture:Done will appear
in the Capture bar.
9.12.5 Typically
data is saved Offline with no plane fitting. This allows you to save
data directly from the AFM, and perform analysis and corrections (leveling,
flattening, etc.) offline. If desired, Offline Planefit can be
set to Full under the Channel 1/2 Control Panel.
9.12.6 Clicking
on Capture twice in a row enters Capture:Forced mode, where you can
force a capture to begin mid-screen.
9.12.7 By
default, captured images go into the !:/ directory and can be viewed and
analyzed in Offline Mode. All users are
responsible for saving their data to disk immediately after use.
There is a Zip™ and floppy Drive on the computer that can be used to
retrieve files. The computer may be formatted at any time as files build.
9.13 Liftoff /
Shutdown Procedure
9.13.1 When done
imaging, lift the SPM by selecting →
Withdraw (or clicking the red up arrow icon).
9.13.2 If a
subsequent scan is desired, select Stage → Focus Surface and move the sample to the new
area. Always be aware of any topography on
samples that may be high enough to crash into the head when translating the stage.
9.13.3 If ready
for unload, check to see if there is enough clearance to withdraw the head. If
not, select Stage → Focus
Surface and defocus such that the head rises sufficiently.
9.13.4 Select Stage
→ Load New
Sample. This should further raise the SPM and pull the chuck
out to the unload position.
9.13.5 Turn off
the vacuum and unload your sample.
9.13.6 If
double-sided adhesive was used, use methanol or ethanol and Kim-wipes to clean
the chuck of all adhesive (to prevent damaging chuck vacuum tubing, do not use
acetone).
9.13.7 Exit
software and then turn off
controllers.
9.13.8 Disable
the AFM on the wand and close the hood.
Note: Exiting the
software and then turning off the controllers avoids stressing the Scan Head.
However, leaving the controllers ON while turning the computer OFF results in
floating voltages driving the piezo in the SPM. This situation is highly
stressful for the piezo crystal and will result in rapid deterioration of the
Scan Head.
9.14 Data
Retrieval / Image Analysis
9.14.1 Captured
Data can be analyzed by selecting Offline Mode (or clicking on
the Offline Mode icon in the upper right hand corner of the left monitor. By
default the file browser opens to the Capture Directory, labeled !:\.
9.14.2 Image
analysis can only be performed on one channel of data at a time. Select
Image → Select
Left <Right> Image to perform analysis on the left <right> image.
When an image is selected, typically the left monitor is used to adjust
parameters, while the right monitor allows for selection of partial areas,
drawing of scales/lines, and execution of desired functions.
9.14.3 Typically,
while in Microscope mode, a Real-time Linefit is used to display collect image
data. For most scans, a linefit is required to visually interpret the data.
Offline however, it is recommended that the data be captured in its raw form.
Hence when first viewing captured data offline, the image will often appear
either warped or non-existent. While it is desirable to modify the raw image
data as little as possible, often some type of fit or flattening is required.
In many cases this fitting process is iterative, with better
planefits/flattening possible as the image becomes clearer. The functions used
to fit/flatten/filter data are located under the Modify menu. Commonly used
functions include:
9.14.3.1 Planefit
Auto/Manual - Planefits are commonly used to remove bow or tilt from
images. Planefit calculates a single polynomial fit for the entire image (or
selected areas) and then subtracts the polynomial fit from the image. Manual
mode allows for the planefit to be calculated from a manually positioned line.
9.14.3.2 Erase Scan
Lines - Removes scan lines from image due to skips, noise, etc.
The selected line is replaced by the average of the two adjacent lines.
9.14.3.3 Flatten - Flatten
may be used to remove image artifacts due to vertical (Z) scanner drift, image
bow, skips, etc. It modifies the image on a line-by-line basis, removing the
vertical offset between scan lines in the fast scan direction by calculating a
least squares fit polynomial for a scan line, and subtracting it from the
polynomial fit from the original line. This makes the average Z value of each
scan line equal to 0V. The result is that information in
the Y direction is removed. Hence when
there are regular feature heights, it is best to scan across these
features in the fast scan direction (i.e. the tip is scanned directly over the
step instead of along the step). On smooth surfaces, Flatten has negligible
effect on roughness measurements.
9.14.4 There are
many Image Analysis tools available under the Analyze menu. Commonly
used tools include:
9.14.4.1 Section - Depth,
height, width and angular measurements can be easily made on cross-sections
with Section.
9.14.4.2 Roughness -
Roughness measurements over both an entire image or a selected area, can be
calculated. Different parameters can be chosen using the Screen Layout
button.
9.14.5 Different
views are also selectable including 3-D isometric views, lit from any angle.
9.14.6 When
modification and analysis is complete, data can be exported to a variety of
formats including TIFF and JPEG. The raw data can also be saved allowing for
custom data manipulation and analysis. Remember to save any desired data onto a
Zip™ or floppy disk. It is advisable to always backup raw captured data onto
disk along with any processed data. Raw data can always be re-examined on the
Nanoscope software without turning on the controllers if the user directly
selects Offline mode.
10.0 Troubleshooting
Guidelines
11.0 Figures
& Schematics
12.0 Appendices