ADDENDUM
IMPORTANT DOCUMENT – BID REVISION
BID NUMBER: ITB1029
OPENING DATE & TIME: MAY 20, 2010 @ 2:00PM
BID TITLE: ATOMIC FORCE MICROSCOPE
ADDENDUM NUMBER: 1
ADDENDUM DATE: MAY 13, 2010
PLEASE MAKE THE FOLLOWING CHANGES AND/OR REVISIONS TO THE BID
DOCUMENTS.
Purpose of this addendum is to answer questions submitted by potential
proposers. Questions and answers begin on page 2.
PLEASE ACKNOWLEDGE RECEIPT OF THIS ADDENDUM AND RETURN IT WITH YOUR PROPSAL.
FAILURE TO SIGN AND RETURN WITH YOUR PORPOSAL COULD RESULT IN REJECTION OF YOUR
PORPOSAL.
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PROPOSERS SIGNATURE
PRINT OR TYPE BIDDER'S NAME
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ADDRESS
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CITY – STATE – ZIP CODE
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ITB 1029
ADDENDUM 1
1.
QUESTION: Tip and sample scanning on line with the ability to switch between tip and sample
scanning to provide Z range of up to 100 microns.
Why do you need a 100 microns Z range?
Is this a parameter needed for a specific application? There is a specific reason why I ask. If you have such a
large Z range, you will not be able to do any high resolution Z work. Most AFM systems usually use around 712 microns Z range. If you use this range you will be able to do sub Angstrom Z measurements. When you use
extended Z ranges you lose sensitivity and introduce more artifacts. This is why most AFM companies offer a
mean range of 10 microns in Z and extended ranges as an option for limited situations that are compromised
cases.
UCF ANSWER:
The high Z range was listed in consideration of load experiments. For example when loading a
cantilever across which a carbon nanotube is suspended, due to high elastic strain capabilities,
we expect the Z range needed could be up to the maximum stated. However, this is a flexible
requirement since alternative loading options are being considered. If the sensitivity is indeed
higher for the smaller Z range (and we request that you list this sensitivity) then the reduced Z
range will be acceptable with alternative loading options suggested by you.
2. QUESTION: Exposed tip normal force probe designed for nanooptical, nanochemical, nanothermal and
nanoelectrical operation
What do you mean by nanoptical, nanochemical, nanothermal and nanoelectrical operation? Please give me
specific definitions.
These modes will come with the system. In AIR: Contact AFM, Lateral Force, Force/distance, Force Modulation,
Semicontact, Noncontact, Phase Imaging, Electrostatic Force Microscopy, Kelvin Probe Microscopy, Conductive
AFM, Piezoresponse Force Microscopy, Nanolithography, Nanomanipulation, Scanning Spreading Resistance
Microscopy, Scanning Capacitance, Magnetic Force Microscopy.
Options in AIR: Atomic Force Acoustic Microscopy, Scanning Thermal Microscopy, micro X-Ray Fluorescence,
Scanning Tunneling Microscopy, External In Plane Magnetic Microscopy, Heating Elements (150C, 200C, 300C),
Purging the Sample Area, Controlled Humidity of the Sample Area, Controlled Temperature of the Sample Area.
Options IN Liquid: Contact AFM, Lateral Force, Force/distance, Force Modulation, Semicontact, Noncontact,
Phase Imaging, Nanolithography, Heating Elements (60C, 120C), Flow Through Liquid Cells, Open Liquid Cells,
Closed Liquid Cells, AFM Electrochemistry, STM Electrochemistry, Quartz Crystal Microbalance.
UCF ANSWER:
The above terms refer to the ability to do PL and Raman at the nanoscale, analysis of chemical
composition at the nanoscale, temperature studies at nanoscale and studies of electrical properties at
the nanoscale.
3. QUESTION: Ability to use tuning fork based probe with the same AFM/NSOM/Confocal head as the one
used for cantilevered glass probes.
Why do you want to use a cantilever glass probes? These cantilever glass probes have a larger tip radius than
the standard AFM probes. The standard AFM probe is less than 10 nm, the glass probes are typically anywhere
from 40 nm to 10,000 nm tip radius. The main reason that a person uses an AFM system is to get the best
image quality in XY & Z (high resolution work) of the data. For an example think about using a very sharp
pencil, it is very sharp after sharpening it (tip radius is smaller). After a while the pencil gets dull (tip radius is
dull). You cannot write with this dull pencil so you sharpen it again and start writing.
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The cantilever glass probe already has a large end radius. This means you get lower resolution right from the
start. As the tip wears and becomes dull, it will get even worse. This means that standard AFM probes will
always be sharper and provide higher resolution. I can provide data to back this up or you can talk to any AFM
person. They will verify this information. Standard AFM probes are commercially available from a number of
suppliers. All of the AFM suppliers in the world use this common format that offers high resolution. The
cantilever glass probes are manufactured by only one company and have limited usefulness. They are a lot
more expensive than AFM probes.
As a side note, we offer the ability to use glass cantilevered probes as an option. We don’t recommend them,
but it is available from us as well.
UCF ANSWER:
While the image quality improves as a result of smaller tip radius with conventional probes, the
Raman spectral signals are also of significance. The transparent glass probes allow for optical
transmission and maximum visibility for mapping of samples. Equivalent standard cantilever probes
should be described as such and options for ability to use glass probes if available should be stated.
4.
QUESTION: Would you be interested in the ability to use glass cantilevered probes as an option. We
don’t recommend them, but it is available from us as well.
UCF ANSWER:
Yes
5.
QUESTION: AC operating mode with all cantilevered optical fiber probes, for near-field optical
imaging,Chemical studies, resistance imaging, thermal imaging and regular AFM sensors.
This statement is very confusing and misleading. Some of these modes like resistance imaging, thermal
imaging, etc. have to be touching the surface in order to work. This is dictated by the physics of the
application. I have a short description of resistance imaging. If you go to the web site, you can watch a short
video. To get a real resistance image, you need a hard, sharp tip and apply a force onto the sample to break
the native oxide layer, then scan in contact mode. This allows you to collect resistance measurements. If you
don’t operate in contact you can’t get a resistance measurement. If you were to do this with a cantilever glass
probe, it would break. Most companies again use special AFM probes with hard coatings to break the oxide
layer for this type of work. All AFM companies do this with one exception, you need to ask yourself why?
See below. http://www.ntmdt.com/spm-principles/view/spreading-resistance-imaging
Spreading resistance imaging depends on using a conductive AFM tip in direct contact with the sample surface
[1] <http://www.ntmdt.com/spm-principles/view/spreading-resistance-imaging#1> . A voltage bias is applied
to the tip and the resulting current through the sample is measured as a function of the tip position on the
surface simultaneously with acquisition topography in Constant <http://www.ntmdt.com/spmprinciples/view/constant-force-mode> Force mode .
It can easily be shown, assuming that the tip-surface contact resistance does not change with position, that
the measured current for a given bias will be proportional to the local resistivity of sample under investigation.
Spreading resistance imaging can be also applied to samples with complicated structures, such as integrated
circuits for example.
A review of current status of Spreading Resistance imaging is submitted in [2] <http://www.ntmdt.com/spmprinciples/view/spreading-resistance-imaging#1> .
References
1.
US Pat. 4992728.
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2.
J. Vac. Sci. Techn. B, 20 (1), 471 (2002).
UCF ANSWER:
The system should accept different tips and the tip would then be selected for the appropriate
application.
6.
QUESTION: Ability to work in thermal conductivity mode using non-contact mode AFM.
Again this would be breaking the laws of physics. You have to be in contact with the sample in order to do this
type of experiment. The probe is heated by running a current through it. As you scan on the surface (you are
in contact with the surface), heat is absorbed by the sample. You measure this as you are scanning. You will
be displaying two images as you scan. One will be the topography and the other will be a thermal conductivity
image.
See the URL for additional information. http://www.ntmdt.com/press-releases/view/skaniruyushcayatermalnaya-mikroskopiya-sterm
UCF ANSWER:
With a high enough thermal response time, only intermittent contact is necessary for thermal and
resistance imaging.
7.
QUESTION: 3D scanning stage with central aperture enabling clear vertical axis for placement of
microscope lenses from above or below.
Please explain this in more detail. What we think is you want an objective lens above the sample and also one
below the sample. If this correct, then this will add noise into the AFM system. Why is it needed? We can do
this but it will add more noise into the system. Most people want to keep the noise level down so that they can
measure sub Angstroms in Z.
UCF ANSWER:
The need here is for an unobstructed optical axis.
8. QUESTION: High resolution scanning with about 35 micron scan range in x and y directions as well as
35 microns z direction.
My first question is about having a 100 micron in Z, now you have reduced it to 35 micron in Z. See my
statement about why people want to do high resolution work in Z only use roughly 7-12 microns Z ranges.
UCF ANSWER:
The resolution should not deteriorate with scan range and if there is deterioration, it should be
indicated.
9. QUESTION: High resolution sample scanning with X Y and Z of about 85 microns.
My first question is about having a 100 micron in Z, now you have reduced it to 85 micron in Z. See my
statement about why people want to do high resolution work in Z only use roughly 7-12 microns Z ranges.
Most AFM companies have scanners for XY that cover from 100 microns range down to tens of nanometers
(nm). So you use one scanner for that sample. You do not have to change scanners. Each time you change
scanners, you cannot find the exact spot on your sample again. With the NT-MDT scanner you will be able to
do very high resolution imaging using one scanner.
See some of our good high resolution work at this URL.
http://www.ntmdt.com/scan-gallery/group/critical-resolution
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UCF ANSWER:
See answer to previous question.
10.
QUESTION: Ability to image in near-field reflection using independent channels of illumination with a
cantilevered fiber probe for excitation and a lens at 90 to the sample plane above the probe for collection and
with no need for other lenses for illuminating the probe or viewing the sample.
Please explain this. I have no clue what it means.
UCF ANSWER:
This pertains to the ability to integrate the AFM with spectrometers in different ways if necessary
(side illumination or bottom illumination). This will allow that future upgrades of the
spectrometer system can be supported by the AFM system.
11.
QUESTION: Ability to have on-line stage scanning AFM auto-focus confocal optical imaging using
cantilevered glass AFM probes with tips exposed to the optical axis and with the optical imaging from the
same side of the sample as the AFM imaging or optical imaging from below the sample.
Please explain this. I have no clue what it means.
UCF ANSWER:
See answer to previous question.
12.
QUESTION: Ability to use a cantilevered near-field optical fiber probe with its waveguide properties
for collection mode near-field optical imaging and probe scanning.
•Ability to connect directly the near-field optical probe to waveguide analysis equipment..
Are you working with Waveguides analysis equipment? If so which makes and models?
UCF ANSWER:
The option is requested for anticipated future work. Should there be only specific models that can
work with the proposed equipment, this should be highlighted.
13.
QUESTION: Ability to use cantilevered transparent glass probes with no Raman background signal
without having to coat such probes with an opaque material.
This statement makes no sense, since glass will scatter Raman signal in all directions whether is it coated or
not. Also, it is very hard to align laser beam to the very end of the glass probe, because it is blunt (huge
compared to an AFM probe).
UCF ANSWER:
Minimal Raman background signal is important for monitoring spectral signals as they shift with
strain. The probes themselves should not contribute to background and that is what is requested
here.
14.
QUESTION: Ability to place on-line the probe off-axis while moving the probe into and out of contact
with the sample and recording spectra at each position of the tip.
I do not know what you are trying to state here. Please explain in more detail. Most people want the AFM
probe and the Raman to collect data at the same pixel simultaneously. If you move the probe back and forth,
you will never get to the exact same spot.
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UCF ANSWER:
This pertains to strain and friction studies using the probe.
15.
QUESTION: Ability to move the sample pixel by pixel while keeping the probe off-axis and moving
the probe into and out of contact with the sample and recording spectra at each position of the tip.
See my question above.
UCF ANSWER:
See answer to previous question
16.
QUESTION: Ability to place on-line the probe off-axis while moving the probe into and out of contact
with the sample and recording spectra at each position of the tip and recording the difference spectra and
image with the difference spectra.
See my two questions above.
UCF ANSWER:
See answer to previous question
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