SPM Fundamentals for the MultiMode
Hardware
Rev. B
MultiMode SPM Instruction Manual
27
Cantilevered Probes—MFM
Another variation of the TappingMode tip is the MFM probe. This is basically a crystal silicon
TappingMode probe having a magnetic coating on the tip. As the magnetized tip oscillates through
magnetic
fi
elds on the sample surface, it modulates the cantilever’s phase and frequency. These are
monitored, providing a measure of magnetic
fi
eld strength and providing images of magnetic
domains.
Cantilevered Probes—EFM
Similar to MFM (see above), EFM is also conducted using NanoProbe tips. Tips may be electrically
connected to the microscope’s circuitry to obtain surface potential maps of the surface, or oscillated
while monitoring phase changes due to electrostatic forces. These techniques yield images of the
sample’s electrical domains.
Note:
Both MFM and EFM may be conducted using the MM-SPM alone; however,
best results are obtained using a NanoScope III with an Basic Extender Module
attached, or a NanoScope IV Controller. For more information regarding this
attachment, contact Veeco.
Specialized Probes
As the
fi
eld of SPM continues its explosive growth, new probes are constantly introduced. Here are
a few examples of specialized probes:
•
Scanning capacitance microscopy (SCM)—Tip acts as an RF antennae to image
microcapacitance phenomena. MFM tips may be used for SCM.
•
Chemical doped tips—Tips doped with a chemical species of interest to the investigator.
The chemically doped tip measures chemical bonding forces on sample surface, images
receptor sites on biological membranes, etc.
•
Thermal imaging—Tip incorporates a tiny thermocouple to image heat.
•
Focused ion beam (FIB)—TappingMode tips up to 6
µ
m in length cut from crystalline
silicon with a focused ion beam. Improved aspect ratio gives them improved angular
resolution on steep side walls.
