NEWS!!!! Anand just got his Ph. D in EE
Work was presented at the following conferences :
InterMag & Magnetism & Magnetic Materials 2002
Nanoscale Devices & System Integration 2004
The Materials Research Society Meeting 2004
and published in
Journal of Nanotechnology
Physica C
Journal of Electronic Materials
IEEE Transactions on Nanotechnology
I'm focusing on fabrication of nano-magnets. My project is an
ontgoing collaboration between our group and Materials Science Division at Argonne National
Laboratory.
Nano-structured
materials have been made using electron-beam lithography, interferometric
lithography, x-ray lithography, nano-imprint lithography, by self-ordering and
self-assembling methods or by using block copolimer lithography. In our work we
rely extensively on electron beam lithography (EBL) because of its flexibility
in providing rapid turnaround of the patterns described only by a CAD file. EBL
systems use a small electron beam spot that is moved with respect to the wafer
to expose the wafer one pixel at a time.
For my work I employed a Raith E-Lines e-beam lithography system with patterning
capability in the 25 nm range.
Fig. 1. Raith E-Lines e-beam writing system with patterning capability in
the 25 nm range (NCF UIC ).
Fig. 2. Scanning Electron Micrograph (SEM) of my pattrns on Si
wafer written with Raith E-Line in the class 100 “clean room” at NCF UIC
We realize that it is important not only to learn how to fabricate
nano-structures and nano-devices, but also be able to characterize them and
understand observed properties.
Fig. 3. Magnetic Force Microscopy (MFM) (NCF UIC ).
The capability to perform the state-of-the-art
fabrication, characterization and imaging combined with existing
fabrication facilities in the NCF
clean room is vital for success of our nano-program.
UIC Electron
Microscopy Center RRC offers
critical support in characterization. The Electron Microscopy Facilities at UIC
are among the best in the world offering transmission (TEM) and scanning
transmission (STEM) electron microscopy.
Magneto-optic Kerr effect
(MOKE) measurements and Brillouin scattering is done in collaboration with Dr.
Marcos Grimsditch from Materials Science Division of Argonne National
Laboratory. Dr. Grimsditch developed a diffraction MOKE (D-MOKE) technique. MOKE
and D-MOKE yield information on the magnetization hysteresis loops, and are
convenient substitutes for SQUID and other magnetometry techniques that are not
always easy to apply to nanoarrays. Brillouin scattering provides information on
dynamic response similar to ferromagnetic resonance, but again having some
advantage in dealing with small samples.
Lorentz microscopy is based on
electron transmission through a thin magnetic film and their deflection due to
the Lorentz force, which is proportional to the local magnetic field. It
provides very high resolution of better than 10 nm. LSTEM is performed in
collaboration with Dr. Nestor Zaluzec. For more details on this technique, visit
our web site http://tpm.amc.anl.gov/MMC/Pubs/NanoMagnet/NanoMagnetic1.html/