Transcript May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI

CMI Project Review:
Optical Properties of Nanoscale Arrays
CMI-001
Fabricate Voltage-Tunable Photonic Devices
Filled with Ferroelectrics
P/097
April-Oct 2003
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Optical Properties of Nanoscale Arrays
Voltage-Tunable Photonic Devices
Cambridge PI : Prof. James F. Scott, Earth Science Dept.
MIT PI : Prof. Keith A Nelson, Chemistry Dept.
• Brief Description of Project:
Fabricate micron- or submicron-arrays of voltage-tunable
ferroelectric devices consisting of two-dimensional
patterns of high refractive index rods
Characterize GHz-THz dielectric responses through
"polaritonics" measurements w/ micron spatial resolution
• Summary of Intended Outcomes:
Delivery and test of a small number of prototype devices
Prototype apparatus for GHz-THz dielectric metrology
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Optical Properties of Nanoscale Arrays
Voltage-Tunable Photonic Devices
Ferroelectric nanotube arrays fabricated by the Cambridge group
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Optical Properties of Nanoscale Arrays
Voltage-Tunable Photonic Devices
International interest in nanotube arrays
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Optical Properties of Nanoscale Arrays
Voltage-Tunable Photonic Devices
"Polaritonics" platform developed by the MIT group
GHz-THz signal generation, guidance, control, focusing, imaging, & readout
Spatiotemporal imaging
allows direct visualization
of wave propagation
Femtosecond laser
machining of polariton
waveguides, tips, & other
functional elements
Spatiotemporal
femtosecond
pulse shaping
sends pulses to
specified
addresses at
specified times
to launch
polariton waves
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Optical Properties of Nanoscale Arrays
Voltage-Tunable Photonic Devices
Polaritonics: The Movies
Polaritons
Coherent Control
Fabricated
Structures
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Progress In Past Six Months
• Important activities, collaborations:
Successfully filled arrays 5 mm x 5 mm in size with ferroelectric nano-tubes as
small as 800 nm in outside diameter; this is an array of ca. 2500 x 2500 = 5
million nanotubes
Collaboration with M. Alexe et al. at Max Planck Institute for Microstructural
Physics, Halle, Germany, and A. Sigov et al., Moscow Technical University,
Russia (reported in invited review Reviews in Advanced Materials Science
4, pp.114-122 (2003))
Interfaced new femtosecond laser system (acquired with CMI support) to
homebuilt and homedesigned femtosecond pulse shaping appartus
Measured GHz-THz complex dielectric responses of ferroelectric materials
(without fine spatial resolution) - found high e' with sufficiently low e",
indicating possibility for extremely fine polariton focusing, high throughput,
high intensity
Conducted 3D finite difference time domain (FDTD) simulations of GHz-THz
polaritons with Beowulf computational cluster (acquired with CMI support)
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Progress In Past Six Months
• Milestones achieved:
Reproducibe deposition via “mist” chemical solution deposition (CSD) of 40-nm
wall-thickness ferroelectric nanotubes of strontium bismuth tantalate (SBT)
Both nanotubes embedded in Si and free-standing arrays (attached only at one
end) reliably produced
Demonstration of spatiotemporal femtosecond pulse shaping method that
permits single light pulse to be directed to selected location with selected
time-dependent waveform
• Deliverables completed:
One porous Si sample with ca. 5 million nanotubes of SBT (embedded – not
free-standing)
Publication: Automated spatiotemporal diffraction of ultrashort pulses, J.C.
Vaughan, T. Feurer, and K.A. Nelson, Optics Letters, in press.
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Plans For Next Six Months
• Expected activities, collaborations :
• New deposition technique (simplified) using fluid pore-wetting rather
than misted CSD
• Use of cheap, commercially available porous alumina rather than
porous Si
• Deposition of palladium electrodes
• Characterization of additional ferroelectric materials GHz-THz dielectric
functions for selection of optimal tip components
• Generation of high-intensity GHz-THz polaritons for potential
applications in ultrafast noncontact switching of ferroelectrics
• FDTD simulations of tips to optimize geometry, composition
• Preliminary attempts at tip fabrication
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Plans For Next Six Months
• Expected milestones:
• Achievement (never reported by other laboratories) of concentric
cylindrical electrodes using organic Pd precursors
• Measurement of voltage-tunable effects
• 10-50 kV/cm polariton field levels reached for attempts at FE switching
• Expected deliverables:
• One to five electrodes prototype devices
• Disclosure and patent filing for GHz-THz scanning microscopy tips and
methods
• Publication of FDTD simulations of GHz-THz polaritons
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Other Items
• Developments worth publicizing:
• Rather exciting and unplanned discoveries have occurred: We recognized
that the nanotube arrays we produce exceed the state-of-the-art wall
thickness uniformity and aspect ratio for trenched dielectric capacitors in
silicon DRAMs (dynamic random access memories). Therefore patents
have been filed on this discovery and application. Our very recent
publication of such prototype device structures (J. Phys. Condensed
Matter , 15, L527-532 (2003)) was immediately picked up by Japanese
industry press (attached article from Nikkan Kogyo Shimbun, 20 August).
• A second, perhaps equally important, application of these devices (since
they are hollow piezoelectric tubes) is for ultra-precise ink-jet print heads.
By the usual cross-tie row-and-column addressing, these permit a 5
mega-pixel page-at-a-time ink-jet printing with no rastering of the head.
• "Polaritonics" platform for GHz-THz wave generation, guidance, control,
focusing, visualization, and readout, with applications in signal processing
& metrology
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Other Items
• Modifications to statement of work and/or funding:
• Because of the unexpected developments above, we suggest
that the work statement be modified to permit further exploration
of these unexpected applications of our nanotube arrays. The
potential financial impact for trenched Si DRAMs is very large
and has already been recognized in Japan. The possible
application to ink-jet printer arrays is facilitated by the proximity
in Cambridge of the Epson-Cambridge Laboratory (SeikoEpson), with which we have close contact.
• However, we emphasize that these new opportunities should not
impair the timely production of the photonic prototypes originally
specified as deliverables.
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Other Items
• Modifications to statement of work and/or funding:
• Because of the high polariton field levels achievable and the unique
focusing prospects in high-dielectric ferroelectrics, exploration of
optically controlled, ultrafast switching of nanoscale ferroelectrics
should be undertaken. This is a completely novel prospect with
potential ultrahigh-bandwidth signal processing applications.
• These new opportunities should complement, not impair, the
originally planned development of polariton-based GHz-THz
metrology methods.
• CMI support should be maintained or increased through the
duration of the CMI project, with following main objectives:
• Nanoscale FE fabrication taken to exportable, practical stage
• New applications brought to commercial development stage
• Exportable prototype GHz-THz metrology instrument demonstrated
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Other Items
• Expected financial profile:
• We believe that several Japanese corporations would be
interested in buying IP at this stage. We have already had
discussions with Samco International Corp. in Kyoto (a mediumsized equipment manufacturer for the semiconductor industry)
about this.
• Anything else:
• PI Scott will be delivering two plenary invited talks on this new
breakthrough this summer (European Physical Society Meeting,
Prague, July; and International Symposium on Ferroelectric
Domains, Tsukuba, August). These are good marketing
opportunities for Europe and Asia.
• PI Nelson will be delivering invited talks and organizing leading
ultrafast spectroscopy meeting in Japan this summer, with good
opportunities for highlighting CMI project.
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Challenges And/or Issues To Address
• Problem/Concern:
• We need to find an inexpensive commercial source of highly
registered photonic silicon substrates. Our German supplier is
no longer producing. The Si substrates are more perfectly
ordered arrays than are the available alumina.
• We need help in marketing the DRAM trench intellectual
property. Suggested market: Infineon/Toshiba; Fujitsu;
Matsushita; or Samsung.
• MIT effort is now highly labor-intensive, with progress in
materials characterization, tip design & fabrication, simulation,
study of samples from Cambridge, generation of high polariton
amplitudes, exploration of polariton-based FE switching, and
construction of scanning metrology instrument all requiring
intense effort and some equipment.
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097
Challenges And/or Issues To Address
• Plan for resolution:
• If Si source is not located, we will limit prototypes to Al2O3.
• Some degree of piggybacking on other polaritonics projects at
MIT can provide help in materials characterization, high polariton
amplitudes, and exploration of FE switching. However, all work on
Cambridge samples, on simulation and fabrication of polaritonic
tips, on measurements with micron spatial resolution, and on
development of scanning metrology instrument are supported by
CMI alone.
• How CMI can help:
• MIT may have local or own source of buying/making porous Si?
• CMI could help with active marketing of the DRAM trenching IP.
• Sustain or increase support level through duration of CMI project.
May-Oct 2003 Review – Optical Properties of Nanoscale Arrays, CMI-001;
Fabricate Voltage-Tunable Photonic Devices Filled With Ferroelectrics, P/097