TOP-DOWN TECHNIQUES (LITHOGRAPHY) FOR MAKING QUANTUM WIRES Lingyun Miao, Limin Ji ECE Dept....
-
date post
21-Dec-2015 -
Category
Documents
-
view
220 -
download
0
Transcript of TOP-DOWN TECHNIQUES (LITHOGRAPHY) FOR MAKING QUANTUM WIRES Lingyun Miao, Limin Ji ECE Dept....
TOP-DOWN TECHNIQUES (LITHOGRAPHY)
FOR MAKING QUANTUM WIRES
Lingyun Miao, Limin Ji
ECE Dept.
University of Rochester
Outline
Introduction Background Technology Future Work
Introduction
What is Nanotechnology? “A field of applied science and
technology covering a broad range of topics.”
-from Wikipedia
What does it do? Control of matter on a scale
smaller than 100nm.
Fig. 1 A parallel-shaft speed reducer gear which is one of the largest nanomechanical devices ever modeled in atomic detail. [1]
Introduction
Why nanotehcnology? Restrict of the current
technology. Wide application area. Fantastic characteristic.
How far has it gone? Beginning of 3rd generation.
Fig. 2. Four generations of nanotechnology. [1]
Outline
Introduction Background Technology Future Work
Background
What is Quantum Wire? “A strip of conducting material
about 10nm or less in width and thickness that displays quantum mechanical effects.”
- from Science and Technology Dictionary
Essential Difference? Not copying quantum info, but
transported-destroy at source
then recreating at destination.
Fig. 3. Illustration of carbon nanotube from www.spacedaily.com/news/nanotech-05zn.html
Fig. 4. A carbon nanotube between two electrodes from http://www.mb.tn.tudelft.nl
Background
Top-down & Bottom-up
Fig. 5 Two approaches to control matter at the nanoscale. [6]
Background
Top-down Techniques: Bulk-/film-machining Surface-machining Mold-machining
Fig. 6 Bulk-/film-machining [7]
Fig. 7 Surface-machining [7]
Fig. 8 Mold-machining with soft lithography [7]
Outline
Introduction Background Technology Lithography Needs to Beat Its Limit
Future Work
Lithography Needs to Beat Its Limit
Lithography == Photolithography?To describe a lithography imaging system:
Resolution (RES) = k1 λ / NA
Depth of focus (DOF) = k2 λ / (NA)^2
k1 and k2 are process-related factors, normally ≥ 0.6According to Rayleigh criteria, theoretical values of k1 and k2 are equal to 0.5
To increase resolutionUse shorter wavelength
Increase NA
In the past decades’ struggle…Continuous advancement of photolithography
Proposal and development of other techniquesElectron beam lithography, nanoimprint lithography, interferometric lithography, X-ray lithography, extremeultraviolet lithography, scanning probe lithography…
Outline
Introduction Background Technology Engineering Tricks with Photolithography
Future Work
Engineering Tricks with Photolithography
“Dear old” photolithography technique MUST be saved !
V-groove Heterostructure Patterning Double-exposure Patterning Immersion Lithography
V-groove Heterostructure Patterning
C. Percival et al. IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 47, NO. 9, 2000
E. Kapon et al. Appl. Phys. Lett. 55, 2715 (1989)
K. F. Karlsson et al. Appl. Phys. Lett. 90, 101108 2007
Double-exposure Patterning
Shift reticle
or 2nd reticle
develop
• Use reduced exposure dose (60-80%)• Stepper movement must be controlled precisely (nm) -> piezoelectric element
http://www.imec.be/wwwinter/mediacenter/en/SR2005/html/142319.html
Immersion Lithography
http://www.nikon.co.jp/main/eng/portfolio/about/technology/nikon_technology/immersion_e/index.htmhttp://oemagazine.com/FromtheMagazine/jul04/underwater.html
Immersion Lithography Results65nm line-and-space pattern
ArF laser with a 1.07 NA imaged these 45-nm features
Outline
Introduction Background Technology Electron Beam Lithography (EBL)
Future Work
Electron Beam LithographyUse high voltage electrons (1 kV – 100 kV) to transfer nano-patterns into resist (ex. PMMA) on the substrate by directly writing.
Define pattern on spin coated E-beam resist
Resist development
RIE etching
Cladding deposition
http://people.ece.cornell.edu/lipson/nature/fabrication.htmhttp://www.ee.pdx.edu/~jeske/litho/electronbeamlitho.html
Masaya Notomi and Toshiaki Tamamura
Outline
Introduction Background Technology Nanoimprint Lithography (NIL)
Future Work
Nanoimprint Lithography
Thermoplastic Nanoimprint lithography Photo Nanoimprint Lithography
http://www.semiconductoronline.com/Content/ProductShowcase/http://www.nanonex.com/Picture/Resists2.jpg
Outline
Introduction Background Technology Scanning Probe Lithography (SPL)
Future Work
Scanning Probe Lithography
mask fabrication and etching to produce quantum wires (a) Starting from a patterned aluminium film(b) “positive” mask (d) “negative” mask(c, e) Reactive ion etching
Local oxidation(anodization process)
A. Notargiacomo et al., Materials Science and Engineering C 19, 185-188 (2002)
Outline
Introduction Background Technology Summary of Different Lithography Techniques
Future Work
Summary of Different Lithography Techniques
Outline
Introduction Background Technology Future Work
Future Work
Figure 1. Two quantum dots connected by a wire behave somewhat like atoms in a molecule, with different energy levels, a property that might be useful as a switch in a quantum computer. ( Arizona State University) from
www.aip.org/tip/INPHFA/vol-9/iss-1/p14.html
Figure 2. Nano robots From http://www.witn.psu.edu/articles/article.phtml?article_id=41&show_id=7
Figure 3.1 Organic Light Emitting Diodes (OLEDs) for displays 2 Photovoltaic film that converts light into electricity 3 Scratch-proof coated windows that clean themselves with UV 4 Fabrics coated to resist stains and control temperature 5 Intelligent clothing measures pulse and respiration 6 Bucky-tubeframe is light but very strong 7 Hipjoint made from biocompatible materials 8 Nano-particle paint to prevent corrosion 9 Thermo-chromic glass to regulate light 10 Magnetic layers for compact data memory 11 Carbon nanotube fuel cells to power electronics and vehicles 12 Nano-engineered cochlear implant