electron beam lithography - 123seminarsonly.com
TRANSCRIPT
![Page 1: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/1.jpg)
Electron Beam Lithography
![Page 2: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/2.jpg)
• Patterning techniques
• The electron beam lithography
• Applications of the EBL
• Future oportunities for EBL
![Page 3: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/3.jpg)
Criteriums about different techniques
ResolutionSpeedEasy fabricationCost
Patterning Techniques
![Page 4: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/4.jpg)
Patterning Techniques
1.OPTICAL LITHOGRAPHY
a) Deep Ultarviolet Lithographyb) Extreme Ultraviolet Lithographyc) X Rays
2. NANOIMPRINT
![Page 5: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/5.jpg)
1) Optical Lithography
• Photoresistive resine
• Patterns: Masks
• Wavelenght resolution dependant
![Page 6: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/6.jpg)
Resolution Limits• Contact
Advantages:
●Good resolution
Drawbacks:
●Masks thin and flexible●Use ->defects
![Page 7: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/7.jpg)
Resolution Limits• Proximity
Advantages:
●Masks lifetime high
Drawbacks:
●Resolution not as good●Diffraction●Fresnel diffraction
Gap~ 20-50 μm
![Page 8: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/8.jpg)
Resolution Limits• Projection
Advantages:
●Good resolution●No deterioration●Image smaller than mask
Drawbacks:
●Fraunhoffer diffraction●Compromise between resolution and depth of focus
![Page 9: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/9.jpg)
b) Extreme Ultraviolet Lithography
• Small wavelenghtBetter resolution
• No lences: mirrors
• Laser plasma sources
• 10 nm
![Page 10: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/10.jpg)
c) X Ray
• < 1nm for Medical purposes
• Problems of masks• Lences, mirrors
• Difficult to produce
![Page 11: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/11.jpg)
2) Nanoimprint
• 2 techniques:
Heat resineCool down
UV radiations
![Page 12: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/12.jpg)
EUV soon in fabrication
NanoimprintE beamfor 22nm
X Rays difficult
Patterning Techniques
![Page 13: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/13.jpg)
The electron beam lithography• Types of EBL
Electron Beam Direct Write Electron Projection Lithography
Bragg-Fresnel lens for x-rays Paul Scherrer Institute
![Page 14: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/14.jpg)
Electron Beam Direct Write• An electron gun or
electron source that supplies the electrons.
• An electron column that 'shapes' and focuses the electron beam.
• A mechanical stage that positions the wafer under the electron beam.
• A wafer handling system that automatically feeds wafers to the system and unloads them after processing.
• A computer system that controls the equipment.
![Page 15: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/15.jpg)
Electron Beam Direct WriteTypes of electron guns• Thermoionic• Field emission
Write-field (WF)
Scanning methods• Raster scan• Vector scan
Raith 150 Manual (Nanostructure Physics Dept. KTH) Anders Liljeborg
![Page 16: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/16.jpg)
Specifications, a real example
Raith150• Beam size ≤ 2nm @
20 keV• Beam energy 100eV -
30 keV • Minimum line width
20 nm • Import file format
GDSII, DXF, CIF, ASCII, BMP
![Page 17: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/17.jpg)
Electron Projection LithographyElectron Beam
Direct Write
• SCALPEL (Bell Laboratories and Lucent technologies) 1995
• PREVAIL (IBM) 1999
Limited throughput
Electron Projection Lithography
Huge penetration depth of electrons
New solutions
![Page 18: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/18.jpg)
Electron Projection Lithography
• SCALPEL– High contrast– Image reduction
• PREVAIL– Larger effective field
![Page 19: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/19.jpg)
Electron beam resists
1. Important parameters 2. Types of resist3. Resist limitations
![Page 20: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/20.jpg)
EBL resists
Types of resist• Positive resist
Polymethyl methacrylate (PMMA)
• Negative resist
Recent progress in electron-beam resists for advanced mask-making by D.R.Medeiros, A.Aviram, C.R.Guarnieri, W.S.Huang, R.Kwong, C.K.Magg, A.P.Mahorowala, W.M.Moreau, K.E.Petrillo, and M.Angelopoulos
Important parameters Resolution (nm) Sensitivity (C/cm^2)
![Page 21: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/21.jpg)
Resist limitations• Tendency of the resist to swell in
the developer solution.
• Electron scattering within the resist.
– Broadens the diameter of the incident electron beam.
– Gives the resist unintended extra doses of electron exposure .
![Page 22: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/22.jpg)
Applications of Electron Beam Lithography
• Research- Nanopatterning on Nanoparticles- Nanowires- Nanopillars- Gratings- Micro Ring Resonators- Nanofluidic Channels
• Industrial / Commercial- Exposure Masks for Optical Lithography- Writing features
![Page 23: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/23.jpg)
Nanopatterning on nanoparticles• Significance
- Photonic Crystals- Quantum Dots- Waveguides
• Electron Beam Lithography- Fine writing at moderate electron energies- 37nm thick lines with 90nm periodicity- 50nm diameter dots with 140nm periodicity
(2003), Patterning of porous Silicon by Electron Beam Lithography, S. Borini, A. M. Rossi, L. Boarino, G. Amato
![Page 24: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/24.jpg)
Nanowires• Applications
- High-Density Electronics (Sensors, Gates in FETs)- Molecular Electronics & Medical/Biological Applications
• EBL with Electrochemical size reduction- High-Resolution Controlled Fabrication- Widths approaching 10nm regime
• Patterning of Films of Gold Nanoclusters with Electron Beam Direct Write Lithography- Sub 50nm wide Nanowires- Controlled thickness at single particle level
Controlled Fabrication of Silicon Nanowires by Electron beam lithography and Electro- chemical size reduction (2005), Robert Juhasz, Niklas Elfstrom and Jan Linnros
Nanometer Scale Petterinng of Langmuir-Blodgett Films of Gold Nanoparticles by Electron Beam Lithography (2001), Martinus H.V Werts, Mathieu Lambert, Jean-Philippe Bourgoin and Mathias Brush
![Page 25: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/25.jpg)
Nanopillars• Significance
- Quantum Confinement Effects- Photoconductive response in Nanopillar arrays
• EBL and Reactive Ion Etching- Etched Pillars with 20nm diameter
Nanotechnology using Electron Beam Lithography, Center for Quantum Devices
![Page 26: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/26.jpg)
Gratings• Applications
- Distributed Feedback Lasers- Vertical Cavity Surface Emitting Lasers
• Continuous Path Control Writing using EBL- Avoids stitching errors
Nanotechnology using Electron Beam Lithography, Center for Quantum Devices
![Page 27: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/27.jpg)
Micro Ring Resonators• Applciations
- Optical Telecommunication and Networks
• EBL and Dry Etching- 105 devices/cm2 density
Nanotechnology using Electron Beam Lithography, Center for Quantum Devices
![Page 28: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/28.jpg)
Nanofluidic Channels• Significance
- Laboratory on a chip
- Single Molecule Detection
• Electron Beam Lithography- Single step planar process
- Tubes with inner dimension of 80nm
(2005) A single-step process for making nanofluidic channels using electron beam lithography, J. L. Pearson and D. R. S. Cumming
![Page 29: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/29.jpg)
Industrial Applications
• Exposure Masks for Optical Lithography using EBL
• Writing Features
![Page 30: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/30.jpg)
Some Applications of E-Beam Lithography
• Cryo-electric devices• Optoelectronic devices• Quantum structures• Multi-gate Devices• Transport mechanism for semi and superconductor
interfaces• Optical devices• Magnetism• Biological Applications
– Nano-MEMS– Nanofluidics
![Page 31: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/31.jpg)
Future opportunities for electron beam lithography
1. Double gate FinFET devices2. Single electron transistors3. Photonic crystals
![Page 32: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/32.jpg)
• Principle
Full control over a very
thin body region by two gates
• Fabrication thanks to e-beam
- Beam diameter smaller than 2nm
- Low energy (5 keV)
- High resolution organic resist
- Overlay accuracy thanks to scanning of registration marks
- Silicon etching
Double gate FinFET devices - Concept
20 nm electron beam lithography and reactive ion etching for the fabrication of double gate FinFET devices (2003), J. Kretz , L. Dreeskornfeld, J. Hartwich, W. Rosner
Nanoscale FinFETs for low power applications (2004), W. Rösner, E. Landgraf, J. Kretz, L. Dreeskornfeld, H. Schäfer, M. Städele,T. Schulz, F. Hofmann, R.J. Luyken, M. Specht, J. Hartwich, W. Pamler, L. Risch
![Page 33: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/33.jpg)
• High performance devices
Transfer characteristic similar to
those obtained with bulk transistors
Appl: SRAM because high density
+ capability of driving a large bitline load
• Low power applications
High on-current, very low off-current
Double gate FinFET devices – Characteristics & Applications
Nanoscale FinFETs for low power applications (2004), W. Rösner, E. Landgraf, J. Kretz, L. Dreeskornfeld, H. Schäfer, M. Städele,T. Schulz, F. Hofmann, R.J. Luyken, M. Specht, J. Hartwich, W. Pamler, L. Risch
![Page 34: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/34.jpg)
Single electron transistor - Concept• Physic principle
Weak external force to bring an additionalelectron to a small conductor “island”=> Repulsing electric field
• SET concept- Down-scaling- Low power consumption
• Difficulties- Need of very small “islands” becausethe addition energy must overload the temperature effects
- Polarization in case of impurities=> randomness background charge
Single-Electron Devices and Their Applications (1999), Konstantin K. Likharev
![Page 35: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/35.jpg)
Single electron transistor - Fabrication
Fabrication of silicon nanowire structures based on proximity effects of electron-beam lithography (2003), S.F. Hua, W.C. Wengb, Y.M. Wanb
• Classic technique
Smallest “island” needed
=> Use of high resolution lithography technique
=> E-beam lithography
• With silicon nanowires
Lithography with e-beam, with specific beam current density and dose
Results: single electron charging effect
Polysilicon grain = “islands”
Grain boundaries = mini tunnel barriers
![Page 36: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/36.jpg)
Single electron transistor - Applications
• Supersensitive electrometryVery small change of gate voltage=> measurable variation of IVery useful for physical experiments
• Single electron spectroscopy
• Replacing MosFET?
• Random access memory- Bit stored in large conductiveisland (floating gate)- Need of a sense amplifier=> association with FET amplifier- Very impressive density: 1011 bit/cm
NO !!!
Single-Electron Devices and Their Applications (1999), Konstantin K. Likharev
![Page 37: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/37.jpg)
Photonic crystals - Concept
• Aim: propagation of light in a controllable manner
• => Optical “chips” with waveguides, cavities, mirrors, filters…Example of very compact quantumoptical integrated circuit:
• Need of a dielectric or metallic lattice, with adjustable parameters: geometry, dielectric constant…
Three-dimensional photonic crystals operating at optical wavelength region (2000), Susumu Noda
![Page 38: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/38.jpg)
• Creation of the desired lattice
- With e-beam lithography at low beam energy (5keV)
- Negative resist. Ex: SU8-2000, with high refractive index (1,69) and good mechanical stability
• Results
A few mode are allowed to propagate, depending of the photonic crystal parameters
2D photonic crystals
Two-dimensional photonic crystal waveguide obtained by e-beam direct writing of SU8-2000 photoresist (2004), M. De Vittorio, M.T. Todaro, T. Stomeo, R. Cingolani, D. Cojoc, E. Di Fabrizio
![Page 39: Electron Beam Lithography - 123seminarsonly.com](https://reader030.vdocuments.mx/reader030/viewer/2022012702/61a4db880094593bc530a2f6/html5/thumbnails/39.jpg)
3D photonic crystals• Several methods to create the lattice
- Wafer-fusion and alignment
techniqueEx: Layers of III-V semiconductors (AlGaAs…)
- XRay and e-beam lithography
• Introduction of defect states, light emitting elements…)
By wafer-fusion, two-resist process…
Three-dimensional photonic crystals operating at optical wavelength region (2000), Susumu NodaXRay and e-beam lithography of three dimensional array structures for photonics (2004), F. Romanato,
E. Di Fabrizio,M. Galli