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Development of Scanning Probe Lithography (SPL). 1) “ Device fabrication by scanned probe oxidation ”, Science, 1995 2) “ Nanofabrication by scanning probe microscope lithography: A review ”, J. Vac. Sci. Tech., 2005 3) “ Scanning Probe Parallel Nanolithography with Multiprobe Cantilever - PowerPoint PPT Presentation
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Development of Scanning Probe Lithography (SPL)
EE C235/NSE C203 Nanofbrication
Jun Suk Rho
1) “Device fabrication by scanned probe oxidation”, Science, 19952) “Nanofabrication by scanning probe microscope lithography: A review”, J. Vac.
Sci. Tech., 20053) “Scanning Probe Parallel Nanolithography with Multiprobe CantileverArray Fabricated by Bulk Silicon Micromachining”, IEEJ, 2008
Group I.P.ODec. 5th 2007
Scanning Probe Lithography
Bottom Up Technique
- Chemical and molecular patterning (DPN)
Top down Technique
- Mechanical Patterning
• Scratching
• Nano Indentation
- Voltage bias application
• Field Enhanced Oxidation
• Electron exposure of resist materials
Substitution Technique
- Manipulation of nanostructures
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Achievements
Dec. 10th. 2008Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Scanning Probe Lithography (SPL)
Atomic Force Microscopy (AFM)
Scanning Tunneling Microscopy (STM)
Scanning Probe Parallel Lithography(SPL Array)
Dec. 10th. 2008Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Scanning Probe Lithography (SPL)
• Began at NIST in 1989
• Typical line width: below 50nm
• Scan rate: 10~20um/s
• Creating patterns with high resolution but are limited in throughputJ. A. Dagata, Vol. 270, pp1625-1626, Science, 1995
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
AFM Lithography Scratching
Dec. 10th. 2008
The advantages of nanoscratching for lithography
- The absence of additional processing steps (i.e etching)
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Electric Field Enhanced Oxidation
Dec. 10th. 2008
• Voltage bias between a sharp probe tip and sample generates an intense electric field at the tip- Oxidization of silicon & Anodization of metals
• The high field desorbs the hydrogen on the silicon surface and enables exposed silicon to oxidize• Oxidation depends on humidity• Can achieve sub-50nm feature sizes
J. A. Dagata, Vol. 270, pp1625-1626, Science, 1995
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Scanned Probe Oxidation- Applications
Fabrication of Si nanowire Fabrication of single tunneling transistor(SET)
J. A. Dagata, Vol. 270, pp1625-1626, Science, 1995
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Electric Field Enhanced Oxidation
Dec. 10th. 2008
AFM anodic Oxidation (Left)
AFM Nanolithography (Below)
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Parallel Field Enhanced Oxidation
Dec. 10th. 2008Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Profile vs. Resist by AFM Lithography
M. Rolandi et al. NANO LETTERS. 2004 Vol. 4, No. 5 889-893
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Non Contact AFM Lithography
Dec. 10th. 2008
• Silicon probe tip acts as a source of electrons• The field emission current from the tip is used as the feedback signal to control the tip sample spacing
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Pros• Making nano patterns without optical apparatus• Making arbitrary patterns by controlling AFM tips• Good linearity allowing excellent line width control• No backscattering which exists in EBL• No proximity which exists in EBL
Cons• Low throughput: serial scan and low speed• Small scan area• Requires higher incident electron dose than EBL
Pros & Cons of SPL (AFM Lithography)
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Scanning Probe Lithography (SPL)
Atomic Force Microscopy (AFM)
Scanning Tunneling Microscopy (STM)
Scanning Probe Parallel Lithography(SPL Array)
Dec. 10th. 2008Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
1D tunneling
Dec. 10th. 2008Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
STM Lithography
Dec. 10th. 2008
• Application of voltage pulse between tip and sample• “Pushing” atoms• Advantages of STM Litho- Information storage devices- Nanometer patterning atoms
M. Crommie (UC Berkley), Vol. 262, Science, 1993
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Scanning Probe Lithography (SPL)
Atomic Force Microscopy (AFM)
Scanning Tunneling Microscopy (STM)
Scanning Probe Parallel Lithography(SPL Array)
Dec. 10th. 2008Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Scanning Probe Arrays Lithography
Hensy Gandjar, Yuki Takagi, Naoki Matsuzuka, Yoshitada Isono, IEEJ, 2008
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Scanning Probe Arrays Lithography
Mar. 9th. 2009 Rho, Jun Suk
Hensy Gandjar, Yuki Takagi, Naoki Matsuzuka, Yoshitada Isono, IEEJ, 2008
Group I.P.ODec. 5th 2007
Comparison
Strength Weakness
All SPL •Nanoscale Resolution•Accurate alignment•Real-time imaging•Array operation
•Low throughput in serial•Lack of controlling array
STM •Higher resolution (atomic)•Minimum proximity effect•Precise control
•Vacuum control•Limited resist thickness•Limited pattern uniformity•Conducting substrate required•Very low processing speed
AFM •Good reproducibility•Wide range of materials•Precise control•Compatible with self assembly
•Limited pattern uniformity•Debris formation in scratching•Low tip life time in scratching•Array synchronization(DPN)
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007
Conclusion
Although Several basic issues are still unresolved
with respect to these techniques, (i.e. the details of
The mechanism of ink transport in DPN are still
unclear), it is very promising and developing technique.
Dec. 10th. 2008
On-wire Lithography
Polymer Pen Lithography
SPL with NSOMSPL with SECMSelf Assembly Monolayer (SAM)ETC
Mar. 9th. 2009 Rho, Jun Suk
Group I.P.ODec. 5th 2007Dec. 10th. 2008Mar. 9th. 2009 Rho, Jun Suk