chemical lift off lithography
TRANSCRIPT
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FABRICATING MICROSCALE PATTERNING BY CHEMICAL LIFT-OFF LITHOGRAPHYROBERT ESPINOZA, DR. WEI-SSU LIAO LABDEPARTMENT OF CHEMISTRY2016-8-11
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REAL WORLD APPLICATIONS
• Chips
• Devices
• Sensors
https://www.a-star.edu.sg/Portals/0/media/Press%20Release/microfluidics-img.jpghttp://ichef-1.bbci.co.uk/news/660/media/images/78547000/jpg/_78547661_78547660.jpg
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EXPERIMENTAL GOALS
• Microdroplet array fabrication
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INTRODUCTION: WHAT IS CHEMICAL LIFT-OFF LITHOGRAPHY?• Micro-/nanoscale etching
• Polydimethylsiloxane (PDMS)
• Self assembled monolayer (SAM)
“Double-Sided Opportunities Using Chemical Lift-Off Lithography”, Liao WS*, Accounts of Chemical Research (2016)
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CHEMICAL LIFT-OFF VS OTHER LITHOGRAPHY TECHNIQUES• Soft Lithography• Electron Beam Lithography
Hsia, K. J.; Huang, Y.; Menard, E.; Park, J.-U.; Zhou, W.; Rogers, J.; Fulton, J. M., Appl. Phys. Lett. 2005, 86, 154106http://www.stoner.leeds.ac.uk/Research/TutFab
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OVERALL EXPERIMENTAL PROCESS
Gold Wafer with Hydrophillic
SAMPerform CLL
Drop ReagentsInto Array
Hydrophobic PFDT
Gold Wafer
Prep SAM Overnight
Place PDMS Stamp for
2 Hours
Backfill into CLL region withPFDT for 1 hour
Wash Wafer with Ethanol
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EXPERIMENTAL PROCESSES
• Clean room processes: • PDMS fabrication
• Photolithography wafers
• Making PDMS stamp
Exposed
PDMS:A:B=10:1
Develop
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CLEAN ROOM EXPERIMENTAL DATA
Photoresist Pillars
PDMS Holes
Photoresist Lines
Photoresist Holes
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EXPERIMENTAL PROCESSES• Laboratory processes:
• Developing SAM
• Oxygen Plasma
• Performing CLL
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LABORATORY EXPERIMENTAL DATA
“Subtractive Patterning via Chemical Lift-Off Lithography” Liao WS, Science 337 (2012): 1517-1521
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LABORATORY EXPERIMENTAL DATALine 42 Micron Circle 5 Micron Square
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FUTURE RESEARCH• Improving the Microdroplet Array
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CONCLUSION
• Many applications
• More accessible lithography
• Superior resolution
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ACKNOWLEDGEMENTS
Dr. LiaoHsiao-Yuan (Mimi)National Taiwan UniversityMinistry of ScienceUniversity of California Education Abroad ProgramUniversity of California, Riverside
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THANK YOUQUESTIONS?