1. Department of Chemistry , SungKyunKwan University
Microcontact Printing and its Applications using Self-Assembled Monolayers
이종현 , 정덕영
Department of Chemistry ,
SungKyunKwan University

2. Nano structure resolution and various precursors of Soft lithography
Introduction
Nano structure resolution and various precursors of Soft lithography
What is SAMs( self assembled monolayers) ?
Microcontact Printing and its Applications
 MOCVD
 CSD
 SOL-GEL Method
 Microfabrication
INORGANIC MATERIALS LAB.

3. Soft Lithography method resolution microcontact printing (CP) 35nm
replica molding(REM) nm
mitrotransfer molding(TM) m
micromolding in capiliaries(MIMIC) m
solvent-assisted micromolding(SAMIM) nm
Soft Lithography
INORGANIC MATERIALS LAB.

4. Self-Assembled Monolayers (SAMs)
SAMs form spontaneously by chemisorption and self-organization of functionalized, long-chain organic molecules onto the surfaces of appropriate substrates.
tilted
2-3nm
substrate
Functional group
Alkyl chain
Reaction group
INORGANIC MATERIALS LAB.

5. OTS : n-octadecyltrichlorosilane (CH3(CH2)17SiCl3)
OTS monolayer
OTS : n-octadecyltrichlorosilane (CH3(CH2)17SiCl3)
Hydrophobic functional groups
Tilted angle 8o - 10o
Cross linking
Chemical bonding on the surface
Oxide layer
INORGANIC MATERIALS LAB.

6. Preparation of PDMS stamp
PDMS : poly(dimethylsiloxane) silicone elastomer
Photoresist Si
Photolithography Si
Pour PDMS against
Master and Cure
PDMS Si
Peal off PDMS from Master
PDMS
“Inking” of SAMs
Microcontact Printing
PDMS Si
Au or other materials
INORGANIC MATERIALS LAB.

7. Microcontact Printing
PDMS
Spin casting of OTS solution
PDMS
Ink
(OTS solution)
Microcontact printing
PDMS Si
PDMS
“Surface chemical Reaction”
Silicone oxide layer Si
Fabrication of patterned OTS SAMs
PDMS
PDMS Si
(hydrophobic area)
(hydrophilic area)
(25Å) Si
INORGANIC MATERIALS LAB.

8. Mechanism of surface reaction
- 2HCl
- HCl
+ 2H2O
+ H2O
under air(spin casting)
in hexane
surface
- H2O +
condensation
surface
surface
INORGANIC MATERIALS LAB.

9. Selectivity of OTS SAMs
Optical Microscope Image
Moisture
OTS SAMs
Substrate : Si(100) p-type wafer
OTS SAMs(hydrophobic area)
Moisture
SiO2 / Si
INORGANIC MATERIALS LAB.

10. MOCVD Applications of patterned OTS SAMs(1)
(Metal Organic Chemical Vapor Deposition)
Optical Microscope Image
TiO2
OTS SAMs
 -Step Profile Å Å
∼1300Å
INORGANIC MATERIALS LAB.

11. CSD Applications of patterned OTS SAMs(2)
(Chemical Solution Deposition)
Optical Microscope Image
CdS
OTS SAMs 1
100m
 -Step Profile
INORGANIC MATERIALS LAB.

12. SOL - GEL Method Applications of patterned OTS SAMs(3) Ta2O5
Optical Microscope Image
Ta2O5
Substrate : Slide glass
Precursor : Tantalum(V) Ethoxide
Deposition Method : spin coating
Baking temperature : 450C
INORGANIC MATERIALS LAB.

13. Microfabrication of double layered thin film
Optical Microscope Image
200m
Ta2O5
CdS
ITO
Slide glass
INORGANIC MATERIALS LAB.

14. Conclusion & Future prospects
Soft lithography tolerates a wide range of materials and surface chemistry.
Patterned OTS-SAMs form very stable organic thin films.
Optimize all about microcontact printing method.
Application of microcontact printing and OTS SAMs on three dimensional nano fabrication.
INORGANIC MATERIALS LAB.