Roll-to-Roll Fabrication Technology for Organic

Semiconductors

Jae Young ChoiNov. 13, 2007

Cost Saving, Simple Fabrication ProcessProducesFlexible Semiconductor Devices !

Roll-to-Roll Process

Motivation

- Low-temperature deposition- Mechanically Flexible- Light weight and shock proof- Chemical Sensitivity- Solution Processing

Organic Semiconductors

Non-Flexible DeviceExpensive Manufacturing Process

Complex Fabrication Process

Silicon Based Semiconductors

Why?

BackgroundOTFT (Organic TFT)

OverviewRoll-to-Roll Processing

Example:e-paper

manufacturing

Technology ISubstrate Materials

GlassPlastic (PEN,

PI)Stainless Steel

• Optical Properties (Transparency)• Surface Smoothness• Thermal Expansion (Maximum Process Temperature)• Stiffness ( Durability, Flexibility, Young’s Modulus)

Properties to be Considered

Technology IINovel Patterning Techniques (1)

Soft Lithography

- Mask and substrate contact may result in defects- Mask damage & stamping material life time

Issues

Technology II

Embosser Mold & Embossed Microcups

Novel Patterning Techniques (2)

E-paper by SiPix

Technology IINovel Patterning Techniques (3)

Laser Ablation

Recent Technology- Resolution: 120 pt/in- Droplet size: 10-80 picoliters- Speed: 200 mm/sec

Suffer form Drop Displacement Accuracy

-Faster than RIE -Produces Cleaner lines than Thermal and Mechanical Drilling

Inkjet Printing

Technology IIIPackaging:Barrier Layer

Low work function metals oxide very easily Moisture & Oxygen Free Environment Needed

Requirement Water transmission rate = less than 10-6 g m‐2/day

Oxygen transmission rates = less than 10‐5 mL m‐2/day

Barix Coating TechniqueUsing continuous, roll-to-roll

vacuum processing

Directly Coating on the Top Eliminating the glued-on

metal can or the extra sheet of glass

Much thinner, lighter, more reliable display with low cost

Conclusion: Now & Future

Organic LED (OLED)

Organic Solar Cell

Organic TFT

Organic Sensors

APPLICATIONS

$5M $339M

83.5 %Per year

Flexible Display Market Growth

2006 2013

1. Cost Saving2. Simple Fabrication Process3. Flexible Semiconductor Devices

Roll-to-Roll Process

Not so much cost saving yet“Killer Application” is Needed

Reference

1. Evan Schwartz, “Roll to Roll Processing for Flexible Electronics,” 2. Jain, K.   Klosner, M.   Zemel, M.   Raghunandan, S., “Flexible electronics and

displays: high-resolution, roll-to-roll, projection lithography and photoablation processing technologies for high-throughput production,”

3. Chin, Spencer. “Report: Flex display market to grow 83.5% a year.” EETimes Online.  March 23, 2006.

4. Jain, K. “Flexible Electronics and Displays: High‐Resolution, Roll‐to‐Roll,  Projection Lithography and Photoablation Processing Technologies for High‐ Throughput Production.” Proc. IEEE, 93, 1500‐1510, (2005).

5. Tan et. al. “Roller Nanoimprint Lithography.” J. Vac. Sci. Technol. B 16, 3926  (1998). 

6. Vitex Systems, Inc. “The Guardian Tool.” Available online:  http://www.vitexsys.com/guardian.html.

7. SiPix Imaging, Inc. “roll-to-roll© Manufacturing Process. Flexible Displays & Electronics”, 2004.