Vapor-Phase Processing - Renewable Bioproducts Institute · polymerization, surface functionalization, and electrochemical processing. • Our primary interests are in materials systems

Losego Lab – www.losegolab.gatech.eduSchool of Materials

Science & Engineering

Vapor-Phase Processing:The Next Revolution in Paper Manufacturing?

Mark D. LosegoAssistant Professor of Materials Science and Engineering, Georgia Techwww.losegolab.gatech.edu

Or Functional Paper: From Hydrophobic to Phosphorescent – What Properties are Possible?

Renewable Bioproducts Institute (RBI) Annual Executive Meeting 2016

http://www.losegolab.gatech.edu



• Introduction to Atomic Layer Deposition

• State-of-the-Art in ALD Manufacturing

• ALD: Near-Term Opportunities for Paper Manufacturing

• Vapor-Phase Modification: Immediate Opportunities for Paper Manufacturing

• Summary

Outline

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• We do Materials Synthesis* including thin film deposition (PVD, CVD, ALD), polymerization, surface functionalization, and electrochemical processing.

• Our primary interests are in materials systems that (a) combine organic and inorganic components or (b) use 3-dimensionality to enhance functionality.

*Note: We design and build all of our own deposition tools (hardware & software) for maximum adaptability.

Nano-scale heat transport

Materials forNational Security

Molecular Catalysis

PlasmonicSensing

FunctionalTextiles

Chemical Synthesis & Vacuum Processing

Materials for Microelectronics

DSSCs

Conductive Oxides

Capacitors

Materials for Renewable Energy

SolarFuels

VaporBarriers

Ferroelectrics

The Losego Lab

0.5 mm

Tungsten Photonic Structure

MOF on Textile

ALD Reactor

Vapor Barriers Film on Foil

Capacitors

Solar Fuels

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Science & Engineering4

Atomic Layer Deposition:

An Introduction to the Basics



Atomic layer deposition (ALD) is a vapor-phase thin film deposition technique that proceeds via a sequential set of surface reactions that are self-limiting.

Precursors chemicals are delivered in the gas phase.

Precursors are delivered sequentially (NOT concurrently).

Precursors only react with solid surfaces, not with other precursors in the gas phase.

Precursors do not react with themselves.

Definition

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Atomic Layer Deposition

Dose Precursor (Metal Organic or Metal Halide)

Purge Precursor(Inert Gas Purge)

Surface Reaction + Byproduct Removal




Dose Co-Reactant (Oxidant or Reductant)

Purge Precursor(Inert Gas Purge)




Dose Precursor (Metal Organic or Metal Halide)

Dose Co-Reactant (Oxidant or Reductant)ETC…

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Virtues of ALD

Ritala, M. et al., Chem. Vap. Dep. 5 7 (1999)

1 mm

Losego & Arpin, Nat. Comm. 4 2630 (2013)

0.5 mm

1. Provides highly conformal coatings,even over complex nanostructured3D architectures

2. Provides very high precision andreproducibility in film thickness.(deposition rates of ≈ 1 Å / cycle)

3. Potential for low process temperaturescompatible with polymer substrate.(Many oxide ALD processes < 150°C)

3.8 nm

50 cycles

Triyoso et al. JVSTB 23 288 (2005)

Nylon Tungsten- Coated Nylon

Spagnola et al. J. Mater. Chem. 20 4213 (2010)



Nuances of ALD1. ALD is NOT like the cartoons!

1 cycle does not necessarily equal1 atomic layer. For example,TMA/H2O cycles are ~1/3 of alayer.

2. Subsurface deposition occurs formany polymeric systems.

3. Film density and organic contentcan change with temperature.

4. Nucleation can be a problem.

5. Byproducts can cause problems.Mackus, Bol, and Kessels, Nanoscale 6 10941 (2014)

Platinum ALD

Delay!

Ligands block sites!

Subsurface!

Al:ZnO ALD

Nylon

Deposition Temperature

Ref

ract

ive

Ind

ex

Elam & George, Chem. Mater. 15 1020(2003)



All Sorts of Materials Can Be Deposited by ALD…

Miikkulainen, Leskala, Ritala, Puurunen J. Appl. Phys. 113, 021301 (2013)

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An ALD Reactor in the Losego Lab

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A Commercial ALD Reactor (Beneq)

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So this is just a research curiosity?



2007

Starting with the 45 nm node (circa2007), all integrated circuits havebeen manufactured using ALD todeposit the transistor’s gate oxide.

(400,000,000+ transistors in this IC)

We all (probably) own something manufactured by ALD

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State-of-the-Art in ALD

Manufacturing



Challenges to ALD Manufacturing

1. Low Throughput–Research systems like our flow tube reactors can take 2 min / cycle, which equates to 1.5 days to deposit 0.1 mm.-Can be overcome by increasing pumping speeds, using batch processing

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Skarp, ECS Trans. 33 447 (2010).

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Large Batch ALD Manufacturing

2007

Used in semiconductor industry (ICs and PVs)-ALD used for gate oxides since 2007

• About 4 s per cycle• 1.5 nm/min or 0.1 mm/hr• Up to 500 wafers per batch

Shown: Applied Materials (USA) and Beneq (Finland)



Challenges to ALD Manufacturing

1. Low Throughput–Research systems like our flow tube reactors can take 2 min / cycle, which equates to 1.5 days to deposit 0.1 mm.-Can be overcome by increasing pumping speeds, using batch processing

2. Non-Continuous Processing–Research reactors that use temporal dose/purge steps are not readily adaptable to a continuous process-Continuous ALD systems use spatial separation of precursors

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Lotus Applied Technologies (USA)

Precursor Zone

Coreactant Zone

Purge Zone

Poodt et al., JVSTA. 30 010802 (2012).

Levitech (Netherlands)

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Continuous Manufacturing: Spatial ALD



Eastman Kodak (USA)

Continuous ALD Manufacturing

ASTRaL (Finland)Poodt et al., JVSTA. 30 010802 (2012).

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Outlook for ALD Manufacturing

1. A number of companies are developing ALD systems for manufacturing

2. Large batch ALD systems are already usedfor manufacturing ICs and PVs

1. Spatial ALD reactors are coming and could revolutionize paper & textile manufacturing (Next 5 to 10 years)

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Atomic Layer Deposition:Opportunities for Paper Modification



Light Bulb!

Before After

Conformal Coating

Micrograph from a cotton ball

Electrically Conductive Paper

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Color Changing Paper?

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In collaboration with the Reynolds Group at GT



Hanson, Oldham, & Parsons J. Vac. Sci. Technol. A, 30 01A117 (2012)

ALD coatings of TiO2 or ZnO act like sunscreen and prevent the UV degradation of mechanically pulped papers like newsprint.

Newspaper That Resists UV Degradation

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Single-Cycle Vapor Modification:An Immediate Opportunity for Paper



Precursor

Pump

Single Cycle Vapor Phase Modification

1. Evacuate chamber

2. Fill chamber with reactive, volatile precursor.

3. Wait for reaction

4. Evacuate chamber.

5. Vent and remove.

Paper

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Gaseous Precursors Get EVERYWHERE

(a) Cotton (b) Paper

(c) Denim (d) Cardboard

We are able to convert cellulosic fibers from hydrophilic to hydrophobic using a single exposures cycle that takes < 1 min.

This effect is irrespective of the cellulose’s form factor because gaseous precursors can diffuse everywhere!

(Or “Look, Mom, No Surface Tension!”)

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Water Repellent Paper

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Water Repellent Cardboard

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Fluorescence

MagnetismAnti-Bacterial

Hydrophobicity

Organics

Erbium,Europium

Iron,Cobalt

Oxides

Potential to Introduce More Functionality

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Burgeoning opportunities in vapor-phase modification of paper-based products.

Roll-to-roll atomic layer deposition has the potential to revolutionize paper and textile manufacturing.(Who will seize this opportunity?)

An even more immediate opportunity is to use single-cycle (or few cycle) vapor phase processing techniques to enhance the properties of FINISHED paper products.

-Water Repellency-Anti-Bacterial-Phosphorescence / Fluorescence-Magnetism

Summary

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Acknowledgments

ACS Petroleum Research

Fund Doctoral New

Investigator Program under

Award Number 55526-

DNI10.

The Losego Group @ Georgia Tech

Brandon Piercy (Graduate Student)Collen Leng (Graduate Student)Daniel Yin (Undergraduate)Derek Henry (Undergraduate)Shawn Gregory (Undergraduate)Andrew Short (Undergraduate)

Georgia Tech Startup Funds

Research Funding

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Kalanyan, Losego et a. Chem. Vap. Deposition 19, 161 (2013).

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“Ideal” ALD

The ALD “Temperature Window”

*Sometimes this window is only a few degrees

• Provide sufficient precursor to saturate the surface

• Purge sufficiently long to remove all excess precursor

• Work within a temperature window where ONLY surface reactions are thermodynamically favored.

Documents

Vapor-Phase Processing - Renewable Bioproducts Institute · polymerization, surface functionalization, and electrochemical processing. • Our primary interests are in materials systems