iaa-99-iaa.12.1.02 diamond film deposition by chemical vapor transport

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IAA-99-IAA.12.1.02 DIAMOND FILM DEPOSITION BY CHEMICAL VAPOR TRANSPORT Liya L. Regel and William R. Wilcox International Center for Gravity Materials Science and Applications, Clarkson University, Potsdam, New York 13699- 5814, USA International Astronautical Congress Amsterdam, October 1999

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IAA-99-IAA.12.1.02 DIAMOND FILM DEPOSITION BY CHEMICAL VAPOR TRANSPORT Liya L. Regel and William R. Wilcox International Center for Gravity Materials Science and Applications, Clarkson University, Potsdam, New York 13699-5814, USA International Astronautical Congress - PowerPoint PPT Presentation

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Page 1: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

IAA-99-IAA.12.1.02DIAMOND FILM DEPOSITION BYCHEMICAL VAPOR TRANSPORTLiya L. Regel and William R. WilcoxInternational Center for Gravity MaterialsScience and Applications, Clarkson University,

Potsdam, New York 13699-5814, USA

International Astronautical CongressAmsterdam, October 1999

Page 2: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

• Some current and many potential applications for diamond films. Improvements needed.

• Techniques and apparatus will be described.• Deposited on silicon, molybdenum, graphite,

carbon felt and glass without typical pre-treatment with diamond powder.

• Selective deposition on copper pattern on oxidized silicon

• Deposition enhanced by centrifugation.• Modeling and current understanding:

radiation heat transfer, buoyancy convection, surface and gas chemistry.

Page 3: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Current applications of CVD diamond

• Heat spreaders for semiconductor devices, photonic devices, high-power amplifiers and Multi Chip Modules

• Hard coatings for tools for cutting, grinding, microdrilling, etc.

• Highly transparent hard windows useful from the infrared to the ultraviolet, and as a radome.

• Chemically resistant coatings, e.g., for biomedical implants.• Cold-cathode field emitters for flat panel displays, electron

guns, amplifiers, oscillators, miniature x-ray sources, etc.

• High frequency speaker diaphragms.

Page 4: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Techniques• Previous techniques use flowing hydrogen gas at ~1/10 atm

containing ~1% methane. Either a hot tungsten filament or a plasma is used to generate H atoms and C-containing deposition species. Nucleation is often difficult and sometimes requires diamond powder. Deposition rates are ~1 micron/hr.

• Our new technique uses hydrogen at ~1/10 atm in a sealed chamber. Hot graphite generates both hydrogen atoms and carbon-containing deposition species. Seems to nucleate on anything without special surface treatment. Deposition rate can be ~10 micron/hr. Appears to be self regulating.

Page 5: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Cooling water

Cooling water TC 1

TC 2

Graphite rod

Substrate

Hydrogen Vacuum Pressuretransducer

Power supply Power supply

This shows the original apparatus. A larger apparatus has been constructed with improved cooling and better control. Power requirement about 300 watts -- a large light bulb!

Page 6: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Complete coating on entire 8.8 sq cm Mo sheet. Grain size ~0.4 micron.

Page 7: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Optical interference pattern from fine-grained deposit on molybdenum

Page 8: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Diamond deposited on roughened (111) silicon for 40 minutes under different conditions.

Page 9: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Deposition of diamond on graphite

Before deposition After deposition

Page 10: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Selective deposition of diamond on copper pattern on oxidized silicon

Cu pattern (lighter color) After deposition

Page 11: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Comparison of temperature distribution in chamber with silicon and glass substrates.

Page 12: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Comparison of convection field in chamber with silicon and glass substrates.

Page 13: IAA-99-IAA.12.1.02 DIAMOND  FILM  DEPOSITION  BY CHEMICAL  VAPOR  TRANSPORT

Equilibrium compositions versus temperature.

2400 2600 28001E-9

1E-8

1E-7

1E-6

1E-5

1E-4

1E-3

0.01

0.1

C2H3

C2

CH2

C2H

C2H4

CH3

C2H2

CH4

H

Gr

H2

H2/C = 1.1P = 5000 Pa

Gr C2 C2H C2H2 C2H3 C2H4 CH2 CH3 CH4 H2 H

Mol

e Fr

actio

n

Temperature, oC