Atomic Layer Deposition of Cr2O3 Raija Matero University of Helsinki

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Atomic Layer Deposition of Cr2O3Raija Matero
University of Helsinki
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SURFOControl of Small Particle Surface
ForcesTFGUH - Thin Film Group in the
Laboratory of Inorganic Chemistry at University
of Helsinki Markku Leskelä, Mikko Ritala, Raija
Matero
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The Principle of ALD
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Cr2O3 by ALD

• growth temperature 350 500 oC
• substrates borosilicate glass
• sources Cr(acac)3 (acac acetylacetonate) and
  air
• (also H2O ?no film, airH2O )
• thicknesses 15 400 nm
• Cr(acac)3 starts to decompose already at 400 oC

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Cr(acac)3
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X-Ray Diffraction of Cr2O3 Films
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Cr2O3 Growth Rate with DifferentCr(acac)3 Pulse
Lengths
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Cr2O3 Growth Rate at Different Temperatures
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Cr2O3 by Radical Enhanced ALD(Antti Niskanen)

• a microwave plasma source (Surfatron) was added
  to F120 reactor
• the plasma dissociates gas producing radicals,
  ions and electrons
• in downstream configuration only radicals reach
  the substrate

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Schematics of the Reactor
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Reaction chamber
Main flow direction
Reactive gas feed (discharge tube)
Pumpline
Surfatron (plasma source)
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Cr(acac)3 O2

• precursors Cr(acac)3 and oxygen radicals
• growth temperature 160 200 oC
• the plasma is on during the oxygen pulse
• pulsing sequence Cr(acac)3 - purge - O2 - purge
• the films are amorphous

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Cr(acac)3 O2 H2O

• Pulsing sequence H2O purge Cr(acac)3 purge
  O2 purge
• the H2O pulse in the beginning helps the
  adsorption of Cr(acac)3
• Films are amorphous.

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Coating of AFM tips for surface force
measurements