Insights into the reactive ion etching mechanism of nanocrystalline diamond films as a function of film microstructure and the presence of fluorine gas

Journal Article · Mon Feb 15 04:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3309420· OSTI ID:21476150

Yoon, Ju-Heon ^[1]; Lee, Wook-Seong; Park, Jong-Keuk; Hwang, Gyu Weon; Baik, Young-Joon; Jeong, Jeung-hyun ^[1]; Seong, Tae-Yeon ^[2]

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1. Thin Film Materials Research Center, Korea Institute of Science and Technology, 39-1, Seoul 136-791 (Korea, Republic of)
2. Department of Materials Science and Engineering, College of Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

Inhomogeneous etching of nanocrystalline diamond (NCD) films, which produces nanopillars during reactive ion etching process, is problematic to the microfabrication of NCD films for the sensor and actuator applications. Thus, its origin was investigated for various initial microstructures of the NCD films, SF{sub 6}/O{sub 2} gas ratios during etching, and plasma powers. The etched NCD film surface roughness became more pronounced (leading to larger pillar diameters and heights) for larger initial microstructural features (larger grain and cluster sizes), particularly at low plasma powers. The surface roughening was significantly reduced with the addition of SF{sub 6}, almost disappearing at SF{sub 6}/O{sub 2} of 5% to 10%. These results indicate that the etch rate was locally enhanced at the interfaces between grains or clusters, and the etch rate disparity between intragranular and intergranular (or cluster) carbons increased with decreasing ion energy, implying a chemical reaction rate-limited etching mechanism. The role of SF{sub 6} could be explained to reduce the energy barrier for the chemical reaction of intragranular carbons. Here we suggest that the etching rate is limited by an energy barrier that could be reduced by defect generation during ion bombardment or by catalytic radicals.

• OSTI ID: 21476150
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 4 Vol. 107; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
ACTUATORS
CARBON
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DIAMONDS
ELEMENTS
ETCHING
FILMS
FLUORIDES
FLUORINE COMPOUNDS
GRAIN SIZE
HALIDES
HALOGEN COMPOUNDS
INTERFACES
METALS
MICROSTRUCTURE
MINERALS
NANOSTRUCTURES
NONMETALS
PLASMA
ROUGHNESS
SENSORS
SIZE
SPUTTERING
SULFUR COMPOUNDS
SULFUR FLUORIDES
SURFACE FINISHING
SURFACE PROPERTIES
SURFACES
THIN FILMS