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Etching Kinetics of (100) Single Crystal Diamond Surfaces in a Hydrogen Microwave Plasma, Studied with In Situ Low‐Coherence Interferometry
Author(s) -
Yurov Vladimir,
Bushuev Egor,
Bolshakov Andrey,
Ashkinazi Evgeny,
Antonova Irina,
Zavedeev Evgeny,
Khomich Andrey,
Voronov Valery,
Ralchenko Victor
Publication year - 2017
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201700177
Subject(s) - etching (microfabrication) , diamond , materials science , analytical chemistry (journal) , substrate (aquarium) , microwave , torr , polishing , reactive ion etching , crystal (programming language) , single crystal , synthetic diamond , hydrogen , plasma , chemistry , layer (electronics) , nanotechnology , crystallography , composite material , oceanography , physics , organic chemistry , chromatography , quantum mechanics , geology , computer science , thermodynamics , programming language
A low‐coherence interferometry (LCI) was used to measure in situ the etch rate (ER) of synthetic single crystal (SC) diamonds in H 2 microwave plasma, at substrate temperatures in the broad range of 800–1370 °C. The method allows the collection of the kinetic data on a single sample without switching off the plasma. (100)‐orientated SC plates of CVD and IIa type HPHT diamond were systematically etched in pure hydrogen at pressure p = 130 Torr and microwave power density of ≈300 W cm −3 . The activation energies E a of 42 ± 5 and 32 ± 4 kCal mol −1 have been determined for the CVD and HPHT substrates. An enhanced etching rate of a subsurface defected layer with thickness of ∼1 μm or less, formed upon polishing of the samples, is revealed. Surface morphology, roughness, and the shape of etch pits produced by a selective etching of defects, were characterized with optical profilometry. CH and dimer C 2 radicals were detected in the H 2 plasma with optical emission spectroscopy, as a result of the diamond etching, and the emission intensity of these species was linked to the substrate etch rate.