Ultra-smooth nanostructured diamond films deposited from He/H2/CH4/N2 microwave plasmas.
Addition of He to a high CH4 content (10.7 vol%) H2/CH4/N2 feedgas mixture for microwave plasma chemical vapor deposition produced hard (58-72 GPa), ultra-smooth nanostructured diamond films on Ti-6AI-4V alloy substrates. Upon increase in He content up to 71 vol%, root mean squared (RMS) surface roughness of the film decreased to 9-10 nm and average diamond grain size to 5-6 nm. Our studies show that increased nanocrystallinity with He addition in plasma is related to plasma dilution, enhanced fragmentation of carbon containing species, and enhanced formation of CN radical.
Konovalov
Valery V
VV
Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama 35294-1170, USA.
Melo
Andrew
A
Catledge
Shane A
SA
Chowdhury
Shafiul
S
Vohra
Yogesh K
YK
D018130:Diamond / Q000737:chemistry*; D006371:Helium; D006859:Hydrogen; D007700:Kinetics; D008697:Methane; D018625:Microscopy, Atomic Force; D008872:Microwaves; D049329:Nanostructures / Q000737:chemistry; D009584:Nitrogen; D014025:Titanium; D014961:X-Ray Diffraction
D006371:Helium; D018130:Diamond; D006859:Hydrogen; D014025:Titanium; D009584:Nitrogen; D008697:Methane