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.
Department of Physics, University of Alabama at Birmingham, Birmingham, Alabama 35294-1170, USA.
Valery V
VV
Konovalov
Andrew
A
Melo
Shane A
SA
Catledge
Shafiul
S
Chowdhury
Yogesh K
YK
Vohra
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