Synthesis of nano-scale diamond tips on micro-size diamond powders/Ni/Al

• Published in: Diamond and related materials 2008-07, Vol.17 (7), p.1821-1825
• Main Authors: Chen, M.Y., Yeh, C.M., Hwang, J., Kou, C.S., Lan, M.S., Chou, C.C.
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Diamond; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Nanoscale materials and structures: fabrication and characterization; Nanotips; Other topics in nanoscale materials and structures; Physics; Plasma; Specific materials
• ISSN: 0925-9635; 1879-0062
• DOI: 10.1016/j.diamond.2008.03.010

Vertically oriented nano-scale diamond tips were synthesized on the micro-size diamond particles in a planar microwave plasma enhanced chemical vapor deposition chamber by varying synthesis time, bias voltage, and gas ratio. Diamond particles were embedded in the thin layer of Ni on an Al plate and then followed by the synthesis of nano-scale diamond tips. Vertically oriented nano-scale diamond tips were selectively synthesized on diamond particles, which were justified by the C KLL Auger spectra taken by an Auger nanoscope. On top of the Ni surface surrounding diamond particles, carbon was deposited in the form of amorphous carbon, rather than diamond, which was confirmed by the corresponding C KLL Auger spectra. The qualities of nano-scale diamond tips were characterized by the diamond characteristic peak at 1332 cm − 1 in the Raman spectra. The morphologies of nano-scale diamond tips strongly depend on the bias voltage. The optimum bias voltage to achieve nano-scale diamond tips of bottle-like shape is about − 250 V. The density of nano-scale diamond tips can be tuned primarily by varying the gas ratio of Ar/CH 4/H 2.