A much larger amount of bonded hydrogen was found in thick nanocrystalline diamond （NCD） films produced by only adding 0.24% N2 into 4% CH4/H2 plasma, as compared to the high quality transparent microcrystalline dia...A much larger amount of bonded hydrogen was found in thick nanocrystalline diamond （NCD） films produced by only adding 0.24% N2 into 4% CH4/H2 plasma, as compared to the high quality transparent microcrystalline diamond （MCD） films, grown using the same growth parameters except for nitrogen. These experimental results clearly evidence that defect formation and impurity incorporation （for example, N and H） impeding diamond grain growth is the main formation mechanism of NCD upon nitrogen doping and strongly support the model proposed in the literature that nitrogen competes with CHx （x = 1, 2, 3） growth species for adsorption sites.展开更多
Nano-crystalline diamond （NCD） films were prepared on poly-crystalline diamond （PCD） thick flims by the microwave plasma enhanced chemical vapor deposition （MPCVD） method. Free standing PCD thick film （50 mm in...Nano-crystalline diamond （NCD） films were prepared on poly-crystalline diamond （PCD） thick flims by the microwave plasma enhanced chemical vapor deposition （MPCVD） method. Free standing PCD thick film （50 mm in diameter） with a thickness of 413 μm was deposited in CHn/H2 plasma. It was then abraded for 2 hours and finally cut into pieces in a size of 10×10 mm^2 by pulse laser. NCD fihns were deposited on the thick film substrates by introducing a micro-crystalline diamond （MCD） interlayer. Results showed that a higher carbon concentration （5%） and a lower substrate temperature （650℃） were feasible to obtain a highly smooth interlayer, and the appropriate addition of oxygen （2%） into the gas mixture was conducive to obtaining a smooth nano-crystalline diamond film with a tiny grain size.展开更多
Diamond-like carbon(DLC) films with different thickness were deposited by filtered cathode vacuum arc(FCVA).Vis-Raman and spectroscopic ellipsometry were employed to analyze the structure of DLC films.The wavelength o...Diamond-like carbon(DLC) films with different thickness were deposited by filtered cathode vacuum arc(FCVA).Vis-Raman and spectroscopic ellipsometry were employed to analyze the structure of DLC films.The wavelength of Vis-Raman is 514.5 nm.Experimental results show that structures of DLC films are affected by film thicknesses.When the film thickness increases from 2 to 30 nm,the G-peak position(G-pos) shifts to higher wavelength,the intensity ratio ID/IG and the extinction coefficient Ks decrease.It is indicated that the content of sp3 bond increases with film thickness.However,when the film thickness increases from 30 nm to 50 nm,ID/IG and Ks increase.The content of sp3 bonds decreases with film thickness.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 10874021)Natural Science Foundation of Educational Department of Jiangsu Province of China (Grant No. 06kja43014)
文摘A much larger amount of bonded hydrogen was found in thick nanocrystalline diamond （NCD） films produced by only adding 0.24% N2 into 4% CH4/H2 plasma, as compared to the high quality transparent microcrystalline diamond （MCD） films, grown using the same growth parameters except for nitrogen. These experimental results clearly evidence that defect formation and impurity incorporation （for example, N and H） impeding diamond grain growth is the main formation mechanism of NCD upon nitrogen doping and strongly support the model proposed in the literature that nitrogen competes with CHx （x = 1, 2, 3） growth species for adsorption sites.
基金supported by the Research Pund of Hubei Provincial Department of Education of China (No.Q20081505)
文摘Nano-crystalline diamond （NCD） films were prepared on poly-crystalline diamond （PCD） thick flims by the microwave plasma enhanced chemical vapor deposition （MPCVD） method. Free standing PCD thick film （50 mm in diameter） with a thickness of 413 μm was deposited in CHn/H2 plasma. It was then abraded for 2 hours and finally cut into pieces in a size of 10×10 mm^2 by pulse laser. NCD fihns were deposited on the thick film substrates by introducing a micro-crystalline diamond （MCD） interlayer. Results showed that a higher carbon concentration （5%） and a lower substrate temperature （650℃） were feasible to obtain a highly smooth interlayer, and the appropriate addition of oxygen （2%） into the gas mixture was conducive to obtaining a smooth nano-crystalline diamond film with a tiny grain size.
文摘Diamond-like carbon(DLC) films with different thickness were deposited by filtered cathode vacuum arc(FCVA).Vis-Raman and spectroscopic ellipsometry were employed to analyze the structure of DLC films.The wavelength of Vis-Raman is 514.5 nm.Experimental results show that structures of DLC films are affected by film thicknesses.When the film thickness increases from 2 to 30 nm,the G-peak position(G-pos) shifts to higher wavelength,the intensity ratio ID/IG and the extinction coefficient Ks decrease.It is indicated that the content of sp3 bond increases with film thickness.However,when the film thickness increases from 30 nm to 50 nm,ID/IG and Ks increase.The content of sp3 bonds decreases with film thickness.
