TY - JOUR
T1 - Decreased hydrogen content in diamond-like carbon grown by CH4/Ar photoemission-assisted plasma chemical vapor deposition with CO2 gas
AU - Ogawa, Shuichi
AU - Sugimoto, Rintaro
AU - Kamata, Nobuhisa
AU - Takakuwa, Yuji
N1 - Funding Information:
This work was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number JP16K14124 . This work was supported in part by “Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials” from the Ministry of Education, Culture, Sports, Science and Technology of Japan ( MEXT ).
Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2018/9/25
Y1 - 2018/9/25
N2 - In this study, we tried to decrease the hydrogen content in diamond-like carbon (DLC) grown by photoemission-assisted plasma enhanced chemical vapor deposition (PA-PECVD) using Ar/CH4 mixed with CO2. When the CO2 flux was changed from 0 to 10 sccm with the Ar and CH4 fluxes maintained at 50 and 10 sccm, respectively, the growth rate decreased from 11 to 3 μm/h. Secondary mass spectroscopy measurements confirmed that the amount of O mixed into the DLC was increased through incorporation of CO2 into feed gas flow. The O concentration in the DLC was quantitatively evaluated by X-ray photoelectron spectroscopy (XPS) to be 0.6 atomic % at a CO2 flow ratio of 14%. Raman spectroscopy and XPS revealed that the amount of H trapped in the DLC decreased as the CO2 flow ratio was increased and the sp3/sp2 ratio remained almost unchanged. These results were interpreted by a model involving O radicals acting on the DLC surface associated with CO/CO2 and H2O, resulting in a decrease of the growth rate and H content. A portion of the O radicals also became incorporated into the DLC as C–O–C bonds.
AB - In this study, we tried to decrease the hydrogen content in diamond-like carbon (DLC) grown by photoemission-assisted plasma enhanced chemical vapor deposition (PA-PECVD) using Ar/CH4 mixed with CO2. When the CO2 flux was changed from 0 to 10 sccm with the Ar and CH4 fluxes maintained at 50 and 10 sccm, respectively, the growth rate decreased from 11 to 3 μm/h. Secondary mass spectroscopy measurements confirmed that the amount of O mixed into the DLC was increased through incorporation of CO2 into feed gas flow. The O concentration in the DLC was quantitatively evaluated by X-ray photoelectron spectroscopy (XPS) to be 0.6 atomic % at a CO2 flow ratio of 14%. Raman spectroscopy and XPS revealed that the amount of H trapped in the DLC decreased as the CO2 flow ratio was increased and the sp3/sp2 ratio remained almost unchanged. These results were interpreted by a model involving O radicals acting on the DLC surface associated with CO/CO2 and H2O, resulting in a decrease of the growth rate and H content. A portion of the O radicals also became incorporated into the DLC as C–O–C bonds.
KW - Diamond-like carbon
KW - Photoemission-assisted plasma
KW - Plasma enhanced CVD
KW - Raman spectroscopy
KW - X-ray photoelectron spectroscopy
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U2 - 10.1016/j.surfcoat.2018.04.016
DO - 10.1016/j.surfcoat.2018.04.016
M3 - Article
AN - SCOPUS:85045537396
SN - 0257-8972
VL - 350
SP - 863
EP - 867
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
ER -