TY - JOUR
T1 - Characterization and electrochemical properties of CF4 plasma-treated boron-doped diamond surfaces
AU - Kondo, Takeshi
AU - Ito, Hiroyuki
AU - Kusakabe, Kazuhide
AU - Ohkawa, Kazuhiro
AU - Honda, Kensuke
AU - Einaga, Yasuaki
AU - Fujishima, Akira
AU - Kawai, Takeshi
N1 - Funding Information:
This work was supported by the CLUSTER of Ministry of Education, Culture, Sports, Science and Technology, Japan, and the Saneyoshi Scholarship Foundation (No. 1725). We are also grateful to Mr. Soukichi Funazaki in the Ohkawa group for operating the plasma etcher.
PY - 2008/1
Y1 - 2008/1
N2 - The effect of CF4 plasma etching on diamond surfaces, with respect to treatment time, was investigated using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. SEM observations and Raman spectra indicated an increase in surface roughening on a scale of 10-20 nm, and an increase in crystal defect density was apparent with treatment time in the range of 10 s to 30 min. In contrast, alteration of the diamond surface terminations from oxygen to fluorine was found to be rather rapid, with saturation of the F/C atomic ratio estimated from XPS analysis after treatment durations of 1 min and more. The redox kinetics of Fe(CN)63-/4- was also found to be significantly modified after 10 s of CF4 plasma treatment. This behavior shows that C-F terminations predominantly affect the redox kinetics compared to the effect on the surface roughness and crystal defects. The double-layer capacitance (Cdl) of the electrolyte/CF4 plasma-treated boron-doped diamond interface was found to show a minimum value at 1 min of treatment. These results indicate that a short-duration CF4 plasma treatment is effective for the fabrication of fluorine-terminated diamond surfaces without undesirable surface damage.
AB - The effect of CF4 plasma etching on diamond surfaces, with respect to treatment time, was investigated using scanning electron microscopy (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. SEM observations and Raman spectra indicated an increase in surface roughening on a scale of 10-20 nm, and an increase in crystal defect density was apparent with treatment time in the range of 10 s to 30 min. In contrast, alteration of the diamond surface terminations from oxygen to fluorine was found to be rather rapid, with saturation of the F/C atomic ratio estimated from XPS analysis after treatment durations of 1 min and more. The redox kinetics of Fe(CN)63-/4- was also found to be significantly modified after 10 s of CF4 plasma treatment. This behavior shows that C-F terminations predominantly affect the redox kinetics compared to the effect on the surface roughness and crystal defects. The double-layer capacitance (Cdl) of the electrolyte/CF4 plasma-treated boron-doped diamond interface was found to show a minimum value at 1 min of treatment. These results indicate that a short-duration CF4 plasma treatment is effective for the fabrication of fluorine-terminated diamond surfaces without undesirable surface damage.
KW - Diamond film
KW - Electrochemical
KW - Surface characterization
UR - http://www.scopus.com/inward/record.url?scp=36749080891&partnerID=8YFLogxK
U2 - 10.1016/j.diamond.2007.10.009
DO - 10.1016/j.diamond.2007.10.009
M3 - Article
AN - SCOPUS:36749080891
SN - 0925-9635
VL - 17
SP - 48
EP - 54
JO - Diamond and Related Materials
JF - Diamond and Related Materials
IS - 1
ER -