The sputtering of a graphite target with N2 ions in an inductively-coupled plasma was employed to deposit C3N4 films in hydrogen-free atmosphere with a high degree of gas dissociation. Transmission electron diffraction patterns of the films indicate the existence of ultrafine-crystallites, structurally analogous to β-C3N4. Scanning electron micrographs show that the crystallites are less than 40 nm in diameter. From X-ray photoelectron spectroscopy (XPS) analysis it is determined that the films exhibit predominantly C - N bonding (with respect to C-to-N triple bonding) and no significant C - C bonding is observed. Besides, both the [N]/[C] ratio and the percentage of C - N bonds in the film, as determined from XPS, increase upon increasing the radio frequency power from 100 W to 600 W, with the [N]/[C] ratio attaining a value of 1.28 at 600 W. The measurement of the [N2+]/[N2] ratio by optical emission spectroscopy indicates the enhancement of the gas dissociation with increasing radio frequency power. The results suggest that β-C3N4 crystallites are favorably formed upon increasing the degree of gas dissociation.
|Journal||Japanese Journal of Applied Physics, Part 2: Letters|
|Issue number||6 A|
|Publication status||Published - 1998|
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)
- Physics and Astronomy(all)