Plasma Chemistry and Plasma Processing, Vol.26, No.3, 277-291, 2006
Spectroscopic analysis of a pulsed-laser deposition system for fullerene-like Cn(x) film production
Plasma produced by a ( 1064 nm) Nd: YAG laser focused onto a graphite target at different nitrogen pressures in the range of 1 - 90 mTorr, was studied spectroscopically. In the spectral range of 350 - 600 nm, emission lines of CI neutral carbon (501.12, and 505.21 nm), NI neutral nitrogen (493.5 nm), CII (426.72, 463.7, 515.11 nm), and CIII ions (465.02 and 569.59 nm), and NII ions (501.06, and 500.73 nm), were dominating. Bands of C-2 Swan (d(3) Pi(g) --> a(3)Pi(u), Delta nu = 2, 1, 0,- 1), and CN Violet (B(2)Sigma(+) --> X(2)Sigma(+), Delta nu = 1, 0,- 1) systems, and ionic emissions from the First Negative system N2(+) ( band head at 391.44 nm), were faintly observed under our specific experimental conditions. From the band intensities, vibrational temperature for CN and C-2 was calculated to be 1.25 and 0.31 eV at 90 mTorr, respectively. The electron density and temperature, measured by Stark broadening, assuming a local thermodynamic equilibrium (LTE), were found to be 2.1 x 10(17) cm(-3) and 0.33 eV at 1mTorr, respectively. The validity of the LTE is discussed according to the results discussed. Pressure dependence shows a decrease in the vibrational temperature when nitrogen pressure increases, while the electron density and temperature increase.