Naslov
Optical emission spectroscopy of inductively coupled RF methane plasma during a:C-H thin film deposition

Autori
Bišćan, Marijan ; Kregar, Zlatko ; Krstulović, Nikša ; Milošević, Slobodan

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
2nd International Conference on advanced plasma technologies with 1st international plasma nanoscience symposium, Conference Proceedings / Cvelbar, Uroš ; Mozetič, Miran - Ljubljana : Slovenian Society for Vacuum Technique (DVTS), 2009, 147-149

ISBN
978-961-90025-8-2

Skup
2nd International Conference on advanced plasma technologies with 1st international plasma nanoscience symposium

Mjesto i datum
Piran, Slovenija, 29.09.2009. - 02.10.2009

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
inductively coupled plasma; methane plasma; optical emission spectroscopy; thin films

Sažetak
Optical spectroscopy techniques were used to characterise methane plasma with the aim to develop in situ control of deposition of very thin carbon films [1]. Inductively coupled RF methane and oxygen plasmas have been created in a linear borosilicate glass tube and observed by optical emission spectroscopy (see figure 1). The source of a RF (13.56 MHz) electromagnetic field has been an eight turn coil connected to a power source via matching network. Spectra of the plasma have been taken by spectrometers LIBS-2000+ and AvaSpec 3648 [2]. Investigated plasma pressures are in the range up to 200 Pa discharge powers up to 300 W and gas flow up to300 ml/min. In methane plasma relative intensities of molecular and atomic lines show the presence of hydrogen, both molecular and atomic, CH radicals and impurities such as CN and N2, as shown in figure 2. Hydrogen spectrum includes the following transitions ; Balmer series (n=3, 4, 5 → n=2), Fulcher band (d3Π → a3Σg+) around 602 nm, band (G 1Σg+→ B 1Σu+) around 460 nm and continuum (a3Σg+ → b3Σu+) from 200-600 nm. Radicals’ bands are ; CH (A2Δ-X2Π) band at 431 nm and CN (B 2Σ+ - X 2Σ+) band at 388 nm. Three strong group of lines in the range from 315 to 357 nm are the fingerprint of molecular nitrogen’s (C 3Πu − B 3Πg) transition. It has been found that methane plasma causes deposition of amorphous hydrocarbon films on the walls of the tube. In order to measure some aspects of this deposition, transmission of a white light through the thin films has been analyzed, figure 3. Transmitted spectrum has been recorded by spectrometer HR2000CG-UV-NIR, figure 1. From transmission curves the deposition rate could be determined [1]. The deposition rate shows a dependence on gas pressure and plasma content (e.g. impurities such as nitrogen etc). Depending on above mentioned conditions and substrate, various thin films were produced, sometimes with strong thermal stress [3]. Deposited films can be removed by exposing them to the oxygen plasma [4]. The speed of removal depends on the oxygen pressure, lower pressure being more effective. Optical emission spectroscopy proves to be efficient method for plasma characterisation during thin film deposition. The importance of such processing control increases with approaching nanoscale dimensions of films and structures imbedded on substrates. References: [1] M. Bišćan, Spectroscopic characterization of RF methane plasma (Croatian), Diploma work, University of Zagreb, Faculty of Physics, 2009. [2] Z Kregar, N Krstulović, N Glavan Vukelić and S Milošević, Space and time resolved optical emission spectroscopy characterization of inductively coupled RF water vapour plasma, J. Phys. D 2009 42 (8pp) in press. [3] X. D.Zhu, K. Narumi, H. Naramoto, Buckling instability in amorphous carbon films, J. Phys.: Condens. Matter 19 236227 (6pp), 2007. [4] U. Cvelbar, N. Krstulović, S. Milošević, M. Mozetič, Inductively coupled RF oxygen plasma characterization by optical emission spectroscopy, Vacuum 82, 224–227, 2007.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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