Spectroscopic study on rotational and vibrational temperature of N{sub 2} and N{sub 2}{sup +} in dual-frequency capacitively coupled plasma
- Jiangsu Key Laboratory of Thin Films, School of Physical Science and Technology, Soochow University, Suzhou 215006 (China)
By using optical emission spectroscopy, the vibrational and rotational temperatures of N{sub 2} and N{sub 2}{sup +} in capacitively coupled plasma (CCP) discharges driven by dual-frequency 41 MHz and 2 MHz are investigated. The vibrational and rotational temperatures are measured based on the N{sub 2}{sup +} first negative system and N{sub 2} second positive system overlapped molecular emission optical spectrum, using the method of comparing the measured and calculated spectra with a least-square procedure. The influence of the rotational and vibrational temperatures with input power of the high frequency (HF) and low frequency (LF) as well as the gas pressure is discussed. It is found that the vibrational or rotational temperatures of N{sub 2} and N{sub 2}{sup +} are decoupled in dual-frequency CCP discharge. The influence of the LF power on N{sub 2}{sup +} rotational and vibrational temperature is much more than that of N{sub 2}, while the influence of HF power is just opposite to the case of LF power. The reason for this is thought to be the variation of electron temperature when applying HF or LF power. Additionally, the increase of gas pressure makes the difference between the vibrational and rotational temperature decrease.
- OSTI ID:
- 21259683
- Journal Information:
- Physics of Plasmas, Vol. 15, Issue 11; Other Information: DOI: 10.1063/1.3025826; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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