Two-dimensional CT images of two-frequency capacitively coupled plasma

T. Kitajima, Y. Takeo, T. Makabe

Research output: Contribution to journalArticle

62 Citations (Scopus)

Abstract

Two-dimensional images of two-frequency capacitively coupled plasma (2f-CCP) in Ar and Ar/CF4(5%) in an axisymmetric parallel plate reactor are investigated by using 2D-t optical emission spectroscopy. Spatially averaged electron density is obtained by microwave interferometry. Results are presented in the form of 2D profiles of the net excitation rate of Ar(3p5)(∈ex=14.5 eV) and Ar+(4p4D7/2)(∈ex=35.0 eV) used as a probe. Large area uniformity of plasma production driven at very high frequency (VHF) (100 MHz) and that driven at high frequency (HF) (13.56 MHz) at low pressure (∼25 mTorr) are compared and discussed under a low frequency (LF) (700 kHz) bias voltage on the wafer. The time modulation of the net excitation rate and the electron density indicate that the LF bias is considerably influential in the production of the plasma and in the confinement of high energy electrons at HF. Functional separation between plasma production in a gas phase and ion acceleration to the wafer is achieved in 2f-CCP excited at VHF (100 MHz). The addition of a small amount of CF4 to the Ar plasma improves the uniformity of the radial profile of the excitation at HF (13.56 MHz).

Original languageEnglish
Pages (from-to)2510-2516
Number of pages7
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Volume17
Issue number5
Publication statusPublished - 1999 Sep

Fingerprint

Plasma sources
Plasmas
Carrier concentration
very high frequencies
Plasma confinement
Optical emission spectroscopy
Bias voltage
Interferometry
wafers
low frequencies
excitation
Gases
Microwaves
Modulation
Ions
optical emission spectroscopy
profiles
parallel plates
Electrons
high energy electrons

ASJC Scopus subject areas

  • Surfaces, Coatings and Films
  • Physics and Astronomy (miscellaneous)
  • Surfaces and Interfaces

Cite this

Two-dimensional CT images of two-frequency capacitively coupled plasma. / Kitajima, T.; Takeo, Y.; Makabe, T.

In: Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films, Vol. 17, No. 5, 09.1999, p. 2510-2516.

Research output: Contribution to journalArticle

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