Diagnostics for an inductively coupled plasma in highly Ar-diluted oxygen

Oxygen plasma has been widely used in microelectronics fabrications. It is known that the growth rate of SiO$_{2}$ in Si-wafer is enhanced in Ar-diluted O$_{2}$ plasma. One of the key reactions in the surface is caused by the oxygen metastable atom O($^{1}$D$_{2})$, which has the potential for the surface activation. The work [1] shows that Ar metastable Ar(1s$_{5})$ contributes greatly to the production of O($^{1}$D$_{2})$ in a CCP in highly Ar-diluted oxygen. In this paper, we have studied the influence of the Ar metastables on the production of O($^{1}$D$_{2})$ in an inductively coupled plasma (ICP) in O$_{2}$(0-20{\%})/Ar. ICP was sustained by a single turn current coil driven at 13.56 MHz. Space-resolved 3D density profiles of O($^{3}$p), Ar(2p$_{1})$, and Ar(2p$_{9})$ were observed by Radon inversion of the line integrated optical emissions. And Ar metastable density was measured by laser absorption spectroscopy. The experimental result would be useful for the understanding of the mechanism of the production of O($^{1}$D$_{2})$. \newline [1] T. Kitajima, T. Nakano, T. Makabe, Appl. Phys. Lett. 88, 091501 (2006).