AVS 53rd International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS2+TF-WeM

Paper PS2+TF-WeM13
Increase of O(@super 1@D) Metastables by Rare-Gas Diluted O@sub 2@ Plasma and Application to the Oxide Growth

Wednesday, November 15, 2006, 12:00 pm, Room 2011

Session: Plasma Deposition
Presenter: T. Kitajima, National Defense Academy of Japan
Authors: T. Kitajima, National Defense Academy of Japan
T. Nakano, National Defense Academy of Japan
T. Makabe, Keio University, Japan
Correspondent: Click to Email
Rare gas diluted O@sub 2@ plasmas are gaining interests for application to high quality SiO@sub 2@ film formation. Especially, metastable O(@super 1@D) atoms produced in rare gas diluted O@sub 2@ plasma is believed to promote higher production rate of the oxide films. We have found the increase of O(@super 1@D) atoms in rare gas diluted O@sub 2@ RF plasma measured by VUV absorption spectroscopy.@footnote 1@ The increase of the O(@super 1@D) density is due to the increase of rare gas metastables that selectively produce O(@super 1@D) atoms via dissociative excitation of O@sub 2@. Among rare gas species, Krypton dilution enables highest O(@super 1@D) density. Then we applied the increased O(@super 1@D) flux of the Kr diluted O@sub 2@ plasma to the formation of SiO@sub 2@ films. Silicon substrate is flashed in the vacuum by direct current heating to form bare Si(001) surface. The surface is exposed to the Inductive coupled plasma operated at 70 MHz in O@sub 2@(3%)/Kr at 0.1 Torr for oxidation. After the oxidation, the sample is introduced to the UHV chamber which have a contact mode AFM for film evaluation. The topography and breakdown voltage of the SiO@sub 2@ films are measured by the biased AFM tip. The topographic images and breakdown current map shows the uniform oxide formation of the rare-gas diluted O@sub 2@ plasma. The breakdown voltage of the film is nearly same to the one of pure O@sub 2@ plasma case. Regarding the increase and the decrease of the O(@super 1@D) and the ground state O(@super 3@P) flux to the surface during oxidation, O(@super 1@D) atom has an order higher oxidation rate of Si(001) than O(@super 3@P). The results show the enhancement of oxidation rate of silicon with using increased O(@super 1@D) selectively produced in rare-gas diluted O@sub 2@ plasma. @FootnoteText@ @footnote 1@ T.Kitajima, T.Nakano, and T.Makabe, Appl. Phys. Lett. 88, 091501 (2006).