Nonthermal and nonequilibrium effects in high-power pulsed ICP and application
to surface modification of materials*
T. Ishigaki1,**, N. Okada1, N. Ohashi1, H. Haneda1, and T. Sakuta2
1Advanced Materials Laboratory, National Institute
for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan;
2Department of Electrical and Electronic Engineering, Kanazawa University,
Kodatsuno, Kanazawa, Ishikawa 920-0942, Japan
Abstract: Newly developed pulse-modulated high-power inductively
coupled plasma (ICP) is expected to offer the unique physicochemical
condition, such as the increased concentration of chemically reactive
species, as well as the appropriate heat flux for materials processing.
Two kinds of oxide materials, titanium and zinc oxide, were placed at
the downstream of ArH2 ICP and irradiated in the plasma of continuous
(CN) and pulse-modulated (PM) modes. The CN-ICP irradiation at the position
close to the plasma tail gave rise to the thermal reduction of oxides.
In the PM-ICP irradiation, the degree of thermal reduction depended
on the lower power level during pulse-off time, as well as the total
electric power. Irradiation in PM-ICP led to the increased formation
of oxygen vacancies in titanium dioxide. In the case of zinc oxide,
the UV emission efficiency was improved by PM-ICP irradiation, while
the green emission became predominant by CN-ICP irradiation at the appropriate
position. Induced effects in the two oxides by PM-ICP would be related
to the high concentration of hydrogen radicals in the plasma.
* Lecture presented at the 15th International Symposium
on Plasma Chemistry, Orléans, France, 9-13 July 2001. Other presentations
are presented in this issue, pp. 317492.
** Corresponding author.
Page last modified 19 April 2002.
Copyright © 2002 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web
manager.