Toto Ltd.

Yoshihide Hayashida

Toshiya Watanabe

Eiichi Kojima

Toshihiro Aoshima

Yuji Aso

Kaduko Ishikawa

Junji Yonezawa

An electrostatic chuck comprises: a dielectric substrate having a protrusion and a planar surface part. The protrusion is formed on a major surface of the dielectric substrate. An adsorption target material is mounted on the major surface. The planar surface part is formed in a periphery of the protrusion. The dielectric substrate is formed from a polycrystalline ceramics sintered body. A top face of the protrusion is a curved surface, and a first recess is formed in the top face to correspond to crystal grains that appear on the surface. The planar surface part has a flat part, and a second recess is formed in the flat part. A depth dimension of the first recess is greater than a depth dimension of the second recess. The electrostatic chuck can suppress the generation of particles and can easily recover a clean state of the electrostatic chuck surface.

Electrostatic chuck

A method of manufacturing a corona discharge device suitable for use as an ozonizer capable of producing a controlled small amount of ozone throughout a prolonged service life. A foreproduct of corona discharge device (50) is first prepared which is provided with first and second planar electrodes (54; 56) capacitively coupled with each other by a third floating electrode (64) which is coated by a protective layer (68) of chemically-resistive electrically-insulatingmaterial. A high frequency alternating voltage having a voltage level higher than an initial minimum flashover voltage level of the foreproduct is then applied until the protective layer is aged. Aging of the protective layer is effective in lowering the initial minimum flashover voltage of the final product thus obtained as well as in reducing any fluctuation of the initial minimum flashover voltage that would otherwise occur from product to product. Various other features are also disclosed.

Method of manufacturing a corona discharge device

Growing community of inventors

Fukuoka-ken, Japan

Yoshihide Hayashida