Production of corrosion-resistant ceramic members
AssigneeNGK Insulators, Ltd.
InventorsYasufumi Aihara, Akira Narukawa, Keiichiro Watanabe, Shinji Kawasaki
Life of this patent
Estimating the term…
Abstract
A process is disclosed for producing a corrosion-resistant ceramic member, which process includes the steps of preparing a sintered body made of a ceramic material containing at least aluminum, immersing the ceramic sintered body in hydrofluoric acid, and forming a film of aluminum fluoride at a surface layer portion of the ceramic sintered body by heating the ceramic sintered body.
Claims37
A process for producing a corrosion-resistant ceramic member, comprising the steps of preparing a sintered body made of a ceramic material containing at least aluminum, immersing the ceramic sintered body in hydrofluoric acid, and forming a film of aluminum fluoride at a surface layer portion of the ceramic sintered body by heating the ceramic sintered body.
A process for producing a corrosion-resistant ceramic member, comprising the steps of preparing a first sintered body made of a ceramic material containing at least aluminum, immersing the ceramic sintered body in hydrofluoric acid, forming a first film of aluminum fluoride at a surface layer portion of the ceramic sintered body by heating the ceramic sintered body, separately preparing at least one second sintered body made of a ceramic material containing at least aluminum, generating a gaseous product containing aluminum fluoride through corroding a surface of said at least one second ceramic sintered body by contacting the second ceramic sintered body with a fluorine-based corrosive gas, and forming a second film of aluminum fluoride by precipitating the gaseous product on the first aluminum fluoride film of the first ceramic sintered body.
A process for producing a corrosion-resistant ceramic member in a semiconductor-producing apparatus, the ceramic member being expected to be exposed to a halogen-based corrosive gas when in use, which process comprises:
- (a) preparing a sintered body made of a ceramic material selected from the group consisting of alumina (Al2O3), aluminum nitride (AlN), mullite (3Al2O3.2SiO2) and spinel (MgO.Al2O3);
- (b) immersing the entire ceramic sintered body into hydrofluoric acid having a concentration of 1 to 50 wt %;
- and
- (c) heating the ceramic sintered body at a temperature of 100 to 250° C. in the hydrofluoric acid, to form a film of aluminum fluoride.
Dependencies are inferred from the claim text.