Polishing apparatus and method of polishing work piece

A method of polishing a work piece in a polishing apparatus comprising:

• a pressure vessel having a lid which opens or closes said pressure vessel;
• a polishing plate being provided in said pressure vessel;
• a pressing plate being provided on said polishing plate, said pressing plate pressing a work piece, which has been set between said polishing plate and said pressing plate, onto said polishing plate;
• a driving unit relatively moving said polishing plate with respect to said pressing plate so as to polish the work piece;
• a gas supplying source being connected to said pressure vessel, said gas supplying source supplying an alkaline gas or an acid gas into said pressure vessel;
• a gas discharging section discharging the supplied gas from said pressure vessel;
• and a pure water supplying unit supplying pure water onto said polishing plate,
• said method comprising the step of:
• supplying the alkaline gas or the acid gas into said pressure vessel from said gas supplying source so as to adjust the pH value of the pure water and use the pure water as slurry.

A polishing apparatus, comprising:

• a pressure vessel having a lid which opens or closes said pressure vessel;
• a polishing plate being provided in said pressure vessel;
• a pressing plate being provided on said polishing plate, said pressing plate pressing a work piece, which has been set between said polishing plate and said pressing plate, onto said polishing plate;
• a driving unit moving said polishing plate relative to said pressing plate so as to polish the work piece;
• a fluid supplying unit for supplying fluid onto said polishing plate, said fluid supplying unit having a gas supplying source being connected to said pressure vessel, said gas supplying source being adapted to selectively supply an alkaline gas or an acid gas into said pressure vessel;
• and
• a gas discharging section for discharging the supplied gas from said pressure vessel, wherein
• a pH value of the fluid is adjustable by dissolving the alkaline gas or the acid gas therein.