Patent ID: 7775853

Claim:
A polishing apparatus for polishing semiconductor wafers comprising: a main polishing structure including a plurality of polishing tables, a plurality of polishing heads and a plurality of load-and-unload stations that are operatively coupled to a main frame structure, said polishing heads being operatively coupled to said main frame structure such that each of said polishing heads can be moved between one of said polishing tables and at least one of said load-and-unload stations, wherein said polishing heads are operatively attached to said main frame structure such that each of said polishing heads can be linearly moved between said one of said polishing tables and said at least one of said load-and-unload stations; and an add-on polishing structure including an additional polishing table and an additional polishing head that are operatively coupled to an add-on frame structure, said add-on polishing structure being configured to be attached to said main polishing structure to form a larger polishing structure with said additional polishing table and said additional polishing head.