Apparatus and methods for chemical mechanical polishing with an advanceable polishing sheet

A chemical mechanical polishing apparatus, comprising:

• a plurality of polishing stations, each polishing station including a rotatable platen base, at least one of the polishing stations having a rectangular platen with a channel formed in a top surface thereof, the station including a drive mechanism to incrementally advance a polishing sheet in a linear direction coupled to the platen base in the polishing station;
• a vacuum source connected to the channel to vacuum-chuck the polishing sheet to the platen;
• and
• a carousel supporting a plurality of polishing heads above the plurality of polishing stations.

An apparatus for polishing at least two substrates, comprising:

• a plurality of polishing stations, at least one of the polishing stations including a rotatable platen with a channel formed in a top surface thereof, a generally linear polishing sheet releasably secured to the platen to rotate with the platen, the polishing sheet having an exposed portion extending over a top surface of the platen for polishing the substrate and having a width greater than a diameter of the substrate, and a drive mechanism to incrementally advance the polishing sheet in a linear direction across the top surface of the platen;
• a vacuum source connected to the channel to vacuum-chuck the polishing sheet to the platen;
• a rotatable carousel;
• at least two substrate head assemblies suspended from said carousel and capable of holding thereon respective ones of said substrates;
• and
• a positioning member coupled to said carousel to move said carousel and thereby position a selected one of said substrate head assemblies over a selected one of said polishing stations.

A method of chemical mechanical polishing, comprising:

• bringing a substrate into contact with a generally linear polishing sheet that extends over a top surface of a rotatable platen, the polishing sheet having a width greater than a diameter of the substrate;
• releasably securing the polishing sheet to the platen by vacuum-chucking the polishing sheet to the platen;
• rotating the platen to rotate the polishing sheet and create relative motion between the substrate and the polishing sheet;
• releasing the polishing sheet from the platen;
• and
• incrementally advancing the polishing sheet in a linear direction across the top surface of the platen after the polishing step has been completed.

A chemical mechanical polishing apparatus, comprising:

• a rotatable platen;
• a generally linear polishing sheet releasably secured to the platen to rotate with the platen, the polishing sheet having an exposed portion extending over a top surface of the platen for polishing a substrate, an unused portion wrapped around a feed roller, and a width greater than a diameter of the substrate;
• a drive mechanism to incrementally advance the polishing sheet in a linear direction across the top surface of the platen;
• a guard including a frame positioned near the feed roller to prevent contamination of the unused portion of the polishing sheet, the frame suspended above the polishing sheet to form a gap;
• and
• a source of pressurized gas to direct gas through the gap.

A chemical mechanical polishing apparatus, comprising:

• a rotatable platen;
• first and second rollers rotatably connected to the platen;
• a generally linear polishing sheet releasably secured to the platen to rotate with the platen, the polishing sheet extending between the first roller and the second rollers and having an exposed portion extending over a top surface of the platen for polishing a substrate, an unused portion wrapped around a feed roller, and a width greater than a diameter of the substrate;
• a drive mechanism to incrementally advance the polishing sheet in a linear direction across the top surface of the platen, the drive mechanism including a spring positioned to urge the second roller to rotate in a first direction and pull the polishing sheet across the top surface of the platen and a ratchet to engage a gear that is connected to the first roller to prevent the first roller from rotating, thereby preventing the polishing sheet from moving across the top surface of the platen.