Polishing head, retaining ring for use therewith and method fo polishing a substrate

A method of polishing a substrate having a surface using a polishing apparatus comprising a polishing surface, a polishing head having a subcarrier and a retaining ring having an inner edge disposed about the subcarrier and a lower surface in contact with the polishing surface during the polishing operation, the lower surface of the retaining ring having a plurality of radial recesses formed therein, at least one of the radial recesses comprising a groove, the method comprising:

• positioning the substrate on the subcarrier;
• pressing the surface of the substrate and the lower surface of the retaining ring against the polishing surface;
• dispensing a chemical onto the polishing surface;
• providing relative motion between the polishing head and the polishing surface;
• and
• distributing the chemical between the substrate held on the subcarrier and the polishing surface through the plurality of radial recesses, wherein at least two of said recesses define a segment of the retaining ring, the segment having a leading edge comprising a chevron shape and a trailing edge comprising a chevron shape, and wherein the leading edge chevron shape and the trailing edge chevron shape are oriented in opposite directions, and further wherein each chevron shape comprises an inner groove portion from the inner edge of the retaining ring to an apex and an outer groove portion from the outer edge of the retaining ring to the apex, said inner groove portion and said outer groove portion forming the only outlets from the apex.

A method of polishing a substrate having a surface using a polishing apparatus comprising a polishing surface, a polishing head having retaining ring having an inner edge and a lower surface in contact with the polishing surface during the polishing operation, the lower surface of the retaining ring having a plurality of radial recesses formed therein, at least one of the radial recesses comprising a groove, the method comprising:

• positioning the substrate within the inner edge of the retaining ring;
• pressing the surface of the substrate and the lower surface of the retaining ring against the polishing surface;
• dispensing a chemical onto the polishing surface;
• providing relative motion between the polishing head and the polishing surface;
• and
• distributing the chemical between the substrate held within the inner edge of the retaining ring and the polishing surface through the plurality of radial recesses, wherein at least two of said recesses define a segment of the retaining ring, the segment having a leading edge comprising a chevron shape and a trailing edge comprising a chevron shape, and wherein the leading edge chevron shape and the trailing edge chevron shape are oriented in opposite directions, and further wherein each chevron shape comprises an inner groove portion from the inner edge of the retaining ring to an apex and an outer groove portion from the outer edge of the retaining ring to the apex, said inner groove portion and said outer groove portion forming the only outlets from the apex.