Polishing head, CMP apparatus including a polishing head, and manufacturing method of semiconductor integrated circuit device using a CMP apparatus
View Patent ↗In a polishing head for a CMP apparatus, a stress distributing plate made of metal or ceramic is placed between a wafer on a polishing pad and an air bag configured to press down the wafer, and a shock absorbing sheet is provided between the stress distributing plate and the underlying wafer, to thereby make pressure applied from the air bag to the wafer uniform.
1. A polishing head for a CMP apparatus, comprising:
a polishing pad;
an air bag mounted on a surface of the polishing pad, and configured to press a front surface of a wafer against the polishing pad from a direction of a back surface of the wafer;
a retainer ring surrounding a side surface of the air bag;
atop ring enveloping the air bag, the wafer, and the retainer ring; and
a stress distributing plate and a shock absorbing sheet both provided between the air bag and the wafer.
2. A polishing head according to claim 1 , wherein the stress distributing plate has a top surface that is in contact with the air bag and that has a spherical shape.
3. A polishing head according to claim 2 , wherein the spherical shape comprises a convex spherical shape.
4. A polishing head according to claim 3 , wherein the convex spherical shape is provided partially below an air flow inlet/outlet of the air bag.
5. A polishing head according to claim 2 , wherein the spherical shape comprises a concave spherical shape.
6. A polishing head according to claim 5 , wherein the concave spherical shape is provided partially below an air flow inlet/outlet of the air bag.
7. A polishing head according to claim 1 , wherein the stress distributing plate has a bottom surface which is in contact with the shock absorbing sheet and that has a spherical shape.
8. A polishing head according to claim 7 , wherein the spherical shape comprises a convex spherical shape.
9. A polishing head according to claim 7 , wherein the spherical shape comprises a concave spherical shape.
10. A polishing head according to claim 9 , wherein the concave spherical shape is provided partially below an air flow inlet/outlet of the air bag.
11. A polishing head according to claim 1 , wherein the stress distributing plate is formed of one of a single metal film, a single ceramic film, and two or more composite films of metal and ceramic.
12. A polishing head according to claim 11 , wherein the composite films comprise a layered member that is made of a plurality of materials different in Young's modulus, and a material that is relatively low in Young's modulus out of the plurality of materials is in contact with the air bag.
13. A CMP apparatus, comprising the polishing head of claim 1 .
14. A semiconductor integrated circuit device manufacturing method, comprising planarizing a front surface of a wafer by using the CMP apparatus of claim 13 .