Retainer ring for polishing head

Abstract

The present inventive concept provides a retainer ring for a polishing head, the retainer ring including: a ring-shaped body including a pressure surface having a plurality of first regions and a plurality of second regions alternately positioned in a circumferential direction of the body; a plurality of slurry grooves disposed in the pressure surface to be spaced apart from each other in the circumferential direction of the body and extending from an inner circumferential surface of the body to an outer circumferential surface of the body; and a plurality of rounded grooves disposed in the plurality of first regions and directly connected to the inner circumferential surface of the body, each of the plurality of rounded grooves having a concave groove surface rounded in a cross-sectional view taken along a radial direction of the body.

What is claimed is: 
     
         1 . A retainer ring for a polishing head, comprising:
 a ring-shaped body including a pressure surface having a plurality of first regions and a plurality of second regions alternately disposed in a circumferential direction of the body;   a plurality of slurry grooves disposed in the pressure surface to be spaced apart from each other in the circumferential direction of the body and extending from an inner circumferential surface of the body to an outer circumferential surface of the body; and   a plurality of rounded grooves disposed in the plurality of first regions and directly connected to the inner circumferential surface of the body, each of the plurality of rounded grooves having a concave groove surface rounded in a cross-sectional view taken along a radial direction of the body.   
     
     
         2 . The retainer ring for a polishing head of  claim 1 , wherein each of the plurality of rounded grooves extends in the circumferential direction of the body. 
     
     
         3 . The retainer ring for a polishing head of  claim 1 , wherein each of the plurality of rounded grooves is connected to at least one of the plurality of slurry grooves. 
     
     
         4 . The retainer ring for a polishing head of  claim 2 , wherein both ends of each of the plurality of rounded grooves are respectively connected to two adjacent slurry grooves among the plurality of slurry grooves. 
     
     
         5 . The retainer ring for a polishing head of  claim 1 , wherein each concave groove surface of the plurality of rounded grooves has an arc shape of a circle or an ellipse in a cross-sectional view taken along a radial direction of the body and arc shapes of the concave groove surface in cross-sectional views taken along radial directions of the body are the same throughout the concave groove surface in the circumferential direction of the body. 
     
     
         6 . The retainer ring for a polishing head of  claim 1 , wherein each of the plurality of rounded grooves has a shape in which a width of the concave groove surface in a radial direction of the body in a plan view gradually increases along a circumferential direction of the body. 
     
     
         7 . The retainer ring for a polishing head of  claim 1 , wherein at least one rounded groove is disposed in each of the plurality of first regions, and
 wherein the inner circumferential surface of the body and each of the plurality of second regions of the pressure surface are perpendicularly connected to each other.   
     
     
         8 . The retainer ring for a polishing head of  claim 7 , wherein the rounded grooves disposed in the plurality of first regions have the same shape. 
     
     
         9 . The retainer ring for a polishing head of  claim 7 , wherein the rounded grooves disposed in the plurality of first regions have different shapes from each other. 
     
     
         10 . The retainer ring for a polishing head of  claim 7 , wherein each of the plurality of first regions has the same area as each of the second regions or an area greater than each of the second regions. 
     
     
         11 . The retainer ring for a polishing head of  claim 7 , wherein the plurality of rounded grooves are spaced apart from each other at equal intervals with vertical connection portions interposed therebetween. 
     
     
         12 . The retainer ring for a polishing head of  claim 1 , wherein a groove depth of the plurality of rounded grooves is the same as or smaller than a depth of the slurry grooves. 
     
     
         13 . The retainer ring for a polishing head of  claim 1 , wherein the slurry grooves are inclined with respect to a radial direction of the body in a plan view. 
     
     
         14 . The retainer ring for a polishing head of  claim 1 , wherein both ends of each of the plurality of rounded grooves are respectively connected to two adjacent slurry grooves among the plurality of slurry grooves, and
 each of the plurality of rounded grooves is formed in a shape in which a width of the concave groove surface in a radial direction of the body gradually increases alone a circumferential direction of the body.   
     
     
         15 . A retainer ring for a polishing head, comprising:
 a ring-shaped body surrounding an accommodating space configured to accommodate a wafer and including a pressure surface having a plurality of first regions and a plurality of second regions alternately disposed in a circumferential direction of the body;   a plurality of slurry grooves disposed in the pressure surface to be spaced apart from each other at equal intervals in the circumferential direction of the body and extending from an inner circumferential surface of the body to an outer circumferential surface of the body; and   a plurality of rounded grooves disposed in the plurality of first regions of the pressure surface, each of the plurality of rounded grooves connected to at least one slurry groove among the plurality of slurry grooves, the plurality of rounded grooves each having a concave groove surface rounded in a cross-sectional view taken along a radial direction of the body,   wherein the inner circumferential surface of the body and each of the plurality of second regions of the pressure surface are perpendicularly connected to each other.   
     
     
         16 . The retainer ring for a polishing head of  claim 15 , wherein both ends of each of the plurality of rounded grooves are connected to two adjacent slurry grooves among the plurality of slurry grooves. 
     
     
         17 . The retainer ring for a polishing head of  claim 16 , wherein, when viewed in a cross-sectional view of the body taken along a radial direction of the body, the concave groove surface of each of the plurality of rounded grooves include a straight line portion connected to the inner circumferential surface of the body and a curved line portion connecting the straight line portion and the pressure surface of the body. 
     
     
         18 . The retainer ring for a polishing head of  claim 17 , wherein a first end of the concave groove surface of each of the plurality of rounded grooves includes a first straight line portion connected to the inner circumferential surface of the body and a first curved line portion connecting the first straight line portion and the pressure surface of the body,
 a second end of the concave groove surface, opposite to the first end, of each of the plurality of rounded grooves includes a second straight line portion connected to the inner circumferential surface of the body and a second curved line portion connecting the second straight line portion and the pressure surface of the body, and   a length of the first straight line portion is shorter than a length of the second straight line portion.   
     
     
         19 . The retainer ring for a polishing head of  claim 16 , wherein some of the rounded grooves disposed in one first region among the plurality of first regions have different shapes from some others of the rounded grooves disposed in another first region among the plurality of first regions. 
     
     
         20 . A retainer ring for a polishing head, comprising:
 a ring-shaped body including a pressure surface having a plurality of first regions and a plurality of second regions alternately disposed in a circumferential direction of the body;   a plurality of slurry grooves disposed in the pressure surface to be spaced apart from each other in the circumferential direction of the body and extending from an inner circumferential surface of the body to an outer circumferential surface of the body; and   a plurality of rounded grooves disposed in the plurality of first regions, the plurality of rounded grooves each having a concave groove surface rounded in a cross-sectional view taken along a radial direction of the body,   wherein the plurality of rounded grooves include a plurality of first rounded grooves disposed in at least one first region among the plurality of first regions and a plurality of second rounded grooves disposed in at least another first region among the plurality of first regions and having at least one different shape and size from the plurality of first rounded grooves.