Substrate polishing head, method of polishing substrate and membrane for substrate polishing head

Abstract

Provided is a substrate polishing head including a head part configured to be rotatable, a membrane mounted on the head part and configured to grip a substrate; a retainer ring surrounding the membrane, and a plurality of first electromagnets disposed within the head part and configured to form a magnetic field; wherein the membrane includes a first material having a hardening degree that changes depending on a magnetic field applied to the membrane.

What is claimed is: 
     
         1 . A substrate polishing head comprising:
 a head part configured to be rotatable;   a membrane connected to the head part on a first side of the membrane and configured to be connected to a substrate on a second side of the membrane opposite the first side of the membrane;   a retainer ring surrounding the membrane; and   a plurality of first electromagnets disposed within the head part and configured to form a first magnetic field;   wherein the membrane includes a first material having a hardening degree that changes depending on a magnetic field applied to the membrane, wherein the magnetic field includes the first magnetic field.   
     
     
         2 . The substrate polishing head of  claim 1 , further comprising a second electromagnet disposed within the retainer ring and configured to form a second magnetic field, wherein the magnetic field further includes the second magnetic field. 
     
     
         3 . The substrate polishing head of  claim 1 , wherein the membrane includes a planar part facing the substrate and a plurality of partition walls intersecting the planar part. 
     
     
         4 . The substrate polishing head of  claim 3 , wherein the planar part, the plurality of partition walls, and the head part define a plurality of spaces, and
 wherein a first particular electromagnet of the plurality of first electromagnets is disposed to overlap at least one space among the plurality of spaces based on a first direction intersecting the planar part.   
     
     
         5 . The substrate polishing head of  claim 3 , wherein each partition wall of the plurality of partition walls is annulus-shaped, and the plurality of partition walls are disposed in a form of concentric circles. 
     
     
         6 . The substrate polishing head of  claim 3 , wherein each partition wall of the plurality of partition walls has a bar shape extending between the planar part and the head part along a first direction intersecting the planar part. 
     
     
         7 . The substrate polishing head of  claim 3 , wherein the planar part includes a first planar part connected to the plurality of partition walls and a second planar part disposed between the first planar part and the substrate. 
     
     
         8 . The substrate polishing head of  claim 7 , wherein the plurality of partition walls and the first planar part include the first material, and
 wherein the second planar part does not include the first material.   
     
     
         9 . The substrate polishing head of  claim 7 , wherein the first planar part and the second planar part both include the first material, and
 wherein a first content ratio of the first material within the first planar part and a second content ratio of the first material within the second planar part, are different from each other.   
     
     
         10 . The substrate polishing head of  claim 3 , wherein at least one first electromagnet of the plurality of first electromagnets is disposed to overlap at least one partition wall of the plurality of partition walls, based on a first direction intersecting the planar part. 
     
     
         11 . The substrate polishing head of  claim 1 , wherein a planar shape of each first electromagnet of the plurality of first electromagnets has a uniform size. 
     
     
         12 . The substrate polishing head of  claim 1 , wherein a planar shape of each first electromagnet of the plurality of first electromagnets has a different size depending on a distance of the first electromagnet from a center of the head part. 
     
     
         13 . The substrate polishing head of  claim 1 , wherein the first material includes Fe 3 O 4 . 
     
     
         14 . A method of polishing a substrate, the method comprising:
 providing a substrate to a substrate polishing head, the substrate polishing head including a membrane including a first material having a hardening degree that changes depending on a magnetic field applied to the membrane, a head part connected to the membrane, and a plurality of first electromagnets disposed within the head part;   providing gas to an internal space formed by the membrane and the head part;   blocking power to a first set of first electromagnets of the plurality of first electromagnets overlapping the internal space along a first direction intersecting the substrate; and   forming a first magnetic field by supplying power to a second set of first electromagnets of the plurality of first electromagnets overlapping the internal space along the first direction.   
     
     
         15 . The method of  claim 14 , wherein the substrate polishing head further includes a retainer ring surrounding the membrane and a second electromagnet disposed within the retainer ring and configured to form a second magnetic field. 
     
     
         16 . The method of  claim 14 , wherein a first polishing amount of a first region of the substrate overlapping in the first direction a first portion of the membrane corresponding to the first set of the first electromagnets of the plurality of first electromagnets to which power is blocked, is different from a second polishing amount of a second region of the substrate overlapping in the first direction a second portion of the membrane corresponding to the second set of the first electromagnets of the plurality of first electromagnets to which power is supplied. 
     
     
         17 . The method of  claim 16 , wherein the first portion of the membrane is pressurized toward the substrate and the second portion is hardened. 
     
     
         18 . The method of  claim 17 , wherein the membrane includes a planar part disposed to be parallel with the head part and a plurality of partition walls intersecting the planar part, and
 wherein the first portion of the membrane overlaps at least one partition wall of the plurality of partition walls in the first direction.   
     
     
         19 . The method of  claim 16 , wherein an internal space formed by the first portion of the membrane and the head part is connected to an internal space formed by the second portion of the membrane and the head part. 
     
     
         20 . A membrane for a substrate polishing head, the membrane comprising:
 a first planar part disposed to be parallel with a substrate;   a plurality of partition walls extending from the first planar part along a first direction intersecting the substrate; and   a second planar part disposed between the first planar part and the substrate,   wherein at least one of the first planar part, the plurality of partition walls, or the second planar part includes a first material of which a hardening degree changes depending on a magnetic field, and   wherein a first content ratio of the first material within the first planar part and a second content ratio of the first material within the second planar part are different from each other.