Cmp apparatus and cmp method

Abstract

A chemical mechanical polishing apparatus in which a rotating head having a polishing pad mounted thereon whose contact area with a polishing object is smaller than surface area of the polishing object is pressed against and brought into contact with a surface of the polishing object mounted face up on a table, and is rotated with the table at rest while supplying slurry onto a contact surface to polish for a predetermined time, and then the rotating head is moved within the surface of the polishing object to polish the entire surface of the polishing object sequentially, including a pressure adjustment mechanism for maintaining a pressing load on the contact surface constant during polishing.

What is claimed is:  
     
         1 . A chemical mechanical polishing apparatus, comprising a rotating head having a polishing pad mounted thereon whose contact area with a polishing object is smaller than surface area of the polishing object is pressed against and brought into contact with a surface of the polishing object mounted face up on a table, and is rotated with the table at rest while supplying slurry onto a contact surface to polish for a predetermined time, and then the rotating head is moved within the surface of the polishing object to polish the entire surface of the polishing object sequentially, further comprising a pressure adjustment mechanism for maintaining a pressing load on the contact surface constant during polishing. 
     
     
         2 . The chemical mechanical polishing apparatus according to  claim 1 , wherein the pressure adjustment mechanism comprises: a support shaft supporting the table along its central axis; a cylinder slidably holding the support shaft along the central axis; a pressure chamber having an air inlet and an air outlet and formed in the cylinder; and an air pressure adjustment means provided on the support shaft located in the pressure chamber. 
     
     
         3 . The chemical mechanical polishing apparatus according to  claim 2 , wherein the air pressure adjustment means comprises a separation wall separating the pressure chamber into a first pressure chamber having the air inlet and a second pressure chamber having the air outlet, and adjusts the amount of air moving from the first pressure chamber to the second pressure chamber through a minute opening provided in the separation wall or a clearance between the separation wall and an inner wall surface of the cylinder to control air pressure in the pressure chamber. 
     
     
         4 . The chemical mechanical polishing apparatus according to  claim 1 , wherein the pressure adjustment mechanism comprises: an inner cylinder horizontally holding the table on its upper surface and having a pressure chamber formed therein;
 an outer cylinder slidably holding the inner cylinder along its central axis; a base having an air inlet and an air outlet and holding the outer cylinder; and an air pressure control unit adjusting the amount of air flowing in the air inlet and out the air outlet to control air pressure in the pressure chamber.   
     
     
         5 . The chemical mechanical polishing apparatus according to  claim 2 , wherein the table is removably attached to the support shaft. 
     
     
         6 . The chemical mechanical polishing apparatus according to  claim 4 , wherein the table is removably attached to the upper surface of the inner cylinder. 
     
     
         7 . The chemical mechanical polishing apparatus according to  claim 1 , wherein a nozzle for supplying slurry is placed close to the rotating head and supplies slurry while moving in synchronization with the movement of the rotating head. 
     
     
         8 . The chemical mechanical polishing apparatus according to  claim 1 , wherein a container capable of storing slurry is attached to the table. 
     
     
         9 . The chemical mechanical polishing apparatus according to any of  claim 1 , wherein a recess is provided near the center of a polishing object facing surface of the rotating head. 
     
     
         10 . A chemical mechanical polishing method, comprising a rotating head having a polishing pad mounted thereon whose contact area with a polishing object is smaller than surface area of the polishing object is pressed against and brought into contact with a surface of the polishing object mounted face up on a table, and is rotated with the table at rest while supplying slurry onto a contact surface to polish for a predetermined time, and then the rotating head is moved within the surface of the polishing object to polish the entire surface of the polishing object sequentially, further comprising a pressing load on the contact surface is maintained constant during polishing. 
     
     
         11 . The chemical mechanical polishing method according to  claim 10 , wherein the surface of the polishing object is divided into a plurality of regions to be polished, and the rotating head is sequentially pressed against and brought into contact with them to polish as polishing time is varied according to section thickness of each divided region to be polished.