Substrate holding device, substrate processing apparatus, substrate processing method, and storage medium

Abstract

A substrate holding device capable of eliminating a variation in a film thickness of a substrate is disclosed. The substrate holding device includes an offset mechanism configured to offset a carrier with respect to a retaining ring.

What is claimed is: 
     
         1 . A substrate holding device, comprising:
 an elastic membrane configured to form at least one pressure chamber for pressing a substrate;   a carrier coupled to the elastic membrane;   a retaining ring surrounding the carrier; and   an offset mechanism configured to offset the carrier relative to the retaining ring.   
     
     
         2 . The substrate holding device according to  claim 1 , wherein the substrate holding device comprises a tilting structure configured to tilt the retaining ring. 
     
     
         3 . The substrate holding device according to  claim 2 , wherein the tilting structure is arranged in an accommodation recess of the carrier and comprises a spherical bearing mounted on a shaft portion of the retaining ring. 
     
     
         4 . The substrate holding device according to  claim 2 , wherein the tilting structure comprises a ball joint coupling the retaining ring and a head shaft. 
     
     
         5 . The substrate holding device according to  claim 1 , wherein the offset mechanism comprises a plurality of pressing actuators supported by the carrier, and
 wherein each of the pressing actuators applies a pressing force to the carrier.   
     
     
         6 . The substrate holding device according to  claim 1 , wherein the offset mechanism comprises a plurality of pressing actuators supported by the retaining ring and configured to apply a pressing force to the carrier. 
     
     
         7 . The substrate holding device according to  claim 1 , wherein the substrate holding device comprises a rotational torque transmission mechanism configured to transmit a rotational torque acting on the retaining ring to the carrier. 
     
     
         8 . A substrate processing apparatus, comprising:
 a substrate holding device according to  claim 1 ;   a polishing table configured to support a polishing pad having a polishing surface against which a substrate held by the substrate holding device is pressed; and   a control device configured to control an operation of the substrate holding device,   wherein the control device is configured to:
 determine an eccentricity direction and an eccentricity of a carrier based on a film thickness distribution of the substrate measured during polishing of the substrate; and 
 operate an offset mechanism to offset the carrier based on the determined eccentricity direction and eccentricity. 
   
     
     
         9 . The substrate processing apparatus according to  claim 8 , wherein the control device is configured to:
 determine whether or not a relative angle of the substrate to the substrate holding device has changed when measuring the film thickness distribution of the substrate; and   when the relative angle has changed, correct the relative angle based on the amount of change in the relative angle to determine the eccentricity direction and the eccentricity of the carrier.   
     
     
         10 . The substrate processing apparatus according to  claim 8 , wherein the control device is configured to:
 after starting polishing of the substrate, determine whether or not the current film thickness distribution in a circumferential direction of the substrate is within a predetermined first target film thickness distribution range;   when the current film thickness distribution is within the first target film thickness distribution range, operate the offset mechanism to return the carrier to an initial position; and   when the current film thickness distribution is not within the first target film thickness distribution range, check whether the eccentricity direction and the eccentricity of the carrier correspond to the film thickness distribution of the substrate.   
     
     
         11 . The substrate processing apparatus according to  claim 8 , wherein the control device is configured to:
 after starting polishing of the substrate, determine whether or not the current film thickness distribution in a radial direction of the substrate is within a predetermined second target film thickness distribution range;   when the current film thickness distribution is within the second target film thickness distribution range, determine whether or not the current film thickness distribution in a circumferential direction of the substrate is within a predetermined first target film thickness distribution range; and   when the current film thickness distribution is not within the second target film thickness distribution range, operate a pressure regulation device to change a pressure of a fluid supplied to a pressure chamber.   
     
     
         12 . A substrate processing method, comprising:
 pressing a substrate held by a substrate holding device against a polishing surface of a polishing pad to polish the substrate;   determining an eccentricity direction and an eccentricity of a carrier coupled to an elastic membrane forming at least one pressure chamber for pressing the substrate based on a film thickness distribution of the substrate measured during polishing of the substrate; and   operating an offset mechanism configured to offset the carrier based on the determined eccentricity direction and eccentricity to offset the carrier.   
     
     
         13 . The substrate processing method according to  claim 12 , comprising:
 determining whether or not a relative angle of the substrate to the substrate holding device has changed when measuring the film thickness distribution of the substrate; and   when the relative angle has changed, correcting the relative angle based on the amount of change in the relative angle to determine the eccentricity direction and the eccentricity of the carrier.   
     
     
         14 . The substrate processing method according to  claim 12 , comprising:
 after starting polishing of the substrate, determining whether or not the current film thickness distribution in a circumferential direction of the substrate is within a predetermined first target film thickness distribution range;   when the current film thickness distribution is within the first target film thickness distribution range, operating the offset mechanism to return the carrier to an initial position; and   when the current film thickness distribution is not within the first target film thickness distribution range, checking whether the eccentricity direction and the eccentricity of the carrier correspond to the film thickness distribution of the substrate.   
     
     
         15 . The substrate processing method according to  claim 12 , comprising:
 after starting polishing of the substrate, determining whether or not the current film thickness distribution in a radial direction of the substrate is within a predetermined second target film thickness distribution range;   when the current film thickness distribution is within the second target film thickness distribution range, determining whether or not the current film thickness distribution in a circumferential direction of the substrate is within a predetermined first target film thickness distribution range; and   when the current film thickness distribution is not within the second target film thickness distribution range, operating a pressure regulation device to change a pressure of a fluid supplied to the pressure chamber.   
     
     
         16 . A non-transitory computer-readable storage medium storing a program for causing a computer to perform the steps of:
 causing a substrate holding device to perform an operation of pressing a substrate against a polishing surface of a polishing pad to polish the substrate;   determining an eccentricity direction and an eccentricity of a carrier coupled to an elastic membrane configured to form at least one pressure chamber for pressing the substrate based on a film thickness distribution of the substrate measured during polishing of the substrate; and   causing an offset mechanism to perform an operation of offsetting the carrier based on the determined eccentricity direction and eccentricity.   
     
     
         17 . The storage medium according to  claim 16 , wherein which causes the computer to perform the steps of:
 determining whether or not a relative angle of the substrate with respect to the substrate holding device has changed when measuring the film thickness distribution of the substrate; and   when the relative angle has changed, correcting the relative angle based on the amount of change in the relative angle to determine the eccentricity direction and the eccentricity of the carrier.   
     
     
         18 . The storage medium according to  claim 16 , wherein which causes the computer to perform the steps of:
 after starting polishing of the substrate, determining whether or not the current film thickness distribution in a circumferential direction of the substrate is within a predetermined first target film thickness distribution range;   when the current film thickness distribution is within the first target film thickness distribution range, causing the offset mechanism to perform an operation of returning the carrier to an initial position; and   when the current film thickness distribution is not within the first target film thickness distribution range, checking whether the eccentricity direction and the eccentricity of the carrier correspond to the film thickness distribution of the substrate.   
     
     
         19 . The storage medium according to  claim 16 , wherein which causes the computer to perform the steps of:
 after starting polishing of the substrate, determining whether or not the current film thickness distribution in a radial direction of the substrate is within a predetermined second target film thickness distribution range;   when the current film thickness distribution is within the second target film thickness distribution range, determining whether or not the current film thickness distribution in the circumferential direction of the substrate is within a predetermined first target film thickness distribution range; and   when the current film thickness distribution is not within the second target film thickness distribution range, causing a pressure regulation device to perform an operation of changing a pressure of a fluid supplied to the pressure chamber.