Method for estimating life of polishing pad and polishing device

Abstract

A method for estimating a life of a polishing pad includes: polishing a workpiece by pressing the workpiece against a polishing surface of a polishing pad with an elastic membrane forming a pressure chamber provided in a polishing head; controlling a pressure in the pressure chamber on the basis of a measured value of a film thickness of the workpiece while measuring the film thickness during the polishing of the workpiece; inputting time-series pressure data representing a change in the pressure in the pressure chamber during the polishing of the workpiece into a learned model; and outputting a life index of the polishing pad from the learned model.

What is claimed is: 
     
         1 . A method for estimating a life of a polishing pad, comprising:
 polishing a workpiece by pressing the workpiece against a polishing surface of a polishing pad with an elastic membrane forming a pressure chamber provided in a polishing head;   controlling a pressure in the pressure chamber on the basis of a measured value of a film thickness of the workpiece while measuring the film thickness during the polishing of the workpiece;   inputting time-series pressure data representing a change in the pressure during the polishing of the workpiece into a learned model; and   outputting a life index of the polishing pad from the learned model.   
     
     
         2 . The method for estimating a life of a polishing pad according to  claim 1 , wherein, in addition to the time-series pressure data, polishing data relating to the polishing of the workpiece is input to the learned model. 
     
     
         3 . The method for estimating a life of a polishing pad according to  claim 2 , wherein the polishing data includes at least one of information of the workpiece and polishing conditions for the workpiece. 
     
     
         4 . The method for estimating a life of a polishing pad according to  claim 1 , wherein, in addition to the time-series pressure data, a cut rate of the polishing pad which has been dressed by a dresser is input to the learned model. 
     
     
         5 . The method for estimating a life of a polishing pad according to  claim 1 , wherein the steps of inputting the time-series pressure data into the learned model and outputting the life index of the polishing pad from the learned model are performed after the polishing of the workpiece and before polishing of a next workpiece. 
     
     
         6 . The method for estimating a life of a polishing pad according to  claim 1 ,
 wherein the pressure chamber is a plurality of pressure chambers,   the step of controlling the pressure in the pressure chamber is a step of controlling pressures in the plurality of pressure chambers on the basis of the measured value of the film thickness of the workpiece while measuring the film thickness during the polishing of the workpiece, and   the step of inputting the time-series pressure data into the learned model is a step of inputting into the learned model a plurality of pieces of time-series pressure data respectively representing changes in the pressures in the plurality of pressure chambers during the polishing of the workpiece.   
     
     
         7 . A polishing device comprising:
 a polishing head that includes a pressure chamber formed by an elastic membrane and polishes a workpiece by pressing the workpiece against a polishing surface of a polishing pad with the elastic membrane;   a film thickness sensor that measures a film thickness of the workpiece;   a polishing control part that controls a pressure in the pressure chamber during the polishing of the workpiece on the basis of a measured value of the film thickness; and   a pad life calculation part that inputs time-series pressure data representing a change in the pressure during the polishing of the workpiece into a learned model and outputs a life index of the polishing pad from the learned model.   
     
     
         8 . The polishing device according to  claim 7 , wherein the pad life calculation part is configured to input polishing data relating to the polishing of the workpiece into the learned model in addition to the time-series pressure data. 
     
     
         9 . The polishing device according to  claim 8 , wherein the polishing data includes at least one of information of the workpiece and polishing conditions for the workpiece. 
     
     
         10 . The polishing device according to  claim 7 , further comprising a dresser that dresses the polishing surface of the polishing pad, wherein
 the pad life calculation part is configured to input a cut rate of the polishing pad dressed by the dresser into the learned model in addition to the time-series pressure data.   
     
     
         11 . The polishing device according to  claim 7 , wherein the pad life calculation part is configured to input the time-series pressure data into the learned model and output the life index of the polishing pad from the learned model after the polishing of the workpiece and before polishing of a next workpiece. 
     
     
         12 . The polishing device according to  claim 7 ,
 wherein the pressure chamber is a plurality of pressure chambers,   the polishing control part is configured to control pressures in the plurality of pressure chambers on the basis of the measured value of the film thickness of the workpiece while measuring the film thickness during the polishing of the workpiece, and   the pad life calculation part is configured to input into the learned model a plurality of pieces of time-series pressure data respectively representing changes in the pressures in the plurality of pressure chambers during the polishing of the workpiece.