Semiconductor polishing apparatus and method of detecting end point of polishing semiconductor

Abstract

A method of detecting an end point improved to enable proper detection of end points of polishing so as to improve throughput and stability of the entire polishing process is provided. A semiconductor polishing apparatus is provided in which a wafer held by a polishing head is brought into contact with a polishing pad adhered on a polishing table, with a prescribed pressure. The apparatus includes a dresser for dressing the polishing pad arranged opposing to the polishing pad, and a sound sensor for detecting sound generated by the friction between the polishing head and the wafer.

What is claimed is:  
     
         1 . An apparatus for polishing a semiconductor, polishing a wafer held by a polishing head by bringing into contact the wafer with a polishing pad adhered on a polishing table, with a prescribed pressure, comprising: 
 a polishing table;    a polishing pad adhered on said polishing table;    a polishing head arranged opposing to said polishing pad;    a dresser arranged opposing to said polishing pad for dressing said polishing pad; and    sound detecting means for detecting sound generated by friction between said polishing head and said wafer.    
     
     
         2 . The apparatus for polishing a semiconductor according to  claim 1 , wherein 
 said sound detecting means is provided inside or outside said polishing head or rotary shaft of the head.    
     
     
         3 . The apparatus for polishing a semiconductor according to  claim 1 , wherein 
 said sound detecting means is provided inside or outside said polishing table.    
     
     
         4 . A method of detecting an end point of polishing by bringing into contact a wafer held by a polishing head with a polishing pad adhered on a polishing table, with a prescribed pressure, wherein 
 sound generated by friction between said polishing head and said wafer is detected by a sound sensor, and an end point of polishing is determined from a change in intensity of the sound signal.    
     
     
         5 . The method of detecting an end point of polishing a semiconductor according to  claim 4 , wherein 
 the signal detected by said sound sensor is amplified and thereafter converted to frequency spectra, and an end point of polishing is determined from a change in intensity of a frequency spectrum related to polishing among the frequency spectra.