Wafer polishing head

Abstract

A wafer polishing head for planarizing a wafer. The wafer polishing head comprises a carrier, a retaining ring, a first pressure chamber, a second pressure chamber and an automatic control system. The retaining ring is surrounding the carrier. The first pressure chamber having a first inner pressure is disposed above the retaining ring. The second pressure chamber having a second inner pressure is disposed on the carrier. The automatic control system is respectively coupled to the first pressure chamber and the second pressure chamber.

What is claimed is:  
     
         1 . A wafer polishing head for planarizing a wafer, comprising: 
 a carrier for loading the wafer;    a wafer adhering layer disposed beneath the carrier;    a retaining ring surrounding the carrier and the wafer adhering layer,    a first pressure chamber having a first inner pressure disposed above the retaining ring;    a second pressure chamber having a second inner pressure disposed on the carrier, wherein a relative height between the retaining ring and the carrier can be adjusted by changing the first and the second inner pressure; and    an automatic control system respectively coupled to the first pressure chamber and the second pressure chamber and for adjusting a relative height between the carrier and the retaining ring, wherein the automatic control system receives a first feedback pressure signal and transmitted from the first pressure chamber and a second feedback pressure signal and transmitted from the second pressure chamber while a chemical-mechanical polishing process is performed, and the automatic control system respectively transmits a first pressure value and a second pressure value to the first pressure chamber and the second pressure chamber.    
     
     
         2 . The wafer polishing head of    claim 1   , wherein the automatic control system comprises: 
 a controller:    a counter coupled to the controller;    a first converter coupled to the first pressure chamber and the controller, wherein the first converter receives the first feedback pressure signal while the chemical-mechanical polishing process is performed and transforms the first feedback pressure into a first feedback digital signal, and the first feedback digital signal is transmitted into the controller;    a second converter coupled to the second pressure chamber and the controller, wherein the second converter receives the second feedback pressure signal while the chemical-mechanical polishing process is performed and transforms the second feedback pressure into a second feedback digital signal, and the second feedback digital signal is transmitted into the controller;    a first regulator coupled to the controller and the first pressure chamber, wherein the first regulator receive a first digital signal transmitted from the controller and transform the first digital signal into the first pressure value; and    a second regulator coupled to the controller and the second pressure chamber, wherein the second regulator receive a second digital signal transmitted from the controller and transform the second digital signal into the second pressure value.    
     
     
         3 . The wafer polishing head of    claim 2   , wherein the first and the second converters can be analog/digital (A/D) converters.  
     
     
         4 . The wafer polishing head of    claim 1   , wherein the second pressure chamber is partly filled by a liquid with a relatively low volatility and a relatively low chemical reactivity.  
     
     
         5 . The wafer polishing head of    claim 1   , wherein the first feedback pressure signal denotes the first inner pressure.  
     
     
         6 . The wafer polishing head of    claim 1   , wherein the second feedback pressure signal denotes the second inner pressure.  
     
     
         7 . A wafer polishing head for planarizing a wafer, comprising: 
 a carrier for loading the wafer;    a retaining ring surrounding the carrier;    a first pressure chamber having a first inner pressure disposed above the retaining ring;    a second pressure chamber having a second inner pressure disposed on the carrier; and    an automatic control system respectively coupled to the first pressure chamber and the second pressure chamber.    
     
     
         8 . The wafer polishing head of    claim 7   , wherein the automatic control system comprises: 
 a controller:    a first converter coupled to the first pressure chamber and the controller;    a second converter coupled to the second pressure chamber and the controller;    a first regulator coupled to the controller and the first pressure chamber; and    a second regulator coupled to the controller and the second pressure chamber.    
     
     
         9 . The wafer polishing head of    claim 8   , wherein the first and the second converters can be analog/digital (A/D) converters.  
     
     
         10 . The wafer polishing head of    claim 8   , wherein the automatic control system further comprises a counter coupled to the controller.  
     
     
         11 . The wafer polishing head of    claim 7   , wherein the second pressure chamber is partly filled by a liquid possesses a relatively low volatility and a relatively low chemical reactivity.