Method for polishing a semiconductor wafer

Abstract

Semiconductor wafers are CMP polished by polishing the rear side of the semiconductor wafer by means of CMP with a material removal with a profile along the diameter of the wafer wherein material removal is higher at the center than at the edge of the rear side; and polishing the front side of the wafer by means of CMP with a material removal with a profile along the diameter of the wafer wherein material removal is lower in the center of the front side than in an edge region of the front side.

What is claimed is: 
     
       1. A method for polishing a semiconductor wafer having a front side and a rear side, comprising:
 polishing the rear side of the semiconductor wafer by means of CMP with a material removal with a profile along the diameter of the semiconductor wafer according to which material removal is higher in a center region of the rear side than in an edge region of the rear side, wherein the material removal is 0.2 to 0.8 μm in the center region of the rear side and is 0.02 to 0.2 μm lower in the edge region of the rear side; and 
 polishing the front side of the semiconductor wafer by means of CMP with a material removal with a profile along the diameter of the semiconductor wafer according to which material removal is lower in a center region of the front side than in an edge region of the front side, wherein the material removal is 0.2 to 0.8 μm in the center region of the front side and is 0.02 to 0.2 μm higher in the edge region of the frontside; and 
 polishing the semiconductor wafer by means of DSP, wherein the DSP is carried out before polishing the rear side of the semiconductor wafer by means of CMP. 
 
     
     
       2. The method of  claim 1 , wherein the material removal is 0.2 to 0.8 μm in the center region of the rear side and is 0.02 to 0.2 μm lower in the edge region of the rear side. 
     
     
       3. The method of  claim 1 , wherein the material removal is 0.2 to 0.8 μm in the center region of the front side and is 0.02 to 0.2 μm higher in the edge region of the front side. 
     
     
       4. The method of  claim 1 , wherein the profile of the material removal which is produced when publishing polishing the rear side of the semiconductor wafer by means of CMP has a course that is mirror-inverted with respect to the course of the profile of the material removal produced when polishing the front side of the semiconductor wafer by means of CMP. 
     
     
       5. The method of  claim 2 , wherein the profile of the material removal which is produced when publishing the rear side of the semiconductor wafer by means of CMP has a course that is mirror-inverted with respect to the course of the profile of the material removal produced when polishing the front side of the semiconductor wafer by means of CMP. 
     
     
       6. The method of  claim 3 , wherein the profile of the material removal which is produced when publishing the rear side of the semiconductor wafer by means of CMP has a course that is mirror-inverted with respect to the course of the profile of the material removal produced when polishing the front side of the semiconductor wafer by means of CMP. 
     
     
       7. The method of  claim 1 , wherein a target profile of the material removal for polishing the front side by means of CMP is determined after polishing the rear side of the semiconductor wafer by means of CMP, by measuring the height deviation of the rear side from a plane along the diameter of the semiconductor wafer and equating the course of the height deviation to the course of the target profile. 
     
     
       8. The method of  claim 2 , wherein a target profile of the material removal for polishing the front side by means of CMP is determined after polishing the rear side of the semiconductor wafer by means of CMP, by measuring the height deviation of the rear side from a plane along the diameter of the semiconductor wafer and equating the course of the height deviation to the course of the target profile. 
     
     
       9. The method of  claim 3 , wherein a target profile of the material removal for polishing the front side by means of CMP is determined after polishing the rear side of the semiconductor wafer by means of CMP, by measuring the height deviation of the rear side from a plane along the diameter of the semiconductor wafer and equating the course of the height deviation to the course of the target profile. 
     
     
       10. The method of  claim 4 , wherein a target profile of the material removal for polishing the front side by means of CMP is determined after polishing the rear side of the semiconductor wafer by means of CMP, by measuring the height deviation of the rear side from a plane along the diameter of the semiconductor wafer and equating the course of the height deviation to the course of the target profile. 
     
     
       11. The method of  claim 1 , wherein the profile of the material removal produced when polishing the rear side by means of CMP has a convex course and the profile of the material removal produced when polishing the front side by means of CMP has a concave course. 
     
     
       12. The method of  claim 1 , comprising at least one further CMP of the front side of the semiconductor wafer, by means of which the roughness of the front side is reduced. 
     
     
       13. The method of  claim 1 , comprising first polishing the semiconductor wafer by means of DSP, wherein the DSP is carried out before the CMP of the rear side of the semiconductor wafer. 
     
     
       14. The method of claim 1, wherein the total amount of material removal in the steps of polishing the rear side and the front side of the semiconductor wafer is not more than 1.5 μm. 
     
     
       15. The method of claim 1, wherein a material removal profile during polishing the front side of the semiconductor wafer is established by applying different pressures to edge and central regions of the semiconductor wafer during polishing.