Method of Chemical Mechanical Polishing

Abstract

[Problem] To improve polishing efficiency while lowering shear force added to semiconductor wafers while increasing polishing speed, without damaging the wafer's processing surface or the membrane under it. [Solution Method] Pressing the revolving head or carrier 34 that holds fixed the semiconductor wafer 10 to the polishing pad or polishing cloth 30 attached to rotating polishing table 32 in this CMP device and while rotating carrier 34 and polishing table 32 respectively, and supplying liquid slurry to polishing pad 30 from nozzle 36 , planarization by chemical processes and mechanical processes is carried out by removing membranes of the lower face of semiconductor wafer 10 (the processing surface). The chemical mechanical polishing process of the present invention in regard to the size of the relationship between the rotation rate of semiconductor wafer 10 f W and the number of rotations of polishing pad 30 f P has 3 f p <f W as its lower limit and 4 f p <f W <8 f p is ideal conditions.

1 . In a chemical mechanical polishing method for reducing damage to the wafer surface in which while a semiconductor wafer is pressed on a polishing pad and each are rotated, slurry is provided to their contact surface and the processed surface of the said semiconductor wafer is chemically and mechanically polished, a method for chemical mechanical polishing wherein the ratio of the rotation rate of said semiconductor wafer and the rotation rate of the said polishing pad are 2:1 or more. 
     
     
         2 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the processed surface layer of the said semiconductor wafer includes organic membranes under that layer. 
     
     
         3 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the processed surface layer of the said semiconductor wafer includes inorganic membranes under that layer. 
     
     
         4 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the processed surface layer of the said semiconductor wafer includes layers of SiO 2  and SiOF under that layer. 
     
     
         5 . In a method for chemical mechanical polishing to remove in a planar fashion copper that has been accumulated on an organic membrane in a damascene process for copper wiring using an organic membrane with a low dielectric in the insulating interlayer membrane in the semiconductor wafer, a chemical mechanical polishing process that reduces damage to the wafer surface wherein the ratio of the rotation rate of said semiconductor wafer and the rotation rate of the said polishing pad is 2:1 or more and the said semiconductor wafer is pressed on the said polishing pad and each are rotated, slurry is provided to their contact surface and the processed surface of the said semiconductor wafer is chemically and mechanically polished. 
     
     
         6 . The chemical mechanical polishing method of  claim 2  or  claim 5  wherein the said organic membrane is a fluorocarbon membrane. 
     
     
         7 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the ratio of the rotation rate of said semiconductor wafer and the rotation rate of the said polishing pad is 3:1 or more. 
     
     
         8 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the ratio of the rotation rate of said semiconductor wafer and the rotation rate of the said polishing pad is 4:1 or more. 
     
     
         9 . The chemical mechanical polishing method of  claim 5  wherein the ratio of the rotation rate of said semiconductor wafer and the rotation rate of the said polishing pad is 8:1 or more 
     
     
         10 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the said pad rotation rate is from 20 rpm to 70 rpm. 
     
     
         11 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the said semiconductor wafer and the said polishing pad rotate in the same direction with respect to their respective rotation axes. 
     
     
         12 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the entire processed surface of the semiconductor wafer is pressed against the said polishing pad in an area offset in the outer radial direction from the center of the said polishing pad. 
     
     
         13 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 12  wherein the pressure by which the said semiconductor wafer is pressed to the polishing pad is relatively greater in the central part of the wafer than at the periphery of the wafer 
     
     
         14 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 12  wherein the pressure received in the central part of the said semiconductor wafer is 1.1 to 3 times the pressure received at the periphery of the wafer. 
     
     
         15 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 12  wherein the pressure received in the central part of the said semiconductor wafer is 1.3 to 2.5 times the pressure received at the periphery of the wafer. 
     
     
         16 . The chemical mechanical polishing method for reducing damage to the wafer surface of  claim 1  wherein the said slurry supply flow rate is 300 ml/min or less.