Device for polishing the edge of a semiconductor substrate

Abstract

Disclosed are devices and methods for chemical and mechanical polishing of the edge of a semiconductor substrate that includes a protruding residual topography in a peripheral region of the substrate resulting from a layer transfer process based on an ion implantation step, a bonding step and a detachment step, such as Smart-Cut™. To be able to remove this step-like region, exemplary devices include a polishing pad, wherein the polishing pad is arranged and configured such that its cross section in a plane perpendicular to the surface of a substrate holder is curved. The disclosure furthermore relates to a pad holder used certain exemplary devices and methods for polishing a semiconductor substrate that has a protruding residual topography.

1 . A device for polishing the edge of a semiconductor substrate that includes a protruding residual topography in a peripheral region of the substrate resulting from a layer transfer process based on an ion implantation step, a bonding step and a detachment step, comprising:
 a) a substrate holder for receiving the semiconductor substrate, and   b) a polishing pad, wherein the polishing pad is arranged and configured such that its cross-section in a plane perpendicular to the surface of the substrate holder is curved.   
     
     
         2 . The device according to  claim 1 , wherein the polishing pad is attached to a pad holder, which is arranged and configured such that its cross-section in the plane perpendicular to the surface of the substrate holder is curved. 
     
     
         3 . The device according to  claim 1 , wherein the cross-section of the polishing pad and/or the pad holder comprises a concave shaped part. 
     
     
         4 . The device according to  claim 3 , wherein the concave shape corresponds to the desired shape of the semiconductor substrate, in particular to a shape with an edge region without protruding topography. 
     
     
         5 . The device according to  claim 1 , wherein the cross-section of the polishing pad and/or the pad holder has at least one convex shaped part. 
     
     
         6 . The device according to  claim 3 , wherein the cross section of the polishing pad and/or the pad holder has the concave shaped part positioned between two convex shaped parts. 
     
     
         7 . The device according to  claim 3 , wherein the cross section of the polishing pad and/or the pad holder has at least one plane part positioned between convex and/or concave shaped parts. 
     
     
         8 . The device according to  claim 1 , wherein the lateral extension of the polishing pad and/or pad holder is at least 1.5 mm, preferably at least 3 mm. 
     
     
         9 . The device according to  claim 1 , wherein the polishing pad and/or the pad holder is ring shaped at least over a segment in the plane parallel to the surface of the substrate holder. 
     
     
         10 . The device according to  claim 9 , wherein the polishing pad and/or the pad holder are formed by a plurality of segments. 
     
     
         11 . The device according to  claim 1 , further comprising a control unit configured to move the polishing pad and/or the pad holder perpendicular with respect to the surface of the substrate holder. 
     
     
         12 . The device according to  claim 1 , wherein the control unit is configured to move the polishing pad and/or the pad holder in a plane parallel to the surface of the substrate holder. 
     
     
         13 . A pad holder for use in a device according to  claim 1 , wherein the surface configured to receive a polishing pad has a curved surface. 
     
     
         14 . A method for reclaiming a surface of a semiconductor substrate that includes a protruding residual topography in a peripheral region of the substrate resulting from a layer transfer process based on an ion implantation step, a bonding step and a delamination step, comprising the steps of:
 a) polishing the surface using a device according to  claim 1 .   
     
     
         15 . The Method according to  claim 14 , wherein more than protruding parts of the topography are removed during polishing. 
     
     
         16 . The method according to  claim 14 , further comprising a de-oxidation step to remove any oxide present on the protruding topography. 
     
     
         17 . The method according to  claim 14 , further comprising an edge polishing step.