Finfet with self-aligned punchthrough stopper

Abstract

A finFET with self-aligned punchthrough stopper and methods of manufacture are disclosed. The method includes forming spacers on sidewalls of a gate structure and fin structures of a finFET device. The method further includes forming a punchthrough stopper on exposed sidewalls of the fin structures, below the spacers. The method further includes diffusing dopants from the punchthrough stopper into the fin structures. The method further includes forming source and drain regions adjacent to the gate structure and fin structures.

What is claimed: 
     
         1 . A structure, comprising:
 a set of fins;   a gate structure directly on the set of fins;   a punchthrough stopper material on sidewalls of the set of fins, wherein a dopant of the punchthrough stopper material is under the set of fins; and   source and drain material directly on the punchthrough stopper material and adjacent to the gate structure and set of fins.   
     
     
         2 . The structure of  claim 1 , further comprising sidewall structures on sidewalls of the gate structure. 
     
     
         3 . The structure of  claim 2 , further comprising recessed shallow trench isolation structures under the sidewall structures, wherein the recessed shallow trench isolation structures are in direct contact with the set of fins. 
     
     
         4 . The structure of  claim 3 , wherein the punchthrough stopper material is provided on the recessed shallow trench isolation structure and under the sidewall structures. 
     
     
         5 . The structure of  claim 4 , wherein the punchthrough stopper laterally extends over the recessed shallow trench isolation structures. 
     
     
         6 . The structure of  claim 4 , wherein the punchthrough stopper is an epitaxial layer. 
     
     
         7 . The structure of  claim 6 , wherein the epitaxial layer is a SiGe material with an n-type dopant. 
     
     
         8 . The structure of  claim 6 , wherein the epitaxial layer is a Si:C material with a p-type dopant. 
     
     
         9 . The structure of  claim 1 , wherein the sidewall structures are recessed to below a top surface of the gate structure. 
     
     
         10 . The structure of  claim 1 , wherein the source and drain material a grown epitaxial layer. 
     
     
         11 . A structure, comprising:
 fin structures formed from at least a BULK substrate;   a gate structure on the fin structures and the BULK substrate;   sidewall spacers on the sidewalls of the fin structures and sidewalls of the gate structure;   recessed shallow trench isolation structures on sidewalls of the fin structures and surfaces of the BULK substrate, which expose sidewalls of the fin structures, below the sidewall spacers;   punchthrough stoppers on the exposed sidewalls of the fin structures and the shallow trench isolation structures, the punchthrough stoppers are diffused with dopants; and   source and drain regions over the punchthrough stoppers.   
     
     
         12 . The structure of  claim 11 , wherein the punchthrough stoppers comprise grown epitaxial material on the exposed sidewalls of the fin structures, which is a strain material.