FINFET WITH SELF-ALIGNED PUNCHTHROUGH STOPPER

• US 20150054033A1
• Filed: 10/30/2014
• Published: 02/26/2015
• Est. Priority Date: 08/29/2012
• Status: Abandoned Application

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Cheng, Kangguo, Haran, Balasubramanian S., Ponoth, Shom, Standaert, Theodorus E., Yamashita, Tenko
• Application Number:
  US14/528,466
• Publication Number:
  US 20150054033A1
• Time in Patent Office: Days
• US Class Current: 257/192
• CPC Class Codes: H01L 29/0653 adjoining the input or output region of a field-effect device, e.g. the source or drain region
• CPC Class Codes: H01L 29/1083 with an inactive supplementary region, e.g. for preventing punch-through, improving capacity effect or leakage current
• CPC Class Codes: H01L 29/161 including two or more of the elements provided for in group H01L29/16 , e.g. alloys H01L29/1604 takes precedence
• CPC Class Codes: H01L 29/165 in different semiconductor regions , e.g. heterojunctions
• CPC Class Codes: H01L 29/66803 with a step of doping the vertical sidewall, e.g. using tilted or multi-angled implants
• CPC Class Codes: H01L 29/7848 the means being located in the source/drain region, e.g. SiGe source and drain
• CPC Class Codes: H01L 29/7849 the means being provided under the channel
• CPC Class Codes: H01L 29/7851 with the body tied to the substrate

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.

Claims

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.