FinFET with trench field plate

• US 10,090,390 B2
• Filed: 07/03/2017
• Issued: 10/02/2018
• Est. Priority Date: 07/11/2012
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Ng, Chun-Wai, Chou, Hsueh-Liang, Su, Po-Chih, Liu, Ruey-Hsin
• Primary Examiner(s): Fan, Bo
• Application Number:
  US15/640,895
• Publication Number:
  US 20170301762A1
• Time in Patent Office: 456 Days
• Field of Search: 438283, 257139, 257330, 257347, 257315, 257255
• CPC Class Codes: H01L 29/0684 characterised by the shape, relative sizes or dispositions of the semiconductor regions or junctions between the regions
• CPC Class Codes: H01L 29/36 characterised by the concentration or distribution of impurities in the bulk material within semiconductor regions H01L29/06
• CPC Class Codes: H01L 29/401 Multistep manufacturing processes
• CPC Class Codes: H01L 29/404 Multiple field plate structures
• CPC Class Codes: H01L 29/407 Recessed field plates, e.g. trench field plates, buried field plates
• CPC Class Codes: H01L 29/66704 with a step of recessing the gate electrode, e.g. to form a trench gate electrode
• CPC Class Codes: H01L 29/7824 with a substrate comprising an insulating layer, e.g. SOI-LDMOS transistors
• CPC Class Codes: H01L 29/7825 with trench gate electrode trench gate electrodes per se H01L29/4236
• CPC Class Codes: H01L 29/7856 with an non-uniform gate, e.g. varying doping structure, shape or composition on different sides of the fin, or different gate insulator thickness or composition on opposing fin sides H01L29/7855 takes precedence

Abstract

An integrated circuit device includes a pad layer having a body portion with a first doping type laterally adjacent to a drift region portion with a second doping type, a trench formed in the pad layer, the trench extending through an interface of the body portion and the drift region portion, a gate formed in the trench and over a top surface of the pad layer along the interface of the body portion and the drift region portion, an oxide formed in the trench on opposing sides of the gate, and a field plate embedded in the oxide on each of the opposing sides of the gate.

Claims

1. An integrated circuit device, comprising:

a pad layer having a body portion with a first doping type laterally adjacent to a drift region portion with a second doping type;

a gate over a top surface of the pad layer, the gate overlapping an interface between the body portion and the drift region portion, the gate extending into the pad layer;

a dielectric material on opposing sides of the gate, the dielectric material extending to a bottom of the gate; and

a first field plate embedded in the dielectric material on a first side of the gate, the dielectric material being interposed between the first field plate and the gate.

2. The integrated circuit device of claim 1, further comprising a second field plate embedded in the dielectric material on a second side of the gate, the first side being on an opposite side of the gate from the second side.

3. The integrated circuit device of claim 1, wherein the first field plate comprises polysilicon.

4. The integrated circuit device of claim 1, further comprising a first heavily-doped region in the body portion, the first heavily-doped region having the second doping type, the first heavily-doped region extending on opposing sides of the dielectric material.

5. The integrated circuit device of claim 4, further comprising a first source/drain region in the body portion, the first source/drain region having the first doping type, the first heavily-doped region being interposed between the first source/drain region and the dielectric material.

6. The integrated circuit device of claim 5, further comprising a second source/drain region in the drift region portion, the second source/drain region having the second doping type, the drift region portion being interposed between the second source/drain region and the dielectric material.

7. The integrated circuit device of claim 1, wherein the pad layer is over an insulating layer, wherein the dielectric material extends to the insulating layer.

8. An integrated circuit device, comprising:

a substrate;

a pad layer over the substrate, the pad layer having a body region with a first doping type laterally adjacent to a drift region with a second doping type;

a gate overlapping the body region and the drift region, the gate extending into the pad layer;

a first dielectric material between a first side of the gate and a portion of the drift region;

a second dielectric material between a second side of the gate and a portion of the body region; and

a first field plate embedded in the first dielectric material, wherein the first dielectric material is interposed between the first field plate and gate.

9. The integrated circuit device of claim 8, further comprising a second field plate embedded in the second dielectric material, wherein the second dielectric material is interposed between the second field plate and the gate.

10. The integrated circuit device of claim 8, further comprising a first source/drain region in the body region and a second source/drain region in the drift region.

11. The integrated circuit device of claim 10, wherein the first source/drain region has the first doping type, and the second source/drain region has the second doping type.

12. The integrated circuit device of claim 11, wherein the first source/drain region is separated from the second dielectric material by the body region.

13. The integrated circuit device of claim 11, wherein the second source/drain region is separated from the first dielectric material by the drift region.

14. The integrated circuit device of claim 8, wherein a thickness of the first field plate is less than a thickness of the pad layer.

15. An integrated circuit device, comprising:

a body region having a first doping type;

a drift region adjacent the body region, the drift region having a second doping type;

a gate over a portion of a top surface of the body region and over a portion of a top surface of the drift region, the gate extending along a sidewall of the drift region and a sidewall of the body region;

a first dielectric material interposed between the gate and the drift region;

a second dielectric material interposed between the gate and the body region; and

a first field plate in the first dielectric material.

16. The integrated circuit device of claim 15, further comprising a second field plate in the second dielectric material.

17. The integrated circuit device of claim 15, wherein upper surfaces of the first dielectric material, the second dielectric material and the first field plate are level.

18. The integrated circuit device of claim 15, wherein the first dielectric material extends completely through the drift region.

19. The integrated circuit device of claim 15, wherein the second dielectric material extends completely through the body region.

20. The integrated circuit device of claim 15, wherein the first field plate comprises a polysilicon material.