Semiconductor device

Patent metadata

Field	Value
Publication number	US-12408367-B2
Application number	US-202318353875-A
Country	US
Kind code	B2
Filing date	Jul 17, 2023
Priority date	Nov 30, 2015
Publication date	Sep 2, 2025
Grant date	Sep 2, 2025

Abstract

A device includes a fin structure, a gate structure, a first source/drain epitaxial structure and, a second source/drain epitaxial structure. The fin structure over a substrate and includes a bottom portion protruding from the substrate and a top portion over the bottom portion. An interface between the bottom portion and the top portion comprises oxygen and has an oxygen concentration lower than about 1.E+19 atoms/cm 3 . The gate structure covers the fin structure. The first source/drain epitaxial structure and the second source/drain epitaxial structure are over the top portion of the fin structure and on opposite sides of the gate structure.

First claim

What is claimed is:

1. A device comprising:
a fin structure over a substrate, wherein the fin structure comprises:
a bottom portion protruding from the substrate; and
a top portion over the bottom portion, wherein a composition of the bottom portion is different from a composition of the top portion, and an interface between the bottom portion and the top portion comprises oxygen and has an oxygen concentration lower than about 1.E+19 atoms/cm 3 ;

a gate structure covering the fin structure; and
a first source/drain epitaxial structure and a second source/drain epitaxial structure over the top portion of the fin structure and on opposite sides of the gate structure.

2. The device of claim 1 , wherein the bottom portion of the fin structure has an implantation region therein.

3. The device of claim 1 , further comprising an isolation structure over the substrate and adjacent to the fin structure.

4. The device of claim 3 , wherein a top surface of the isolation structure is higher than the interface between the bottom portion and the top portion.

5. The device of claim 3 , wherein a top surface of the isolation structure is higher than an interface between the top portion of the fin structure and the first source/drain epitaxial structure.

6. The device of claim 1 , wherein a part of the top portion of the fin structure directly beneath the first source/drain epitaxial structure has a vertical thickness less than a vertical thickness of the bottom portion of the fin structure.

7. The device of claim 1 , wherein the top portion of the fin structure is a silicon layer.

8. A device comprising:
a semiconductive fin comprising:
a bottom semiconductive portion; and
a top semiconductive portion covering the bottom semiconductive portion, wherein an oxygen concentration of the top semiconductive portion is greater than an oxygen concentration of the bottom semiconductive portion;

a first source/drain epitaxial structure and a second source/drain epitaxial structure over the top semiconductive portion; and
a gate structure across the semiconductive fin and between the first source/drain epitaxial structure and the second source/drain epitaxial structure.

9. The device of claim 8 , wherein a gradient of the oxygen concentration of the top semiconductive portion of the semiconductive fin in a depth direction is higher than a gradient of the oxygen concentration of the bottom semiconductive portion of the semiconductive fin in the depth direction.

10. The device of claim 8 , wherein the oxygen concentration of the bottom semiconductive portion of the semiconductive fin is about 1.E+18 atoms/cm 3 .

11. The device of claim 8 , wherein the oxygen concentration of the top semiconductive portion of the semiconductive fin is lower than about 1.E+21 atoms/cm 3 .

12. The device of claim 8 , wherein the bottom semiconductive portion of the semiconductive fin has an implantation region therein.

13. The device of claim 8 , further comprising sidewall spacers on opposite sides of the first source/drain epitaxial structure.

14. The device of claim 13 , wherein the sidewall spacers are spaced apart from the top semiconductive portion of the semiconductive fin.

15. A device comprising:
a substrate comprising a protruding portion;
a gate structure over the substrate and covering the protruding portion;
a first source/drain epitaxial structure and a second source/drain epitaxial structure over the protruding portion of the substrate and on opposite sides of the gate structure; and
a semiconductive layer over the protruding portion of the substrate and extending from beneath the first source/drain epitaxial structure to beneath the second source/drain epitaxial structure, wherein an oxygen concentration of the semiconductive layer decreases in a depth direction of the semiconductive layer.

16. The device of claim 15 , wherein the oxygen concentration of the semiconductive layer decreases in the depth direction to about 1.E+18 atoms/cm 3 .

17. The device of claim 15 , wherein a bottom surface of the semiconductive layer has a lowest oxygen concentration in the semiconductive layer.

18. The device of claim 15 , wherein the protruding portion of the substrate comprises P-type or N-type dopants.

19. The device of claim 15 , wherein the semiconductive layer is in contact with the protruding portion.

20. The device of claim 15 , wherein the semiconductive layer is in contact with the first source/drain epitaxial structure.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Lin Che-Yu
• Yu Ming-Hua
• Lee Tze-Liang
• Yang Chan-Lon

Classifications

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10P70/20

  Cleaning during device manufacture · CPC title

• H10P30/204

  into Group IV semiconductors · CPC title

• H10P30/21

  of electrically active species · CPC title

• H10W46/501

  for use before dicing · CPC title