Semiconductor device having source/drain with a protrusion

Patent metadata

Field	Value
Publication number	US-2020266069-A1
Application number	US-202016869125-A
Country	US
Kind code	A1
Filing date	May 7, 2020
Priority date	Dec 14, 2016
Publication date	Aug 20, 2020
Grant date	—

Abstract

A device includes a source/drain (S/D) in a substrate and adjacent to a gate structure, wherein the S/D comprises a protrusion extending from a top surface of the S/D, and the protrusion has a tapered profile. The device further includes a contact plug electrically connected to the protrusion.

First claim

What is claimed is:

1 . A device comprising:
a source/drain (S/D) in a substrate and adjacent to a gate structure, wherein the S/D comprises a protrusion extending from a top surface of the S/D, and the protrusion has a tapered profile; and a contact plug electrically connected to the protrusion.

2 . The device of claim 1 , wherein the S/D comprises a first material and a second material.

3 . The device of claim 2 , wherein the S/D comprises:
a first sub-region, wherein the first sub-region has a first percentage of the first material; and a second sub-region, wherein the second sub-region has a second percentage of the first material, and the second percentage is different from the first percentage.

4 . The device of claim 3 , wherein the first sub-region is between the contact plug and the second sub-region.

5 . The device of claim 4 , wherein the first material is germanium, and the first percentage is less than the second percentage.

6 . The device of claim 4 , wherein the first material is carbon, and the first percentage is less than the second percentage.

7 . A device comprising:
a gate structure over a substrate; a source/drain (S/D) in the substrate adjacent to the gate structure, wherein the S/D comprises at least one protrusion extending from a top surface of the S/D; a silicide layer extending along the at least one protrusion and along the top surface of the S/D, wherein the silicide layer extends along an entire sidewall of the at least one protrusion.

8 . The device of claim 7 , further comprising a contact plug over the silicide layer, wherein the contact plug extends over the gate structure.

9 . The device of claim 8 , wherein the gate structure comprises a capping layer, and a thickness of the capping layer beneath the contact plug is less than a thickness of the capping layer beyond the contact plug.

10 . The device of claim 8 , wherein the S/D includes silicon and a second material.

11 . The device of claim 10 , wherein the S/D comprises:
a first sub-region in contact with the silicide layer, wherein the first sub-region has a first percentage of the second material; a second sub-region, wherein the second sub-region has a second percentage of the second material, and the second percentage is different from the first percentage; and a third sub-region, wherein the third sub-region has a third percentage of the second material, the third percentage is different from the second percentage, and the second sub-region is between the first sub-region and the third sub-region.

12 . The device of claim 11 , wherein the second material is carbon.

13 . The device of claim 11 , wherein the second material is germanium.

14 . A device comprising:
a source/drain (S/D) in a substrate and adjacent to a gate structure, wherein the S/D comprises a first protrusion extending from a top surface of the S/D, and a first width of the first protrusion adjacent to the substrate is greater than a second width of the first protrusion distal from the substrate; and a silicide layer electrically connected to the protrusion.

15 . The device of claim 14 , wherein the first width ranges from about 4 nanometers (nm) to about 6 nm.

16 . The device of claim 14 , wherein the second width ranges from about 0.5 nm to about 1.5 nm.

17 . The device of claim 14 , wherein a height of the first protrusion above the top surface of the S/D ranges from about 3 nm to about 7 nm.

18 . The device of claim 14 , wherein the S/D further comprises a second protrusion, and a size of the second protrusion is different from a size of the first protrusion.

19 . The device of claim 18 , wherein the second protrusion is larger than the first protrusion, and the second protrusion is closer to a gate structure than the first protrusion.

20 . The device of claim 14 , wherein the S/D comprises:
a first sub-region having a first composition; and a second sub-region having a second composition different from the first composition.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Wu Chia-Yang
• Jangjian Shiu-Ko
• Chang Keng-Chuan
• Su Ting-Siang

Classifications

• H10P14/44

  Physical vapour deposition [PVD] · CPC title

• H10P14/42

  using a gas or vapour · CPC title

• H10W20/083

  the openings being via holes penetrating underlying conductors · CPC title

• H10W20/069

  by forming self-aligned vias or self-aligned contact plugs · CPC title

• H10W20/047

  by introducing additional elements therein · CPC title