Semiconductor device structure with raised source/drain having cap element

Patent metadata

Field	Value
Publication number	US-2016276481-A1
Application number	US-201514658688-A
Country	US
Kind code	A1
Filing date	Mar 16, 2015
Priority date	Mar 16, 2015
Publication date	Sep 22, 2016
Grant date	—

Abstract

Structures and formation methods of a semiconductor device structure are provided. The semiconductor device structure includes a gate stack over a semiconductor substrate and a source/drain structure adjacent to the gate stack. The semiconductor device structure also includes a cap element over the source/drain structure. The cap element has a top surface and a side surface. A width ratio of the top surface to the side surface of the cap element is in a range from about 0.125 to about 1.

First claim

1 . A semiconductor device structure, comprising:
a gate stack over a semiconductor substrate; a source/drain structure adjacent to the gate stack; and a cap element over the source/drain structure, wherein the cap element has a top surface and a side surface, and a width ratio of the top surface to the side surface of the cap element is in a range from about 0.125 to about 1.

2 . The semiconductor device structure as claimed in claim 1 , wherein the top surface of the cap element is substantially parallel to a top surface of the source/drain structure, and the side surface of the cap element is substantially parallel to a side surface of the source/drain structure.

3 . The semiconductor device structure as claimed in claim 1 , wherein:
the cap element has a first thickness substantially equal to a distance between the top surface of the cap element and a top surface of the source/drain structure, the cap element has a second thickness substantially equal to a distance between the side surface of the cap element and a side surface of the source/drain structure, and a ratio of the first thickness to the second thickness is in a range from about 0.8 to about 1.2.

4 . The semiconductor device structure as claimed in claim 1 , wherein the cap element comprises silicon, silicon germanium, or a combination thereof.

5 . The semiconductor device structure as claimed in claim 1 , wherein a surface orientation of the top surface of the cap element is {311}, and a surface orientation of the side surface of the cap element is {111}.

6 . The semiconductor device structure as claimed in claim 1 , wherein the source/drain structure is in direct contact with the cap element.

7 . The semiconductor device structure as claimed in claim 1 , wherein the source/drain structure comprises a lower portion and an upper portion between the lower portion and the cap element, and compositions of the lower portion and the upper portion are different.

8 . The semiconductor device structure as claimed in claim 7 , wherein an atomic concentration of germanium in the upper portion is greater than an atomic concentration of germanium in the lower portion.

9 . The semiconductor device structure as claimed in claim 8 , wherein the atomic concentration of germanium in the lower portion is greater than an atomic concentration of germanium in the cap element.

10 . The semiconductor device structure as claimed in claim 1 , further comprising:
a second source/drain structure adjacent to the source/drain structure; and a second cap element over the second source/drain structure, wherein a ratio of a shortest distance between the cap element and the second cap element to a width of the top surface of the cap element is in a range from about 0.6 to about 0.8.

11 . A semiconductor device structure, comprising:
a gate stack over a semiconductor substrate; a source/drain structure adjacent to the gate stack; and a cap element over the source/drain structure, wherein:
the cap element has a first thickness substantially equal to a distance between a top surface of the cap element and a top surface of the source/drain structure,
the cap element has a second thickness substantially equal to a distance between a side surface of the cap element and a side surface the source/drain structure, and
a ratio of the first thickness to the second thickness is in a range from about 0.8 to about 1.2.

12 . The semiconductor device structure as claimed in claim 11 , wherein the source/drain structure is in direct contact with the cap element.

13 . The semiconductor device structure as claimed in claim 11 , wherein the cap element comprises silicon, silicon germanium, or a combination thereof.

14 . The semiconductor device structure as claimed in claim 11 , wherein a surface orientation of the top surface of the cap element is {311}, and a surface orientation of the side surface of the cap element is {111}.

15 . The semiconductor device structure as claimed in claim 11 , wherein the source/drain structure comprises silicon germanium.

16 - 20 . (canceled)

21 . The semiconductor device structure as claimed in claim 11 , wherein the cap element contains substantially no germanium.

22 . The semiconductor device structure as claimed in claim 11 , further comprising a metal silicide feature directly on the cap element.

23 . A semiconductor device structure, comprising:
a gate stack over a semiconductor substrate; a source/drain structure adjacent to the gate stack; and a cap element over the source/drain structure, wherein the cap element has a first top plane, the source/drain structure has a second top plane, and the first top plane of the cap element is wider than the second top plane of the source/drain structure.

24 . The semiconductor device structure as claimed in claim 23 , wherein the first top plane of the cap element is substantially parallel to the second top plane of the source/drain structure.

25 . The semiconductor device structure as claimed in claim 23 , wherein the source/drain structure has an atomic concentration of germanium greater than an atomic concentration of germanium of the cap element.

Assignees

• Taiwan Semiconductor Mfg Co Ltd
• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Wu Shing-Huang
• Chen Jian-Shian

Classifications

• H10P14/3411

  Silicon, silicon germanium or germanium · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10P14/27

  using selective deposition, e.g. simultaneous growth of monocrystalline and non-monocrystalline semiconductor materials · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title

• H10D64/017

  using dummy gates in processes wherein at least parts of the final gates are self-aligned to the dummy gates, i.e. replacement gate processes · CPC title