Semiconductor device and method for fabricating the same

Patent metadata

Field	Value
Publication number	US-9577043-B2
Application number	US-201514826174-A
Country	US
Kind code	B2
Filing date	Aug 13, 2015
Priority date	Oct 10, 2014
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

A semiconductor device includes a buffer layer on a semiconductor substrate including first and second regions, a first channel layer on the buffer layer of the first region, a second channel layer on the buffer layer of the second region, and a spacer layer between the second channel layer and the buffer layer. The buffer layer, the first and second channel layers, and the spacer layer are formed of semiconductor materials including germanium. A germanium concentration difference between the first and second channel layers is greater than a germanium concentration difference between the buffer layer and the second channel layer. The spacer layer has a germanium concentration gradient.

First claim

What is claimed is:

1. A semiconductor device comprising:
a semiconductor substrate including first and second regions;
a buffer layer formed on the semiconductor substrate in the first and second regions;
a first channel layer formed on the buffer layer of the first region;
a second channel layer formed on the buffer layer of the second region; and
a spacer layer disposed between the second channel layer and the buffer layer,
wherein the buffer layer, the first and second channel layers, and the spacer layer are formed of semiconductor materials including germanium (Ge),
a germanium concentration difference between the first channel layer and the second channel layer is greater than a germanium concentration difference between the buffer layer and the second channel layer, and
the spacer layer has a germanium concentration gradient.

2. The semiconductor device of claim 1 , wherein the buffer layer has a first germanium concentration,
the second channel layer has a second germanium concentration greater than the first germanium concentration, and
the germanium concentration of the spacer layer has a graded profile such that a region adjacent to a bottom surface of the spacer layer has a first germanium concentration and a region adjacent to a top surface of the spacer layer has a second germanium concentration greater than the first germanium concentration.

3. The semiconductor device of claim 1 , wherein a top surface of the second channel layer is coplanar with a top surface of the first channel layer, and
a thickness of the second channel layer is smaller than a thickness of the first channel layer.

4. The semiconductor device of claim 1 , wherein a top surface of the second channel layer is coplanar with a top surface of the first channel layer, and
a thickness of the second channel layer is substantially equal to or greater than a thickness of the first channel layer.

5. The semiconductor device of claim 1 , wherein the germanium concentration of the spacer layer has a discontinuously varied profile.

6. The semiconductor device of claim 1 , wherein the germanium concentration of the spacer layer has a continuously varied profile.

7. The semiconductor device of claim 1 , wherein the spacer layer comprises: a first portion being in contact with the buffer layer and having a uniform germanium concentration; and a second portion being in contact with the second channel layer and having the germanium concentration gradient.

8. The semiconductor device of claim 1 , wherein:
the spacer layer comprises: a first portion being in contact with the buffer layer; a second portion being in contact with the second channel layer; and a third portion between the first portion and the second portion,
each of the first to third portions has a uniform germanium concentration, and
the germanium concentration of the third portion is greater than the germanium concentration of the first portion and smaller than the germanium concentration of the second portion.

9. The semiconductor device of claim 1 , wherein:
the buffer layer is formed of Si 1×x Ge x (0<x<1),
the first channel layer is formed of Si 1×y Ge y (0≦y<x),
the second channel layer is formed of Si 1×z Ge z (x<z≦1), and
the spacer layer is formed of Si 1×w ,Ge w (x≦w<z).

10. The semiconductor device of claim 1 , further comprising:
a first gate electrode formed on the first channel layer;
first source/drain patterns disposed at opposite sides of the first gate electrode;
a second gate electrode formed on the second channel layer; and
second source/drain patterns disposed at opposite sides of the second gate electrode,
wherein the first source/drain patterns are formed of a semiconductor material of which a lattice constant is different from that of the second source/drain patterns.

11. A semiconductor device comprising:
a semiconductor substrate including first and second regions;
a buffer layer formed on the semiconductor substrate, the buffer layer having a lattice constant different from that of the semiconductor substrate;
a first channel layer formed on the buffer layer of the first region, the first channel layer having a lattice constant smaller than the lattice constant of the buffer layer;
a second channel layer formed on the buffer layer of the second region, the second channel layer having a lattice constant greater than the lattice constant of the buffer layer; and
a spacer layer disposed between the second channel layer and the buffer layer, the spacer layer having a lattice constant that gradually increases from a top surface of the buffer layer toward a bottom surface of the second channel layer,
wherein top surfaces of the first and second channel layers are coplanar with each other, and
a bottom surface of the spacer layer is disposed at substantially the same level as or a lower level than a bottom surface of the first channel layer.

12. The semiconductor device of claim 11 , wherein the buffer layer, the first and second channel layers, and the spacer layer are formed of semiconductor materials including germanium (Ge),
a germanium concentration difference between the first channel layer and the second channel layer is greater than a germanium concentration difference between the buffer layer and the second channel layer, and
the spacer layer has a germanium concentration gradient.

13. The semiconductor device of claim 12 , wherein:
the buffer layer is formed of Si 1×x Ge x (0<x<1),
the first channel layer is formed of Si 1×y Ge y (0≦y<x),
the second channel layer is formed of Si 1×z Ge z (x<z≦1), and
the spacer layer is formed of Si 1×w ,Ge w (x≦w<z).

14. A semiconductor device comprising:
a semiconductor substrate including a first region and a second region;
a first fin structure on the first region, the first fin structure including a first buffer pattern and a first channel pattern sequentially stacked;
a second fin structure on the second region, the second fin structure including a second buffer pattern, a second channel pattern on the second buffer pattern, and a spacer pattern disposed between the second buffer pattern and the second channel pattern,

a first metal-oxide-semiconductor (MOS) transistor provided on the first fin structure, a first gate electrode, and a first gate insulating layer between the first fin structure and the first gate electrode; and
a second MOS transistor provided on the second fin structure, a second gate electrode, and a second gate insulating layer between the second fin structure and the second gate electrode,
wherein the first and second buffer patterns include a first semiconductor material of which a lattice constant is different from that of the semiconductor substrate,
wherein the first channel pattern includes a second semiconductor material of which a lattice constant is smaller than the lattice constant of the first semiconductor material,
wherein the second channel pattern includes a third semiconductor material of which a lattice constant is greater than the lattice constant of the first semiconductor material, and
wherein the spacer pattern has a lattice constant that gradually increases from the second buffer pattern toward the second channel pattern.

15. The semiconductor device of claim 14 , wherein:
the first and second buffer patterns, the first and second channel patterns, and the spacer pattern are formed of semiconductor materials including germanium (Ge),
a germanium concentration difference between the first channel pattern and the second channel pattern is greater than a germanium concentration difference between t

Assignees

• Yoo Jongryeol
• Lee Hyun Jung
• Kim Sunjung
• Lee Seung Hun
• Choi Eunhye
• Samsung Electronics Co Ltd

Inventors

• Yoo Jongryeol
• Lee Hyun Jung
• Kim Sunjung
• Lee Seung Hun
• Choi Eunhye

Classifications

• H10D30/62 Primary

  Fin field-effect transistors [FinFET] · CPC title

• H01L27/0886

  Electricity · mapped topic

• H01L21/823814

  Electricity · mapped topic

• H01L21/823412

  Electricity · mapped topic

• H01L29/7849

  Electricity · mapped topic