Method of fabricating epitaxial gate dielectrics and semiconductor device of the same

Patent metadata

Field	Value
Publication number	US-9853150-B1
Application number	US-201615236541-A
Country	US
Kind code	B1
Filing date	Aug 15, 2016
Priority date	Aug 15, 2016
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A method of fabricating epitaxial gate dielectric includes forming a Sr x Ba y M z TiO 3 gate dielectric on a fin, and 0≦x, y and z≦1, x+y+z=1, and M is calcium or magnesium. One of x and y is not 0. The Sr x Ba y M z TiO 3 gate dielectric includes a plurality of Sr x Ba y M z TiO 3 dielectric films. Each of the Sr x Ba y M z TiO 3 dielectric films has different ratio of x, y, and z. The fin is then oxidized to form a silicon oxide in between the Sr x Ba y M z TiO 3 gate dielectric and the fin. A dielectric layer is disposed on the Sr x Ba y M z TiO 3 gate dielectric. Subsequently a metal gate layer is deposited on the dielectric layer.

First claim

What is claimed is:

1. A method of fabricating epitaxial gate dielectrics, comprising:
forming a ferroelectric gate material on a fin;
forming a silicon oxide between the ferroelectric gate material and the fin; and
forming a metal gate layer on the ferroelectric gate material.

2. The method of fabricating epitaxial gate dielectrics according to claim 1 , wherein forming the ferroelectric gate material on the fin includes epitaxially growing the ferroelectric gate material.

3. The method of fabricating epitaxial gate dielectrics according to claim 1 , wherein forming the ferroelectric gate material on the fin includes forming a plurality of ferroelectric films.

4. The method of fabricating epitaxial gate dielectrics according to claim 3 , wherein forming the plurality of ferroelectric films includes varying an amount of a ferroelectric material.

5. The method of fabricating epitaxial gate dielectrics according to claim 4 , wherein the ferroelectric material includes strontium and barium.

6. The method of fabricating epitaxial gate dielectrics according to claim 1 , wherein forming the silicon oxide between the ferroelectric gate material and the fin includes oxidizing the fin.

7. The method of fabricating epitaxial gate dielectrics according to claim 6 , wherein oxidizing the fin includes thermal oxidation, plasma oxidation, and high-pressure oxidation.

8. The method of fabricating epitaxial gate dielectrics according to claim 1 , further comprising:
forming a dielectric layer on the ferroelectric gate material.

9. A method of forming epitaxial gate dielectrics comprising:
forming a Sr x Ba y M z TiO 3 gate dielectric on a fin, wherein 0≦x, y and z≦1, x+y+z=1, x is not equal to y, and M is calcium or magnesium;
oxidizing the fin; and
forming a metal gate layer on the Sr x Ba y M z TiO 3 gate dielectric.

10. The method of forming epitaxial gate dielectrics according to claim 9 , wherein forming the Sr x Ba y M z TiO 3 gate dielectric on the fin includes epitaxially growing the Sr x Ba y M z TiO3 gate dielectric.

11. The method of forming epitaxial gate dielectrics according to claim 9 , wherein forming the Sr x Ba y M z TiO 3 gate dielectric on the fin includes forming a plurality of Sr x Ba y M z TiO 3 dielectric films.

12. The method of forming epitaxial gate dielectrics according to claim 11 , wherein forming the plurality of Sr x Ba y M z TiO 3 dielectric films includes varying the amount of x, y, and z of each of the Sr x Ba y M z TiO 3 dielectric films.

13. The method of forming epitaxial gate dielectrics according to claim 9 , further comprising:
forming a dielectric layer on the Sr x Ba y M z TiO 3 gate dielectric.

14. The method of forming epitaxial gate dielectrics according to claim 11 , wherein forming the plurality of Sr x Ba y M z TiO 3 dielectric films includes:
forming a first Sr x Ba y M z TiO 3 dielectric film on the fin; and
forming a second Sr x Ba y M z TiO 3 dielectric film on the first Sr x Ba y M z TiO 3 dielectric film, wherein x of the first Sr x Ba y M z TiO 3 dielectric film and the second Sr x Ba y M z TiO 3 dielectric film are different.

15. A method of forming epitaxial gate dielectrics, the method comprising:
forming a fin on a semiconductor substrate;
forming a ferroelectric gate material on the fin;
oxidizing the fin to form a silicon oxide between the fin and the ferroelectric gate material; and
forming a metal gate layer on the ferroelectric gate material.

16. The method of claim 15 , wherein the oxidizing the fin comprises thermal oxidation, plasma oxidation, and high-pressure oxidation.

17. The method of claim 15 , wherein the forming the ferroelectric gate material comprises epitaxially growing a Sr x Ba y M z TiO 3 gate dielectric film on the fin, wherein 0≦x, y and z≦1, x+y+z=1, x is not equal to y, and M is calcium or magnesium.

18. The method of claim 16 , further comprising:
forming a plurality of Sr x Ba y M z TiO 3 ferroelectric films on the fin; and
varying the amount of x, y and z in each of the Sr x Ba y M z TiO 3 ferroelectric films.

19. The method of claim 15 , wherein the ferroelectric gate material comprises strontium and barium.

20. The method of claim 15 , further comprising:
forming a dielectric layer on the ferroelectric gate material.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Colinge Jean-Pierre
• Goto Ken-Ichi
• Wu Zhiqiang

Classifications

• H01L29/785

  Electricity · mapped topic

• H01L29/516

  Electricity · mapped topic

• H01L29/6684

  Electricity · mapped topic

• H01L21/28291

  Electricity · mapped topic

• H01L29/78391 Primary

  Electricity · mapped topic