Thin film metal silicides and methods for formation

Patent metadata

Field	Value
Publication number	US-10032635-B2
Application number	US-201615007867-A
Country	US
Kind code	B2
Filing date	Jan 27, 2016
Priority date	Feb 5, 2015
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

The disclosed subject matter provides thin films including a metal silicide and methods for forming such films. The disclosed subject matter can provide techniques for tailoring the electronic structure of metal thin films to produce desirable properties. In example embodiments, the metal silicide can comprise a platinum silicide, such as for example, PtSi, Pt2Si, or Pt3Si. For example, the disclosed subject matter provides methods which include identifying a desired phase of a metal silicide, providing a substrate, depositing at least two film layers on the substrate which include a first layer including amorphous silicon and a second layer including metal contacting the first layer, and annealing the two film layers to form a metal silicide. Methods can be at least one of a source-limited method and a kinetically-limited method. The film layers can be deposited on the substrate using techniques known in the art including, for example, sputter depositing.

First claim

The invention claimed is:

1. A method for forming a thin film comprising a metal silicide, comprising:
providing a substrate;
depositing at least two film layers on the substrate, the at least two film layers comprising a first layer comprising amorphous silicon and a second layer comprising metal contacting the first layer;
annealing the at least two film layers to form a metal silicide; and
tuning a selected phase of the metal silicide using at least one of a source-limited method and a kinetically-limited method.

2. The method of claim 1 , wherein the substrate comprises silicon.

3. The method of claim 1 , further comprising depositing a diffusion barrier between the substrate and the at least two film layers.

4. The method of claim 3 , wherein the diffusion barrier comprises at least one of aluminum nitride and silicon nitride.

5. The method of claim 1 , wherein depositing comprises first depositing the first layer and subsequently depositing the second layer on top of the first layer.

6. The method of claim 1 , wherein depositing comprises sputter depositing.

7. The method of claim 1 , wherein the metal comprises platinum.

8. The method of claim 1 , wherein the metal comprises at least one of titanium, nickel, tungsten, cobalt, molybdenum, and chromium.

9. The method of claim 1 , wherein the metal silicide comprises platinum silicide.

10. The method of claim 9 , wherein the platinum silicide comprises Pt 3 Si.

11. The method of claim 10 , wherein the platinum silicide is selected from a group consisting of at least about 40% Pt 3 Si, at least about 45% Pt 3 Si, at least about 50% Pt 3 Si, at least about 55% Pt 3 Si, at least about 60% Pt 3 Si, at least about 65% Pt 3 Si, at least about 70% Pt 3 Si, at least about 74% Pt 3 Si, at least about 75% Pt 3 Si, at least about 80% Pt 3 Si, at least about 85% Pt 3 Si, and at least about 88% Pt 3 Si.

12. A source-limited method for forming a thin film comprising a metal silicide, comprising:
identifying a desired phase of a metal silicide;
determining a ratio of an amount of a metal to an amount of amorphous silicon based on the desired phase of the metal silicide;
providing a substrate;
depositing at least two film layers on the substrate, the at least two film layers comprising a first layer comprising amorphous silicon and a second layer comprising metal contacting the first layer, the at least two film layers comprising the amorphous silicon and the metal in amounts based on the determined ratio; and
annealing the at least two film layers to form the desired phase of the metal silicide.

13. The method of claim 12 , wherein the determining comprises experimentally determining the ratio.

14. The method of claim 12 , wherein the determining comprises calculating the ratio.

15. The method of claim 12 , wherein the substrate comprises a wafer.

16. The method of claim 12 , further comprising depositing a diffusion barrier between the substrate and the at least two film layers.

17. The method of claim 12 , wherein the metal comprises platinum.

18. The method of claim 12 , wherein the metal comprises at least one of titanium, nickel, tungsten, cobalt, molybdenum, and chromium.

19. The method of claim 12 , wherein the metal silicide comprises platinum silicide.

20. The method of claim 19 , wherein the desired phase of the platinum silicide comprises Pt 3 Si.

21. The method of claim 20 , wherein the platinum silicide is selected from a group consisting of at least about 40% Pt 3 Si, at least about 45% Pt 3 Si, at least about 50% Pt 3 Si, at least about 55% Pt 3 Si, at least about 60% Pt 3 Si, at least about 65% Pt 3 Si, at least about 70% Pt 3 Si, and at least about 74% Pt 3 Si.

22. A kinetically-limited method for forming a thin film comprising a metal silicide, comprising:
identifying a desired phase of a metal silicide;
determining a time-temperature regime based on the desired phase;
providing a substrate;
depositing at least two film layers on the substrate, the at least two film layers comprising a first layer comprising amorphous silicon and a second layer comprising metal contacting the first layer; and
annealing the at least two film layers using the determined time-temperature regime to form the desired phase of the metal silicide.

23. The method of claim 22 , wherein the determining comprises experimentally determining the time-temperature regime.

24. The method of claim 22 , wherein the substrate comprises a wafer.

25. The method of claim 22 , further comprising depositing a diffusion barrier between the substrate and the at least two film layers.

26. The method of claim 22 , wherein the metal comprises platinum.

27. The method of claim 22 , wherein the metal comprises at least one of titanium, nickel, tungsten, cobalt, molybdenum, and chromium.

28. The method of claim 22 , wherein the metal silicide comprises platinum silicide.

29. The method of claim 28 , wherein the desired phase of the platinum silicide comprises Pt 3 Si.

30. The method of claim 29 , wherein the platinum silicide is selected from a group consisting of at least about 40% Pt 3 Si, at least about 45% Pt 3 Si, at least about 50% Pt 3 Si, at least about 55% Pt 3 Si, at least about 60% Pt 3 Si, at least about 65% Pt 3 Si, at least about 70% Pt 3 Si, at least about 75% Pt 3 Si, at least about 80% Pt 3 Si, at least about 85% Pt 3 Si, and at least about 88% Pt 3 Si.

31. A thin film comprising a metal silicide formed by a process comprising:
providing a substrate;
depositing at least two film layers on the substrate, the at least two film layers comprising a first layer comprising amorphous silicon and a second layer comprising metal contacting the first layer; and
annealing the at least two film layers to form a metal silicide;
tuning a selected phase of the metal silicide using at least one of a source-limited method and a kinetically-limited method.

32. A thin film comprising a metal silicide formed by a process comprising:
identifying a desired phase of a metal silicide;
determining a ratio of an amount of a metal to an amount of amorphous silicon based on the desired phase of the metal silicide;
providing a substrate;
depositing at least two film layers on the substrate, the at least two film layers comprising a first layer comprising amorphous silicon and a second layer comprising metal contacting the first layer, the at least two film layers comprising the amorphous silicon and the metal in amounts based on the determined ratio; and
annealing the at least two film layers to form the desired phase of the metal silicide.

33. A thin film comprising a metal silicide formed by a process comprising:
identifying a desired phase of a metal silicide;
determining a time-temperature regime based on the desired phase;
providing a substrate;
depositing at least two film layers on the substrate, the at least two film layers comprising a first layer comprising amorphous silicon and a second layer comprising metal contacting the first layer; and
annealing the at least two film layers using the determined time-temperature regime to form the desired phase of the metal silicide.

34. A nanoelectromechanical switch comprising the thin film of claims 32 .

35. A jet engine comprising

Assignees

• Univ Pennsylvania

Inventors

• Carpick Robert W
• Streller Frank
• Agarwal Rahul
• Mangolini Filippo

Classifications

• H10D64/0112 Primary

  using conductive layers comprising silicides · CPC title

• C01B33/06

  Metal silicides (alloys C22) · CPC title

• B81B2203/04

  Electrodes · CPC title

• B81C1/00698

  Electrical characteristics, e.g. by doping materials · CPC title

• B81B3/0086

  Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage · CPC title