Metal silicide, metal germanide, methods for making the same

• US 9,129,897 B2
• Filed: 04/20/2012
• Issued: 09/08/2015
• Est. Priority Date: 12/19/2008
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Pore, Viljami J., Haukka, Suvi P., Blomberg, Tom E., Tois, Eva E.
• Primary Examiner(s): PARKER, ALLEN L
• Application Number:
  US13/452,402
• Publication Number:
  US 20120270393A1
• Time in Patent Office: 1,236 Days
• Field of Search: 438/581, 438/583, 438/649, 438/651, 427/255.393, 427/305
• US Class Current: 1/1
• CPC Class Codes: C23C 16/06 characterised by the deposition of metallic material
• CPC Class Codes: C23C 16/406 of iron group metals
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
• CPC Class Codes: H01L 21/28518 the conductive layers comprising silicides H01L21/28537 takes precedence
• CPC Class Codes: H01L 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/3215 Doping the layers
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76855 After-treatment introducing at least one additional element into the layer
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/456 on silicon
• CPC Class Codes: H01L 29/4933 with a silicide layer contacting the silicon layer, e.g. Polycide gate with a barrier layer between the silicide and silicon layers H01L29/4941
• CPC Class Codes: H01L 29/665 using self aligned silicidation, i.e. salicide formation of conductive layers comprising silicides H01L21/28518
• CPC Class Codes: H01L 29/66666 Vertical transistors H01L29/66712, H01L29/66742 take precedence
• CPC Class Codes: H01L 29/7827 Vertical transistors H01L29/7802, H01L29/78642 take precedence

Abstract

In one aspect, methods of silicidation and germanidation are provided. In some embodiments, methods for forming metal silicide can include forming a non-oxide interface, such as germanium or solid antimony, over exposed silicon regions of a substrate. Metal oxide is formed over the interface layer. Annealing and reducing causes metal from the metal oxide to react with the underlying silicon and form metal silicide. Additionally, metal germanide can be formed by reduction of metal oxide over germanium, whether or not any underlying silicon is also silicided. In other embodiments, nickel is deposited directly and an interface layer is not used. In another aspect, methods of depositing nickel thin films by vapor phase deposition processes are provided. In some embodiments, nickel thin films are deposited by ALD.

Claims

1. A method for silicidation, comprising:

providing a substrate having at least one exposed silicon region;

depositing an interface layer on the exposed silicon region, wherein the interface layer is a material different from that of the exposed silicon region;

depositing by atomic layer deposition (ALD) or CVD a metal oxide film over the interface layer; and

heating the substrate to form a metal silicide film over the exposed silicon regions using metal from the metal oxide film and silicon from the exposed silicon region.

2. The method of claim 1, wherein the interface layer comprises antimony (Sb).

3. The method of claim 2, wherein the interface layer has a thickness between about 3 nm and 5 nm.

4. The method of claim 2, wherein the metal oxide film comprises nickel.

5. The method of claim 2, wherein the metal silicide film is chosen from a group consisting of Ni₂Si, NiSi, NiSi₂.

6. The method of claim 2, wherein the substrate comprises a three-dimensional structure.

7. The method of claim 2, wherein the metal oxide film is reduced to a metal film with a vapor phase reducing agent.

8. The method of claim 1, wherein the interface layer comprises a semiconductor element.

9. The method of claim 8, wherein the interface layer comprises a germanium layer.

10. The method of claim 9, wherein the interface layer comprises an epitaxial germanium layer.

11. The method of claim 1, wherein the interface layer comprises an elemental film or mixtures of elemental films.

12. The method of claim 1, further comprising reducing the metal oxide film to a metal.

13. The method of claim 12, wherein heating the substrate and reducing are performed simultaneously in a reducing environment.

14. The method of claim 12, wherein heating the substrate comprises providing hydrogen gas in a chamber housing the substrate.

15. The method of claim 1, wherein depositing by ALD the metal oxide film comprises alternately and sequentially exposing the substrate to a metal source precursor and an oxygen precursor.

16. The method of claim 15, wherein the metal source precursor comprises at least one of Ni, Co, Cu, Fe, Ru, Rh, Pt and Pd.

17. The method of claim 16, wherein the metal source precursor comprises nickel.

18. The method of claim 15, wherein the oxygen source comprises O₃.

19. The method of claim 1, wherein the metal oxide film comprises two different metals.

20. The method of claim 1, wherein the interface layer has a thickness of 1 nanometer to 15 nanometers.

21. The method of claim 20, wherein the interface layer has a thickness of up to 5 nanometers.

22. A method for selective silicidation, comprising:

providing an interface film over an exposed silicon-containing region in a manner that avoids oxidation of the exposed silicon-containing region, wherein the interface film is a material different from that of the exposed silicon-containing region;

forming a metal oxide thin film on the interface film by CVD, pulsed CVD or at least one cycle of an atomic layer deposition (ALD) or ALD-type process, wherein one cycle comprises;

contacting a substrate with a metal source precursor, and

contacting the substrate with an oxygen source precursor; and

reacting the metal from the metal oxide film with silicon from the silicon-containing region to form a metal silicide film over remaining portions of the silicon-containing region.

23. The method of claim 22, wherein the metal source precursor is a nickel source precursor.

24. The method of claim 22, wherein the oxygen source precursor is chosen from a group consisting of O₂, H₂O, O₃, oxygen plasma, oxygen radicals or oxygen atoms or a reactive oxygen gas.

25. A method for forming metal germanide, comprising:

providing a substrate having at least one exposed silicon region;

depositing a germanium layer on the exposed silicon region;

depositing a metal oxide film over germanium layer; and

heating the substrate to form a metal germanide film using metal from the metal oxide film and a metal silicide under the metal germanide.

26. The method of claim 25, wherein the germanium layer is deposited by CVD.

27. The method of claim 25, wherein the metal oxide is a nickel oxide.

28. A method for forming a doped metal silicide layer on a substrate, comprising:

providing a substrate having at least one exposed silicon region;

depositing a metal film comprising a first metal over the silicon region, wherein depositing the metal film comprises multiple cycles of a primary metal atomic layer deposition-type process;

depositing a dopant film comprising a second metal over the silicon region, wherein depositing the dopant film comprises one or more cycles of a dopant atomic layer deposition-type process; and

annealing the substrate to form a metal silicide of the first metal that is doped with the second metal, wherein the cycles of the primary metal atomic layer deposition-type process and the cycles of the dopant atomic layer deposition-type process are carried out at a specific ratio to achieve a desired dopant concentration in the doped metal silicide layer.

29. The method of claim 28, wherein the first metal is nickel and the second metal is platinum.