Method of forming a tantalum-containing layer from a metalorganic precursor

• US 20070054046A1
• Filed: 09/06/2005
• Published: 03/08/2007
• Est. Priority Date: 09/06/2005
• Status: Abandoned Application

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Gomi, Atsushi, Ishizaka, Tadahiro
• Application Number:
  US11/218,471
• Publication Number:
  US 20070054046A1
• Time in Patent Office: Days
• US Class Current: 427/248.100
• CPC Class Codes: C23C 16/16 from metal carbonyl compounds
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence

Abstract

A method and precursor for forming and integrating a Ta-containing layer in semiconductor processing. The tantalum precursor has the formula (CpR₁)(CpR₂)TaH(CO), where Cp is a cyclopentadienyl functional group and R₁ and R₂ are H or alkyl groups. The method includes providing a substrate in a process chamber of a deposition system, and exposing a process gas comprising the tantalum precursor to the substrate to form the Ta-containing layer. The Ta-containing layer may be treated to remove contaminants and modify the layer. The Ta-containing layer may contain tantalum metal, tantalum carbide, tantalum nitride, or tantalum carbonitride, or a combination thereof, and may be deposited in a TCVD, ALD, or PEALD process. A semiconductor device containing a Ta-containing layer formed on a patterned substrate containing one or more vias or trenches is provided.

Claims

1. A method of processing a substrate, the method comprising:

providing the substrate in a process chamber;

exposing the substrate to a process gas comprising a metalorganic tantalum precursor that is free of halogen and N to form a Ta-containing layer on the substrate.

2. The method according to claim 1, wherein the metalorganic tantalum precursor has a vapor pressure at 100°

C. in the range of from 0.1 to 3 torr.

3. The method according to claim 1, wherein the metalorganic tantalum precursor has a thermal decomposition temperature in a range of from 200 to 500°

C.

4. The method according to claim 1, wherein the metalorganic tantalum precursor comprises a total of 5 ppb or less of impurities selected from the group consisting of alkaline earth metals, Fe, Cr, Ni, H₂O, F and Cl.

5. The method according to claim 1, wherein the metalorganic tantalum precursor has the following characteristics:

a vapor pressure at 100°

C. in the range of from 0.1 to 3 torr;

a thermal decomposition temperature in a range of from 200 to 500°

C.; and

a total of 5 ppb or less of impurities selected from the group consisting of alkaline earth metals, Fe, Cr, Ni, H₂O, F and Cl.

6. The method according to claim 1, wherein the process gas further comprises at least one of an inert gas or a noble gas.

7. The method according to claim 1, where the exposing the substrate comprises maintaining the substrate at a temperature between 150°

C. and about 600°

C.

8. The method according to claim 1, where the exposing the substrate comprises maintaining a chamber pressure of between about 0.1 Torr and about 760 Torr.

9. The method according to claim 1, wherein the process gas is plasma excited.

10. The method according to claim 1, wherein the method is an atomic layer deposition (ALD) process comprising:

exposing the substrate to said process gas; and

exposing the substrate to a reducing gas configured to reduce the metalorganic tantalum precursor.

11. The method according to claim 10, wherein said reducing gas comprises at least one selected from the group consisting of noble gases, H₂, SiH₄, B₂H₆ and HCOOH.

12. The method according to claim 10, wherein the reducing gas is plasma excited.

13. The method according to claim 10, wherein said reducing gas comprises H₂.

14. The method according to claim 13, wherein said reduction gas consists of H₂.

15. The method according to claim 14, wherein the H₂ is plasma excited.

16. The method according to claim 10, further comprising performing a first purging of said chamber after exposing the substrate to the processing gas.

17. The method according to claim 16, wherein said first purging comprises injecting at least one of an inert gas and a noble gas into the chamber.

18. The method according to claim 16, further comprising performing a second purging of said chamber after exposing the substrate to the reducing gas.

19. The method according to claim 18, wherein said second purging comprises injecting Ar into the chamber.

20. The method according to claim 18, wherein said second purging comprises evacuating the chamber without injecting a gas into the chamber.

21. The method according to claim 1, wherein the method is an atomic layer deposition (ALD) process comprising:

exposing the substrate to said process gas;

performing a first purge of said chamber including injecting H₂ into the chamber;

exposing the substrate to H₂ excited into a plasma in order to reduce the metalorganic tantalum precursor; and

performing a second purge of said chamber including injecting Ar into the chamber or evacuating the chamber without introducing a gas into the chamber.

22. The method according to claim 10, wherein

the Ta-containing layer is a first Ta-containing layer;

and

the method further comprises

exposing the first Ta-containing layer to another process gas comprising the metalorganic tantalum precursor to form a second Ta-containing layer, and

exposing the second Ta-containing layer to a reducing gas configured to reduce the metalorganic tantalum precursor.

23. The method according to claim 22, wherein

the first Ta-containing layer comprises TaC_x;

and

the second Ta-containing layer has a higher Ta content than the first Ta-containing layer.

24. The method according to claim 1, further comprising

depositing a seed layer on the Ta-containing layer;

and

depositing a Cu layer on the seed layer.

25. The method according to claim 24, further comprising

posttreating the Ta-containing layer prior to depositing the seed layer, wherein

the posttreating comprises at least one selected from the group consisting of degassing the substrate, and exposing the Ta-containing layer to a cleaning plasma.

26. The method according to claim 24, wherein the seed layer comprises at least one selected from the group consisting of Cu and Ru.

27. A computer readable medium containing program instructions for execution on a substrate processing system processor, which when executed by the processor, cause the substrate processing system to perform the steps of the method recited in claim 1.