A METHOD FOR FORMING A RUTHENIUM METAL LAYER ON A PATTERNED SUBSTRATE

• US 20060211228A1
• Filed: 03/16/2005
• Published: 09/21/2006
• Est. Priority Date: 03/16/2005
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Matsuda, Tsukasa
• Granted Patent: US 7,273,814 B2
• Time in Patent Office: Days
• US Class Current: 438/575
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/4481 by evaporation using carrier gas in contact with the source material C23C16/4486 takes precedence
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take 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 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance

Abstract

A method for forming a ruthenium metal layer includes providing a patterned substrate in a process chamber of a deposition system, where the patterned substrate contains one or more vias or trenches, or combinations thereof, depositing a first ruthenium metal layer on the substrate in an atomic layer deposition process, and depositing a second ruthenium metal layer on the first ruthenium metal layer in a thermal chemical vapor deposition process. The deposited ruthenium metal layer can be used as a diffusion barrier layer, a seed layer for electroplating, or both.

Claims

1. A method for forming a ruthenium metal layer, comprising:

providing a patterned substrate in a process chamber of a deposition system, wherein the patterned substrate comprises one or more vias or trenches, or combinations thereof;

depositing a first ruthenium metal layer on the substrate in an atomic layer deposition process; and

depositing a second ruthenium metal layer on the first ruthenium metal layer in a thermal chemical vapor deposition process.

2. The method according to claim 1, wherein the depositing a first ruthenium metal layer comprises a plasma-enhanced atomic layer deposition process.

3. The method according to claim 2, wherein the plasma-enhanced atomic layer deposition process comprises the alternating steps of:

first, exposing the substrate to a ruthenium organometallic precursor; and

second, exposing the substrate to a plasma containing a hydrogen-containing gas comprising H₂, NH₃, or a combination thereof.

4. The method according to claim 3, further comprising:

purging the process chamber with an inert gas between the alternating exposure steps.

5. The method according to claim 3, wherein the first and second alternating exposure steps are performed a desired number of times to deposit the first ruthenium metal layer to a thickness of about 1-10 nm.

6. The method according to claim 1, wherein the depositing a first ruthenium metal layer comprises a thermal atomic layer deposition process.

7. The method according to claim 6, wherein the thermal atomic layer deposition process comprises the alternating steps of:

first, exposing the substrate to a ruthenium organometallic precursor; and

second, exposing the substrate to a hydrogen-containing gas containing H₂ or NH₃, or a combination thereof.

8. The method according to claim 7, further comprising:

purging the process chamber with an inert gas between the alternating exposure steps.

9. The method according to claim 6, wherein the first and second alternating exposure steps are performed a desired number of times to deposit the first ruthenium metal layer to a thickness of about 1-10 nm.

10. The method according to claim 1, wherein the depositing a second ruthenium metal layer comprises:

concurrently exposing the substrate to a ruthenium organometallic precursor and a reducing gas.

11. The method according to claim 1, wherein the thickness of the second ruthenium metal layer is greater than the thickness of the first ruthenium metal layer.

12. The method according to claim 1, wherein the first and second ruthenium metal layers are deposited from a ruthenium organometallic precursor comprising at least one of (2,4-dimethylpentadienyl)(ethylcyclopentadienyl) ruthenium, bis(2,4-dimethylpentadienyl) ruthenium, 2,4-dimethylpentadienyl) (methylcyclopentadienyl) ruthenium, or bis(ethylcyclopentadienyl) ruthenium, or a combination thereof.

13. The method according to claim 1, further comprising:

maintaining the substrate at a temperature between about 50°

C. and about 500°

C. during the depositing of the first and second ruthenium metal layers.

14. The method according to claim 1, further comprising:

maintaining the substrate at a temperature between about 200°

C. and about 300°

C. during the depositing of the first and second ruthenium metal layers.

15. The method according to claim 1, further comprising:

maintaining the substrate at a first temperature during the depositing of the first ruthenium metal layer; and

maintaining the substrate at a second temperature during the depositing of the second ruthenium metal layer, wherein the second temperature is greater than the first temperature.

16. The method according to claim 1, further comprising:

maintaining the process chamber at a first pressure during the depositing of the first ruthenium metal layer; and

maintaining the process chamber at a second pressure during the depositing of the second ruthenium metal layer, wherein the second pressure is greater than the first pressure.

17. The method according to claim 16, wherein the first pressure is between about 5 mTorr and about 500 mTorr and the second pressure is between about 500 mTorr and about 30 Torr.

18. The method according to claim 1, wherein the patterned substrate further comprises a tantalum-containing or a tungsten-containing barrier layer formed thereon onto which the first ruthenium metal layer is deposited.

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

19. A method for forming a ruthenium metal layer, comprising:

providing a patterned substrate in a process chamber of a deposition system, wherein the patterned substrate contains one or more vias or trenches, or combinations thereof;

depositing a first ruthenium metal layer on the substrate in a plasma-enhanced atomic layer deposition process including alternating exposures of the substrate to a) a ruthenium organometallic precursor and b) a hydrogen-containing gas in a plasma; and

depositing a second ruthenium metal layer on the first ruthenium metal layer in a thermal chemical vapor deposition process by exposing the substrate concurrently to a ruthenium organometallic precursor and a hydrogen-containing gas.

20. A method for forming a ruthenium metal layer, comprising:

providing a patterned substrate in a process chamber of a deposition system, wherein the patterned substrate contains one or more vias or trenches, or combinations thereof;

depositing a first ruthenium metal layer on the substrate in an atomic layer deposition process, wherein the atomic layer deposition process comprises a thermal atomic layer deposition process including alternating exposures of the substrate by a) a ruthenium organometallic precursor and b) a hydrogen-containing gas; and

depositing a second ruthenium metal layer on the first ruthenium metal layer in a thermal chemical vapor deposition process by exposing the substrate concurrently to a ruthenium organometallic precursor and a hydrogen-containing gas.