Method and apparatus for reducing particle formation in a vapor distribution system

• US 20070218200A1
• Filed: 03/16/2006
• Published: 09/20/2007
• Est. Priority Date: 03/16/2006
• Status: Abandoned Application

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Gomi, Atsushi, Suzuki, Kenji, Hara, Masamichi, Mizusawa, Yasushi
• Application Number:
  US11/377,237
• Publication Number:
  US 20070218200A1
• 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 16/4402 Reduction of impurities in the source gas
• 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 16/45512 Premixing before introduction in the reaction chamber
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45574 Nozzles for more than one gas

Abstract

A method and system is described for reducing particle contamination in a vapor distribution system. The vapor distribution system comprises a housing and a vapor distribution head comprising a plurality of openings configured to introduce a film precursor vapor to a deposition system. The housing and vapor distribution head define a plenum coupled to a film precursor evaporation system, and configured to receive the film precursor vapor from the evaporation system and distribute the film precursor vapor within the deposition system through the plurality of openings. In order to reduce particle contamination, the vapor distribution system is designed to reduce the difference, or ratio, between the pressure in the plenum and the pressure in the deposition system. For example, the plenum pressure can be less than twice the pressure in the process space, or can be less than 50 mTorr, 30 mTorr or even 20 mTorr than the pressure in the process space.

Claims

1. A deposition system for forming a refractory metal film on a substrate, comprising:

a process chamber having a substrate holder configured to support said substrate and heat said substrate, and a pumping system configured to evacuate said process chamber;

a metal precursor evaporation system configured to evaporate a metal precursor to form a metal precursor vapor;

a vapor distribution system configured to introduce metal precursor vapor to a process space in said process chamber above said substrate, wherein said vapor distribution system comprises;

a housing having an inlet; and

a vapor distribution head coupled to said housing, wherein the combination of said housing and said vapor distribution head form a plenum configured to receive a carrier gas and said metal precursor vapor and distribute said carrier gas and said metal precursor vapor in said process chamber through one or more openings in said vapor distribution head, and wherein a first pressure in said plenum is greater than a second pressure in said process space and has either a) a ratio thereto of less than approximately a value of two or b) a difference thereover of less than approximately 50 mTorr or c) a ratio thereto of less than approximately a value of two and a difference thereover of less than approximately 50 mTorr;

a vapor delivery system having a first end coupled to an outlet of said metal precursor evaporation system and a second end coupled to said inlet of said vapor distribution system; and

a carrier gas supply system coupled to at least one of said metal precursor evaporation system or said vapor delivery system, or both, and configured to supply a carrier gas to transport said metal precursor vapor in said carrier gas through said vapor delivery system to said inlet of said vapor distribution system.

2. The deposition system of claim 1, wherein said first pressure is greater than said second pressure by less than approximately 30 mTorr.

3. The deposition system of claim 1, wherein said first pressure is greater than said second pressure by less than approximately 20 mTorr.

4. The deposition system of claim 1, further comprising:

one or more particle diffusers disposed within said deposition system along a flow path of said carrier gas and said metal precursor vapor.

5. The deposition system of claim 4, wherein said one or more particle diffusers are disposed within said metal precursor evaporation system, said vapor delivery system, or said vapor distribution system, or two or more thereof.

6. The deposition system of claim 4, wherein said metal precursor evaporation system comprises one or more precursor trays configured to support said metal precursor, and wherein said one or more particle diffusers are coupled to at least one of said one or more precursor trays above said metal precursor.

7. The deposition system of claim 4, wherein said one or more particle diffusers are coupled to an outlet of said metal precursor evaporation system.

8. The deposition system of claim 4, wherein said metal precursor evaporation system comprises one or more precursor trays configured to support said metal precursor, and wherein said one or more particle diffusers are coupled to an outlet of at least one of said one or more precursor trays.

9. The deposition system of claim 4, wherein said one or more particle diffusers are coupled to said first end of said vapor delivery system, or said second end of said vapor delivery system, or any location therebetween.

10. The deposition system of claim 4, wherein each of said one or more particle diffusers comprise one or more openings therethrough in order to permit the passage of said carrier gas and said metal precursor vapor, and wherein said one or more openings are substantially aligned with said flow path.

11. The deposition system of claim 4, wherein each of said one or more particle diffusers comprise one or more openings therethrough in order to permit the passage of said carrier gas and said metal precursor vapor, and wherein said one or more openings are angled, or curved relative to said flow path.

12. The deposition system of claim 1, wherein said metal precursor comprises a metal-carbonyl.

13. The deposition system of claim 12, wherein said metal-carbonyl precursor comprises a tungsten-carbonyl, a molybdenum-carbonyl, a cobalt-carbonyl, a rhodium-carbonyl, a rhenium-carbonyl, a chromium-carbonyl, a ruthenium-carbonyl, or an osmium-carbonyl, or a combination of two or more thereof.

14. The deposition system of claim 12, wherein said metal-carbonyl precursor comprises W(CO)₆, Mo(CO)₆, Co₂(CO)₈, Rh₄(CO)₁₂, Re₂(CO)₁₀, Cr(CO)₆, Ru₃(CO)₁₂, or Os₃(CO)₁₂, or a combination of two or more thereof.

15. A vapor distribution system configured to introduce a metal precursor vapor to a process space in a process chamber above a substrate, comprising:

a housing having an inlet configured to be coupled to a metal precursor evaporation system; and

a vapor distribution head coupled to said housing, wherein the combination of said housing and said vapor distribution head form a plenum configured to receive said metal precursor vapor and distribute said metal precursor vapor in said process chamber through one or more openings in said vapor distribution head, and wherein a first pressure in said plenum is greater than a second pressure in said process space and has either a) a ratio thereto of less than approximately a value of two or b) a difference thereover of less than approximately 50 mTorr or c) a ratio thereto of less than approximately a value of two and a difference thereover of less than approximately 50 mTorr.

16. The deposition system of claim 15, wherein said first pressure is greater than said second pressure by less than approximately 30 mTorr.

17. The deposition system of claim 15, wherein said first pressure is greater than said second pressure by less than approximately 20 mTorr.

18. A method of depositing a metal layer on a substrate, the method comprising:

providing a substrate within a process space in a process chamber of a deposition system;

forming a process gas containing a metal-carbonyl precursor vapor and a CO gas;

introducing said process gas from a plenum in a vapor distribution system to said process space in said process chamber;

selecting a first pressure in said plenum to be greater than a second pressure in said process space and to have either a) a ratio thereto of less than approximately a value of two or b) a difference thereover of less than approximately 50 mTorr or c) both; and

exposing said substrate to said diluted process gas to deposit a metal layer on said substrate by a vapor deposition process.

19. The method of claim 18, wherein said first pressure is greater than said second pressure by less than approximately 30 mTorr.

20. The method of claim 18, wherein said first pressure is greater than said second pressure by less than approximately 20 mTorr.