Epitaxial deposition process and apparatus

• US 20070181057A1
• Filed: 02/03/2006
• Published: 08/09/2007
• Est. Priority Date: 02/03/2006
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Kao, Chien-Teh, Lu, Xinliang, Kim, Yihwan, Phan, See-Eng, Kuppurao, Satheesh, Lam, Andrew
• Granted Patent: US 7,494,545 B2
• Time in Patent Office: Days
• US Class Current: 117/92
• CPC Class Codes: C23C 16/0236 by etching with a reactive gas
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/505 using radio frequency discharges
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/67069 for drying etching

Abstract

An epitaxial deposition process including a dry etch process, followed by an epitaxial deposition process is disclosed. The dry etch process involves placing a substrate to be cleaned into a processing chamber to remove surface oxides. A gas mixture is introduced into a plasma cavity, and the gas mixture is energized to form a plasma of reactive gas in the plasma cavity. The reactive gas enters into the processing chamber and reacts with the substrate, forming a thin film. The substrate is heated to vaporize the thin film and expose an epitaxy surface. The epitaxy surface is substantially free of oxides. Epitaxial deposition is then used to form an epitaxial layer on the epitaxy surface.

Claims

1. An epitaxial deposition method comprising:

introducing a substrate into a processing chamber;

introducing a gas mixture into a plasma cavity;

energizing the gas mixture to form a plasma of reactive gas in the cavity;

introducing into the processing chamber the reactive gas;

processing the substrate with the reactive gas to expose an epitaxy surface; and

forming an epitaxial layer on the epitaxy surface.

2. The method of claim 1 wherein the plasma does not contact the substrate.

3. The method of claim 2 wherein the plasma cavity is separated from the processing chamber

4. The method of claim 1 wherein forming the epitaxial layer comprises moving the substrate into an epitaxial deposition reactor without exposing the substrate to ambient air.

5. The method of claim 4 wherein the plasma cavity, the processing chamber, and the epitaxial deposition reactor, are all vacuum-connected to a multi-chamber processing system.

6. The method of claim 1 further comprising:

reacting the substrate with the reactive gas to form a volatile film; and

heating the substrate to a first temperature to vaporize the volatile film to expose the epitaxy surface.

7. The method of claim 6 further comprising maintaining the substrate at or below a second temperature while the substrate reacts with the reactive gas.

8. The method of claim 7 wherein the second temperature is between 15°

C. and 65°

C.

9. The method of claim 6 wherein the first temperature is at least 75°

C.

10. The method of claim 9 wherein the first temperature is less than 250°

C.

11. The method of claim 6 wherein the gas mixture comprises ammonia (NH₃) and nitrogen trifluoride (NF₃).

12. The method of claim 11 wherein the reactive gas comprises ammonia fluoride (NH₄F) or ammonium hydrogen fluoride (NH₄F.HF).

13. The method of claim 12 wherein the volatile film comprises ammonium hexafluorosilicate ((NH₄)₂SiF₆).

14. A multi-chamber apparatus comprising:

an epitaxial deposition reactor;

a dry etch processor in vacuum-tight connection with the epitaxial deposition reactor, the dry etch processor comprising;

a processing chamber adapted to hold a substrate; and

a plasma cavity adapted to form a plasma remotely from the processing chamber; and

a transfer robot to transfer a substrate from the dry etch processor to the epitaxial deposition reactor.

15. The multi-chamber apparatus of claim 14, wherein the processing chamber includes a substrate support including one or more fluid channels capable of cooling a substrate and at least a lower portion of a lid assembly in fluid communications with the plasma cavity, the lower portion of the lid assembly adapted to convectively heat the substrate.

16. The apparatus of claim 15, wherein the plasma cavity includes a first electrode and a second electrode, first electrode coupled to a radio frequency source, a microwave source or a source of direct current, and the second electrode grounded and in fluid communication with the lower portion of the lid assembly.

17. The apparatus of claim 16, wherein the support assembly is adapted to move within the chamber between a heating position proximate the lower portion of the lid assembly and an etch position away from the lower portion of the lid assembly.

18. The apparatus of claim 17, wherein the support includes a substrate support surface having a first and second end, and one or more gas passageways in fluid communication with the first end and a purge gas source or vacuum source at the second end.

19. The apparatus of claim 16, wherein the plasma cavity is coupled to sources capable of providing ammonia (NH₃) and nitrogen trifluoride (NF₃).

20. The apparatus of claim 16, wherein the dry reactor is adapted to form a reactive gas including ammonia fluoride (NH₄F) or ammonium hydrogen fluoride (NH₄F.HF).