Epitaxial deposition process and apparatus

• US 7,494,545 B2
• Filed: 02/03/2006
• Issued: 02/24/2009
• Est. Priority Date: 02/03/2006
• Status: Expired due to Fees

• 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
• Primary Examiner(s): HITESHEW, FELISA CARLA
• Application Number:
  US11/346,804
• Publication Number:
  US 20070181057A1
• Time in Patent Office: 1,117 Days
• Field of Search: 117/1, 117/84, 117/89, 257/1, 438/1, 438/638
• US Class Current: 117/84
• 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 having an oxide layer 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;

reacting the substrate with the reactive gas to form a volatile film while maintaining the substrate at a temperature below 65°

C. while the substrate reacts with the reactive gas;

heating the substrate to a temperature of at least about 75°

C. to vaporize the volatile film and remove the oxide layer, thereby exposing 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 3, wherein the plasma cavity comprises a first electrode connected to a power source and a second electrode connected to a ground.

5. The method of claim 4, wherein the second electrode comprises a top plate, distribution and plate blocker plate separating the substrate in the processing chamber from the plasma cavity.

6. 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.

7. The method of claim 6 wherein the plasma cavity, the processing chamber, and the epitaxial deposition reactor, are all vacuum-connected to a multi-chamber processing system.

8. The method of claim 1 wherein the substrate is heated to a temperature of at least 100°

C.

9. The method of claim 8 wherein the substrate is heated to a temperature of 100°

C. and 200°

C.

10. The method of claim 1 wherein the gas mixture comprises ammonia (NH₃) and nitrogen trifluoride (NF₃), wherein the reactive gas comprises ammonia fluoride (NH₄F) or ammonium hydrogen fluoride (NH₄F·

HF), and the volatile film comprises ammonium hexafluorosilicate ((NH₄)₂SiF₆).