Method for high density plasma chemical vapor deposition of dielectric films

• US 6,270,862 B1
• Filed: 07/26/1999
• Issued: 08/07/2001
• Est. Priority Date: 06/28/1996
• Status: Expired due to Term

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Berney, Butch, Nguyen, Huong, Barnes, Michael, McMillin, Brian
• Primary Examiner(s): Mills, Gregory
• Assistant Examiner(s): ALEJANDRO MULERO, LUZ L
• Application Number:
  US09/359,639
• Time in Patent Office: 743 Days
• Field of Search: 427/569, 427/574, 427/578, 427/579, 438/758, 438/767, 438/787, 438/788
• US Class Current: 427/569
• CPC Class Codes: C23C 16/455 characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
• CPC Class Codes: C23C 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45572 Cooled nozzles
• CPC Class Codes: C23C 16/45578 Elongated nozzles, tubes with holes
• CPC Class Codes: C23C 16/507 using external electrodes, e.g. in tunnel type reactors
• CPC Class Codes: C30B 25/105 by irradiation or electric discharge
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means

Abstract

A plasma processing system for processes such as chemical vapor deposition includes a plasma processing chamber, a substrate holder for supporting a substrate within the processing chamber, a dielectric member having an interior surface facing the substrate holder, the dielectric member forming a wall of the processing chamber a gas supply for supplying gas to the chamber, directed towards the substrate, and an RF energy source such as a planar coil which inductively couples RF energy through the dielectric member and into the chamber to energize the process gas into a plasma state. The gas supply may comprise a primary gas ring and a secondary gas ring for supplying gases or gas mixtures into the chamber. The gas supply may further include injectors attached to the primary gas ring which inject gas into the chamber, directed toward the substrate. The plasma processing system may also include a cooling mechanism for cooling the primary gas ring during processing.

Claims

1. A method of depositing a layer of on a substrate comprising:

placing a substrate on a substrate holder in a processing chamber, wherein an interior surface of a dielectric member forming a wall of the process chamber faces the substrate holder;

supplying process gas into the processing chamber from a gas supply including a plurality of injectors having orifices, at least some of the orifices being in close proximity to the substrate and orienting the process gas along an axis of injection which intersects an exposed surface of the substrate at an acute angle such that a plurality of gas flows overlap each other in a plane parallel to the exposed surface of the substrate, the injectors injecting more of the process gas at the periphery of the substrate than in the middle of the substrate; and

energizing the process gas into the plasma state by inductively coupling RF energy through the dielectric member into the processing chamber, the process gas being plasma phase reacted with the exposed surface of the substrate such that a layer of material is deposited on the exposed surface.

2. The method of claim 1, wherein said step of supplying a gas comprises the steps of:

supplying a gas or gas mixture from a primary gas ring located inside the processing chamber, wherein at least some of said gas or gas mixture passes through said injectors and is directed toward said substrate.

3. The method of claim 2, wherein said step of applying a gas further comprises the steps of:

supplying an additional gas or gas mixture from a secondary gas ring.

4. The method of claim 3, wherein the process gas supplied through the injectors is SiH₄ and the process gas supplied from the secondary gas ring comprises argon and oxygen.

5. The method of claim 2, wherein the injectors are connected to said primary gas ring, the injectors injecting at least some of said gas or gas mixture into said chamber and directed toward said substrate.

6. The method of claim 5, wherein the injectors are located near or outside of the substrate periphery.

7. The method of claim 2, wherein said injectors inject at least some of said gas or gas mixture into said chamber at an angle over 15 degrees with respect to the exposed surface of said substrate.

8. The method of claim 2, wherein said primary gas ring is cantilevered, and the method further comprises a step of cooling the primary gas ring during processing.

9. The method of claim 8, wherein said step of cooling comprises passing an electrically non-conductive cooling liquid in heat transfer contact with the primary gas ring to prevent excessive heating of the primary gas ring during processing of the substrate.

10. The method of claim 8, wherein the primary gas ring is cooled sufficiently to maintain a temperature thereof below 100°

C.

11. The method of claim 2, wherein the primary gas ring is electrically grounded.

12. The method of claim 1, wherein the process gas is energized by an RF antenna in the form of a planar coil.

13. The method of claim 12, wherein the layer of material deposited on the substrate comprises a silicon-containing layer.

14. The method of claim 1, wherein the process gas is energized by an RF antenna in the form of a non-planar coil.

15. The method of claim 1, wherein substrates are consecutively processed in the processing chamber by contacting the substrates with the plasma gas.

16. The method of claim 1, wherein some of the orifices supply the process gas in a direction which does not intersect the exposed surface of the substrate.

17. The method of claim 16, wherein the gas supply further includes a gas distribution member located adjacent the dielectric member, and the orifices are located between the gas distribution member and the substrate holder.

18. The method of claim 1, wherein the orifices are located between an inductive plasma generation region in the plasma processing chamber and the exposed surface of the substrate.

19. The method of claim 1, wherein the layer of material deposited on the exposed surface comprises SiO₂.

20. The method of claim 1, wherein the substrate comprises a 12 inch semiconductor wafer.

21. The method of claim 1, wherein the interior of the processing chamber is at a pressure of 1 to 100 mTorr.

22. The method of claim 1, wherein the process gas is supplied through the injectors is SiH₄.

23. The method of claim 1, wherein the substrate holder applied an RF bias to the substrate.

24. The method of claim 1, wherein the layer of materials is deposited at a rate of at least 9000 Å

/minute.

25. The method of claim 1, wherein the orifices of the injectors are sized such that sonic flow of the process gas occurs at the orifices of the injectors.