Apparatus and concept for minimizing parasitic chemical vapor deposition during atomic layer deposition

• US 6,305,314 B1
• Filed: 12/17/1999
• Issued: 10/23/2001
• Est. Priority Date: 03/11/1999
• Status: Expired due to Fees

• Current Assignee: Aixtron Inc. (Aixtron AG)
• Original Assignee: Genvs Incorporated
• Inventors: Sneh, Ofer, Galewski, Carl J.
• Primary Examiner(s): Everhart, Caridad
• Application Number:
  US09/466,100
• Time in Patent Office: 676 Days
• Field of Search: 118/723.R, 118/723.E, 118/724, 118/725
• US Class Current: 118/723.00R
• CPC Class Codes: C23C 16/44 characterised by the method of coating C23C16/04 takes precedence
• CPC Class Codes: C23C 16/4401 Means for minimising impurities, e.g. dust, moisture or residual gas, in the reaction chamber
• 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 16/45536 Use of plasma, radiation or electromagnetic fields
• CPC Class Codes: C23C 16/45544 characterized by the apparatus
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• 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 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31616 Deposition of Al2O3
• CPC Class Codes: H01L 21/31637 Deposition of Tantalum oxides, e.g. Ta2O5
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 21/31691 with perovskite structure
• CPC Class Codes: H01L 21/318 composed of nitrides

Abstract

A new method and apparatus for avoiding contamination of films deposited in layered depositions, such as Atomic Layer Deposition (ALD) and other sequential chemical vapor deposition (CVD) processes, is taught, wherein CVD-deposited contamination of ALD films is prevented by use of a pre-reaction chamber that effectively causes otherwise-contaminating gaseous constituents to deposit on wall elements of gas-delivery apparatus prior to entering the ALD chamber.

Claims

1. A pre-reaction apparatus for a coating system having a processing chamber for holding a substrate during coating and a source of differing precursor materials to be supplied to the processing chamber in alternating cycles for reacting in the coating process, wherein in the alternation of materials, one or more of said precursor materials from one cycle may adversely effect process in an alternate cycle, the pre-reaction apparatus comprising;

at least one passage for delivery of said precursor materials between the source and the processing chamber; and

an energy provision system for providing activation energy sufficient to cause unwanted precursor materials to deposit by CVD reaction in the pre-reaction apparatus.

2. The apparatus of claim 1 wherein the process comprises Atomic Layer Deposition (ALD).

3. The apparatus of claim 1 wherein the pre-reaction apparatus comprises a separate chamber between the source and the processing chamber.

4. The apparatus of claim 3 wherein the activation energy is provided by heating a surface within the confines of the separate chamber.

5. The apparatus of claim 3 wherein the activation energy is provided by striking a plasma in the separate chamber.

6. The apparatus of claim 1 wherein the pre-reaction apparatus is gas supply tubing between the source and the processing chamber.

7. The apparatus of claim 6 wherein the activation energy is provided by heating walls of the tubing.

8. The apparatus of claim 1 wherein the pre-reaction apparatus comprises a gas distribution showerhead within the processing chamber.

9. The apparatus of claim 8 wherein the activation energy is provided by heat transfer to a wall of the showerhead facing the substrate from the substrate and a hearth heating the substrate.

10. The apparatus of claim 8 wherein the activation energy is provided by striking a plasma within the showerhead.

11. A substrate coating system comprising:

a processing chamber for holding a substrate during coating;

a source of differing precursor materials to be supplied to the processing chamber in alternating cycles for reacting in the coating process, wherein in the alternation of materials, one or more of said precursor materials from one cycle may effect processing in an alternate cycle; and

a pre-reaction apparatus;

characterized in that energy is provided to the pre-reaction apparatus sufficient to cause the unwanted precursor materials to deposit by CVD reaction in the pre-reaction apparatus.

12. The system of claim 11 wherein the process comprises Atomic Layer Deposition (ALD).

13. The system of claim 11 wherein the pre-reaction apparatus comprises a separate chamber between the source and the processing chamber.

14. The system of claim 13 wherein the activation energy is provided by heating a surface within the confines of the separate chamber.

15. The system of claim 13 wherein the activation energy is provided by striking a plasma in the separate chamber.

16. The system of claim 11 wherein the pre-reaction apparatus comprises gas supply tubing between the source and the processing chamber.

17. The system of claim 16 wherein the activation energy is provided by heating walls of the tubing.

18. The apparatus of claim 13 wherein the pre-reaction apparatus comprises a gas distribution showerhead within the processing chamber.

19. The apparatus of claim 18 wherein the activation energy is provided by heat transfer to a wall of the showerhead facing the substrate from the substrate and a hearth heating the substrate.

20. The apparatus of claim 18 wherein the activation energy is provided by striking a plasma within the showerhead.