Method of Thermally Oxidizing Silicon Using Ozone

• US 20070026693A1
• Filed: 09/08/2006
• Published: 02/01/2007
• Est. Priority Date: 04/05/2005
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: CZARNIK, Cory, OLSEN, Christopher, BEHDJAT, Mehran, RAMAMURTHY, Sundar, ACHUTHARAMAN, Vedapuram, YOKOTA, Yoshitaka
• Application Number:
  US11/530,375
• Publication Number:
  US 20070026693A1
• Time in Patent Office: Days
• US Class Current: 438/795
• CPC Class Codes: H01L 21/0214 the material being a silicon oxynitride, e.g. SiON or SiON:H
• CPC Class Codes: H01L 21/02238 silicon in uncombined form, i.e. pure silicon
• CPC Class Codes: H01L 21/02249 formation by combined oxidation and nitridation performed simultaneously
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/31658 by thermal oxidation, e.g. of SiGe
• CPC Class Codes: H01L 21/31662 of silicon in uncombined form
• CPC Class Codes: H01L 21/67109 mainly by convection
• CPC Class Codes: H01L 21/67115 mainly by radiation

Abstract

A method and apparatus for oxidizing materials used in semiconductor integrated circuits, for example, for oxidizing silicon to form a dielectric gate. An ozonator is capable of producing a stream of least 70% ozone. The ozone passes into an RTP chamber through a water-cooled injector projecting into the chamber. Other gases such as hydrogen to increase oxidation rate, diluent gas such as nitrogen or O₂, enter the chamber through another inlet. The chamber is maintained at a low pressure below 20 Toir and the substrate is advantageously maintained at a temperature less than 800° C. Alternatively, the oxidation may be performed in an LPCVD chamber including a pedestal heater and a showerhead gas injector in opposition to the pedestal.

Claims

1. A method of treating a surface of a substrate to be formed into an integrated circuit, comprising the steps of:

maintaining a processing surface of said substrate at a temperature; and

flowing from a first gas port into a processing chamber accommodating said substrate an oxygen-based gas mixture containing at least 30% ozone.

2. The method of claim 1, wherein said gas mixture contains at least 50% ozone.

3. The method of claim 2, wherein said gas mixture contains at least 70% ozone.

4. The method of claim 3, wherein said gas mixture contains at least 90% ozone.

5. The method of claim 1, wherein said substrate comprises a silicon-containing material and said ozone oxidizes the silicon-containing material.

6. The method of claim 5, further comprising flowing into said processing chamber hydrogen.

7. The method of claim 6, wherein said hydrogen flows into said processing chamber through a second port.

8. The method of claim 5, further comprising flowing oxygen gas into said chamber through a second port.

9. The method of claim 5 wherein the temperature is less than 800°

C.

10. The method of claim 9, wherein the temperature is less than 600°

C.

11. The method of claim 10, wherein the temperature is less than 400°

C.

12. The method of claim 1, wherein the gas mixture is not excited into a plasma adjacent said substrate.

13. The method of claim 1, wherein the maintaining step is performed by radiant lamps directed at the substrate.

14. The method of claim 1, wherein said flowing step includes flowing said gas mixture into a said processing chamber through an injector projecting into said processing chamber and further comprising cooling said injector with a cooling liquid.

15. The method of claim 1, wherein the maintaining step includes electrically heating a pedestal accommodated within said processing chamber and supporting the substrate.

16. The method of claim 15, wherein said flowing step includes flowing said gas mixture into a gas manifold separated from the processing chamber by a showerhead including a plurality of apertures therethough and disposed in opposition to the pedestal.

17. The method of claim 1, further comprising flowing molecular oxygen gas through an ozonator external of the chamber to produce said oxygen-based gas mixture.

18. The method of claim 1, wherein a pressure within the processing chamber is maintained no higher than 20 Torr.

19. The method of claim 18, where the pressure is maintained no higher than 5 Torr.

20. The method of claim 1, further comprising flowing another processing gas into the processing chamber from a port different than a port admitting said oxygen-based gas into said processing chamber.