Method and apparatus for cleaning a substrate surface

• US 8,008,166 B2
• Filed: 06/25/2008
• Issued: 08/30/2011
• Est. Priority Date: 07/26/2007
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Doherty, Roisin L., Sanchez, Errol Antonio C., Swenberg, Johanes, Carlson, David K.
• Primary Examiner(s): CHEN, JACK S J
• Application Number:
  US12/146,177
• Publication Number:
  US 20090029528A1
• Time in Patent Office: 1,161 Days
• Field of Search: 438/478, 438/476, 438/770, 438/976, 438/402, 438/471, 257/E21.001
• US Class Current: 438/478
• CPC Class Codes: C30B 25/08 Reaction chambers; Selection of materials therefor
• CPC Class Codes: C30B 29/06 Silicon
• CPC Class Codes: H01L 21/02046 Dry cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/02238 silicon in uncombined form, i.e. pure silicon
• 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 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02661 In-situ cleaning
• CPC Class Codes: H01L 21/31662 of silicon in uncombined form
• CPC Class Codes: H01L 21/67017 Apparatus for fluid treatment H01L21/67126, H01L21/6715 take precedence
• CPC Class Codes: H01L 21/67028 for cleaning followed by drying, rinsing, stripping, blasting or the like
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: Y10S 438/976 Temporary protective layer

Abstract

The present invention generally provides apparatus and method for forming a clean and damage free surface on a semiconductor substrate. One embodiment of the present invention provides a system that contains a cleaning chamber that is adapted to expose a surface of substrate to a plasma cleaning process prior to forming an epitaxial layer thereon. In one embodiment, a method is employed to reduce the contamination of a substrate processed in the cleaning chamber by depositing a gettering material on the inner surfaces of the cleaning chamber prior to performing a cleaning process on a substrate. In one embodiment, oxidation and etching steps are repeatedly performed on a substrate in the cleaning chamber to expose or create a clean surface on a substrate that can then have an epitaxial placed thereon. In one embodiment, a low energy plasma is used during the cleaning step.

Claims

1. A method of forming an epitaxial layer on a semiconductor substrate, comprising:

depositing a gettering layer on a surface of a chamber component that is disposed in a processing region of a processing chamber, wherein the gettering layer comprises a material selected from the group consisting of silicon and germanium;

oxidizing a surface of a substrate;

positioning the substrate on a substrate support disposed in the processing chamber after depositing the gettering layer on the chamber component;

removing at least a portion of the oxidized surface from the substrate positioned on the substrate support to expose a non-oxidized surface; and

depositing an epitaxial layer on at least a portion of the non-oxidized surface.

2. The method of claim 1, further comprising:

positioning a dummy substrate on the substrate support that is positioned within the processing region of a processing chamber; and

depositing a gettering layer on a surface of the dummy substrate while depositing the gettering layer on the surface of the chamber component.

3. The method of claim 1, wherein the removing at least a portion of the oxidized surface is performed using a RF power between about 25 and about 500 Watts delivered to a conductive electrode disposed in the substrate support.

4. The method of claim 1, further comprising passivating the surface of the substrate after removing at least a portion of the oxidized surface by exposing the surface to a hydrogen containing gas, wherein passivating the surface is performed before depositing the epitaxial layer.

5. The method of claim 1, further comprising transferring the substrate from the processing chamber to an epitaxial layer deposition chamber after removing at least a portion of the oxidized surface, wherein the transferring process is performed by a robot disposed in a central transfer chamber which is coupled to the processing chamber and the epitaxial layer deposition chamber.

6. The method of claim 5, further comprising timing the end of the removing at least a portion of the oxidized surface from the substrate performed in the processing chamber with the a time when the epitaxial layer deposition chamber is able to receive the substrate.

7. The method of claim 1, further comprising removing material disposed on a surface of the chamber component prior to depositing the gettering layer by exposing the surface to a reactive gas and an RF generated plasma, wherein the reactive gas comprises a chlorine or a fluorine containing gas.

8. The method of claim 1, wherein removing at least a portion of the oxidized surface comprises sputtering the surface with a gas contains argon (Ar) and a gas selected from a group consisting of helium (He), neon (Ne), and hydrogen (H₂).

9. The method of claim 1, further comprising disposing a plasma shield between the surface of the substrate and the plasma generated in the processing region during the removing at least a portion of the oxidized surface from the substrate, wherein the plasma shield comprises a dielectric material having a plurality of holes formed therein.

10. The method of claim 1, wherein the removing at least a portion of the oxidized surface from the substrate is performed at temperature between 50°

C. and about 700°

C.

11. The method of claim 1, further comprising:

removing at least a portion of an oxidized surface from a plurality of substrates that are each separately positioned on the substrate support; and

depositing another gettering layer on the surface of the chamber component after removing the at least a portion of an oxidized surface from the plurality of substrates.

12. The method of claim 1, further comprising:

reoxidizing the surface of a substrate after the removing at least a portion of an oxidized surface from the surface of the substrate; and

removing at least a portion of the reoxidized surface to expose a non-oxidized surface before the depositing an epitaxial layer on at least a portion of the non-oxidized surface.

13. A method for forming an epitaxial layer on a semiconductor substrate, comprising:

a.) transferring a first substrate to a processing region of a processing chamber;

b.) depositing a gettering layer on a surface of a chamber component that is disposed in the processing region of the processing chamber;

c.) transferring the first substrate out of the processing region and transferring a second substrate to the processing region;

d.) oxidizing a surface of the second substrate;

e.) removing at least a portion of the oxidized surface from the second substrate to expose a non-oxidized surface; and

f.) depositing an epitaxial layer on at least a portion of the non-oxidized surface.

14. The method of claim 13, wherein the gettering layer comprises a material selected from the group consisting of silicon and germanium.

15. The method of claim 13, wherein the surface is oxidized at a temperature of about 400 degrees C. to about 700 degrees C.

16. The method of claim 15, wherein the chamber component is maintained at a temperature of less than about 400 degrees C.

17. The method of claim 13, wherein steps d.) and e.) are repeated one or more times prior to depositing the epitaxial layer on the non-oxidized surface.

18. The method of claim 13, wherein steps d.) and e.) are performed in different processing chambers.

19. The method of claim 13, wherein the removing at least a portion of the oxidized surface is performed using a RF power between about 25 and about 500 Watts delivered to a conductive electrode disposed in the processing chamber.

20. A method for forming an epitaxial layer on a semiconductor substrate, comprising:

transferring a first substrate to a substrate support disposed in a processing chamber;

depositing a gettering layer on a surface of a chamber component that is disposed in a processing region of the processing chamber adjacent the substrate support, wherein the gettering layer comprises a material selected from the group consisting of silicon and germanium;

transferring the first substrate out of the processing chamber and transferring a second substrate to the processing chamber;

oxidizing a surface of the second substrate;

removing at least a portion of the oxidized surface from the second substrate to expose a non-oxidized surface; and

depositing an epitaxial layer on at least a portion of the non-oxidized surface of the second substrate.