METHOD AND APPARATUS FOR CLEANING RESIDUE FROM AN ION SOURCE COMPONENT

• US 20110108058A1
• Filed: 11/11/2009
• Published: 05/12/2011
• Est. Priority Date: 11/11/2009
• Status: Abandoned Application

• Current Assignee: Axcelis Technologies Incorporated
• Original Assignee: Axcelis Technologies Incorporated
• Inventors: DiVergilio, William F., Gilchrist, Glen R., Srivastava, Aseem K.
• Application Number:
  US12/616,662
• Publication Number:
  US 20110108058A1
• Time in Patent Office: Days
• US Class Current: 134/1.1
• CPC Class Codes: C23C 14/48 Ion implantation
• CPC Class Codes: H01J 2237/022 Avoiding or removing foreign or contaminating particles, debris or deposits on sample or tube
• CPC Class Codes: H01J 2237/0225 Detecting or monitoring foreign particles
• CPC Class Codes: H01J 37/08 Ion sources; Ion guns
• CPC Class Codes: H01J 37/3171 for ion implantation

Abstract

Some techniques disclosed herein facilitate cleaning residue from a molecular beam component. For example, in an exemplary method, a molecular beam is provided along a beam path, causing residue build up on the molecular beam component. To reduce the residue, the molecular beam component is exposed to a hydro-fluorocarbon plasma. Exposure to the hydro-fluorocarbon plasma is ended based on whether a first predetermined condition is met, the first predetermined condition indicative of an extent of removal of the residue. Other methods and systems are also disclosed.

Claims

1. A method for removing residue from an ion source component used to extract a molecular beam, comprising:

using a first plasma comprising fluorine to facilitate removal of the residue from the ion source component.

2. The method of claim 1, wherein a gas used to generate the first plasma comprises at least one of a fluorocarbon species or a hydro-fluorocarbon species.

3. The method of claim 1, wherein the gas used to generate the first plasma has at least a substantial absence, if not a complete absence, of NF₃.

4. The method of claim 1, wherein the first plasma gives rise to a first afterglow downstream of the first plasma, the first afterglow comprising fluorine atoms that come into contact with the residue to remove the residue.

5. The method of claim 1, further comprising:

selectively ending exposure to the first plasma based on whether a first predetermined condition is met, the first predetermined condition indicative of an extent of removal of the residue.

6. The method of claim 5, where the first condition relates to whether a predetermined time has expired as measured from a starting time of the exposure to the plasma.

7. The method of claim 5, where the first condition relates to whether optical spectroscopic analysis using a secondary plasma source indicates whether the first plasma has completely removed the residue from the ion source component.

8. The method of claim 5, where the first condition relates to whether a residual gas mass analysis indicates whether the first plasma has completely removed the residue from the ion source component.

9. The method of claim 5, where the first condition relates to whether a temperature measurement indicates whether the first plasma has completely removed the residue from the ion source component.

10. The method of claim 1, where the residue comprises a boron-based compound.

11. The method of claim 1, further comprising:

exposing the ion source component to a second plasma that includes oxygen;

selectively ending the exposure to the second plasma based on whether a second predetermined condition is met.

12. The method of claim 11, where the residue includes a carbon-based compound.

13. The method of claim 11, where the second condition relates to whether a predetermined time has expired as measured from a starting time of the exposure to the second plasma.

14. The method of claim 11, where the second condition relates to whether optical spectroscopic analysis using a secondary plasma source indicates whether the second plasma has completely removed the residue from the ion source component.

15. The method of claim 11, where the second condition relates to whether a residual gas mass analysis indicates whether the second plasma has completely removed the residue from the ion source component.

16. A method for removing residue from an ion source component used to extract a molecular beam, comprising:

extracting a first molecular beam along a beam path and concurrently building up a first residue on the ion source component, where the first molecular beam is generated by using a first gas that includes a first molecular species;

extracting a second molecular beam along the beam path and concurrently building up a second residue on the ion source component, where the second molecular beam is generated by using a second gas that includes a second molecular species and where the second residue differs in composition from the first residue;

selectively generating a first cleaning plasma discharge and a second cleaning plasma discharge to facilitate removal of the first residue and the second residue, respectively, from the ion source component.

17. The method of claim 16, wherein the first and second cleaning plasma discharges give rise to first and second afterglows, respectively, that are downstream of the first and second plasma discharges, respectively;

and wherein the first and second afterglows come into contact with the first and second residue, respectively to remove the first and second residues, respectively.

18. The method of claim 16, wherein the first gas comprises fluorine and has at least a substantial absence, if not a complete absence, of NF₃.

19. The method of claim 18, where the first molecular species comprises boron.

20. The method of claim 18, wherein the second gas comprises oxygen.

21. The method of claim 20, where the second molecular species comprises carbon.

22. A reactive gas delivery system for facilitating removal of residue from a beam component, comprising:

a flow control assembly in fluid connection with a plurality of different dopant gas supplies, a plurality of different cleaning gas supplies, and at least one plasma chamber;

a controller adapted to instruct the flow control assembly to selectively deliver the gas from the different dopant gas supplies to one or more of the at least one plasma chamber to facilitate extraction of molecular beams having different respective species along a beamline; and

the controller further adapted to selectively deliver gas from the different cleaning gas supplies to generate different types of plasma discharge in the one or more of the at least one plasma chamber, where the different types of plasma discharge are adapted to reduce buildup of different types of residue formed when the molecular beams having different species are extracted along the beamline.

23. An ion implantation system, comprising:

an ion source comprising a first plasma chamber situated adjacent to a second plasma chamber;

a gas supply line adapted to selectively supply one of a plurality of cleaning gases towards the first plasma chamber;

where the gas supply line comprises a dielectric conduit coupled laterally between first and second conductive conduits; and

a plasma generation component adapted to generate a plasma within a cavity defined by an inner-surface of the dielectric conduit.

24. The ion implantation system of claim 23, wherein the plasma is generated so an afterglow of the plasma drifts or diffuses into at least one of the first or second plasma chamber to remove residue built up in the ion source.

25. The ion implantation system of claim 23, wherein the dielectric conduit comprises sapphire.

26. The ion implantation system of claim 23, wherein the plasma generation component comprises:

a radio-frequency (RF) coil that is wound around the dielectric conduit; and

an RF power supply to drive the RF coil.

27. The ion implantation system of claim 23, wherein the plasma generation component comprises a microwave source.