Implantation using solid aluminum iodide (ALI3) for producing atomic aluminum ions and in situ cleaning of aluminum iodide and associated by-products

Patent metadata

Field	Value
Publication number	US-10774419-B2
Application number	US-201715627989-A
Country	US
Kind code	B2
Filing date	Jun 20, 2017
Priority date	Jun 21, 2016
Publication date	Sep 15, 2020
Grant date	Sep 15, 2020

Abstract

An ion implantation system is provided having an ion source configured to form an ion beam from aluminum iodide. A beamline assembly selectively transports the ion beam to an end station configured to accept the ion beam for implantation of aluminum ions into a workpiece. The ion source has a solid-state material source having aluminum iodide in a solid form. A solid source vaporizer vaporizes the aluminum iodide, defining gaseous aluminum iodide. An arc chamber forms a plasma from the gaseous aluminum iodide, where arc current from a power supply is configured to dissociate aluminum ions from the aluminum iodide. One or more extraction electrodes extract the ion beam from the arc chamber. A water vapor source further introduces water to react residual aluminum iodide to form hydroiodic acid, where the residual aluminum iodide and hydroiodic acid is evacuated from the system.

First claim

The invention claimed is:

1. An ion source for an ion implantation system, comprising:
a solid-state material source comprising aluminum iodide in a solid form;
a solid source vaporizer configured to vaporize the aluminum iodide, thus defining gaseous aluminum iodide;
a power supply;
a water introduction apparatus configured to introduce water vapor to the ion source;
an arc chamber configured to form a plasma from the gaseous aluminum iodide, wherein arc current from the power supply is configured to dissociate aluminum ions from the aluminum iodide; and
one or more extraction electrodes configured to extract an ion beam from the arc chamber, wherein the ion beam is comprised of aluminum ions.

2. The ion source of claim 1 , wherein the solid source vaporizer comprises one or more heating elements configured to heat the aluminum iodide to a vaporization temperature.

3. The ion source of claim 1 , wherein the solid source vaporizer is configured to heat the aluminum iodide to between approximately 90° C. and 100° C.

4. The ion source of claim 1 , wherein the aluminum iodide is in one or more a powder form, a granular form, and a bulk solid form.

5. The ion source of claim 1 , further comprising an extraction power supply associated with the one or more extraction electrodes, wherein the one or more extraction electrodes comprise an extraction aperture, and wherein an extraction current from the extraction power supply is configured to extract the ion beam through the extraction aperture.

6. The ion source of claim 1 , further comprising a vacuum system configured to selectively substantially evacuate the arc chamber.

7. The ion source of claim 1 , further comprising a co-gas source configured to provide a co-gas to the arc chamber for aiding in the formation of the plasma.

8. The ion source of claim 7 , wherein the co-gas comprises argon.

9. An ion implantation system, comprising:
an ion source configured to form an ion beam from aluminum iodide, wherein the ion beam is comprised of aluminum ions;
a water introduction apparatus configured to introduce water vapor to the ion implantation system;
a beamline assembly configured to selectively transport the ion beam; and
an end station configured to accept the ion beam for implantation of the aluminum ions into a workpiece.

10. The ion implantation system of claim 9 , wherein the workpiece comprises silicon carbide.

11. The ion implantation system of claim 9 , wherein the ion source comprises:
a solid-state material source comprising aluminum iodide in a solid form;
a solid source vaporizer configured to vaporize the aluminum iodide, thus defining gaseous aluminum iodide;
a power supply;
an arc chamber configured to form a plasma from the gaseous aluminum iodide, wherein arc current from the power supply is configured to dissociate the aluminum ions from the aluminum iodide; and
one or more extraction electrodes configured to extract the ion beam from the arc chamber.

12. The ion implantation system of claim 9 , further comprising a vacuum system configured to substantially evacuate one or more portions of the ion implantation system.

13. The ion implantation system of claim 9 , wherein the aluminum iodide is in one or more a powder form, a granular form, and a bulk solid form.

14. The ion source of claim 11 , further comprising a co-gas source configured to provide a co-gas to the arc chamber for aiding in the formation of the plasma.

15. The ion source of claim 14 , wherein the co-gas comprises argon.

16. A method for implanting aluminum ions into a workpiece, the method comprising:
vaporizing a solid aluminum iodide source material, therein defining a vaporized aluminum iodide source material;
providing the vaporized aluminum iodide source material to an ion source of an ion implantation system;
ionizing the aluminum iodide source material in the ion source;
extracting an ion beam containing aluminum ions from the ion source; and
directing the ion beam toward the workpiece, thereby implanting the aluminum ions into the workpiece;
forming one or more of residual aluminum iodide and hydroiodic acid on one or more internal components of the ion implantation system; and
cleaning one or more of the residual aluminum iodide and hydroiodic acid from the one or more internal components of the ion implantation system, wherein cleaning one or more of the residual aluminum iodide and hydroiodic acid comprises introducing water vapor to the internal components of the ion implantation system and evacuating the ion implantation system, therein substantially removing the water vapor and residual aluminum iodide and hydroiodic acid.

17. The method of claim 16 , wherein the solid aluminum iodide source material is initially in one of a powder form, a granular form, and a bulk solid form.

18. The method of claim 16 , wherein introducing water vapor to the internal components of the ion implantation system comprises introducing one or more of atmospheric air and vaporized water to the internal components of the ion implantation system.

19. The method of claim 16 , comprising iteratively introducing the water vapor and evacuating the ion implantation system.

20. The method of claim 16 , wherein the water vapor is introduced in-situ.

Assignees

• Axcelis Tech Inc

Inventors

• Kamenitsa Dennis Elliott
• Rzeszut Richard J
• Silva Fernando M
• Beringer Jason R
• Wu Xiangyang

Classifications

• H10P50/00

  Etching of wafers, substrates or parts of devices · CPC title

• H10P30/2042

  into crystalline silicon carbide · CPC title

• H10P30/208

  of electrically inactive species · CPC title

• H10P30/204

  into Group IV semiconductors · CPC title

• H10P30/21

  of electrically active species · CPC title