Ion source gas injection beam shaping

Patent metadata

Field	Value
Publication number	US-11769648-B2
Application number	US-202117513245-A
Country	US
Kind code	B2
Filing date	Oct 28, 2021
Priority date	Oct 28, 2021
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

An ion source for extracting a ribbon ion beam with improved height uniformity is disclosed. Gas nozzles are disposed in the chamber proximate the extraction aperture. The gas that is introduced near the extraction aperture serves to shape the ribbon ion beam as it is being extracted. For example, the height of the ribbon ion beam may be reduced by injecting gas above and below the ion beam so as to compress the extracted ion beam in the height direction. In some embodiments, the feedgas is introduced near the extraction aperture. In other embodiments, a shield gas, such as an inert gas, is introduced near the extraction aperture.

First claim

What is claimed is:

1. An ion source comprising:
a chamber comprising a first end, a second end and a plurality of walls connecting the first end and the second end, wherein one of the plurality of walls is an extraction plate having an extraction aperture having a width greater than its height;
a plasma generator to generate a plasma within the chamber;
a gas inlet in communication with gas channels;
a supply channel in communication with the gas inlet to supply feedgas to the chamber; and
gas nozzles disposed within the chamber near the extraction aperture, in communication with the gas channels to provide a flow of feedgas near the extraction aperture so as to shape an ion beam extracted from the ion source.

2. The ion source of claim 1 , wherein the plurality of walls comprises a bottom wall opposite the extraction plate and side walls that are adjacent to the extraction plate, and wherein the gas channels are disposed in the side walls.

3. The ion source of claim 1 , wherein the plurality of walls comprises a bottom wall opposite the extraction plate and side walls that are adjacent to the extraction plate, and wherein the gas channels comprise tubes disposed proximate an interior or exterior surface of the side walls.

4. The ion source of claim 1 , further comprising plate gas channels disposed in the extraction plate and in communication with the gas channels, wherein the gas nozzles are disposed on an interior surface of the extraction plate proximate the extraction aperture.

5. The ion source of claim 1 , wherein the plurality of walls comprises a bottom wall opposite the extraction plate and side walls that are adjacent to the extraction plate, and wherein the gas nozzles are disposed on interior surfaces of the side walls proximate the extraction plate.

6. The ion source of claim 1 , wherein the extraction plate comprises a face plate and an extraction liner disposed between an interior of the chamber and the face plate, wherein the extraction liner is formed such that there is a gap between the extraction liner and the face plate, wherein the gap is in communication with the gas channels, and further comprising plate gas channels disposed in the extraction liner and in communication with the gap, wherein the gas nozzles are disposed on a surface of the extraction liner proximate the extraction aperture.

7. The ion source of claim 1 , wherein a dimension of the gas nozzles varies along the width of the extraction aperture to achieve an improved height uniformity of an extracted ribbon ion beam.

8. The ion source of claim 1 , wherein the plasma generator comprises an indirectly heated cathode (IHC).

9. An ion implantation system comprising:
the ion source of claim 1 ;
a mass analyzer; and
a platen.

10. An ion source comprising:
a chamber comprising a first end, a second end and a plurality of walls connecting the first end and the second end, wherein one of the plurality of walls is an extraction plate having an extraction aperture having a width greater than its height;
a plasma generator to generate a plasma within the chamber;
a gas inlet in communication with gas channels;
gas nozzles disposed within the chamber near the extraction aperture, in communication with the gas channels so as to shape an ion beam extracted from the ion source; and
a second gas inlet in communication with a supply channel to supply feedgas to the chamber;
wherein the supply channel and the gas channels are not in fluid communication with one another.

11. The ion source of claim 10 , wherein the plurality of walls comprises a bottom wall opposite the extraction plate and side walls that are adjacent to the extraction plate, and wherein the gas channels are disposed in the side walls.

12. The ion source of claim 10 , wherein the plurality of walls comprises a bottom wall opposite the extraction plate and side walls that are adjacent to the extraction plate, and wherein the gas channels comprise tubes disposed proximate an interior or exterior surface of the side walls.

13. The ion source of claim 10 , further comprising plate gas channels disposed in the extraction plate and in communication with the gas channels, wherein the gas nozzles are disposed on an interior surface of the extraction plate proximate the extraction aperture.

14. The ion source of claim 10 , wherein the plurality of walls comprises a bottom wall opposite the extraction plate and side walls that are adjacent to the extraction plate, and wherein the gas nozzles are disposed on interior surfaces of the side walls proximate the extraction plate.

15. The ion source of claim 10 , wherein the extraction plate comprises a face plate and an extraction liner disposed between an interior of the chamber and the face plate, wherein the extraction liner is formed such that there is a gap between the extraction liner and the face plate, wherein the gap is in communication with the gas channels, and further comprising plate gas channels disposed in the extraction liner and in communication with the gap, wherein the gas nozzles are disposed on a surface of the extraction liner proximate the extraction aperture.

16. The ion source of claim 10 , further comprising a first gas container in fluid communication with the gas inlet and a second gas container in fluid communication with the second gas inlet.

17. The ion source of claim 10 , further comprising a gas container in fluid communication with a first mass flow controller and a second mass flow controller, wherein the first mass flow controller controls a flow rate through the gas inlet and the second mass flow controller controls a flow rate through the second gas inlet, wherein the flow rate through the gas inlet and the second gas inlet is independently controlled.

18. The ion source of claim 10 , wherein a dimension of the gas nozzles varies along the width of the extraction aperture to achieve an improved height uniformity of an extracted ribbon ion beam.

19. The ion source of claim 10 , wherein the plasma generator comprises an indirectly heated cathode (IHC).

20. An ion implantation system comprising:
the ion source of claim 10 ;
a mass analyzer; and
a platen.

Assignees

• Applied Materials Inc

Inventors

• Mclaughlin Adam M

Classifications

• H01J2237/31701

  Ion implantation · CPC title

• H01J2237/05

  Arrangements for energy or mass analysis · CPC title

• H01J2237/006

  Details of gas supplies, e.g. in an ion source, to a beam line, to a specimen or to a workpiece, (H01J37/3244 takes precedence; environmental cells for electron microscopes H01J2237/2003; microscopes with environmental specimen chamber H01J2237/2608) · CPC title

• H01J37/3171

  for ion implantation · CPC title

• H01J27/024

  Extraction optics, e.g. grids · CPC title