RF resonator for ion beam acceleration

Patent metadata

Field	Value
Publication number	US-10342114-B2
Application number	US-201816124676-A
Country	US
Kind code	B2
Filing date	Sep 7, 2018
Priority date	Sep 15, 2017
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

An RF feedthrough has an electrically insulative cone that is hollow having first and second openings at first and second ends having first and second diameters. The first diameter is larger than the second diameter, defining a tapered sidewall of the cone to an inflection point. A stem is coupled to the second end of the cone, and passes through the first opening and second opening. A flange is coupled to the first end of the cone and has a flange opening having a third diameter. The third diameter is smaller than the first diameter. The stem passes through the flange opening without contacting the flange. The flange couples the cone to a chamber wall hole. Contact portions of the cone may be metallized. The cone and flange pass the stem through the hole while electrically insulating the stem from the wall of the chamber.

First claim

What is claimed is:

1. An RF feedthrough for an ion implantation system, the RF feedthrough comprising:
an electrically insulative cone having a first cone end and a second cone end, wherein the electrically insulative cone is generally hollow and has a first opening at the first cone end and a second opening at the second cone end, wherein the first opening has a first diameter associated therewith and the second opening has a second diameter associated therewith, and wherein the first diameter is larger than the second diameter, therein generally defining a tapered sidewall of the electrically insulative cone;
a stem operably coupled to the second cone end of the electrically insulative cone, wherein the stem passes through the first opening and second opening of the electrically insulative cone; and
a flange operably coupled to the first cone end of the electrically insulative cone, wherein the flange has a flange opening defined therein, wherein the flange opening has a third diameter associated therewith, wherein the third diameter is smaller than the first diameter, and wherein the stem passes through the flange opening without contacting the flange, and wherein the flange is configured to operably couple the electrically insulative cone to a hole defined in a wall of a chamber, wherein the electrically insulative cone and flange are configured to pass the stem through the hole in the wall of the chamber while electrically insulating the stem from the wall of the chamber.

2. The RF feedthrough of claim 1 , further comprising a padding cap operably coupled to the stem in a region proximate to the flange, wherein the padding cap extends outwardly a predetermined distance from an outer diameter of the stem, therein generally preventing a line-of-sight from a region within the chamber to an inner surface of the cone.

3. The RF feedthrough of claim 2 , wherein the padding cap has a fourth diameter associated therewith, wherein the fourth diameter is greater than the third diameter.

4. The RF feedthrough of claim 1 , wherein the flange is comprised of aluminum.

5. The RF feedthrough of claim 1 , wherein the stem comprises a first stem end and a second stem end, wherein the first stem end comprises an accelerating electrode operably coupled thereto, and wherein the second stem end is configured to be coupled to a resonator coil.

6. The RF feedthrough of claim 5 , wherein respective interfaces between the electrically insulative cone, stem, flange, and wall of the chamber seal a chamber environment within the chamber from an environment associated with the resonator coil.

7. The RF feedthrough of claim 6 , wherein one or more o-rings generally seal an interface between the flange and the electrically insulative cone, and another one or more o-rings seal an interface between the stem and the electrically insulative cone.

8. The RF feedthrough of claim 1 , wherein a first surface of the first end of the electrically insulative cone and a second surface of the second end of the electrically insulative cone are metallized.

9. The RF feedthrough of claim 8 , further comprising one or more metal shorting strips disposed between the first surface of the first end of the electrically insulative cone and the flange, and one or more metal shorting strips are disposed between the second surface of the electrically insulative cone and the stem.

10. The RF feedthrough of claim 9 , wherein the one or more metal shorting strips comprise one or more metal springs.

11. The RF feedthrough of claim 1 , wherein a body of the electrically insulative cone is comprised of a ceramic.

12. The RF feedthrough of claim 1 , wherein a body of the electrically insulative cone comprises one or more of alumina and quartz.

13. The RF feedthrough of claim 1 , further comprising one or more location features configured to operably couple the electrically insulative cone to the flange, whereby a position of the electrically insulative cone is selectively fixed with respect to the flange via the one or more location features.

14. The RF feedthrough of claim 1 , wherein the electrically insulative cone comprises a cylindrical region extending a predetermined distance from the first end of the cone toward the second end of the electrically insulative cone to an inflection point, wherein the cylindrical region has a fixed diameter, and where an internal diameter of the electrically insulative cone tapers from the inflection point toward the second end of the electrically insulative cone.

15. The RF feedthrough of claim 14 , wherein the electrically insulative cone comprises an interface surface between the first end of the electrically insulative cone and the flange, wherein the interface surface is generally perpendicular to an inner surface of the electrically insulative cone in the cylindrical region.

16. The RF feedthrough of claim 14 , wherein the flange comprises a lip extending from a region associated with the first end of the electrically insulative cone toward the second end of the electrically insulative cone, wherein the lip has curved region configured to ameliorate arcing between the flange and the electrically insulative cone.

17. An RF resonator for an ion implantation system, the RF resonator comprising:
a resonator chamber defining a chamber environment, wherein the chamber environment is generally isolated from a vacuum environment by a wall of the chamber;
a resonator coil disposed within the resonator chamber; and
an RF feedthrough, comprising:
an electrically insulative cone having a first cone end and a second cone end, wherein the electrically insulative cone is generally hollow and has a first opening at the first cone end and a second opening at the second cone end, wherein the first opening has a first diameter associated therewith and the second opening has a second diameter associated therewith, and wherein the first diameter is larger than the second diameter, therein generally defining a tapered sidewall of the electrically insulative cone;
a stem operably coupled to the second cone end of the electrically insulative cone, wherein the stem passes through the first opening and second opening of the electrically insulative cone;
a flange operably coupled to the first cone end of the electrically insulative cone, wherein the flange has a flange opening defined therein, wherein the flange opening has a third diameter associated therewith, wherein the third diameter is smaller than the first diameter, and wherein the stem passes through the flange opening without contacting the flange, and wherein the flange is configured to operably couple the electrically insulative cone to a hole defined in the wall of the chamber, wherein the electrically insulative cone and flange are configured to pass the stem through the hole in the wall of the chamber while electrically insulating the stem from the wall of the chamber; and
a padding cap operably coupled to the stem in a region proximate to the flange, wherein the padding cap extends outwardly a predetermined distance from an outer diameter of the stem to a fourth diameter, wherein the fourth diameter is greater than the third diameter, and wherein a line-of-sight is generally prevented from a region within the chamber to an inner surface of the cone by the flange, padding cap, and stem.

18. The RF resonator of claim 17 , wherein the electrically insulative cone comprises a cylindrical region extending a predetermined distance from the first end of the cone toward the second end of the electrically insulative cone to an inflection point,

Assignees

• Axcelis Tech Inc

Inventors

• Satoh Shu

Classifications

• H01J37/248 Primary

  Components associated with high voltage supply · CPC title

• H01J5/56

  Shape of the separate part · CPC title

• C23C14/48

  Ion implantation · CPC title

• H01J37/3171

  for ion implantation · CPC title

• H01J37/24

  Circuit arrangements not adapted to a particular application of the tube and not otherwise provided for · CPC title