Conductive beam optic containing internal heating element

Patent metadata

Field	Value
Publication number	US-10504682-B2
Application number	US-201815901778-A
Country	US
Kind code	B2
Filing date	Feb 21, 2018
Priority date	Feb 21, 2018
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

Provided herein are approaches for reducing particles in an ion implanter. An electrostatic filter may include a housing and a plurality of conductive beam optics within the housing. The conductive beam optics are arranged around an ion beam-line directed towards a wafer, and may include entrance aperture electrodes proximate an entrance aperture of the housing. The conductive beam optics may further include energetic electrodes downstream along the ion beam-line from the entrance aperture electrodes, and ground electrodes downstream from the energetic electrodes. The energetic electrodes are positioned farther away from the ion beam-line than the entrance electrodes and the ground electrodes, thus causing the energetic electrodes to be physically blocked from impact by an envelope of back-sputter material returning from the wafer. The electrostatic filter may further include an electrical system for independently delivering a voltage and a current to each of the conductive beam optics.

First claim

What is claimed is:

1. An electrostatic filter for delivering an ion beam to a wafer, the electrostatic filter comprising:
a housing; and
a plurality of conductive beam optics within the housing, the plurality of conductive beam optics arranged around an ion beam-line, wherein at least one conductive beam optic of the plurality of conductive beam optics includes an internal heating element, and wherein the internal heating element is a heating lamp surrounded by a hollow shell, the heating lamp electrically connected with a conductor.

2. The electrostatic filter of claim 1 , wherein the hollow shell is a glassy carbon.

3. The electrostatic filter of claim 1 , wherein the hollow shell is graphite.

4. The electrostatic filter of claim 1 , further comprising an insulator disposed within each end of the hollow shell.

5. The electrostatic filter of claim 1 , the plurality of conductive beam optics comprising:
a set of entrance aperture electrodes proximate an entrance aperture of the housing;
a set of energetic electrodes downstream along the ion beam-line from the set of entrance aperture electrodes; and
a set of ground electrodes downstream along the ion beam-line of the set of energetic electrodes, wherein the set of energetic electrodes is positioned farther away from the ion beam-line than the set of entrance aperture electrodes and the set of ground electrodes.

6. The electrostatic filter of claim 5 , wherein each of the set of energetic electrodes includes an internal heating element.

7. The electrostatic filter of claim 1 , further comprising an electrical system in communication with the plurality of conductive beam optics, the electrical system configured to independently supply a voltage and a current to each of the plurality of conductive beam optics.

8. The electrostatic filter of claim 7 , the electrical system comprising a set of relays operable to control the voltage and the current to the internal heating element.

9. An ion implantation system, comprising:
an electrostatic filter for delivering an ion beam to a wafer, the electrostatic filter comprising:
a housing having an exit proximate the wafer; and
a plurality of conductive beam optics within the housing, the plurality of conductive beam optics arranged around an ion beam-line, and the plurality of conductive beam optics comprising:
a set of entrance aperture electrodes proximate an entrance aperture of the housing;
a set of energetic electrodes downstream along the ion beam-line from the set of entrance aperture electrodes; and
a set of ground electrodes downstream along the ion beam-line of the set of energetic electrodes, wherein the set of energetic electrodes is positioned farther away from the ion beam-line than the set of entrance aperture electrodes and the set of ground electrodes, wherein at least one of the plurality of conductive beam optics includes an internal heating element, and wherein the internal heating element comprises a heating lamp surrounded by a hollow shell; and

an electrical system in communication with the electrostatic filter, the electrical system configured to supply a voltage and a current to the plurality of conductive beam optics.

10. The ion implantation system of claim 9 , wherein the at least one of the plurality of conductive beam optics including the internal heating element further comprises:
a conductor electrically connected with the heating lamp, wherein the conductor is part of the electrical system; and
an insulator disposed within an opening at each end of the hollow shell.

11. The ion implantation system of claim 9 , wherein each of the plurality of conductive beam optics is connected in parallel to allow independent adjustment of the voltage and the current.

12. The ion implantation system of claim 9 , further comprising a set of exit plates extending from the housing, wherein the set of exit plates is oriented approximately parallel to a direction of travel of the ion beam.

13. The ion implantation system of claim 12 , wherein the set of ground electrodes comprises a set of exit apertures proximate the exit, wherein the set of exit apertures define a maximum envelope of back-sputter material traveling from the wafer and through the exit, between the set of exit apertures, wherein a first pair of exit apertures of the set of exit apertures is positioned proximate a downstream end of the set of exit plates, and wherein a second pair of exit apertures of the set of exit apertures is positioned proximate an upstream end of the set of exit plates.

14. A conductive beam optic, comprising:
a heating lamp;
a hollow shell concentrically disposed about the heating lamp, the hollow shell extending along an entire length of the heating lamp; and
a conductor electrically connected with the heating lamp.

15. The conductive beam optic of claim 14 , further comprising an insulator disposed within an interior of the hollow shell.

16. The conductive beam optic of claim 15 , wherein conductor extends through the insulator.

17. The conductive beam optic of claim 14 , wherein the heating lamp is tubular-shaped.

18. The conductive beam optic of claim 14 , wherein the hollow shell is one of: a glassy carbon, and graphite.

Assignees

• Varian Semiconductor Equipment Ass Inc

Inventors

• Chang Shengwu
• Sinclair Frank
• Likhanskii Alexandre
• Campbell Christopher
• Lindberg Robert C
• Hermanson Eric D

Classifications

• H01J2237/057

  Energy or mass filtering · CPC title

• H01J37/3171 Primary

  for ion implantation · CPC title

• H01J37/05 Primary

  Electron or ion-optical arrangements for separating electrons or ions according to their energy {or mass}(particle separator tubes H01J49/00) · CPC title

• H01J2237/022

  Avoiding or removing foreign or contaminating particles, debris or deposits on sample or tube · CPC title

• H01J2237/31705

  Impurity or contaminant control · CPC title