Method and system for the removal and/or avoidance of contamination in charged particle beam systems
A charged particle beam system is disclosed, comprising: a charged particle beam generator for generating a beam of charged particles; a charged particle optical column arranged in a vacuum chamber, wherein the charged particle optical column is arranged for projecting the beam of charged particles onto a target, and wherein the charged particle optical column comprises a charged particle optical element for influencing the beam of charged particles; a source for providing a cleaning agent; a conduit connected to the source and arranged for introducing the cleaning agent towards the charged particle optical element; wherein the charged particle optical element comprises: a charged particle transmitting aperture for transmitting and/or influencing the beam of charged particles, and at least one vent hole for providing a flow path between a first side and a second side of the charged particle optical element, wherein the vent hole has a cross section which is larger than a cross section of the charged particle transmitting aperture. Further, a method for preventing or removing contamination in the charged particle transmitting apertures is disclosed, comprising the step of introducing the cleaning agent while the beam generator is active.
1. A method for preventing or removing contamination of a charged particle transmitting aperture in a charged particle beam system comprising a charged particle optical column arranged in a vacuum chamber, a cleaning agent source, and a conduit connected to the cleaning agent source, the charged particle optical column being configured to project a beam of charged particles onto a target and comprising:
a charged particle optical element configured to influence the beam of charged particles and comprising:
the charged particle transmitting aperture configured to transmit and/or influence the beam of charged particles, and
a vent hole configured to provide a flow path between a first side and a second side of the charged particle optical element, wherein the vent hole has a larger cross section than a cross section of the charged particle transmitting aperture,
the method comprising:
introducing the cleaning agent from the cleaning agent source towards the charged particle optical element via the conduit extending into and within the vacuum chamber to guide the cleaning agent towards the charged particle optical element.
2. The method of claim 1 , wherein introducing the cleaning agent towards the charged particle optical element comprises: introducing the cleaning agent towards the charged particle optical element while maintaining a vacuum in the vacuum chamber.
3. The method of claim 2 , wherein maintaining the vacuum comprises providing a flow of at least part of species of the cleaning agent at least through the charged particle optical element.
4. The method of claim 1 , wherein introducing the cleaning agent towards the charged particle optical element comprises: guiding the cleaning agent by use of the conduit over a surface of the charged particle optical element.
5. The method of claim 4 , wherein introducing the cleaning agent towards the charged particle optical element comprises: introducing the cleaning agent towards the charged particle optical element while the beam of charged particles is present at or near the aperture of the charged particle optical element.
6. The method of claim 1 , wherein the charged particle beam system comprises a charged particle beam generator that is configured to generate the beam of charged particles, wherein introducing the cleaning agent towards the charged particle optical element comprises: introducing the cleaning agent towards the charged particle optical element while the beam generator is generating the beam of charged particles.
7. The method of claim 3 , wherein the vacuum chamber being connected to a vacuum arrangement, wherein providing the flow comprises providing the flow at least through the charged particle optical element to the vacuum arrangement.
8. The method of claim 1 , wherein the charged particle optical element comprises an array of charged particle transmitting apertures, wherein projecting the beam of charged particles comprises projecting a plurality of beams of charged particles onto a target through the array of charged particle transmitting apertures.
9. The method of claim 3 , wherein introducing the cleaning agent from the cleaning agent source towards the charged particle optical element comprises guiding the cleaning agent over a surface of the charged particle optical element.
10. The method of claim 9 , wherein the surface of the charged particle optical element comprising the charged particle transmitting aperture comprises an array of charged particle transmitting apertures.
11. A charged particle beam system comprising a charged particle optical column arranged in a vacuum chamber and a cleaning agent source configured to provide a cleaning agent, and a conduit connected to the cleaning agent source, the charged particle optical column configured to project a beam of charged particles onto a target and comprising:
a charged particle optical element configured to influence the beam of charged particles and comprising: a charged particle transmitting aperture configured to transmit and/or influence the beam of charged particles, and a vent hole configured to provide a flow path between a first side and a second side of the charged particle optical element, wherein the vent hole has a larger cross section than a cross section of the charged particle transmitting aperture,
wherein the charged particle optical column is configured to prevent or remove contamination of the charged particle transmitting aperture, and
wherein the cleaning agent is introduced towards the charged particle optical element via the conduit extending into and within the vacuum chamber to guide the cleaning agent towards the charged particle optical element.
12. The system of claim 11 , wherein the cleaning agent is introduced towards the charged particle optical element while the beam of charged particles is present at or near the aperture of the charged particle optical element.
13. The system of claim 11 , wherein when the cleaning agent is introduced towards the charged particle optical element, the cleaning agent is guided over a surface of the charged particle optical element.
14. The system of claim 11 , wherein the cleaning agent is introduced towards the charged particle optical element via the conduit connected to the cleaning agent source while the beam of charged particles are projected towards the target.
15. The system of claim 11 , wherein the charged particle beam system comprises a charged particle beam generator that is configured to generate the beam of charged particles.
16. The system of claim 15 , wherein the charged particle optical element comprises an array of charged particle transmitting apertures and the charged particle optical column is configured to project a plurality of beams of charged particles onto a target through the array of charged particle transmitting apertures.
17. The system of claim 11 , further comprising a vacuum arrangement connected to the vacuum chamber so that at least part of species of the cleaning agent flows to the vacuum arrangement at least through the charged particle optical element.
18. A method for preventing or removing contamination of an array of charged particle transmitting apertures in a charged particle beam system arranged in a vacuum chamber that is connected to a vacuum source, the charged particle beam system comprising a charged particle optical column for projecting a plurality of beams of charged particles onto a target through the array of charged particle transmitting apertures,
the charged particle optical column comprising a charged particle optical element for influencing the beams of charged particles, the charged particle optical element comprises the array of charged particle transmitting apertures for transmitting or influencing the plurality beams of charged particles, and a vent hole configured to provide a flow path between a first side and a second side of the charged particle optical element, wherein the vent hole has a larger cross section than a cross section of the charged particle transmitting aperture;
the method comprising:
providing from a cleaning agent source a cleaning agent;
introducing the cleaning agent towards the charged particle optical element via a conduit connected to the cleaning agent source;
guiding the cleaning agent over a surface of the charged particle optical element by use of the conduit, the surface comprising the array of charged particle transmitting apertures; and
maintaining a vacuum in the vacuum chamber.
19. The method of claim 18 , wherein introducing the cleaning agent towards the charged particle optical element comprises: introducing the cleaning agent towards the charged particle optical element while maintaining the vacuum in the vacuum chamber.
20. The method of claim 18 , wherein maintaining the vacuum comprises enabling a flow or movement of species of the cleaning agent or contaminants at least through the charged particle optical element.