Charged particle beam system and method for evacuation of the system

摘要

The present invention provides a charged particle beam system which can perform evacuation on an electron gun chamber or an ion-gun chamber having a non-evaporable getter pump in a short time and can maintain the ultra-high vacuum for a long time, and a technology of evacuation therefor. Provided is a charged particle beam system equipped with a charged particle optics which makes the charged particle beam emitted from a charged particle source incident on a sample and means of evacuation for evacuating the charged particle optics, characterized in that the evaporation means has: a vacuum vessel with a charged particle source disposed in the vessel; a non-evaporable getter pump which connects with the vacuum vessel through a vacuum pipe and evacuates the interior of the vacuum vessel as a subsidiary vacuum pump; a valve interposed in the vacuum pipe connecting between the vacuum vessel and the non-evaporable getter pump; a rough pumping port which is provided closer to the non-evaporable getter pump than the valve and performs rough pumping; an open and shut valve for opening and shutting the rough pumping port; and a main vacuum pump which is provided closer to the vacuum vessel than the valve and evacuates the interior of the vacuum vessel.