Patent ID: 9659749
Date: 2017-05-23
CPC Classifications: H01J

Claim:
1. A beam extraction slit structure of an ion source plasma chamber adjacent to an extraction electrode, the extraction electrode positioned across a gap from an elongated slit of the beam extraction slit structure in a beam extraction direction, the elongated slit arranged along a slit longitudinal direction perpendicular to the beam extraction direction, the beam extraction slit structure comprising: a plasma chamber interior surface that is, in operation, in contact with a plasma; a plasma chamber exterior surface that faces the extraction electrode; and an elongated slit surface that extends from the interior surface to the exterior surface in the beam extraction direction to define the elongated slit, the elongated slit surface including a plasma meniscus fixing part formed in a center of the elongated slit in the slit longitudinal direction to fixingly maintain a plasma meniscus of the plasma and a plasma meniscus non-fixing part formed in an end of the elongated slit in the slit longitudinal direction to movably maintain the plasma meniscus of the plasma in the beam extraction direction.