Patent ID: 8356575

Claim:
An ion source, comprising: a plasma generating chamber; a partition wall made of a dielectric material and partitioning the plasma generating chamber, the partition wall having a projection; a high-frequency antenna having a winding and installed at an external portion of said partition wall for generating a plasma in the plasma generating chamber; and a shield body installed inside the plasma generating chamber the shield body made of a dielectric material, covering the inner surface of the partition wall, and having at least one slot formed therein in a direction crossing a winding direction of the high-frequency antenna, wherein the projection is made of a dielectric material and formed on at least one part of the inner surface of the partition wall and extended in a direction crossing a winding direction of the high-frequency antenna, and wherein the shield body has a groove formed on an outer surface thereof to accommodate the projection, the groove formed at a position opposite to the projection in a radial direction of the high-frequency antenna.