Ion generation method and ion source

摘要

An ion generation method uses a direct current discharge ion source provided with an arc chamber formed of a high melting point material, and includes: generating ions by causing molecules of a source gas to collide with thermoelectrons in the arc chamber and producing plasma discharge; and causing radicals generated in generating ions to react with a liner provided to cover an inner wall of the arc chamber at least partially. The liner is formed of a material more reactive to radicals generated as the source gas is dissociated than the material of the arc chamber.

主权项

1. An ion generation method using a direct current discharge ion source provided with an arc chamber formed of a high melting point material, comprising:
generating ions by causing molecules of a source gas to collide with thermoelectrons in the arc chamber and inducing plasma discharge; extracting ions generated in the arc chamber from an opening; causing radicals generated in generating ions to react with a liner in contact with an inner wall of the arc chamber and provided to cover the inner wall of the arc chamber at least partially, wherein the liner is formed of a material more reactive to radicals generated as the source gas is dissociated than the material of the arc chamber, and the arc chamber is provided, in a part of the arc chamber inner wall opposite to the opening, with a first exposed area not covered by the liner, and provided, in a neighborhood of the opening, a second exposed area of the inner wall not covered by the liner, the liner is provided, in a part of the inner wall formed with the opening, with a lined part covering a neighborhood of the second exposed area, and the lined part is disposed between a plasma generated in the arc chamber and the inner wall formed with the opening.