Ion generation method and ion source
AssigneeSumitomo Heavy Industries Ion Technology Co., Ltd.
InventorMasateru Sato
Life of this patent
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Abstract
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.
Claims14
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.
The ion generation method according to 1, further comprising exhausting, from the ion source, a compound gas produced by reaction between radicals and the material forming the liner.
The ion generation method according to 1, wherein the liner used in a reaction with ions is formed of a material including silicon or germanium.
An ion source comprising:
- an arc chamber formed of a high melting point material;
- a thermoelectronic emission unit configured to emit thermoelectrons in the arc chamber;
- a gas introduction port configured to guide a source gas into the arc chamber;
- a liner that is in contact with an inner wall of the arc chamber and configured to cover an inner wall of the arc chamber at least partially;
- and
- an opening configured to extract ions generated in the arc chamber,
- 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.
Dependencies are inferred from the claim text.