Ion sources for ion implantation apparatus

An ion implantation apparatus including an ionization chamber having a gas inlet port and an outlet through which ions created in the chamber can exit the chamber, the chamber containing an ion source body comprising a material selected from the group consisting of aluminium, aluminium nitride, magnesium, magnesium oxide, magnesium nitride, indium, indium oxide, indium nitride, and refractory metals, and compounds thereof, capable of providing ions intended for implantation, a source of etchant gas selected from the group consisting of nitrogen trifluoride, boron trifluoride, fluorine and sulphur hexafluoride under pressure connected to the inlet port of the chamber, and an energy source to ionize etchant gas in the chamber and thereby to form a plasma containing ions of aluminium derived from said ion source body.

A method of generating aluminium ions for implantation into a substrate mounted in an ion implantation apparatus, the method comprising placing a preformed body of solid alumina as ion source material in an ionization chamber, supplying a gas selected from the group consisting of fluorine and sulphur hexafluoride to the chamber to contact the ion source material, generating a plasma in the ionization chamber to cause dissociation and ionization of the ion source material and the gas, and extracting the resultant aluminium ions from the ionization chamber for implantation.

A method of generating ions for implantation into a substrate mounted in an ion implantation apparatus, the method comprising placing a preformed body of solid ion source material, selected from the group consisting of aluminium nitride, magnesium, indium and oxides and nitrides thereof, and refractory metals and oxides and nitrides thereof, all capable of providing ions intended for implantation, in an ionization chamber, the ion source material being in the form of a preformed solid which at least partially lines the interior of the chamber, supplying a gas selected from the group consisting of nitrogen trifluoride, boron trifluoride, fluorine and sulphur hexafluoride to the chamber to contact the solid ion source material, generating a plasma in the ionisation chamber to cause dissociation and ionisation of the source material and the gas, and extracting the resultant ions from the ionisation chamber for implantation, the ion source material and the etchant gas being selected such that no additional ions are created having the same or similar charge/mass ratio to that of the selected ions.