A displacement reaction source demonstrated for aluminum implantation and proposed for indium implantation

To date source technology has focused on the production of hot and bright plasmas. Subsequently, the literature generally describes simple systems utilizing gases that are dissociated in the source plasma or external vaporizers to produce metal vapors which are transported into the source plasma with carrier gases. This paper describes a displacement reaction approach which leverage the chemistry within a plasma source to generate the desired implant species. This source requires no vaporizer. Prior approaches for Al⁺ utilize AlCl ₃ as a source gas. This approach is shown to provide significant beam current utilizing Al₂O₃ as the source material situated within the source cavity. The Al is extracted using a fluorine plasma. The F⁺ displaces the oxygen in the aluminum oxide to create a volatile aluminum fluoride species. This volatile species is in turn dissociated in the source plasma, producing the Al⁺ ion. Application of this approach to indium ion production resulted in the generation of surprisingly high beam currents even in the absence of F⁺