Vaporiser for generating feed gas for an arc chamber

• Main Authors: POVALL SIMON, BURGIN DAVID RICHARD, PONTEFRACT JOHN, KING MICHAEL J
• Format: Patent
• Language: English
• Published: 02.10.2003
• Edition: 7
• Subjects: AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUSPOLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR; BASIC ELECTRIC ELEMENTS; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; CRYSTAL GROWTH; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; REFINING BY ZONE-MELTING OF MATERIAL; SEMICONDUCTOR DEVICES; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITHDEFINED STRUCTURE; SINGLE-CRYSTAL-GROWTH; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL ORUNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL

A vaporiser generating feed gas for the arc chamber of an ion source has a crucible which is heated to a temperature at which material in the crucible sublimes to produce a vapour for use as the feed gas. In addition to the heating element for heating the crucible, there is a cooling element in the form of a cooling duct extending along the length of the crucible for receiving the cooling fluid. Forced cooling of the crucible when the heating element is switched off enables the crucible to be cooled more quickly so that the supply of a feed gas can be terminated sooner. This is important if an ion source is being switched from one feed gas to another. Also, the crucible may be forced cooled simultaneously while energising the heating element to enable the crucible to be accurately controlled at a lower operating temperature if desired.