Development of a novel kind of ion implanter

• Grant number: 11/17457-8
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Duration: January 15, 2012 - January 28, 2012
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Maria Cecília Barbosa da Silveira Salvadori
• Grantee: Maria Cecília Barbosa da Silveira Salvadori
• Visiting researcher: Ian Gordon Brown
• Visiting researcher institution: Pessoa Física - EUA, United States
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

In this project we propose develop and construct of a new type of ion implanter that will constitute a significant technological contribution. This device for ion implantation will be of interest to the ion source and ion implantation communities, worldwide. An ion implanter consists of an ion source for the production of the requisite ion beam which is located within geometry suitable to allow the energetic ions to bombard the implantation target. The ion energy may be acquired as part of the ion source extractor system, or by a post-extraction acceleration. The kind of ion source that is widely used for the production of high energy, broad, metal ion beams is the Mevva ion source (Metal vapor vacuum arc) and such systems are used worldwide for carrying out metal ion implantation. In the Mevva ion source, as in all present-day ion sources, the plasma (from which the ions are extracted) is held at high positive potential and thus when the ion beam is formed by the beam-forming electrodes, the ions acquire the energy given by the extractor voltage drop. The post-extraction energetic ions enter the main vacuum chamber in which the target is located, which is at ground potential. The hardware complication and the expense of this kind of traditional ion implanter is largely a result of having to float the plasma, together with all of the plasma formation electrical systems, to high voltage - the plasma (within the ion source) is at high (positive) potential and the chamber and target are at ground potential. In our proposed new setup we will invert this potential configuration, making a system in which the plasma and all its associated electrical systems are at ground potential while the chamber into which the beam is injected and the target at the end of the chamber are at high (negative) potential. We call this configuration an "inverted ion source". An implanter based on an inverted ion source can be vastly smaller, simpler and cheaper than with the usual "non-inverted" ion source configuration, but the trade-off is that the target must be held at high voltage. However, for the small target dimensions, typical of research needs, this is not a major disadvantage. (AU)