Characterisation of extended life ion source in Eaton's NV-8250 medium current ion implanter

In this work a comparison of the indirectly heated cathode extended life source (ELS) relative to the enhanced Bernas source (EBS) has been carried out in the medium current regime typical of the Eaton's 8250. Particular attention has been paid to BF/sub 2/(49)-B(11) fractions for beams of different arc power for both high pressure and enriched BF/sub 3/ gases. Results clearly show a much more effective performance of the ELS where about 60% lower arc power is required to achieve the same beam current of an EBS. This is related to the different BF/sub 2/(49)-B(11) relative amounts produced in the two arc chambers, when the same arc power is used. A similar investigation for safe delivery system (SDS) phosphine and arsine gases was also performed. The present evaluation allowed us also to determine the different optimum arc condition to be used in running B/sup +/ and BF/sub 2//sup +/ beams which in turn results in even longer source life.