Preparation and application of neutron transmutation doped silicon for power device research

Very uniform phosphorus-doped high resistivity silicon suitable for power device research and production can be prepared using the thermal neutron activation of Si³⁰to produce P³¹[1], [2], [4]. Some aspects of this process are described here, and it is shown that the method is also suitable for rapid production of silicon with precise resistivity tolerances in relatively small quantities for R and D purposes. Some of the considerable advantages to be gained by using this material for research purposes are described. Detailed studies of blocking characteristics and of the relationship between Au concentration, carrier lifetime, and resistivity using spreading resistance are shown to be possible, whereas using standard floating zone silicon, the resistivity fluctuations present are too large to allow this.