Measurement of Neutral Base Lifetime in Neutron-Irradiated Transistors

New data are reported for the neutral bulk lifetime of electrons in neutron-irradiated p-type silicon. The measurements are made in special uniform-base transistors and n+p gated diodes. The resistivity range of 0.2 to 9¿-cm is covered. In the higher resistivity samples, injection levels of slightly greater than unity are achieved. A range of neutron fluences from 1013 to 1015 n/cm2 (E > 10 keV) is examined and the lifetime damage constant is found to be fluence independent. The data are compared with previous bulk and solar cell measurements.