System to Measure Semiconductor Characteristics over Decades of Time after a Radiation Pulse

The system described in this paper generates a set of semiconductor device driving pulses, logarithmic in time, which are used to display a sequence of characteristic responses on a scope. The system is especially suited for damage annealing studies following a radiation (neutron, gamma, electron) pulse. The sequence of measurements begins as soon as 50ns after the beginning of the radiation pulse and can be terminated after milliseconds, seconds, hours, or even a day. This is the only system known which can produce this range of times on a single oscilloscope picture. Representative data from experiments designed to measure the turn-on characteristics of a MOSFET following electron irradiation, the DC gain (hfE) of a 2N2222-A transistor following electron irradiation, and the fast beta annealing of transistors following a 14 MeV neutron burst, are given.