The Effects of Neutron Irradiation on Germanium and Silicon

Recombination statistics for the neutron-induced base current component

“…The activation energy, ER' has been studied by several investigators, and the values determined [23][24][25][26][27] were in good agreement with that presented here. The current-…”

“…This component was identified by Goben and has the following expression One important limitation of transistors operated in a neutron environment is the decrease in transistor current gain observed upon exposure to neutron irradiation. The reduction in current gain results from the degradation of minority lifetime in the base region (i.e., to the resultant [14][15][16][17][18] reduction of the base recombination term ) and the re- 8-12 8-12 duction in the emitter efficiency In Goben's work have been noted for large charge3, 5-7. exp(qV/nkT) Bulk recombination-generation in the bulk n -1.5…”

“…Pr (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24) 2. when b = 1, it yields 4(VT-VBE 2 sinh ' 2kT…”

“…and calculating zl' z2 and b by equations (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) and (5-21 With m sets of data, (y., X..), the following model was then the multivariate least-squares fitting technique was used to determine a, B, y and 6 in equation (G-12). Finally, equation (G-12) was substituted into equation (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) to yield equation , it can be assumed that the density NR of the recombination centers is small compared to the equilibrium concentrations of carriers, n and p. Furthermore, it is assumed that the centers all lie at a dominant single energy value ER in the forbidden band.…”

“…Finally, equation (G-12) was substituted into equation (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) to yield equation , it can be assumed that the density NR of the recombination centers is small compared to the equilibrium concentrations of carriers, n and p. Furthermore, it is assumed that the centers all lie at a dominant single energy value ER in the forbidden band.…”