LAUSR

ABSTRACT The response to transient irradiation of npn SiGe HBT (BG35 SiGe BiCMOS), i.e. device under test (DUT) was studied with online measurement of 1 MeV equivalent pulse neutron fluence of 0.8 × 1013n/cm2. The differently biased DUT1 and DUT2 in test circuit were irradiated in the first day with neutron fluence (0.8 × 1013n/cm2) termed as Fluence1 and with an additional neutron fluence (0.8 × 1013n/cm2) in the second day to make Fluence2 equals to 1.6 × 1013n/cm2. The experimental results show that pulsed neutron irradiation causes voltage surges in the DUTs exhibited by a negative and positive peak known to be radiation damage (RD). The RD in DUTs induced by pulse neutron Fluence1 initially created unstable displacement defects and the defects later reordered (cluster defects) to form more stable configurations via neutron Fluence2. The irradiated DUTs experienced online instantaneous annealing after 2.03 × 10−9 s and offline measurement (i.e. without irradiation) of DUTs showed recovery to normal mode of operation after 24 h annealing. The level of pulse peaks in the base voltage terminals of DUT1 and DUT2 were compared as Vb2Fluence1 > Vb1Fluence1 and Vb2Fluence2 > Vb1Fluence2. A comprehensive analysis of RD region in DUTs with reference to Area (A1, A2), Peak (P1, P2), Height (H), and Full width at half maximum (FWHM) were investigated.