Test structures for analyzing proton radiation effects in bipolar technologies

Structures integrated onto a BiCMOS test chip are specially designed to characterize the complex mechanisms related to proton radiation response in bipolar technologies. Bipolar devices from a commercial process are modified to include independent gate terminals. Through the use of gate control, the effects of proton-induced defects on discrete bipolar devices and analog bipolar circuits can be analyzed independently, thereby facilitating a quantitative description of the nonlinear relationship between the radiation defects and electrical response at both the device and circuit level. Index Terms--Base current, bipolar junction transistors, bulk traps, displacement damage, high-energy protons, input bias current, interface traps, ionizing radiation, oxide trapped charge, surface recombination.