Test structures for analyzing radiation effects in bipolar technologies

Structures integrated onto BiCMOS test chips were specially designed to characterize the complex mechanisms related to radiation effects in bipolar technologies. Bipolar devices from two commercial processes were modified to include independent gate terminals. Through the use of gate control, the effects of radiation-induced defects on discrete bipolar devices and analog bipolar circuits can be analyzed independently, thereby facilitating a quantitative, experimentally verified, description of the non-linear relationship between the radiation defects and electrical response at both the device and circuit level.