Space Radiation Aspects of Silicon Bipolar Technologies

Abstract

Bipolar Junction Transistors (BJT) have important applications in analog or mixed signal ICs and BiCMOS (Bipolar Complementary Metal-Oxide-Semiconductor) circuits because of their current-drive capability, linearity, low noise and excellent matching characteristics. Furthermore, their microwave performance compares favorably with respect to CMOS, explaining the use in GHz telecommunications applications and low-cost system-on-chip (SOC) solutions. The implementation of a SiGe heterojunction base will further push the penetration of BiCMOS in the microwave IC market. In addition, BJTs are frequently used in space systems, including operational amplifiers, comparators and voltage regulators, in order to accomplish analog functions. Early generations of BJT based circuits mainly suffered from radiation-induced leakage currents associated with the degraded field-oxide isolation regions. However, solutions for these problems have been implemented in present-day technologies, so that other degradation mechanisms have become more important. In this chapter, an overview will be given related to radiation damage in submicron BJTs and HBTs. First the different type of device ar-chitectures (vertical, substrate, lateral BJT) will be briefly defined and the basic degradation mechanisms described. In Sect. 5.3, focus is on the radiation effects in vertical n-p-n BJTs, while Sect. 5.4 covers the radiation degradation in lateral and substrate BJTs. Sect. 5.5 is devoted to the radiation response of SiGe HBTs, while in the last section, some conclusions will be drawn.