Bipolar circuit design techniques for thermally stable and high-speed amplifiers

The adoption of advanced isolation techniques such as fully Dielectric Isolation (DI) or trench isolation reduces the parasitic capacitance to aid the design of high-speed transistors, but increases self-heating effects due to the poor thermal conductivity of silicon dioxide. In the first part of the thesis, such a complementary bipolar process X4 developed by National Semiconductor is used to design and fabricate high-speed and high slew-rate current-feedback (CFOA) and voltage-feedback (VFA) amplifiers having greater stability with capacitive loads. DC characterization and scaling effects for the X4 process devices is verified using spice gummel-poon and VBIC (vertical bipolar intercompany) bipolar models. Analytical and spice based macromodels for the current-feedback amplifier are developed and the effect of internal parameters like impedances, biasing currents and devices sizes on overall amplifier performance is studied. With these concepts, a high-speed voltage-feedback amplifier is designed by combining the CFOA and VFA topologies in order to integrate their advantages in a single design. In the second part, different layout structures as explained below were developed, fabricated and tested, to measure the thermal resistance and self-heating effects in the X4 process devices. (Abstract shortened by UMI.)...