High-performance TTL bipolar integrated circuits in 4H-silicon carbide.

摘要

The focus of this work is on robust high speed intelligent power electronics, i.e. power electronics that provide increased survivability due to the robust nature of the system components. Silicon carbide (SiC), due to its wide bandgap and superior physical properties, is an attractive material for applications in harsh environments especially high temperature electronics applications. An ideal device for these applications is the bipolar junction transistor (BJT). To exploit the full temperature capabilities of SiC, this work entails an exploratory development effort to investigate and create monolithic bipolar integrated circuits (ICs) capable of robust operation at temperatures above 300°C. These circuits will be suitable for small-scale integration applications in smart power, aerospace, automotive, and well logging applications.;For this research, various types of bipolar technologies are studied and analyzed. Simulation models are created for the bipolar transistor and are used to simulate the behavior of the circuits. ICs are designed in order to achieve excellent DC characteristics with high-speed capability. Transistor-Transistor Logic (TTL) technology is used for all ICs owing to its excellent DC and high-speed characteristics. To achieve high speeds, semi-insulating substrates are used and the design of the basic TTL gates is optimized. The fabricated ICs include basic logic gates with fan-outs of one and ten, an 11-stage ring oscillator, a D flip-flop, and a half adder. These circuits are characterized over a wide range of supply voltages and temperatures, with results demonstrating the potential of bipolar integrated circuits in SiC for small-scale, high temperature applications.