SiC bipolar integrated circuits on semi-insulating substrates

Because of its wide bandgap, silicon carbide is attractive for applications in harsh environments, especially high temperature applications. The intrinsic carrier concentration in 4H-SiC is about 10
⁻⁸
cm
⁻³
at room temperature, and only 2×10
¹¹
cm
⁻³
at 600 °C. Thermal generation currents are negligible in SiC, even at high temperatures, and the intrinsic temperature of SiC is above 900 °C. As a result, the upper temperature of SiC devices is limited by the stability of the associated metallurgy or dielectrics, rather than by the semiconductor. One of the most severe limitations is imposed by the SiO
2
gate insulator in MOS devices, which limits their maximum operating temperature to about 200 °C. For applications above 200 °C, bipolar devices are required. In this work we report the performance of second-generation bipolar integrated circuits in 4H-SiC. These circuits are suitable for small-scale integration applications in smart power, aerospace, automotive, and well logging applications.