Scalable, Wide Bandgap Integrated Circuit Technology for Wide Temperature, Harsh Environment Applications

ABSTRACT: During this program, United Silicon Carbide (USCi), Inc. will develop basic analog and digital integrated circuit blocks capable of operation up to 350 oC, based on silicon carbide (SiC) complementary lateral Junction Field Effect Transistor (JFET) technology. In order to reduce the complexity of the fabrication process and to ensure better compatibility with the standard processes available in modern silicon fabs, we propose to develop a completely planar lateral JFET technology to realize a complementary JFET structure that would enable more efficient and faster logic architectures for digital and mixed signal high temperature capable integrated circuits. USCi will fully develop the fabrication technology and the associated process design kit (PDK) and demonstrate the technologys high temperature performance and reliability through fabrication of an operational amplifier and logic gates. Following our commercialization strategy, the fully planar fabrication process will be compatible with the processes available in modern silicon wafer foundries. This approach will create a high temperature capable, commercial integrated circuit technology that is suitable for high levels of integration and high volume manufacturing. BENEFIT: Harsh environment applications such as electrical actuation on military and commercial aircraft, advanced engine controls, downhole energy exploration, propulsion systems of hybrid and all electric vehicles, and space exploration require sensor interfaces, control circuits, and power systems require electronics capable of operating at high temperatures in excess of 200 oC. Electronic circuits based on silicon devices are generally not able to operate at temperatures above 210 C because of excessive junction leakage currents and limited operational lifetime and even the most advanced silicon-on-insulator (SOI) commercial products are rated at 225 C. Wide band-gap materials can be used to build devices capable of operation at significantly higher temperatures. SiC is the most mature wide band-gap material for high temperature circuit applications. Even when operating at the same temperatures as SOI circuits (200 C - 250 C), lower leakage currents and improved reliability are expected from circuits based on SiC. SiC wafers are also poised to move from 4-inch- to 6-inch size, opening up the possibility of using existing, low cost silicon fabs to implement SiC integrated circuits (ICs). Therefore, silicon carbide (SiC) is the ideal material for implementing high temperature ICs. The advanced engine controls market is not yet well established and one major reason distributed engine controls have not yet been realized in military or commercial applications is the extremely limited supply of ICs that can reliably operate above 250 C. There is a well-established market for high temperature electronics in the downhole oil & gas and geothermal industries. Trends towards deeper wells and more advanced drilling heads require electronics capable of higher operating temperatures while providing more reliable operation. For example, a modern drilling head costs tens of thousands of dollars and its lifetime can be greatly increased by using electronics for automatic control in the drill head rather than from an operator at the surface. There is also a very large potential market for automotive engine controls. The results of this program will enable ICs operating up to temperatures of 350 C to 500 C enabling further development of these systems.