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The Basics of SiC: Unique Properties of Silicon Carbide By Paul Golata, Mouser Electronics | 4 | Silicon carbide (SiC) has been in use since the late 1800s, beginning as an abrasive material and later finding applications in a wide variety of industries, including semiconductors (Figure 1). Today's wide-ranging use of SiC is a natural consequence of the material's extraordinary physical attributes. SiC gets employed in bulletproof vests, ceramic plates, thin- filament pyrometers, foundry crucibles, and car clutches. This article will look at some of the unique properties that make SiC beneficial for use in semiconductor applications. Wide Bandgap Bandgap refers to the energy difference between the top of the valence band and the bottom of the conduction band. A bandgap represents the amount of energy measured in electron volts (eV) needed for an electron to successfully make the jump between the top of the valence band and the conduction band. Because semiconductors can both conduct and insulate, they will always have a non-zero bandgap that lies somewhere between what you would see with an insulator and a conductor. The bandgap of SiC is 3.26eV, compared to that of silicon (Si) at 1.12eV and gallium arsenide (GaAs) at 1.42eV. Therefore, SiC is referred to as having a wide bandgap (WBG). Wide bandgap semiconductor materials offer several advantages. Bandgaps shrink as temperatures rise. Employing wide bandgap materials in semiconductors means that rising temperatures will have far less effect on functionality. Because SiC has a wide bandgap, it can continue to function in much higher temperatures, often up to 400°C. Because SiC has a high energy bandgap, it is incredibly resistant to electromagnetic disturbances and the damaging effects of radiation. Components made from SiC are also faster, smaller, and Figure 1: Silicon carbide (SiC), also known as carborundum, is a semiconductor containing silicon and carbon.

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