Silicon Carbide High-Temperature Power Rectifiers Fabricated and Characterized

Lewis' HTIES group recently fabricated and characterized high-temperature SiC rectifier diodes whose record-breaking characteristics represent significant progress toward the realization of advanced high-temperature actuator control circuits. The first figure illustrates the 600 °C probe- testing of a Lewis SiC pn-junction rectifier diode sitting on top of a glowing red-hot heating element. The second figure shows the current-versus-voltage rectifying characteristics recorded at 600 °C. At this high temperature, the diodes were able to "turn-on" to conduct 4 A of current when forward biased, and yet block the flow of current ($quot;turn-off") when reverse biases as high as 150 V were applied. This device represents a new record for semiconductor device operation, in that no previous semiconductor electronic device has ever simultaneously demonstrated 600 °C functionality, and 4-A turn-on and 150-V rectification. The high operating current was achieved despite severe device size limitations imposed by present-day SiC wafer defect densities. Further substantial increases in device performance can be expected when SiC wafer defect densities decrease as SiC wafer production technology matures.

Current versus voltage-rectifying characteristics of a 4-A, 150-V SiC diode measured at 600 °C.










SiC rectifier diode being probe-tested at 600 °C. The circular heating element and the square, 5- by 5-mm SiC chip are both glowing red hot.