Abstract: A novel p-SiC/n-Si heterostructure negative-differential-resistance (NDR) diode with special current-voltage (I-V) characteristics is reported. Under reverse biases, the I-V curve of this device possesses an N-shaped NDR with a high peak-to-valley current ratio (PVCR) and a broad high-impedance valley region. For use as a switch, it can easily achieve a very low off-state current and a high on/off current ratio, as compared to the conventional N-shaped NDR devices. Hence, performance with a more effective switching action and lower power dissipation can be expected. Furthermore, obvious NDR's can even be obtained at a temperature up to 300/spl deg/C, indicating this device is also potential for high-temperature applications.