Normally-off type high speed SI-Thyristor

The design, fabrication, and characterization of a normally-off type static induction thyristor (SIThy) with a surface gate structure were made with an intention to use it in high speed switching at high currents. The device chip had a size of 7 × 10 mm²and included 9,000 channels, where each channel stripe had a width of 1.5 m and a length of 250 m. The double LOCOS technique was used in the fabrication process of the device. By mounting the chips in specially designed packages, a very low forward voltage drop of 1.2 V at 100 A and a high switching speed of 300 ∼ 600 nsec in turn-on and turn-off times were obtained. A bipolar mode static induction transistor (BSIT) was also made by using the same photomasks and the same fabrication process as SIThy. It also exhibited a low forward voltage drop of 0.7 V at 100 A and a high switching speed of 100 ∼ 200 nsec in turn-on and turn-off times.