Ultra-Fast-Turn-On Medium Power Double Thyristor

A medium power (80V, 50A pulsed) Silicon double thyristor with turn-on speed of 10ns range has been designed and fabricated. The integrated launching thyristor allows to trigger the device with a low signal of CMOS logic output range, so that the resulting gate turn-on charges are at least a factor of 1000 smaller than the equivalent power MOS transistor gate-control charges. The high tum-on sensitivity has given a possibility to increase and stabilize the holding current level via introducing the cathode shorting and thereby also assure natural turn-off of the thyristor for time intervals between current pulses. Numerical analysis by simulators DYNAMIT-1DT, 2DT has confirmed that the key factors for turn-on rise time minimization are the minority carrier diffusion transit times through the quasineutral regions of the p- and n-bases. Also it has been shown by simulations that the tum-on delay time is defined largely by the auxiliary thyristor and applied gate current only and the practically observed rise times are rather inductance-limited than device-limited. Design methodology for this medium power range differs from conventional Silicon high power (1000V-1000A) methodology, and in some respect resembles the of future downscaled SiC power devices design.