SiC Materials And Devices, Volume 1
With contributions by recognized leaders in SiC technology and materials and device research, this book gives a comprehensive, up-to-date review of silicon carbide materials properties and devices.
TABLE OF CONTENTS SiC Materials And Devices, Volume 1
4: Turn-Off Performances
4 Turn-Off Performances
There are three ways to turn the thyristor off. Any thyristor structure can be turned-off if cathode-anode bias reduces to the value at which the cathode-anode current is smaller than the holding current I h Gate turn-off thyristors (GTOs) can be turned-off by appropriate current pulse applying to the controlling gate electrode (conventional GTO mode). The third way to switch off a GTO is to short-circuit the gate and the anode (cathode) of the structure using low-resistance channel of field effect transistor (FET controlled mode). The second and third techniques provide the most effective, convenient and fast ways to turn the thyristor off.
4.1 Conventional Turn-Off GTO Mode
Conventional gate turn-off operation in SiC thyristors was studied for the first time in low-voltage (100 V) 6H-SiC thyristors in Ref. [54]. The doping level in the n-type blocking base was approximately 3 l0 15 cm ?3, the operation area S was 3.5 l0 ?4 cm 2. The turn-off time t off of less than 100 ns was achieved, and very high frequency operation up to 600 kHz (at current density 30A/cm 2) was realized.
The gate turn-off operation in 600-800 V 4H-SiC thyristors with p-type blocking base was studied in Refs. [81] [82]. The t off of less than 1 ?s (at current density 800 A/cm 2) was observed in Ref. [81]. In addition to the voltage blocking capability, turn-off time, and holding current, the...
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