The effect of substrate doping on the performance of anode-shorted n-channel lateral insulated-gate bipolar transistors

The performance of n-channel lateral-insulated-gate bipolar transistors (n-LIGBTs) with anode shorts on p/sup -/ epi/p/sup +/ substrates is compared to that of anode-shorted n-LIGBTs on p/sup -/ substrates, as well as to that of conventional n-LIGBTs on either substrate. It is shown that both forward-voltage drop and turn-off time are better for anode-shorted devices fabricated on p/sup -/ epi/p/sup +/ substrate than for those on p/sup -/ substrates, due to a larger percentage component of vertical bipolar current and a lower collector resistance. Forward-voltage drops of 3.05 and 3.3 V at 133 A/cm/sup 2/ and turn-off times of 400 and 750 ns have been measured for devices on p/sup -/ epi/p/sup +/ and p/sup -/ substrates respectively. All the LIGBTs showed current limiting at two to four times the ON-state conduction current during dynamic switching.<
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