The influence of gate-metallization potential drop on transient GTO characteristics

A surveillance instrument has been developed for the measurement of the excess-carrier distribution in GTO (gate turn-off thyristor) samples at all stages of operation. The instrument, an optical scanner, allows the visualization of the measurements as 3-D maps of the distributions for time- and space-resolved inspections of the electrical behavior of the component. The optical scanner was used to investigate whether the gate-metallization pattern resistance would influence the transient characteristics of the GTO components. The findings clearly show a strong dependence of turn-off behavior on lateral gate-metallization potential drop in a two-fingered structure.<
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