Behaviour of punch-through and non-punch-through insulated gate bipolar transistors under high temperature gate bias stress

Abstract

The work presented in this paper is concerned with the effects of a high temperature gate bias (HTGB) stress on punch-through (PT) and non-punch-through (NPT) insulated gate bipolar transistors (IGBTs). A selection of PT IGBTs and a selection of NPT IGBTs all of the same nominal range were gate biased at their maximum gate-to-emitter voltage with drain and emitter short circuited at 140 /spl deg/C during 1200 hours. A particular interest was taken in the switching parameters. The turn-on delay time t/sub don/ increases for the PT IGBTs while it decreases for the NPT IGBTs. The switching losses and the rise time increase for the two technologies. The turn-off delay time monotonically decreases for both the PT and NPT IGBTs. The fall time decreases for the PT IGBTs whereas it increases but in a less important way for the other technology. The on state voltage drop increases in both cases and in a more important way for the PT IGBTs. The gale threshold voltage is quiet insensitive to this type of stress for the NPT IGBTs whereas it increases during the first hundred hours of stress and remains unchanged thereafter for the PT IGBTs. The gate leakage current increases strongly for the two technologies while the collector leakage current, such as the threshold voltage, increases to remain constant after some hours of stress for the PT IGBTs.