Abstract: This invention is basically related to an insulated gate bipolar transistor comprising a first conductivity type semiconductor substrate, a second conductivity type semiconductor layer formed on the substrate and having a low concentration of impurities, a first conductivity type base layer formed on a surface of the semiconductor layer, a second conductivity type source layer formed on the surface of the base layer and having a channel region at at least one end thereof, a gate electrode, a source electrode and a drain electrode, and is characterized in that a voltage dropping portion is provided either inside the source layer or between the source layer and the source electrode. Accordingly an insulated gate bipolar semiconductor transistor having this configuration can prevent a latch up phenomenon caused by a voltage drop in a source layer.

Abstract: A thermoelectric generating composite functioning apparatus used as a glow plug in a diesel engine has sintered semiconductor elements respectively formed in the shape of a bar of N-type and P-type thermoelectric semiconductor materials. The N-type and P-type semiconductor elements are provided oppositely with a gap between them, and their end portions are put in mutual contact to form a P-N junction. A low thermal conductivity insulator is filled in the interval between the N-type and the P-type semiconductor elements. The N-type and P-type semiconductor elements provided in the P-N junction state are contained through the insulator in a housing. Lead terminals connected to the N-type and P-type semiconductor elements are formed in the housing. The apparatus may provide heat to the combustion chamber, or generate electricity from the heat in the combustion chamber.