Measurement and compensation of piezoresistive coefficient /spl pi//sub 44/ for minority carrier concentration

The piezoresistive coefficient π44 for holes in the base of a PNP lateral transistor characterises the main source of the stress-induced changes in the saturation current in such a device. The authors show how this coefficient can be measured. Furthermore, it is shown that, when the common square or circular emitter geometry is applied, most of the piezojunction effect is inherently compensated for.