Majority and minority carrier transport in polysilicon emitter contacts

The minority hole transport in polysilicon emitter contacts has been studied with a novel pnp test transistor. Segregated arsenic at the polysilicon/silicon interface is mostly responsible for the base current reduction in polysilicon-contacted npn transistors. This improvement comes at a price of a higher emitter resistance. This resistance was measured with a Kelvin resistor structure and the base current/ emitter resistance trade-off is quantified.