Hot-carrier effects in polysilicon emitter bipolar transistors

The degradation of self-aligned, polysilicon emitter transistors is described for a wide range of constant current stress on several device sizes. The experimental results indicate that ΔI _B can be expressed as AQⁿ, with n=0.5 for these devices. Except for large values of I _R, A varies in a power-lay fashion with I _R. The dependence of ΔI_B upon the forward current at which the device is operating can be expressed as A=BJ^γ_C. It is observed that n is characteristic of all devices and stress currents, B is constant for a given device size, and γ varies with device size and reverse current