Epitaxial emitter reverse saturation current density: Modeling and experimental validation

Through numerical simulation we explore the sensitivity of the emitter reverse saturation current density (J_0e) to surface recombination velocity (SRV) of a uniformly doped phosphorus emitter compared with gaussian profile with similar sheet resistance. The uniformly doped emitter is capable of extremely low J_0e's of <; 10 fA/cm², but is very transparent and thus extremely sensitive to the surface recombination velocity. While the gaussian profile cannot reach as low recombination, it is however more resilient to higher SRV's. Finally, we experimentally demonstrate a 2 fA/cm² total device J₀ on a test structure with the same epi emitter explored in the previous simulations.