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.