Investigation of noise characteristics of pn diodes by using a device simulator

The noise characteristics of pn diodes obtained using a partial differential equation (PDE) based device simulator with the transfer impedance method and the diffusion and the generation-recombination processes as the fundamental noise sources are investigated. From this approach, the noise behaviors over the entire operating region from the reverse to the very high forward bias regions for both long- and short-base diodes are obtained, and the results demonstrate good agreement with the previously reported data, except for the high forward bias region. A noise equivalent circuit model is introduced to explain the noise behaviors for that region and is proven to be useful for long-base diodes.