Profiling the Boron Distribution in Asymmetric n~+-p Silicon Photodiodes and a New Concept for Creating Selectively Sensitive Photocells for Megapixel Color-Image Receivers

摘要

The spectral photosensitivity of n~+ - p silicon photodiodes with a p~+ layer implanted in the substrate is studied experimentally. It is demonstrated that such p~+ doping effectively shifts the long-wavelength edge of the photosensitivity in the optical spectral range and the shift depends on the depth of the p~+ layer. A new concept for creating selectively sensitive photocells for megapixel color-image receivers is proposed. The receivers are based on n~+-p photodiode structures containing a few layers that are implanted at different depths and form desired color-separating potential barriers and lateral diffusion channels for collection of the minority carriers generated by photons of different colors.