Light absorbing layer to enhance p-type diffusion for dti in image sensors

Abstract

In some embodiments, the present disclosure relates to a method for forming an integrated chip (IC), including forming a plurality of image sensing elements including a first doping type within a substrate, performing a first removal process to form deep trenches within the substrate, the deep trenches separating the plurality of image sensing elements from one another, performing an epitaxial growth process to form an isolation epitaxial precursor including a first material within the deep trenches and to form a light absorbing layer including a second material different than the first material within the deep trenches and between sidewalls of the isolation epitaxial precursor, performing a dopant activation process on the light absorbing layer and the isolation epitaxial precursor to form a doped isolation layer including a second doping type opposite the first doping type, and filling remaining portions of the deep trenches with an isolation filler structure.