BSI METHOD OF FORMING SELF ALIGNED GRIDS IN BSI IMAGE SENSOR

摘要

A method of fabricating self-aligned grids in a BSI image sensor is provided. The method includes depositing a first dielectric layer over a back surface of a substrate having a plurality of photodiodes formed therein, forming a grid of trenches, and filling the trenches with a dielectric material to form a trench isolation grid. include Here, a trench extends through the first dielectric layer into the substrate. The method also includes etching back dielectric material in the trenches to a level that is below a top surface of a first dielectric layer to form recesses covering the trench isolation grid, and a metallic grid aligned with the trench isolation grid. and filling the recesses with a metallic material to form