FORMING IMPLANTED PLATES FOR HIGH ASPECT RATIO TRENCHES USING STAGED SACRIFICIAL LAYER REMOVAL

摘要

A method of forming a deep trench structure for a semiconductor device includes forming a mask layer over a semiconductor substrate. An opening in the mask layer is formed by patterning the mask layer, and a deep trench is formed in the semiconductor substrate using the patterned opening in the mask layer. A sacrificial fill material is formed over the mask layer and into the deep trench. A first portion of the sacrificial fill material is recessed from the deep trench and a first dopant implant forms a first doped region in the semiconductor substrate. A second portion of the sacrificial fill material is recessed from the deep trench and a second dopant implant forms a second doped region in the semiconductor substrate, wherein the second doped region is formed underneath the first doped region such that the second doped region and the first doped region are contiguous with each other.