Apparatus having overlapping deep trench and shallow trench with low defect density, and its manufacturing method

摘要

A method (200) for fabricating conductive deep trenches relative to shallow trench isolation in semiconductor devices.The method to be described is the deep trench etched (230) and filled (240) before the shallow trench is etched (210) and introduced (220) an integrated sequence.The method described advantageously reduces cone defects and process complexity associated with the formation of conductive deep trenches in shallow trench isolation structures.Fabricated in an integrated sequence, the conductive deep trench can extend into the substrate through the shallow trench dielectric layer, where there is substantially no cone on the top surface of both the conductive deep trench and the shallow trench dielectric layer.