MULTIPLE LAYER STRUCTURE FOR SUBSTRATE NOISE ISOLATION

摘要

A method of forming a semiconductor structure, comprising: providing a substrate having a buried insulative layer and a heavily doped layer; forming a first trench within the substrate around a protected area; filling the first trench with an insulative material, wherein the first trench filled with the insulative material and the buried insulative layer combine to form a high impedance noise isolation that surrounds the protected area on all sides except one side of the protected area to isolate noise from the protected area; forming a second trench within the substrate around the first trench; and filling the second trench with a conductive material, wherein the second trench filled with the conductive material and the heavily doped layer combine to form a low impedance ground path that surrounds the high impedance noise isolation on all sides except one side of the high impedance noise isolation to isolate noise from the protected area.