Multiple layer structure for substrate noise isolation

A method of forming a semiconductor structure, comprising:

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

A semiconductor structure, comprising:

• a substrate having a burial insulative layer;
• a first heavily doped layer within the substrate beneath the buried insulative layer;
• a first trench within the substrate around a protected area, wherein the first trench is filled with a first insulative material, wherein the first trench filled with the first insulative material and the buried insulative layer combine to form a first 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;
• a second trench within the substrate around the first trench, wherein the second trench is filled with a first conductive material, wherein the second trench filled with the first conductive material and the first heavily doped layer combine to form a low impedance ground path that surrounds the first high impedance noise isolation on all sides except one side of the first high impedance noise isolation to isolate noise from the protected area;
• and
• a third trench within, the substrate around the second trench, wherein the third trench is filled with a second insulative material, and wherein the third trench filled with the second insulative material forms a second high impedance noise isolation around the low impedance ground path.

A semiconductor structure, comprising:

• a substrate having a buried insulative layer;
• a first heavily doped layer within the substrate beneath and in direct physical contact with a bottom surface of the buried insulative layer;
• a semi-conductive layer on a top surface the buried insulative layer such that a bottom surface of the semi-conductive layer is in direct contact with a top surface the buried insulative layer;
• and
• a first trench in only the semi-conductive layer and extending through a total thickness of the semi-conductive layer, wherein the first trench surrounds a protected area consisting of a portion of the semi-conductive layer, wherein the first trench is filled with a first insulative material, and wherein the first trench filled with the first insulative material and the buried insulative layer combine to form a high impedance noise isolation that surrounds and is in direct physical contact with the protected area on all sides except one side of the protected area to isolate noise from the protected area.