Apparatus and methods for shielding integrated circuitry
Systems and methods are provided for shielding integrated circuits from electromagnetic or electrostatic fields by locating an active device layer between two conductors that are electrically coupled together. In certain embodiments, a sensor comprises a conductive substrate that provides structural support and shielding to circuit elements in a semiconductor device layer. The device layer is between the conductive substrate and a shield layer that are electrically coupled together to create a shield or “Faraday box.” In certain embodiments, the device layer is substantially isolated from the conductive substrate and the shield layer by insulative layers. In certain embodiments, an input voltage powers the device layer and is also coupled to the substrate and the shield layer. Thus, the conductive substrate and the shield layer absorb and/or repel electrostatic charges or ions in a medium surrounding the sensor.
1. An electronic device comprising:
a conductive substrate including a cut-out region fluidly coupled to a substantial vacuum having a pressure of approximately zero;
a first insulative layer over at least a portion of the substrate;
a device layer over the first insulative layer, the device layer comprising a plurality of electrically conductive elements including a plurality of resistive elements electrically coupled together through conductive lines, the electrically conductive elements forming a resistive network;
a second insulative layer over the device layer; and
a conductive shield layer over the second insulative layer, the shield layer electrically coupled to the substrate.
2. The electronic device of claim 1 , wherein the conductive substrate comprises a doped semiconductor material.
3. The electronic device of claim 2 , wherein the doped semiconductor material comprises silicon.
4. The electronic device of claim 1 , wherein the first insulative layer comprises a dielectric layer.
5. The electronic device of claim 4 , wherein the dielectric layer is below a top surface of the substrate.
6. The electronic device of claim 1 , wherein the shield layer is over a substantial portion of the electrically conductive elements.
7. The electronic device of claim 1 , wherein the second insulative layer comprises a dielectric layer.
8. The electronic device of claim 1 , wherein the shield layer comprises a metallic layer or a conductive semiconductor layer.
9. The electronic device of claim 1 , wherein the device layer is electrically coupled to the substrate and the shield layer.
10. The electronic device of claim 9 , wherein the device layer has a voltage applied thereto, and the substrate and the shield layer each have the voltage applied thereto.
11. The electronic device of claim 1 , further comprising:
a first voltage electrically coupled to the device layer; and
a second voltage electrically coupled to the substrate and the shield layer.
12. The electronic device of claim 1 , wherein the resistive network comprises a Wheatstone bridge.
13. The electronic device of claim 1 , wherein the shield layer comprises a plurality of sections.
14. The electronic device of claim 13 , wherein the plurality of sections are sized and positioned so as to cover the resistive elements without covering the entire device layer.
15. The electronic device of claim 11 , wherein the second voltage comprises ground potential.