Radiation-Blocking Structures

• US 20140026653A1
• Filed: 03/14/2013
• Published: 01/30/2014
• Est. Priority Date: 07/25/2012
• Status: Active Grant

• Current Assignee: Silicon Laboratories Incorporated
• Original Assignee: Silicon Laboratories Incorporated
• Inventors: Del Signore, Bruce P., O'Connell, John O.
• Granted Patent: US 9,287,219 B2
• Time in Patent Office: Days
• US Class Current: 73/335.04
• CPC Class Codes: G01D 11/245 Housings for sensors
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Stacked layers of non-continuous opaque layer structures are disclosed herein that may be configured to block radiation such as visible light or other forms of light, while at the same time allowing penetration of ambient gases. In one example, such non-continuous opaque layer structures may be configured as stacked non-continuous metal layer structures that together fully block penetration of radiation while at the same provide sufficient open spaces between and/or within the metal layer segments of a given integrated circuit layer to meet maximum metal spacing rules. In another example, such non-continuous opaque layer structures may be configured as capacitive structures.

Claims

1. A multi-layer semiconductor device, comprising:

a first device layer including one or more non-continuous first radiation-opaque layer structures defining radiation transmissive areas in the first device layer; and

a second device layer underlying the first device layer, the second device layer including one or more non-continuous second radiation-opaque layer structures defining radiation transmissive areas in the second device layer;

where the first non-continuous opaque structures of the first device layer are cooperatively spaced in overlapping relationship with the second non-continuous opaque structures of the second device layer to form a continuous barrier that completely blocks all radiation that impinges on the first device layer from above the semiconductor device from penetrating through the combination of the first and second device layers of the multi-layer structure.

2. The semiconductor device of claim 1, further comprising a third device layer disposed between the first and second device layers, the third device layer comprising radiation-transmissive dielectric material;

and where each of the first and second non-continuous opaque structures comprise non-continuous metal structures.

3. The semiconductor device of claim 2, where the semiconductor comprises a gas sensor device;

where the first non-continuous opaque structures of the first device layer comprise sensor electrodes for the gas sensor device; and

where the second non-continuous opaque structures of the second device layer comprise ground planes.

4. The semiconductor device of claim 2, where the first non-continuous opaque structures of the first device layer together comprise at least one top plate of a metal-insulator-metal (MIM) capacitor with one or more radiation-transmissive openings defined therein;

where the second non-continuous opaque structures of the second device layer together comprise at least one bottom plate of the MIM capacitor with one or more radiation-transmissive openings defined therein.

5. The semiconductor device of claim 1, where the blocked electromagnetic radiation comprises at least one of sunlight, artificial light, ultraviolet radiation, infrared radiation, or a combination thereof.

6. The semiconductor device of claim 1, further comprising one or more additional device layers underlying the third device layer, the additional device layers having radiation-sensitive active circuitry formed therein;

where the first non-continuous opaque structures of the first device layer are cooperatively spaced in overlapping relationship with the second non-continuous opaque structures of the second device layer to form a continuous barrier that completely blocks all radiation that impinges on the first device layer from above the semiconductor device from penetrating further into the semiconductor device to the underlying radiation-sensitive circuitry.

7. The semiconductor device of claim 6, where the semiconductor comprises a gas sensor device;

where the first non-continuous opaque structures of the first device layer comprise sensor electrodes for the gas sensor device; and

where the second non-continuous opaque structures of the second device layer comprise ground planes.

8. The semiconductor device of claim 7, further comprising a radiation-opaque package surrounding the multiple device layers of the gas sensor device with a radiation-transmissive opening being defined in the package over the gas sensor electrodes and underlying ground planes and radiation-sensitive circuitry, the opening being configured to expose the gas sensor electrodes to ambient conditions outside the package.

9. A capacitive gas sensor, comprising:

a gas sensitive material, the gas sensor configured to allow the exposure of the gas sensitive material to a gas;

first non-continuous radiation-opaque structures comprising spaced metal capacitor electrodes of a capacitive sensor cell provided in a first device layer, the capacitive sensor cell being electrically coupled to at least a portion of the gas sensitive material;

second non-continuous radiation-opaque structures comprising one or more metal non-continuous ground planes in a second device layer underlying the capacitor electrodes; and

lower level circuitry underlying the capacitive electrodes and ground planes of the first and second device layers;

where the gas sensor is configured to utilize a detected capacitance between the electrodes of the capacitive sensor cell to obtain a gas sensor measurement; and

where the capacitor electrodes of the first device layer are cooperatively spaced in overlapping relationship with the non-continuous ground planes of the second device layer to block impinging light from further penetration into the lower level circuitry.

10. The gas sensor of claim 9, further comprising a third device layer disposed between the first and second device layers, the third device layer comprising radiation-transmissive dielectric material.

11. The gas sensor of claim 9, further comprising a radiation-opaque package surrounding the multiple device layers of the gas sensor with a radiation-transmissive opening being defined in the package over the capacitive electrodes and underlying ground planes and lower level circuitry, the opening being configured to expose the capacitive electrodes to ambient conditions outside the package.

12. The gas sensor of claim 9, where the first non-continuous opaque structures of the first device layer further comprise at least one top plate of a metal-insulator-metal (MIM) capacitor that is non-continuous with the capacitive electrodes of the gas sensor and that defines one or more radiation transmissive areas in the first device layer;

and where the second non-continuous opaque structures of the second device layer together comprise at least one bottom plate of the MIM capacitor defining one or more radiation transmissive areas in the second device layer.

13. The gas sensor of claim 12, further comprising a radiation-opaque package surrounding the multiple device layers of the gas sensor with a radiation-transmissive opening being defined in the package over the capacitive electrodes and underlying ground planes and lower level circuitry;

and where the radiation-transmissive opening is also defined in the package over at least a portion of the MIM capacitor and underlying lower level circuitry, the opening being configured to expose the capacitive electrodes to ambient conditions outside the package.

14. A method of forming a multi-layer semiconductor device, the method comprising:

providing a first device layer including one or more non-continuous first radiation-opaque layer structures defining radiation transmissive areas in the first device layer;

providing a second device layer underlying the first device layer, the second device layer including one or more non-continuous second radiation-opaque layer structures defining radiation transmissive areas in the second device layer; and

configuring the first non-continuous opaque structures of the first device layer to be cooperatively spaced in overlapping relationship with the second non-continuous opaque structures of the second device layer to form a continuous barrier that completely blocks all radiation that impinges on the first device layer from above the semiconductor device from penetrating through the combination of the first and second device layers of the multi-layer structure.

15. The method of claim 14, further comprising providing a third device layer disposed between the first and second device layers, the third device layer comprising radiation-transmissive dielectric material;

where the semiconductor comprises a gas sensor device;

where the first non-continuous opaque structures of the first device layer comprise sensor electrodes for the gas sensor device;

where the second non-continuous opaque structures of the second device layer comprise ground planes; and

where each of the first and second non-continuous opaque structures comprise non-continuous metal structures.

16. The method of claim 14, further comprising providing a third device layer disposed between the first and second device layers, the third device layer comprising radiation-transmissive dielectric material;

where the first non-continuous opaque structures of the first device layer together comprise at least one top plate of a metal-insulator-metal (MIM) capacitor with one or more radiation-transmissive openings defined therein;

where the second non-continuous opaque structures of the second device layer together comprise at least one bottom plate of the MIM capacitor with one or more radiation-transmissive openings defined therein.

17. The method of claim 14, further comprising providing one or more additional device layers underlying the third device layer, the additional device layers having radiation-sensitive active circuitry formed therein;

where the first non-continuous opaque structures of the first device layer are cooperatively spaced in overlapping relationship with the second non-continuous opaque structures of the second device layer to form a continuous barrier that completely blocks all radiation that impinges on the first device layer from above the semiconductor device from penetrating further into the semiconductor device to the underlying radiation-sensitive circuitry.

18. A method of forming a capacitive gas sensor, comprising:

providing a gas sensitive material, the gas sensor provided to allow the exposure of the gas sensitive material to a gas;

providing first non-continuous radiation-opaque structures comprising spaced metal capacitor electrodes in a first device layer of a capacitive sensor cell, the capacitive sensor cell being electrically coupled to at least a portion of the gas sensitive material;

providing second non-continuous radiation-opaque structures comprising one or more metal non-continuous metal ground planes in a second device layer underlying the capacitor electrodes;

providing lower level circuitry underlying the capacitive electrodes and ground planes of the first and second device layers;

configuring the gas sensor to utilize a detected capacitance between the electrodes of the capacitive sensor cell to obtain a gas sensor measurement; and

configuring the capacitor electrodes of the first device layer to be cooperatively spaced in overlapping relationship with the non-continuous ground planes of the second device layer to block impinging light from further penetration into the lower level circuitry.

19. The method of claim 18, further comprising providing a third device layer disposed between the first and second device layers, the third device layer comprising radiation-transmissive dielectric material.

20. The method of claim 18, further comprising providing a radiation-opaque package surrounding the multiple device layers of the gas sensor with a radiation-transmissive opening being defined in the package over the capacitive electrodes and underlying ground planes and lower level circuitry, the opening being configured to expose the capacitive electrodes to ambient conditions outside the package.

21. The method of claim 18, where the first non-continuous opaque structures of the first device layer further comprise at least one top plate of a metal-insulator-metal (MIM) capacitor that is non-continuous with the capacitive electrodes of the gas sensor and that defines one or more radiation transmissive areas in the first device layer;

and where the second non-continuous opaque structures of the second device layer together comprise at least one bottom plate of the MIM capacitor defining one or more radiation transmissive areas in the second device layer.

22. The method of claim 21, further comprising providing a radiation-opaque package surrounding the multiple device layers of the gas sensor with a radiation-transmissive opening being defined in the package over the capacitive electrodes and underlying ground planes and lower level circuitry, the radiation-transmissive opening also being defined in the package over at least a portion of the MIM capacitor and underlying lower level circuitry, the opening being configured to expose the capacitive electrodes to ambient conditions outside the package.