SENSOR STRUCTURES, SYSTEMS AND METHODS WITH IMPROVED INTEGRATION AND OPTIMIZED FOOTPRINT

• US 20150210533A1
• Filed: 01/24/2014
• Published: 07/30/2015
• Est. Priority Date: 01/24/2014
• Status: Active Grant

• Current Assignee: Infineon Technologies Dresden GmbH (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Dresden GmbH (Infineon Technologies AG)
• Inventors: Kautzsch, Thoralf, Frhlich, Heiko, Vogt, Mirko, Stegemann, Maik, Rth, Andre, Winkler, Bernhard, Binder, Boris
• Granted Patent: US 9,546,923 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2203/0127 Diaphragms, i.e. structures separating two media that can control the passage from one medium to another; Membranes, i.e. diaphragms with filtering function
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: G01L 9/0041 Transmitting or indicating the displacement of flexible diaphragms
• CPC Class Codes: G01L 9/0072 using variations in capacitance
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm

Abstract

Embodiments relate to sensors and more particularly to structures for and methods of forming sensors that are easier to manufacture as integrated components and provide improved deflection of a sensor membrane, lamella or other movable element. In embodiments, a sensor comprises a support structure for a lamella, membrane or other movable element. The support structure comprises a plurality of support elements that hold or carry the movable element. The support elements can comprise individual points or feet-like elements, rather than a conventional interconnected frame, that enable improved motion of the movable element, easier removal of a sacrificial layer between the movable element and substrate during manufacture and a more favorable deflection ratio, among other benefits.

Claims

1. A sensor device comprising:

a substrate;

a plurality of support elements spaced apart from each other and arranged on the substrate; and

a moveable element supported on and spaced apart from the substrate by the plurality of support elements, wherein the moveable element, the substrate and the plurality of support elements define a cavity into which the moveable element can deflect in response to a physical quantity to be sensed by the sensor device.

2. The sensor device of claim 1, wherein the moveable element comprises a membrane or a lamella.

3. The sensor device of claim 2, wherein the moveable element comprises silicon.

4. The sensor device of claim 3, wherein the silicon comprises polycrystalline silicon.

5. The sensor device of claim 1, wherein the sensor device comprises a pressure sensor device, and wherein the physical quantity to be sensed is pressure.

6. The sensor device of claim 5, wherein the pressure is sensed by sensing a capacitance between the moveable element and the substrate.

7. The sensor device of claim 1, wherein the plurality of support elements comprise punctiform structures.

8. The sensor device of claim 7, wherein a lateral dimension of a punctiform structure is less than about 3,000 nanometers (nm).

9. The sensor device of claim 8, wherein the punctiform structure has lateral dimensions of about 500 nm by about 500 nm.

10. The sensor device of claim 1, wherein the sensor device comprises a plurality of sensors, each of the plurality of sensors comprising a plurality of support elements and a portion of the moveable element supported on that plurality of support elements.

11. The sensor device of claim 10, wherein adjacent ones of the plurality of sensors have at least one of the plurality of support elements in common.

12. The sensor device of claim 10, further comprising a sealing layer arranged between the substrate and the moveable element along a perimeter of the sensor device.

13. The sensor device of claim 12, wherein the sealing layer comprises a dielectric layer.

14. The sensor device of claim 1, wherein the substrate comprises a plurality of isolation portions, and wherein each of the plurality of support elements is arranged on a respective one of the plurality of isolation portions.

15. The sensor device of claim 1, wherein a ratio of maximum deflection of the moveable element to average deflection of the moveable element is less than about 2.

16. The sensor device of claim 1, wherein the moveable element and the plurality of support elements are integrally formed with one another.

17. A method comprising:

providing a substrate;

providing a moveable element supported on the substrate by a plurality of support elements spaced apart from one another; and

sensing a physical quantity by a deflection of the moveable element toward the substrate into a cavity defined by the substrate, the moveable element and the plurality of support elements.

18. The method of claim 17, wherein sensing a physical quantity further comprises sensing a capacitance between the substrate and the moveable element.

19. The method of claim 17, wherein for each of the plurality of support elements a distance to an adjacent one of the plurality of support elements is in a range of about 2 micrometers (μ

m) to about 20 μ

m.

20. The method of claim 17, wherein the moveable element comprises a silicon layer.