SENSOR DEVICE AND RELATED FABRICATION METHODS

• US 20130283912A1
• Filed: 04/27/2012
• Published: 10/31/2013
• Est. Priority Date: 04/27/2012
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Lin, Yizhen
• Granted Patent: US 9,046,546 B2
• Time in Patent Office: Days
• US Class Current: 73/514.16
• CPC Class Codes: G01L 13/025 using diaphragms
• CPC Class Codes: G01L 15/00 Devices or apparatus for measuring two or more fluid pressure values simultaneously
• CPC Class Codes: G01L 19/0092 Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26
• CPC Class Codes: G01L 19/02 Arrangements for preventing, or for compensating for, effects of inclination or acceleration of the measuring device; Zero-setting means for aneroid barometers G01L7/14
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0047 Diaphragm with non uniform thickness, e.g. with grooves, bosses or continuously varying thickness
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm
• CPC Class Codes: G01L 9/125 with temperature compensating means non electric temperature compensating means G01L19/04
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Apparatus and related fabrication methods are provided for a sensor device. An exemplary sensor device includes a first structure including a first sensing arrangement and a second sensing arrangement formed therein and a second structure affixed to the first structure. The second structure includes a cavity aligned with the first sensing arrangement to provide a first reference pressure on a first side of the first sensing arrangement and an opening aligned with the second sensing arrangement to expose the first side of the second sensing arrangement to an ambient pressure.

Claims

1. A sensor device comprising:

a first structure including a first sensing arrangement and a second sensing arrangement formed therein; and

a second structure affixed to the first structure, wherein the second structure includes;

a cavity aligned with the first sensing arrangement to provide a first reference pressure on a first side of the first sensing arrangement; and

an opening aligned with the second sensing arrangement to expose the first side of the second sensing arrangement to an ambient pressure.

2. The sensor device of claim 1, further comprising a third structure coupled to a second side of the first structure to provide a second reference pressure on the second side of the first sensing arrangement and the second side of the second sensing arrangement, wherein the first reference pressure and the second reference pressure are different.

3. The sensor device of claim 2, wherein the third structure provides a sealed chamber adjacent to the second side of the first sensing arrangement and the second side of the second sensing arrangement, the sealed chamber having the second reference pressure.

4. The sensor device of claim 2, wherein:

the first sensing arrangement includes a first diaphragm region to deflect in response to a difference between the first reference pressure and the second reference pressure; and

the second sensing arrangement includes a second diaphragm region to deflect in response to a difference between the ambient pressure and the second reference pressure.

5. The sensor device of claim 2, further comprising a third sensing arrangement formed in the first structure, wherein:

the third structure provides a sealed chamber adjacent to the second side of the first sensing arrangement, the second side of the second sensing arrangement, and the second side of the third sensing arrangement; and

the sealed chamber is at the second reference pressure.

6. The sensor device of claim 2, further comprising a molding compound encapsulating the third structure.

7. The sensor device of claim 1, further comprising a third sensing arrangement formed in the first structure.

8. The sensor device of claim 7, wherein the third sensing arrangement comprises an inertial sensing arrangement.

9. The sensor device of claim 1, wherein:

the first sensing arrangement comprises a first pressure sensing arrangement; and

the second sensing arrangement comprises a second pressure sensing arrangement.

10. The sensor device of claim 9, wherein:

the first reference pressure is at vacuum; and

a second reference pressure on a second side of the first sensing arrangement and the second side of the second sensing arrangement is at partial vacuum.

11. The sensor device of claim 1, wherein:

the first sensing arrangement comprises a first pressure sensing arrangement; and

the second sensing arrangement comprises a second pressure sensing arrangement.

12. The sensor device of claim 11, the first pressure sensing arrangement including a first diaphragm region and the second pressure sensing arrangement including a second diaphragm region, deflection of the first diaphragm region being influenced by the first reference pressure, wherein deflection of the second diaphragm region is influenced by the ambient pressure and independent of the first reference pressure.

13. The sensor device of claim 12, further comprising control circuitry to determine a pressure metric indicative of the ambient pressure based on a relationship between a first electrical signal from the first sensing arrangement and a second electrical signal from the second sensing arrangement, wherein the first electrical signal is influenced by the deflection of the first diaphragm region and the second electrical signal is influenced by the deflection of the second diaphragm region.

14. A sensor device comprising:

a first sensing arrangement including a first diaphragm region;

a second sensing arrangement including a second diaphragm region exposed to an ambient pressure;

a first sealed chamber adjacent to a first side of the first sensing arrangement, the first sealed chamber having a first reference pressure; and

a second sealed chamber adjacent to a second side of the first sensing arrangement and the second side of the second sensing arrangement, the second sealed chamber having a second reference pressure different from the first reference pressure, wherein first diaphragm region deflects in response to a difference between the first reference pressure and the second reference pressure and the second diaphragm region deflects in response to a difference between the ambient pressure and the second reference pressure.

15. The sensor device of claim 14, further comprising an integrated circuit die having control circuitry formed thereon, the control circuitry being coupled to the sensor device to determine a pressure metric indicative of the ambient pressure based on a relationship between a first electrical signal from the first sensing arrangement and a second electrical signal from the second sensing arrangement, wherein the first electrical signal is influenced by the deflection of the first diaphragm region and the second electrical signal is influenced by the deflection of the second diaphragm region.

16. The sensor device of claim 15, further comprising a package substrate structure having the sensor device and the integrated circuit die affixed thereto, wherein the package substrate structure includes an opening aligned with the second sensing arrangement to expose the second diaphragm region to the ambient pressure.

17. The sensor device of claim 14, further comprising:

an inertial sensing arrangement; and

a substrate of semiconductor material having the first sensing arrangement, the second sensing arrangement, and the inertial sensing arrangement formed therein, wherein the second sealed chamber encompasses a side of the inertial sensing arrangement.

18. A method of fabricating a sensor device, the method comprising:

forming a first structure having a cavity;

affixing the first structure to a first side of a second structure at a first pressure, the cavity providing a first sealed chamber at the first pressure adjacent to the first side of a first sensing arrangement of the second structure in response to affixing the first structure to the second structure;

forming an opening in the first structure, the opening being aligned with a second sensing arrangement of the second structure to expose the first side of the second sensing arrangement to an ambient pressure; and

affixing a third structure to a second side of the second structure at a second pressure, the second pressure being different from the first pressure, the third structure being configured to provide a second sealed chamber at the second pressure adjacent to the second side of the first sensing arrangement and the second sensing arrangement in response to affixing the third structure to the second structure.

19. The method of claim 18, further comprising:

forming a first diaphragm region for the first sensing arrangement on the second structure, the first side of the first diaphragm region being adjacent to the first sealed chamber when the second structure is affixed to the first structure;

forming a second diaphragm region for the second sensing arrangement on the second structure, the opening in the first structure being aligned with the second diaphragm region to expose the first side of the second diaphragm region to the ambient pressure; and

forming openings in the second structure to expose the second side of the first diaphragm region and the second side of the second diaphragm region to the second pressure.

20. The method of claim 19, further comprising forming a third sensing arrangement in the second structure, wherein the third sensing arrangement is at the second pressure when the third structure is affixed to the second structure.