Integrated circuit with a pressure sensor

Patent metadata

Field	Value
Publication number	US-2016377497-A1
Application number	US-201615258988-A
Country	US
Kind code	A1
Filing date	Sep 7, 2016
Priority date	Jun 12, 2012
Publication date	Dec 29, 2016
Grant date	—

Abstract

Disclosed is an integrated circuit, comprising a semiconductor substrate carrying a plurality of circuit elements; and a pressure sensor including a cavity on said semiconductor substrate, said cavity comprising a pair of electrodes laterally separated from each other; and a flexible membrane over and spatially separated from said electrodes such that said membrane interferes with a fringe field between said electrodes, said membrane comprising at least one aperture. A method of manufacturing such an IC is also disclosed.

First claim

What is claimed is:

1 . An integrated circuit, comprising:
a semiconductor substrate carrying a plurality of circuit elements; and a pressure sensor including a cavity on said semiconductor substrate, said cavity comprising: a pair of electrodes laterally separated from each other; and a flexible membrane spatially separated from said electrodes such that said membrane interferes with a fringe field between said electrodes, wherein the flexible membrane comprises a metal layer having at least one aperture and a capping layer filling the at least one aperture.

2 . The integrated circuit of claim 1 ,
wherein the electrodes are interdigitated electrodes.

3 . An integrated circuit, comprising:
a semiconductor substrate carrying a plurality of circuit elements; and a pressure sensor including a cavity on said semiconductor substrate, said cavity comprising: a pair of electrodes laterally separated from each other; and a flexible membrane spatially separated from said electrodes such that said membrane interferes with a fringe field between said electrodes, wherein the flexible membrane comprises a conductive layer that is connected to ground.

4 . The integrated circuit of claim 3 ,
wherein the semiconductor substrate is grounded.

5 . The integrated circuit of claim 3 ,
wherein the integrated circuit comprises an interconnect layer underneath the pair of electrodes, and wherein the interconnect layer is grounded.

6 . An integrated circuit, comprising:
a semiconductor substrate carrying a plurality of circuit elements; and a pressure sensor including a cavity on said semiconductor substrate, said cavity comprising: a pair of electrodes laterally separated from each other; and a flexible membrane spatially separated from said electrodes such that said membrane interferes with a fringe field between said electrodes, wherein the integrated circuit comprises one or more trenches defining a guard around the cavity, wherein the trenches are filled with a conductive material.

7 . The integrated circuit of claim 6 ,
wherein the guard is realized as a guard ring around the cavity.

8 . The integrated circuit of claim 6 ,
wherein the flexible membrane comprises a conductive layer, and wherein the one or more trenches are filled with the conductive material that is deposited such that the conductive layer is formed.

9 . An integrated circuit, comprising:
a semiconductor substrate carrying a plurality of circuit elements; and a pressure sensor including a cavity on said semiconductor substrate, said cavity comprising: a pair of electrodes laterally separated from each other; and a flexible membrane spatially separated from said electrodes such that said membrane interferes with a fringe field between said electrodes, wherein at least some of the plurality of circuit elements define a capacitance measurement circuit, wherein said electrodes are conductively coupled to the capacitance measurement circuit that comprises a sigma/delta capacitance-to-digital converter.

Assignees

• Ams Int Ag

Inventors

• Nackaerts Axel
• Besling Willem Frederik Adrianus
• Reimann Klaus

Classifications

• H10D64/011

  of electrodes ohmically coupled to a semiconductor · CPC title

• B81B2203/0127

  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 title

• B81B7/008

  MEMS characterised by an electronic circuit specially adapted for controlling or driving the same (B81B7/0087 takes precedence; arrangements for starting, regulating, braking, or otherwise controlling an actuator H02N; control arrangements or circuits for visual indicators G09G3/00) · CPC title

• B81C1/00246

  Monolithic integration, i.e. micromechanical structure and electronic processing unit are integrated on the same substrate · CPC title

• H10D48/50

  Devices controlled by mechanical forces, e.g. pressure · CPC title