MEMS capacitive pressure sensors in fully depleted semiconductor on insulator (FDSOI)

• US 10,466,126 B2
• Filed: 02/27/2018
• Issued: 11/05/2019
• Est. Priority Date: 02/27/2018
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: GlobalFoundries, Inc.
• Inventors: Faul, Juergen, Jakubowski, Frank
• Primary Examiner(s): Kielin, Erik
• Application Number:
  US15/906,368
• Publication Number:
  US 20190265117A1
• Time in Patent Office: 616 Days
• Field of Search: None
• 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: B81B 2203/0315 Cavities
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81B 3/0021 Transducers for transforming electrical into mechanical energy or vice versa dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: B81C 2201/0133 Wet etching
• CPC Class Codes: B81C 2201/0161 Controlling physical properties of the material
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm

Abstract

The present disclosure relates to semiconductor structures and, more particularly, to pressure sensors and methods of manufacture. The structure includes: a top membrane of semiconductor material having edges defined by epitaxial material and a liner material; a back gate under the top membrane; and a cavity defined between the top membrane and the back gate.

Claims

1. A structure, comprising:

a top membrane of semiconductor material having edges defined by epitaxial material and a liner material;

a back gate under the top membrane; and

a cavity defined between the top membrane and the back gate,

wherein the liner material is an insulator material and the epitaxial material is a semiconductor material of a different polarity type than the top membrane.

2. The structure of claim 1, wherein the back gate is a bottom membrane of a capacitive pressure sensor, and the top membrane and the bottom membrane have a same polarity.

3. The structure of claim 1, wherein the back gate is a bottom membrane of a capacitive pressure sensor, and the top membrane and the bottom membrane have different polarities.

4. The structure of claim 1, wherein the epitaxial material is a doped epitaxially grown semiconductor material and the liner material is SiN, SiO₂, a-Si or combinations thereof.

5. The structure of claim 1, wherein the semiconductor material of the top membrane is semiconductor on insulator (SOI) material, and the back gate is a doped bulk semiconductor material.

6. A structure, comprising:

a top membrane of semiconductor material having edges defined by epitaxial material and a liner material;

a back gate under the top membrane; and

a cavity defined between the top membrane and the back gate,

wherein the cavity is defined by the top membrane, the bottom membrane and its edges are defined by the epitaxial material and the liner material.

7. A structure comprising:

a top membrane of semiconductor material having it edges defined by epitaxial material and a liner material;

a bottom membrane of doped bulk semiconductor material; and

a cavity defined by the top membrane and the bottom membrane, with its edges defined by the epitaxial material on one edge and the liner material on remaining edges.

8. The structure of claim 7, wherein top membrane and the bottom membrane are part of a capacitive pressure sensor, and the top membrane and the bottom membrane have a same polarity.

9. The structure of claim 7, wherein the top membrane and the bottom membrane are part of a capacitive pressure sensor, and the top membrane and the bottom membrane have different polarities.

10. The structure of claim 7, wherein the epitaxial material is a semiconductor material of a different polarity type than the top membrane.