MEMS Device and Method of Making a MEMS Device

• US 20130264663A1
• Filed: 04/04/2012
• Published: 10/10/2013
• Est. Priority Date: 04/04/2012
• Status: Active Grant

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Dehe, Alfons, Wurzer, Martin, Herzum, Christian
• Granted Patent: US 9,409,763 B2
• Time in Patent Office: Days
• US Class Current: 257/416
• CPC Class Codes: B81B 2201/0257 Microphones or microspeakers
• CPC Class Codes: B81B 3/0018 Structures acting upon the moving or flexible element for transforming energy into mechanical movement or vice versa, i.e. actuators, sensors, generators
• CPC Class Codes: B81B 3/0035 Constitution or structural means for controlling the movement of the flexible or deformable elements
• CPC Class Codes: B81B 3/0051 For defining the movement, i.e. structures that guide or limit the movement of an element mechanical arrangements for preventing or damping vibration or shock H01H3/60
• CPC Class Codes: B81B 3/007 For controlling stiffness, e.g. ribs
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: H04R 19/005 using semiconductor materials
• CPC Class Codes: H04R 19/04 Microphones H04R19/01 takes precedence
• CPC Class Codes: H04R 7/06 comprising a plurality of sections or layers

Abstract

A MEMS device and a method of making a MEMS device are disclosed. In one embodiment a semiconductor device comprises a substrate, a moveable electrode and a counter electrode, wherein the moveable electrode and the counter electrode are mechanically connected to the substrate. The movable electrode is configured to stiffen an inner region of the movable membrane.

Claims

1. A semiconductor device comprising:

a substrate;

a moveable electrode comprising a corrugation line, the corrugation line configured to stiffen an inner region of the movable electrode; and

a first counter electrode, wherein the moveable electrode and the first counter electrode are mechanically connected to the substrate.

2. The semiconductor device according to claim 1, wherein the corrugation line comprises a plurality of radial corrugation lines.

3. The semiconductor device according to claim 1, wherein the moveable electrode further comprises at least one circumferential corrugation line.

4. The semiconductor device according to claim 3, wherein the radial corrugation line is located in an inner region of the moveable electrode, and wherein the conferential corrugation line is located in an outer region of the moveable electrode.

5. The semiconductor device according to claim 1, wherein at least one of the moveable electrode and the first counter electrode comprise a plurality of electrodes.

6. The semiconductor device according to claim 1, further comprising a second counter electrode, the second counter electrode arranged such that the moveable electrode is located between the first counter electrode and the second counter electrode.

7. The semiconductor device according to claim 6, wherein the first counter electrode comprises first corrugation lines, and wherein the second counter electrode comprises second corrugation lines.

8. A MEMS structure comprising:

a substrate;

a moveable electrode comprising radial corrugation lines in an inner region and circular corrugation lines in an outer region; and

a first perforated counter electrode comprising first ridges, wherein the moveable electrode and the first perforated counter electrode are mechanically connected to the substrate.

9. The MEMS structure according to claim 8, wherein moveable electrode is arranged below the first perforated counter electrode closer to the substrate.

10. The MEMS structure according to claim 8, wherein the first perforated counter electrode is arranged below the moveable electrode closer to the substrate.

11. The MEMS structure according to claim 8, further comprising a second perforated counter electrode comprising second ridges, and wherein the moveable electrode is arranged between the first perforated counter electrode and the second perforated counter electrode.

12. The MEMS structure according to claim 8, wherein the first perforated counter electrode comprises a first counter electrode and a second counter electrode, wherein the first counter electrode is in register with the inner region of the moveable electrode, and wherein the second counter electrode is in register with the outer region of the moveable electrode.

13. The MEMS structure according to claim 12, wherein the moveable electrode comprises a first moveable electrode and a second moveable electrode, wherein the inner region comprise the first electrode, and wherein the outer region comprises the second electrode.

14. The MEMS structure according to claim 8, wherein moveable electrode comprises a radius, wherein an inner area of the inner region is defined by about 80% of the radius, and wherein an outer area of the outer region is defined by about 20% of the radius.

15. A method of making an electrode of a MEMS device, the method comprising:

forming radial openings in a mask layer, the mask layer disposed over a first sacrificial layer, the radial openings exposing surface portions of the first sacrificial layer, the radial openings leading away from a central point of the first sacrificial layer;

forming isolation regions at the exposed surface portions;

forming a second sacrificial layer over the first sacrificial layer;

forming a conductive layer over the second sacrificial layer;

removing a first portion of the first sacrificial layer forming a first spacer; and

removing a second portion of the second sacrificial layer forming a second spacer.

16. The method according to claim 15, wherein forming isolation regions comprises oxidizing or nitriding the exposed surface portions.

17. The method according to claim 15, further comprising removing the mask layer and the isolation regions before forming the second sacrificial layer.

18. The method according to claim 17, wherein the openings are located in an inner region of the first sacrificial layer.

19. The method according to claim 15, wherein the openings are located in an outer region of the first sacrificial layer and in an inner region of the first sacrificial layer, and wherein the openings all have substantially the same width.

20. A method of making an electrode of a MEMS device, the method comprising:

forming trenches in a first sacrificial layer, each trench has substantially the same depth;

forming a second sacrificial layer lining a top surface of the first sacrificial layer, sidewalls and a bottom surface of the trenches;

forming a conductive material layer over a top surface of the second sacrificial layer and filling the trenches;

removing a first portion of the first sacrificial layer forming a first spacer; and

removing a second portion of the second sacrificial layer forming a second spacer thereby exposing the conductive material layer.

21. The method according to claim 20, wherein forming the conductive material layer comprises forming fin lines, and wherein two parallel fin lines are connected via a connecting fin line.

22. The method according to claim 20, wherein forming the conductive material layer comprises forming fin lines, and wherein the fin lines form a honeycomb configuration.

23. A method of making an electrode of a MEMS device, the method comprising:

forming a first sacrificial layer over a substrate;

forming mesas in the first sacrificial layer;

forming a second sacrificial layer over the mesas;

forming a conductive layer over the second sacrificial layer and the mesas;

removing a first portion of the substrate forming a first spacer;

removing a second portion of the second sacrificial layer forming a second spacer; and

removing the mesas.

24. The method according to claim 23, wherein the mesas are radial mesas leading away from a central point of the substrate.

25. The method according to claim 24, further comprising circumferential mesas, wherein the radial mesas are located on an inner region of the substrate, and wherein the circumferential mesas are located on an outer region of the substrate.