Micro-electro-mechanical system (mems) structures and design structures

Patent metadata

Field	Value
Publication number	US-2018201503-A1
Application number	US-201815923013-A
Country	US
Kind code	A1
Filing date	Mar 16, 2018
Priority date	Apr 12, 2013
Publication date	Jul 19, 2018
Grant date	—

Abstract

Micro-Electro-Mechanical System (MEMS) structures, methods of manufacture and design structures are disclosed. The method includes forming a Micro-Electro-Mechanical System (MEMS) beam structure by venting both tungsten material and silicon material above and below the MEMS beam to form an upper cavity above the MEMS beam and a lower cavity structure below the MEMS beam.

First claim

What is claimed:

1 . A method of forming a Micro-Electro-Mechanical System (MEMS) beam structure comprising:
forming both tungsten material and semiconductor material above and below a MEMS beam; and etching both the tungsten material and the semiconductor material at least above and below the MEMS beam, using an XeF 2 etchant.

2 . The method of claim 1 , wherein the etching is preformed by venting both the tungsten material and the semiconductor material at least above and below the MEMS beam to form an upper cavity structure above the MEMS beam and a lower cavity structure below the MEMS beam.

3 . The method of claim 2 , wherein the MEMS beam comprises a cantilevered beam structure.

4 . The method of claim 3 , wherein the cantilevered beam structure comprises a first cantilevered beam and a second cantilevered beam separated from one another by a via which connects the upper cavity structure and the lower cavity structure to one another.

5 . The method of claim 2 , wherein the venting and film thicknesses are controlled to ensure that all or substantially all of the tungsten material is removed, prior to the semiconductor material.

6 . The method of claim 5 , wherein the venting comprises forming a vent hole to expose at least the semiconductor material above the MEMS beam and performing an XeF 2 etching process.

7 . The method of claim 1 , wherein the semiconductor material is silicon material.

8 . The method of claim 7 , wherein forming the tungsten material and silicon material below the MEMS beam comprises forming the tungsten material on a substrate and forming the silicon material over the tungsten material.

9 . The method of claim 8 , wherein the tungsten material above and below the MEMS beam is formed by a physical vapor deposition process followed by a chemical vapor deposition process.

10 . A Micro-Electro-Mechanical System (MEMS) beam structure comprising:
a cantilevered beam structure formed within a cavity which includes an upper cavity portion formed over the cantilevered beam structure, and a lower cavity portion formed below the cantilevered beam structure, wherein the cantilevered beam structure comprises first and second cantilevered Micro-Electro-Mechanical System (MEMS) beams located within the cavity to separate the cavity into the upper cavity portion and the lower cavity portion: a via formed in the cantilever beam structure to separate end portions of the first and second cantilevered MEMS beams from one another, wherein the via connects the upper cavity portion and lower cavity portion to one another; and a lid formed over the upper cavity portion, the lid including at least two vent holes, wherein a first one of the at least two vent holes is vertically aligned with the via.

11 . The structure of claim 10 , wherein a first recess is in an upper surface of the first cantilevered MEMS beam facing toward the upper cavity portion.

12 . The structure of claim 11 , wherein a second recess is in an upper surface of the second cantilevered MEMS beam facing toward the upper cavity portion.

13 . The structure of claim 12 , wherein the upper cavity portion is over entire upper surfaces of the first and second cantilevered MEMS beams, including over the first and second recesses.

14 . The structure of claim 10 , further comprising a plug in a second one of the at least two vent holes.

15 . The structure of claim 14 , wherein the plug is comprised of a dielectric material or a metal material.

16 . The structure of claim 15 , wherein the first and second vent holes each have a diameter of about 1 μm.

17 . The structure of claim 16 , wherein the first and second vent holes are separated from one another by at least 6 μm.

18 . The structure of claim 17 , wherein the lid has a thickness of about 3 μm.

Assignees

• IBM

Inventors

• Brigham Michael T
• Jahnes Christopher V
• Luce Cameron E
• Maling Jeffrey C
• Murphy William J
• Stamper Anthony K
• White Eric J

Classifications

• B81C2201/0132

  Dry etching, i.e. plasma etching, barrel etching, reactive ion etching [RIE], sputter etching or ion milling · CPC title

• B81B2203/0315

  Cavities · CPC title

• B81C2201/0125

  Blanket removal, e.g. polishing · CPC title

• B81B3/0021

  Transducers for transforming electrical into mechanical energy or vice versa (dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00) · CPC title

• B81C2201/0121

  involving addition of material followed by removal of parts of said material, i.e. subtractive planarization · CPC title