Method of manufacturing MEMS switches with reduced voltage

Patent metadata

Field	Value
Publication number	US-9824834-B2
Application number	US-201514883836-A
Country	US
Kind code	B2
Filing date	Oct 15, 2015
Priority date	Apr 22, 2008
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

An approach includes a method of fabricating a switch. The approach includes forming a first fixed electrode and a second fixed electrode, forming a first cantilevered electrode aligned vertically over the first fixed electrode and the second fixed electrode, and operable to directly contact the second fixed electrode upon an application of a voltage to the first fixed electrode, forming a second cantilevered electrode aligned vertically over the second fixed electrode, and which has an end that overlaps the first cantilevered electrode, and forming a hermetically sealed volume encapsulating the first fixed electrode, the second fixed electrode, the first cantilevered electrode, and the second cantilevered electrode.

First claim

It is claimed:

1. A method of fabricating a switch comprising:
forming a first fixed electrode and a second fixed electrode;
forming a first cantilevered electrode aligned vertically over the first fixed electrode and the second fixed electrode, and operable to directly contact the second fixed electrode upon an application of a positive voltage to the first fixed electrode;
forming a second cantilevered electrode aligned vertically over the second fixed electrode, and which has an end that overlaps and is parallel to an end of the first cantilevered electrode; and
forming a hermetically sealed volume encapsulating the first fixed electrode, the second fixed electrode, the first cantilevered electrode, and the second cantilevered electrode,
wherein the forming the hermetically sealed volume comprises:
forming at least one hole in a nitride liner to gain access to a sacrificial resist;
etching the sacrificial resist; and
closing the at least one hole by deposition of additional liner material.

2. The method of claim 1 , wherein the hermetically sealed volume is a dome.

3. The method of claim 2 , wherein the dome is oval shaped.

4. The method of claim 1 , wherein overlapping portions of the first cantilevered electrode and the second cantilevered electrode are separated by a vertical distance of about two microns.

5. The method of claim 1 , wherein the second cantilevered electrode is formed above the first cantilevered electrode.

6. The method of claim 1 , wherein the first cantilevered electrode is formed such that upon application of a negative voltage to the second cantilevered electrode, the first cantilevered electrode is operable to directly contact the second fixed electrode.

7. The method of claim 1 , wherein an arm of the first cantilevered electrode is longer than an arm of the second cantilevered electrode.

8. The method of claim 1 , wherein the second cantilevered electrode is in direct contact with the hermetically sealed volume.

9. The method of claim 8 , wherein the hermetically sealed volume is directly on an upper surface of the second cantilevered electrode.

10. The method of claim 1 , wherein the hermetically sealed volume comprises nitride.

11. The method of claim 1 , wherein the positive voltage is about 50 volts.

12. A method of fabricating a switch comprising:
forming a first fixed electrode and a second fixed electrode;
forming a first cantilevered electrode aligned vertically over the first fixed electrode and the second fixed electrode, and operable to directly contact the second fixed electrode upon an application of a voltage to the first fixed electrode;
forming a second cantilevered electrode aligned vertically over the second fixed electrode, and which has an end that overlaps the first cantilevered electrode; and
forming a hermetically sealed volume encapsulating the first fixed electrode, the second fixed electrode, the first cantilevered electrode, and the second cantilevered electrode,
wherein the forming the hermetically sealed volume comprises:
forming at least one hole in a nitride liner to gain access to a sacrificial resist;
etching the sacrificial resist; and
closing the at least one hole by deposition of additional liner material.

Assignees

• IBM

Inventors

• Luce Stephen E
• Stamper Anthony K

Classifications

• B81C1/00166

  Electrodes · CPC title

• B81C2201/0133

  Wet etching · CPC title

• H01H49/00

  Apparatus or processes specially adapted to the manufacture of relays or parts thereof · CPC title

• B81C2201/0132

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

• H01H50/005

  using micromechanics · CPC title