Method of manufacturing MEMS switches with reduced switching voltage
An approach includes a method of fabricating a switch. The approach includes forming a first cantilevered electrode, forming a second cantilevered electrode over an electrode and operable to contact the first cantilevered electrode upon an application of a voltage to the electrode, and forming an arm on the first cantilevered electrode with an extending protrusion extending upward from an upper surface of the arm.
1. A method of fabricating a switch comprising:
forming a first cantilevered electrode;
forming a second cantilevered electrode over an electrode and operable to directly contact an end of the first cantilevered electrode upon an application of a voltage to the electrode;
forming an arm on the first cantilevered electrode with an extending protrusion extending upward from an upper surface of the arm; and
forming a hermetically sealed volume encapsulating the 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 formed with the nitride liner.
3. The method of claim 1 , wherein the hermetically sealed volume is a dome.
4. The method of claim 3 , wherein the dome is oval shaped.
5. The method of claim 1 , wherein the second cantilevered electrode is formed with an end which overlaps the first cantilevered electrode.
6. The method of claim 5 , wherein overlapping portions of the first cantilevered electrode and the second cantilevered electrode are separated by a vertical distance of about two microns.
7. The method of claim 1 , wherein the second cantilevered electrode is formed above the first cantilevered electrode.
8. The method of claim 1 , wherein the second cantilevered electrode is operable to directly contact the end of the first cantilevered electrode upon a positive voltage applied to the electrode.
9. The method of claim 8 , wherein the positive voltage is about 100 volts.
10. The method of claim 1 , further comprising forming an arm with an extending protrusion on the second cantilevered electrode.
11. The method of claim 1 , wherein the forming the hermetically sealed volume comprises forming a bonded chip.
12. The method of claim 1 , wherein the forming the hermetically sealed volume comprises forming a wafer cap.
13. The method of claim 12 , wherein the first cantilevered electrode comprises a stationary cantilevered electrode.
14. The method of claim 13 , wherein the wafer cap comprises a rectangular shaped dome.
15. A method of fabricating a switch comprising:
forming a first cantilevered electrode;
forming a second cantilevered electrode over an electrode and operable to contact the first cantilevered electrode upon an application of a voltage to the electrode;
forming an arm on the first cantilevered electrode with an extending protrusion extending upward from an upper surface of the arm; and
forming a hermetically sealed volume encapsulating the 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.