Trilayered beam MEMS device and related methods

A method for fabricating an actuator having a trilayered beam, comprising:

• (a) forming a first electrode on a substrate;
• (b) depositing a sacrificial layer on the first electrode and the substrate;
• (c) forming a second electrode on the sacrificial layer;
• (d) depositing a structural layer on the second electrode and the sacrificial layer;
• (e) forming a via through the structural layer to the second electrode;
• (f) depositing a conductive layer on the structural layer and in the via;
• (g) forming a conductive microstructure by removing a portion of the conductive layer, wherein the conductive microstructure electrically communicates with the second electrode through the via;
• and
• (h) removing a sufficient amount of the sacrificial layer so as to separate the second electrode from the substrate, wherein the structural layer is supported by the substrate at a first end and is freely suspended above the substrate at an opposing second end.

A method for fabricating a microscale switch having a trilayered beam, comprising:

• (a) forming a first electrode on a substrate;
• (b) forming a first contact on the substrate;
• (c) depositing a sacrificial layer on the first electrode, the first contact, and the substrate;
• (d) forming a second electrode on the sacrificial layer;
• (e) forming a second contact on the sacrificial layer;
• (f) depositing a structural layer on the second electrode, the second contact, and the sacrificial layer;
• (g) forming a first conductive, interconnect via through the structural layer to the second electrode;
• (h) forming a second conductive, interconnect via through the structural layer to the second contact;
• (i) forming an electrode interconnect on the structural layer that contacts the first interconnect via;
• and
• (j) forming a contact interconnect on the structural layer that contacts the second interconnect via.

A method for fabricating a microscale switch having a cross-bar interconnect, comprising:

• (a) forming a conductive interconnect on a substrate;
• (b) depositing dielectric layer on the conductive interconnect;
• (c) forming a first conductive, interconnect via through the dielectric layer to the conductive interconnect;
• (d) forming a first contact on the dielectric layer wherein the first contact connects to the first interconnect via;
• (e) forming a first electrode on the substrate;
• (f) depositing a sacrificial layer on the first electrode, the first contact, and the substrate;
• (g) forming a second electrode on the sacrificial layer;
• (h) forming a second contact on the sacrificial layer;
• (i) depositing a structural layer on the second electrode, the second contact, and the sacrificial layer;
• (j) forming a second conductive, interconnect via through the structural layer to the second electrode;
• (k) forming a third conductive, interconnect via through the structural layer to the second contact;
• (l) forming an electrode interconnect on the structural layer that contacts the second interconnect via;
• and
• (m) forming a contact interconnect on the structural layer that contacts the third interconnect via.

A method for fabricating a microscale switch having a trilayered beam, comprising:

• (a) forming a first and second conductive interconnect on a substrate;
• (b) depositing at least one dielectric layer on the first and second conductive interconnect;
• (c) forming a first and second conductive, interconnect via through the at least one dielectric layer to the first and second conductive interconnects, respectively;
• (d) forming a first and second contact on the dielectric layer wherein the first contact connects to the first interconnect via and the second contact connects to the second interconnect via;
• (e) forming a first electrode on the substrate;
• (f) depositing a sacrificial layer on the first electrode, the first contact, and the second contact;
• (g) forming a second electrode on the sacrificial layer;
• (h) forming a third and fourth contact on the sacrificial layer;
• (i) depositing a structural layer on the second electrode, the third contact, the fourth contact, and the sacrificial layer;
• (j) forming a third conductive, interconnect via through the structural layer to the second electrode;
• (k) forming a fourth and fifth conductive, interconnect via through the structural layer to the third and fourth contacts, respectively;
• (l) forming an electrode interconnect on the structural layer that contacts the third interconnect via;
• and
• (m) forming a contact interconnect on the structural layer that contacts the fourth and fifth interconnect vias.

A method of implementing switching function in a switch having conductive interconnects, the method comprising:

• (a) providing a switch having conductive interconnects, the switch comprising:
• (i) a substrate having a first and second conductive interconnect and a stationary electrode;
• (ii) first and second dielectric layers formed on the first and second conductive interconnects, respectively;
• (iii) first and second stationary contacts attached to the first and second dielectric layers, respectively, and having electrical communication with the first and second conductive interconnects, respectively;
• (iv) a movable structural layer including a bottom surface suspended over the first and second stationary contacts and a top surface opposing the bottom surface;
• (v) a movable electrode attached to the bottom surface of the structural layer whereby the movable electrode is separated from the stationary electrode by a gap;
• (vi) an electrode interconnect attached to the top surface of the structural layer and connected to the movable electrode for electrical communication;
• and
• (vii) a movable contact attached to the bottom surface of the structural layer and positioned to contact the first and second stationary contacts when the structural layer moves towards the first and second stationary contacts;
• and
• (b) applying a voltage between the electrode interconnect and the stationary electrode to electrostatically couple the movable electrode with the stationary electrode across the gap, whereby the resilient structural layer is deflected toward the substrate and the movable contact contacts the first and stationary contacts for establishing electrical communication between the first and second conductive interconnects.