Flexible MEMS device having hinged sections

Patent metadata

Field	Value
Publication number	US-11705298-B2
Application number	US-202016907138-A
Country	US
Kind code	B2
Filing date	Jun 19, 2020
Priority date	Jun 22, 2019
Publication date	Jul 18, 2023
Grant date	Jul 18, 2023

Abstract

A method of forming a microelectromechanical device is disclosed wherein a beam of the microelectromechanical device may deviate from a resting to an engaged or disengaged position through electrical biasing. The microelectromechanical device comprises a beam disposed above a first RF conductor and a second RF conductor. The microelectromechanical device further comprises at least a center stack, a first RF stack, a second RF stack, a first stack formed on a first base layer, and a second stack formed on a second base layer, each stack disposed between the beam and the first and second RF conductors. The beam is configured to deflect downward to first contact the first stack formed on the first base layer and the second stack formed on the second base layer simultaneously or the center stack, before contacting the first RF stack and the second RF stack simultaneously.

First claim

What is claimed is:

1. A microelectromechanical device, comprising:
a backplane comprising at least two RF conductors;
a plurality of bottom electrodes disposed on the backplane;
a top electrode disposed above and spaced from the backplane;
a beam disposed between the backplane and the top electrode, the beam moveable between the at least two RF conductors and the top electrode, wherein the beam comprises one or more hinge sections and at least two stiff waffle sections, wherein a hinge section of the one or more hinge sections is disposed between adjacent waffle sections of the at least two stiff waffle sections;
at least two RF stacks disposed above the at least two RF conductors; and
a center stack disposed between the at least two RF stacks, wherein the one or more hinge sections comprise a first hinge section configured to contact the center stack prior to the beam contacting the at least two RF stacks.

2. The microelectromechanical device of claim 1 , wherein the one or more hinge sections further comprise a second hinge section and a third hinge section.

3. The microelectromechanical device of claim 2 , wherein the at least two stiff waffle sections comprise a first stiff waffle section disposed adjacent to the second hinge section, a second stiff waffle section disposed between the second hinge section and the first hinge section, a third stiff waffle section disposed between the first hinge section and the third hinge section, and a fourth stiff waffle section disposed adjacent to the third hinge section.

4. The microelectromechanical device of claim 1 , further comprising:
a first base layer and a second base layer disposed on the backplane below and spaced from the beam; and
at least two stacks of layers disposed on the at least the first and second base layers, wherein the at least two stacks of layers are disposed adjacent to the at least two RF stacks.

5. The microelectromechanical device of claim 4 , wherein the at least two stacks of layers disposed on the at least the first and second base layers have a greater height than each of the at least two RF stacks and the center stack.

6. The microelectromechanical device of claim 1 , wherein the beam comprises a bottom beam layer and a top beam layer.

7. The microelectromechanical device of claim 6 , wherein one or more portions of a spun layer disposed between the bottom beam layer and the top beam layer are removed to form the one or more hinge sections.

8. The microelectromechanical device of claim 6 , wherein the at least two stiff waffle sections comprise a plurality of vias disposed between the bottom beam layer and the top beam layer.

9. The microelectromechanical device of claim 6 , wherein the bottom beam layer comprises at least two beam contact layers disposed above the at least two RF stacks.

10. The microelectromechanical device of claim 9 , wherein the at least two beam contact layers are recessed into the bottom beam layer.

11. A method of forming a microelectromechanical device, comprising:
forming a plurality of bottom electrodes on a backplane comprising at least two RF conductors;
depositing a bottom dielectric layer over the backplane and plurality of bottom electrodes;
etching one or more portions of the bottom dielectric layer;
depositing at least two RF stacks in at least two of the one or more etched portions, wherein the at least two RF stacks are disposed above the at least two RF conductors;
depositing a center stack in one of the one or more etched portions, wherein the center stack is disposed between the at least two RF stacks;
depositing a bottom beam layer above the bottom dielectric layer, the at least two RF stacks, and the center stack, wherein the bottom beam layer is spaced from the bottom dielectric layer, the at least two RF stacks, and the center stack, and wherein the bottom beam layer comprises one or more hinge sections and at least two stiff waffle section, such that a hinge section of the one or more hinge sections is disposed between two adjacent waffle sections of the at least two stiff waffle sections;
depositing a spun layer on the bottom beam layer;
etching one or more vias in the spun layer to form one or more hinge sections;
depositing a top beam layer on the spun layer and within the one or more vias, wherein the bottom beam layer and the top beam layer form a beam;
depositing a partial cavity layer above the beam, wherein a portion of the partial cavity layer forms a top electrode;
removing the spun layer; and
depositing a seal layer above the beam and the partial cavity layer to enclose the beam in a cavity.

12. The method of claim 11 , wherein a first hinge section of the one or more hinge sections of the beam is configured to contact the center stack prior to the beam contacting the at least two RF stacks.

13. The method of claim 11 , wherein the one or more hinge sections further comprise a second hinge section and a third hinge section, and wherein the at least two stiff waffle sections comprise a first stiff waffle section disposed adjacent to the second hinge section, a second stiff waffle section disposed between the second hinge section and the first hinge section, a third stiff waffle section disposed between the first hinge section and the third hinge section, and a fourth stiff waffle section disposed adjacent to the third hinge section.

14. The method of claim 11 , further comprising:
etching one or more openings in the bottom dielectric layer prior to depositing the at least two RF stacks;
depositing a first base layer and a second base layer onto the one or more openings of the bottom dielectric layer; and
depositing at least two of layers stacks on at least the first and second base layers, wherein the at least two stacks of layers disposed on the at least the first and second base layers have a greater height than each of the at least two RF stacks and the center stack.

Assignees

• Qorvo Us Inc

Inventors

• Van Kampen Robertus Petrus
• Barron Lance
• Knipe Richard L

Classifications

• H01H59/0009 Primary

  making use of micromechanics · CPC title

• H01H2059/0072

  with stoppers or protrusions for maintaining a gap, reducing the contact area or for preventing stiction between the movable and the fixed electrode in the attracted position · CPC title

• B81B3/0051

  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 title

• B81B2201/016

  having a bridge fixed on two ends and connected to one or more dimples · CPC title

• H01P1/127

  Strip line switches · CPC title