Micro-electro-mechanical system (MEMS) and related actuator bumps, methods of manufacture and design structures

• US 9,120,667 B2
• Filed: 06/20/2011
• Issued: 09/01/2015
• Est. Priority Date: 06/20/2011
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Jahnes, Christopher V., Stamper, Anthony K.
• Primary Examiner(s): Mullins, Burton
• Assistant Examiner(s): Andrews, Michael
• Application Number:
  US13/164,331
• Publication Number:
  US 20120319528A1
• Time in Patent Office: 1,534 Days
• Field of Search: 310/309, 310/308, 310/310, 298/27, 216/2, 216/14, 216/17, 216/39
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/016 having a bridge fixed on two ends and connected to one or more dimples
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 2203/04 Electrodes
• CPC Class Codes: B81B 3/001 Structures having a reduced contact area, e.g. with bumps or with a textured surface
• CPC Class Codes: B81B 7/0006 Interconnects
• CPC Class Codes: B81C 1/0015 Cantilevers switches using MEMS H01H1/0036; electrostatic relays using micromechanics H01H59/0009; microelectro-mechanical resonators H03H9/02244
• CPC Class Codes: B81C 1/00293 maintaining a controlled atmosphere with processes not provided for in B81C1/00285
• CPC Class Codes: B81C 2203/0145 Hermetically sealing an opening in the lid
• CPC Class Codes: G06F 2115/04 Micro electro-mechanical systems [MEMS]
• CPC Class Codes: G06F 30/30 Circuit design
• CPC Class Codes: G06F 30/39 Circuit design at the physical level physical level design for reconfigurable circuits G06F30/347
• CPC Class Codes: H01H 1/0036 Switches making use of microelectromechanical systems [MEMS] for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009
• CPC Class Codes: H01H 2001/0057 the contact materials containing refractory materials, e.g. tungsten
• CPC Class Codes: H01H 59/0009 making use of micromechanics
• CPC Class Codes: Y10T 29/49121 Beam lead frame or beam lead device

Abstract

Micro-Electro-Mechanical System (MEMS) structures, methods of manufacture and design structures are provided. The method of forming a MEMS structure includes forming fixed actuator electrodes and a contact point on a substrate. The method further includes forming a MEMS beam over the fixed actuator electrodes and the contact point. The method further includes forming an array of actuator electrodes in alignment with portions of the fixed actuator electrodes, which are sized and dimensioned to prevent the MEMS beam from collapsing on the fixed actuator electrodes after repeating cycling. The array of actuator electrodes are formed in direct contact with at least one of an underside of the MEMS beam and a surface of the fixed actuator electrodes.

Claims

1. A method of forming a MEMS structure, comprising:

patterning a wiring layer on a substrate to form fixed actuator electrodes and a contact point;

forming a sacrificial material on the wiring layer;

patterning the sacrificial material with an array of trenches above the wiring layer, the trenches being dimensioned to a predetermined height and width;

filling the array of trenches with material;

forming a MEMS beam above the filled array of trenches and in contact with the material in the array of trenches;

forming additional sacrificial material over the MEMS beam;

forming a lid over the additional sacrificial material over the MEMS beam;

forming at least one vent hole in the lid; and

venting the sacrificial material under the MEMS beam and the additional sacrificial material over the MEMS beam, such that the material within the array of trenches becomes suspended from an underside of the MEMS beam, forming an array of actuator bumps at the predetermined height and width.

2. The method of claim 1, wherein the array of actuator bumps are in direct contact with and extend from an insulator material forming an underside of the MEMS beam.

3. The method of claim 1, wherein the array of actuator bumps are formed in alignment with the fixed actuator electrodes under the MEMS beam.

4. The method of claim 1, wherein the array of actuator bumps are formed in alignment with spaces or openings between the fixed actuator electrodes under the MEMS beam so as to land on the substrate when the MEMS beam is actuated downward.

5. The method of claim 1, wherein:

the array of actuator bumps are formed in alignment with dummy actuator electrodes in a fixed actuator level under the MEMS beam; and

the dummy actuator electrodes are formed on the wiring layer as one of;

individually electrically floating electrodes; and

connected individually electrically floating electrodes.

6. The method of claim 5, wherein the individually electrically floating electrodes or the connected individually electrically floating electrodes are biased to a known voltage.

7. The method of claim 1, wherein the array of actuator bumps are formed in alignment with insulator material between portions of the fixed actuator electrodes.

8. The method of claim 1, wherein the array of actuator bumps are all formed with a uniform height and width.

9. The method of claim 1, wherein the array of actuator bumps are formed with differing heights and widths using at least one of different etch rates and masking steps.

10. The method of claim 9, wherein the actuator bumps farthest away from the contact point are formed deeper than the actuator bumps formed closer to the contact point.

11. The method of claim 1, wherein the array of actuator bumps are formed under insulator material and between portions of conductor material forming the MEMS beam.

12. The method of claim 1, wherein an additional array of actuator bumps are formed on the wiring layer, and extend towards the MEMS beam.