Method of forming a micro-electro-mechanical system (MEMS) structure

• US 9,593,007 B2
• Filed: 10/21/2014
• Issued: 03/14/2017
• 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): Kim, Paul D
• Application Number:
  US14/519,772
• Publication Number:
  US 20150054100A1
• Time in Patent Office: 875 Days
• Field of Search: 295/921, 295/94, 296/06, 296/091, 296/22, 298/25, 298/30, 298/43, 298/46, 298/74, 361/277, 361/278, 361/280, 361/281
• 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 2203/0163 Spring holders
• 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 3/0021 Transducers for transforming electrical into mechanical energy or vice versa dynamo-electric machines H02K99/00; electrostatic machines H02N1/00; piezoelectric devices H10N30/00
• CPC Class Codes: B81B 3/0059 Constitution or structural means for controlling the movement not provided for in groups B81B3/0037 - B81B3/0056
• CPC Class Codes: B81B 3/0072 For controlling internal stress or strain in moving or flexible elements, e.g. stress compensating layers
• CPC Class Codes: B81B 7/0006 Interconnects
• CPC Class Codes: B81B 7/008 MEMS characterised by an electronic circuit specially adapted for controlling or driving the same B81B7/0087 takes precedence; arrangements for starting, regulating, braking, or otherwise controlling an actuator H02N; control arrangements or circuits for visual indicators G09G3/00
• CPC Class Codes: B81C 1/00015 for manufacturing microsystems
• 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 1/00476 removing a sacrificial layer B81C1/00912 takes precedence
• CPC Class Codes: G06F 30/30 Circuit design
• CPC Class Codes: H10N 30/2042 Cantilevers, i.e. having one fixed end
• CPC Class Codes: H10N 30/304 Beam type
• CPC Class Codes: H10N 30/308 Membrane type
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/4908 Acoustic transducer
• 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. A wiring layer is formed on a substrate comprising actuator electrodes and a contact electrode. A MEMS beam is formed above the wiring layer and at least one spring is formed and attached to at least one end of the MEMS beam. At least one spring has a predetermined spring constant based on a coefficient of thermal expansion (CTE) mismatch between materials of the MEMS structure and the spring. Additionally, an array of mini-bumps is formed between the wiring layer and the MEMS beam. A size of a space between fixed actuator electrodes or dummy actuators is determined based on a lateral shift of the MEMS beam.

Claims

1. A method of forming a Micro-Electro-Mechanical (MEMS) structure, comprising:

forming a MEMS beam;

forming a plurality of electrodes;

forming an array of mini-bumps between the MEMS beam and the plurality of electrodes; and

determining a size of a space between fixed actuator electrodes of the plurality of electrodes or a dummy actuator based on a lateral shift of the MEMS beam,

forming at least one spring extending both ends of the MEMS beam, wherein the at least one spring has a predetermined spring constant based on a coefficient of thermal expansion (CTE) mismatch between materials of the MEMS structure and the at least one spring.

2. The method of claim 1, wherein the determining provides a landing location of the array of mini-bumps when there is the lateral shift of the MEMS beam.

3. The method of claim 1, wherein determining comprises a location in which the array of the mini-bumps centered or nearly centered within the space between the fixed actuator electrodes.

4. The method of claim 1, further comprising forming a spring extending from at least one end of the MEMS beam.

5. The method of claim 1, wherein the MEMS beam comprises one or more layers of metal and dielectric and the layers have differing thermal expansion coefficients which, over a temperature range, induces beam curvature upwards or downwards, and the at least one spring provides for lateral beam shift when temperature changes, thereby reducing temperature-induced variation in actuation gap or beam curvature.