PLANAR CAVITY MEMS AND RELATED STRUCTURES, METHODS OF MANUFACTURE AND DESIGN STRUCTURES

• US 20130221454A1
• Filed: 02/15/2013
• Published: 08/29/2013
• Est. Priority Date: 06/25/2010
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: DUNBAR, George A. III, MALING, Jeffrey C., MURPHY, William J., STAMPER, Anthony K.
• Granted Patent: US 9,041,128 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 2201/014 having a cantilever fixed on one side connected to one or more dimples
• CPC Class Codes: B81B 2203/0118 Cantilevers
• CPC Class Codes: B81B 2203/04 Electrodes
• 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 1/00365 having low tensile stress between layers
• CPC Class Codes: B81C 1/00476 removing a sacrificial layer B81C1/00912 takes precedence
• CPC Class Codes: B81C 1/00619 Forming high aspect ratio structures having deep steep walls
• CPC Class Codes: B81C 1/00626 Processes for achieving a desired geometry not provided for in groups B81C1/00563 - B81C1/00619
• CPC Class Codes: B81C 1/00666 Treatments for controlling internal stress or strain in MEMS structures
• CPC Class Codes: B81C 2201/0109 Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108
• CPC Class Codes: B81C 2201/013 Etching
• CPC Class Codes: B81C 2201/0167 by adding further layers of materials having complementary strains, i.e. compressive or tensile strain
• CPC Class Codes: B81C 2201/017 Methods for controlling internal stress of deposited layers not provided for in B81C2201/0164 - B81C2201/0169
• CPC Class Codes: B81C 2203/0136 Growing or depositing of a covering layer
• CPC Class Codes: B81C 2203/0172 Seals
• CPC Class Codes: G06F 2115/04 Micro electro-mechanical systems [MEMS]
• 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 2057/006 Micromechanical piezoelectric relay
• CPC Class Codes: H01H 57/00 Electrostrictive relays; Piezoelectric relays
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H10N 30/306 : Cantilevers
• CPC Class Codes: Y10S 438/937 : Hillock prevention
• CPC Class Codes: Y10T 29/42 : Piezoelectric device making
• CPC Class Codes: Y10T 29/435 : Solid dielectric type
• CPC Class Codes: Y10T 29/49002 : Electrical device making
• CPC Class Codes: Y10T 29/49105 : Switch making
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49126 : Assembling bases
• CPC Class Codes: Y10T 29/4913 : Assembling to base an electrical component, e.g., capacitor, etc.
• CPC Class Codes: Y10T 29/49155 : Manufacturing circuit on or in base
• CPC Class Codes: Y10T 29/5313 : Means to assemble electrical device

Abstract

A Micro-Electro-Mechanical System (MEMS). The MEMS includes a lower chamber with a wiring layer and an upper chamber which is connected to the lower chamber. A MEMS beam is suspended between the upper chamber and the lower chamber. A lid structure encloses the upper chamber, which is devoid of structures that interfere with a MEMS beam. The lid structure has a surface that is conformal to a sacrificial material vented from the upper chamber.

Claims

1. A structure, comprising:

a lower chamber with a wiring layer;

an upper chamber which is connected to the lower chamber;

a MEMS beam suspended between the upper chamber and the lower chamber; and

a lid structure enclosing the upper chamber, which is devoid of structures that interfere with a MEMS beam, wherein the lid structure has a surface that is conformal to a sacrificial material vented from the upper chamber.

2. The structure of claim 1, wherein at least one of:

electrical vias within the upper chamber have a top view profile of rounded or chamfered profiles; and

a cavity via connecting the upper chamber with the lower chamber has a top view profile of rounded or chamfered profiles.

3. The structure of claim 1, wherein a bottom surface of the lid structure comprises a tapered sidewall profile having an angle of less than 90 degrees.

4. The structure of claim 1, wherein the upper chamber and the lower chamber are connected together by a cavity via.

5. The structure of claim 1, further comprising electrical vias with a top view profile of rounded or chamfered edges.

6. The structure of claim 5, wherein at least one of the electrical vias is formed with a taper to reduce a seam or void in subsequent sacrificial material deposition processes.

7. The structure of claim 1, wherein at least one vent hole in the lid structure is circular or nearly circular, to minimize an amount of subsequent material needed to pinch off the at least one vent hole.

8. The structure of claim 1, wherein the MEMS beam is a cantilever beam.

9. The structure of claim 1, wherein the MEMS beam comprises an oxide bumper.

10. The structure of claim 1, wherein the MEMS beam is a composite beam.

11. The structure of claim 10, wherein the MEMS beam comprises at least an insulator material and a metal layer.

12. The structure of claim 10, wherein the MEMS beam comprise a lower electrode, an insulator material and an upper electrode.

13. The structure of claim 12, wherein a ratio of the lower electrode to the upper electrode has a pattern factor of 0.8:

1.

14. The structure of claim 12, wherein the lower electrode and the upper electrode are unbalanced.