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

• US 20150041932A1
• Filed: 10/16/2014
• Published: 02/12/2015
• Est. Priority Date: 06/25/2010
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: HERRIN, Russell T., JAHNES, Christopher V., STAMPER, Anthony K., WHITE, Eric J.
• Granted Patent: US 10,173,889 B2
• Time in Patent Office: Days
• US Class Current: 257/418
• 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 method of forming at least one Micro-Electro-Mechanical System (MEMS) cavity includes forming a first sacrificial cavity layer over a wiring layer and substrate. The method further includes forming an insulator layer over the first sacrificial cavity layer. The method further includes performing a reverse damascene etchback process on the insulator layer. The method further includes planarizing the insulator layer and the first sacrificial cavity layer. The method further includes venting or stripping of the first sacrificial cavity layer to a planar surface for a first cavity of the MEMS.

Claims

1. A planar MEMS structure, comprising:

a lower cavity having a planar upper surface;

an upper cavity having a planar upper surface;

a via connecting the upper cavity to the lower cavity;

electrodes formed in the upper cavity which act as beams for the MEMS structure; and

a fixed wire formed in the lower cavity, below the beams.

2. The structure of claim 1, further comprising an opening over the lower cavity.

3. The structure of claim 1, further comprising an oxide film formed over the electrodes.

4. The structure of claim 1, further comprising:

an insulator material formed over the fixed wire;

a first electrode of the electrodes formed over the insulator material;

a second insulator material formed over the first electrode and exposed portions of the insulator material;

a second electrode of the electrodes formed over the second insulator layer, and within vias to contact the first electrode;

a trench in the insulator material, exposing portions of the lower cavity.

5. The structure of claim 1, wherein at least one of a corner of the upper cavity and the lower cavity are chamfered.

6. The structure of claim 5, wherein the chamfering is at a 45 degree corner angle.