Integrated circuit switches, design structure and methods of fabricating the same

• US 9,284,185 B2
• Filed: 09/16/2013
• Issued: 03/15/2016
• Est. Priority Date: 08/27/2009
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: GlobalFoundries, Inc.
• Inventors: Anderson, Felix P., McDevitt, Thomas L., Stamper, Anthony K., Costa, Julio C., Hammond, Jonathan H.
• Primary Examiner(s): SUN, YU-HSI DAVID
• Application Number:
  US14/027,939
• Publication Number:
  US 20140017844A1
• Time in Patent Office: 911 Days
• Field of Search: 438/52
• US Class Current: 1/1
• CPC Class Codes: B81B 2201/014 having a cantilever fixed on one side connected to one or more dimples
• CPC Class Codes: B81B 3/0018 Structures acting upon the moving or flexible element for transforming energy into mechanical movement or vice versa, i.e. actuators, sensors, generators
• 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 1/00333 Aspects relating to packaging of MEMS devices, not covered by groups B81C1/00269 - B81C1/00325
• CPC Class Codes: B81C 2203/0136 Growing or depositing of a covering layer
• CPC Class Codes: B81C 2203/0145 Hermetically sealing an opening in the lid
• CPC Class Codes: G06F 30/39 Circuit design at the physical level physical level design for reconfigurable circuits G06F30/347
• CPC Class Codes: H01L 21/302 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting

Abstract

Integrated MEMS switches, design structures and methods of fabricating such switches are provided. The method includes forming at least one tab of sacrificial material on a side of a switching device which is embedded in the sacrificial material. The method further includes stripping the sacrificial material through at least one opening formed on the at least one tab which is on the side of the switching device, and sealing the at least one opening with a capping material.

Claims

1. A method of manufacturing a structure, comprising:

depositing a first sacrificial material directly on a contact electrode and a forcing electrode of a switching device;

forming the switching device on the first sacrificial material;

forming at least one tab on a side of the switching device, which is embedded in the first sacrificial material, wherein the at least one tab is formed by depositing additional sacrificial material over a dielectric layer in a separate deposition process from that of the depositing of the first sacrificial material directly on the contact electrode and the forcing electrode;

depositing a second sacrificial material in a separate deposition process from that of the deposition of the additional sacrificial material, and the second sacrificial material is deposited on the switching device, on a side of the at least one tab formed with the additional sacrificial material;

depositing a cap layer on the second sacrificial material over the switching device and the at least one tab formed with the additional sacrificial material;

stripping the first sacrificial material, the second sacrificial material and the at least one tab through at least one opening formed in the cap layer on the at least one tab which is on the side of the switching device; and

sealing the at least one opening with an additional layer.

2. The method of claim 1, wherein the additional sacrificial material forming the at least one tab is deposited at a level lower than an underside surface of a cantilever beam which forms a upper structure of the switching device.

3. The method of claim 1, wherein the at least one opening is fully aligned over at the least one tab.

4. The method of claim 1, wherein the at least one opening is offset with respect to the at least one tab.

5. The method of claim 1, wherein the at least one opening is formed on a side of the at least one tab.

6. The method of claim 1, wherein the first sacrificial material is silicon and the stripping is performed using XeF₂ gas.

7. The method of claim 1, wherein the first sacrificial material is PMGI and the stripping is performed using N-methyl-2-pyrrolidine (NMP) and/or dimethylsulfoxide (DMSO)-based removers.

8. The method of claim 1, wherein the sealing the at least one opening with the additional layer eliminates material variability of a cantilever beam which forms a portion of the switching device.

9. The method of claim 1, wherein the cap layer and the additional layer are dielectric material.

10. The method of claim 1, wherein the additional layer completely fills the at least one opening.

11. The method of claim 1, further comprising forming a cantilever beam on the first sacrificial material, the cantilever beam forming an upper structure of the switching device, the cantilever beam comprising AlCu with an electroplated gold liner on an underside of the cantilever beam, and the at least one tab is formed at a corner of the structure.

12. The method of claim 1, further comprising forming a cantilever beam on the first sacrificial material, the cantilever beam forming an upper structure of the switching device, the first sacrificial material is about 50 microns wide and about 200 microns long, the additional sacrificial material is about 0.2 microns in height and about 10 microns in length, and the cantilever beam is about 100 microns long and about 0.5 microns to 10 microns thick.

13. A method in a computer-aided design system for generating a functional design model for manufacturing a physical MEMS structure, said method comprising:

generating a functional representation of a first sacrificial material deposited directly on a contact electrode and a forcing electrode of a switching device;

generating a functional representation of the switching device deposited on the first sacrificial material;

generating a functional representation of at least one tab deposited on a side of the switching device, which is embedded in the first sacrificial material, wherein the at least one tab is formed by depositing additional sacrificial material only directly on a dielectric layer in a separate deposition process from that of a deposition process used to deposit the first sacrificial material directly on the contact electrode and the forcing electrode;

generating a function representation of a second sacrificial material deposited in a separate deposition process from that of the deposition of the additional sacrificial material, and the second sacrificial material is deposited on the switching device, on a side of the at least one tab formed with the additional sacrificial material;

generating a functional representation of the first sacrificial material, the second sacrificial material and the at least one tab stripped through at least one opening formed on the at least one tab which is on the side of the switching device; and

generating a functional representation of the at least one opening sealed with a capping material deposited on the second sacrificial material over the switching device and the at least tab deposited with the additional sacrificial material.

14. The method of claim 13, wherein the at least one opening is offset with respect to the at least one tab.

15. The method of claim 13, wherein the at least one opening is formed on a side of the at least one tab.

16. The method of claim 13, further comprising manufacturing the physical MEMS structure.