INTEGRATED CIRCUIT SWITCHES, DESIGN STRUCTURE AND METHODS OF FABRICATING THE SAME

• US 20140017844A1
• Filed: 09/16/2013
• Published: 01/16/2014
• Est. Priority Date: 08/27/2009
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: ANDERSON, Felix P., McDevitt, Thomas L., Stamper, Anthony K.
• Granted Patent: US 9,284,185 B2
• Time in Patent Office: Days
• US Class Current: 438/52
• 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:

forming at least one tab of sacrificial material on a side of a switching device which is embedded in the sacrificial material;

depositing a cap layer over the switching device and the at least one tab;

stripping the sacrificial material 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 material.

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

3. The method of claim 1, wherein the 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.

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

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

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

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

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

9. The method of claim 1, wherein the sacrificial material forming the at least one tab is deposited at a same time as depositing the sacrificial material embedding a bottom portion of the switching device.

10. The method of claim 1, wherein the sacrificial material forming the at least one tab is deposited at a same time as depositing the sacrificial material embedding a top portion of the switching device.

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

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

13. A method of forming a structure, comprising:

performing a wet etching process to strip sacrificial material that embeds a lower and an upper portion of an active device formed within a dome structure; and

performing a dry etching process to strip a layer of a thin sacrificial layer deposited on a lower metal layer of the active device.

14. The method of claim 13, wherein the sacrificial layer deposited on the lower metal layer is a sacrificial silicon layer or Polyarylene Ether.

15. A MEMS structure, comprising:

a lower forcing electrode and a lower contact electrode, remote from the lower forcing electrode;

a cantilever beam positioned above the lower forcing electrode and the lower contact electrode; and

a capping layer which hermetically seals the lower forcing electrode, the lower contact electrode and the cantilever beam, the capping layer having a sealed portion positioned on a side of the lower contact electrode, remote from the lower forcing electrode and an end portion of the cantilever beam.

16. The structure of claim 15, wherein the cantilever beam is devoid of stresses from material variability of a sealing material used to seal the capping layer.

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

generating a functional representation of at least one tab of sacrificial material on a side of a switching device which is embedded in the sacrificial material;

generating a functional representation of the sacrificial material 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.

18. The method of claim 17, wherein the at least one opening is offset with respect to the at least one tab.

19. The method of claim 17, wherein the at least one opening is formed on a side of the at least one tab.

20. The method of claim 17, wherein the sacrificial material of the at least one tab is deposited at approximately a level of an underside surface of a cantilever beam which forms an upper structure of the switching device.