Electro-mechanical device having a charge dissipation layer and a method of manufacture therefor

• US 6,869,815 B2
• Filed: 08/22/2002
• Issued: 03/22/2005
• Est. Priority Date: 08/22/2002
• Status: Expired due to Term

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global)), Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.)
• Inventors: Jin, Sungho, Zhu, Wei, Gasparyan, Arman, Shea, Herbert R., Van Dover, Robert B.
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Lee, Calvin
• Application Number:
  US10/226,930
• Publication Number:
  US 20040047546A1
• Time in Patent Office: 943 Days
• Field of Search: 438 29- 32, 438/38, 438 69- 79, 438 50- 52
• US Class Current: 438/29
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 3/0035 Constitution or structural means for controlling the movement of the flexible or deformable elements
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/3518 the reflective optical element being an intrinsic part of a MEMS device, i.e. fabricated together with the MEMS device MEMS devices in general B81B; manufacture of MEM devices in general B81C; micromechanical devices controlling the direction of light G02B26/0833
• CPC Class Codes: G02B 6/3544 2D constellations, i.e. with switching elements and switched beams located in a plane
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02B 6/357 Electrostatic force electrostatic forces controlling reflecting elements in general G02B26/0841
• CPC Class Codes: G02B 6/3584 constructional details of an associated actuator having a MEMS construction, i.e. constructed using semiconductor technology such as etching MEMS per se B81B, B81C
• CPC Class Codes: G02B 6/3594 Characterised by additional functional means, e.g. means for variably attenuating or branching or means for switching differently polarized beams

Abstract

The present invention provides a micro-electro-mechanical system (MEMS) device, a method of manufacture therefore, and an optical communications system including the same. The device includes an electrode located over a substrate and a charge dissipation layer located proximate and electrically coupled to the substrate. The device may further include a moveable element located over the electrode.

Claims

1. A micro-electro-mechanical system (MEMS) device, comprising:

a substrate;

an electrode located in contact with the substrate;

a charge dissipation layer having an electrical resistivity ranging from about 1E2 ohm-cm to about 1E12 ohm-cm located proximate and electrically coupled to the substrate; and

a moveable element located over the electrode.

2. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer is a tunable charge dissipation layer.

3. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer comprises a conductive or semi-conductive material.

4. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer comprises a material selected from the group of materials consisting of:

cobalt iron oxide;

nickel iron oxide;

nickel zinc iron oxide;

manganese zinc iron oxide; and

iron-iron oxide.

5. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer comprises a material selected from the group of materials consisting of:

gadolinium iron oxide;

lanthanum nickel oxide;

lanthanum cobalt oxide;

lanthanum chromium oxide;

lanthanum manganese oxide;

lanthanum strontium manganese oxide;

lanthanum calcium manganese oxide; and

yttrium barium copper oxide.

6. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer comprises a single or multi-oxide material containing a valence defect.

7. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the substrate comprises a material susceptible to a static charge build-up.

8. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer has an electrical resistivity ranging from about 1E5 ohm-cm to about 1E9 ohm-cm.

9. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer has a thickness ranging from about 5 nm to about 100 nm.

10. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer is located on the substrate but under the electrode.

11. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the charge dissipation layer is located on the substrate and over the electrode.

12. The micro-electro-mechanical system (MEMS) device as recited in claim 1 wherein the electrode is a first electrode, and further including a second electrode positioned proximate the first electrode, and wherein the charge dissipation layer is located in an inter-electrode gap created by the first and second electrodes.

13. A method of manufacturing a micro-electro-mechanical system (MEMS) device, comprising:

providing a substrate;

creating an electrode in contact with the substrate;

forming a charge dissipation layer having an electrical resistivity ranging from about 1E2 ohm-cm to about 1E12 ohm-cm proximate and electrically coupled to the substrate; and

placing a moveable element over the electrode.

14. The method as recited in claim 13 wherein providing a substrate includes providing a substrate comprising a material susceptible to a static charge build-up.

15. The method as recited in claim 13 further including tuning a resistivity of the charge dissipation layer using a post-formation heat treatment.

16. The method as recited in claim 13 wherein forming the charge dissipation layer includes forming the charge dissipation layer using a material selected from the group of materials consisting of:

cobalt iron oxide;

nickel iron oxide;

nickel zinc iron oxide;

manganese zinc iron oxide;

iron—

iron oxide;

gadolinium iron oxide;

lanthanum nickel oxide;

lanthanum cobalt oxide;

lanthanum chromium oxide;

lanthanum manganese oxide;

lanthanum strontium manganese oxide;

lanthanum calcium manganese oxide;

yttrium barium copper oxide; and

a single or multi-oxide material containing a valence defect.

17. The method as recited in claim 13 wherein forming the charge dissipation layer includes forming the charge dissipation layer having an electrical resistivity ranging from about 1E5 ohm-cm to about 1E9 ohm-cm.

18. The method as recited in claim 13 wherein forming the charge dissipation layer includes forming the charge dissipation layer having a thickness ranging from about 5 nm to about 100 nm.

19. The method as recited in claim 13 wherein forming the charge dissipation layer includes forming the charge dissipation layer on the substrate but under the electrode, forming the charge dissipation layer on the substrate and over the electrode, or forming the charge dissipation layer in an inter-electrode gap created by the electrode and a second electrode.

20. The method as recited in claim 13 wherein forming the charge dissipation layer includes fanning the charge dissipation layer using a process selected from the group of processes consisting of:

reactive sputtering;

radio frequency (RF) sputtering;

co-sputtering;

e-beam evaporation;

electro-deposition;

ion-beam evaporation; and

chemical vapor deposition.

21. The optical communications system recited in claim 20 wherein the micro-electro-mechanical system (MEMS) device is a surface machined micro-electro-mechanical system (MEMS) device or a two-part SOI micro-electro-mechanical system (MEMS) device.

22. An optical communications system, comprising:

input/output fiber bundles;

a micro-electro-mechanical system (MEMS) device, comprising;

a substrate;

an electrode located over in contact with the substrate;

a charge dissipation layer having an electrical resistivity ranging from about 1E2 ohm-cm to about 1E12 ohm-cm located proximate and electrically coupled to the substrate; and

a moveable element located over the electrode;

imaging lenses interposed between the input/output fiber bundles and the micro-electro-mechanical system (MEMS) device; and

a reflector.

23. The optical communications system recited in claim 22 that comprises one or more devices selected from the group consisting of:

a micro-electro-mechanical system (MEMS) cross connect system;

an optical power gain equalizer system;

a wavelength division multiplexing telecommunications system;

a light signal switch in an optical communications system; and

a variable optical attenuator in an optical communications system.