Systems and methods of controlling micro-electromechanical devices

• US 7,355,782 B2
• Filed: 11/29/2006
• Issued: 04/08/2008
• Est. Priority Date: 10/05/1999
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Miles, Mark W.
• Primary Examiner(s): Ben; Loha
• Application Number:
  US11/564,800
• Publication Number:
  US 20070146376A1
• Time in Patent Office: 496 Days
• Field of Search: 359290-292, 359/237, 359/238, 359/260, 359/298, 345/31, 345/85, 345/212, 345/540, 327/108, 327/309, 327/381, 327/382, 735/141.6, 735/141.8, 735/143.2, 257/22, 257/38, 257/414, 330/168, 330/277, 330/302, 349/1, 385/147, 324/76.11, 324/761, 361/139, 200/181, 326/38, 326/101
• US Class Current: 359/291
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01J 3/0256 Compact construction
• CPC Class Codes: G01J 3/26 using multiple reflection, e.g. Fabry-Perot interferometer, variable interference filters
• CPC Class Codes: G01L 5/0047 measuring forces due to residual stresses
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 2006/12109 Filter
• CPC Class Codes: G02B 2006/12126 Light absorber
• CPC Class Codes: G02B 2006/12159 Interferometer
• CPC Class Codes: G02B 2006/12164 Multiplexing; Demultiplexing
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 26/02 for controlling the intensity of light G02B26/004 takes precedence
• CPC Class Codes: G02B 26/08 for controlling the direction of light in light guides G02B6/35
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/122 Basic optical elements, e.g. light-guiding paths
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: G02B 6/13 Integrated optical circuits characterised by the manufacturing method
• CPC Class Codes: G02B 6/266 the optical element being an attenuator
• CPC Class Codes: G02B 6/3516 : the reflective optical element moving along the beam path, e.g. controllable diffractive effects using multiple micromirrors within the beam
• CPC Class Codes: G02B 6/3522 : the optical element enabling or impairing total internal reflection using evanescent coupling G02B6/3536
• CPC Class Codes: G02B 6/353 : the optical element being a shutter, baffle, beam dump or opaque element absorbers on light guide termination G02B6/243
• CPC Class Codes: G02B 6/3536 : involving evanescent coupling variation, e.g. by a moving element such as a membrane which changes the effective refractive index mode converters G02B6/14; adjustable lateral coupling between waveguides G02B6/283; electro- optical refractive index variations G02F1/0118
• CPC Class Codes: G02B 6/3546 : NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/3548 : 1xN switch, i.e. one input and a selectable single output of N possible outputs
• 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 6/3578 : Piezoelectric force piezoelectric forces controlling reflecting elements in general G02B26/0858; piezo-optic devices G02F1/0131
• 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
• CPC Class Codes: G02B 6/3598 : Switching means directly located between an optoelectronic element and waveguides, including direct displacement of either the element or the waveguide, e.g. optical pulse generation based on changing the optical properties of the medium G02F1/00; optical pulse generation in optical transmitters H04B10/508; optical pulse generation by controlling laser operation H01S3/00
• CPC Class Codes: G02B 6/43 : Arrangements comprising a plurality of opto-electronic elements and associated optical interconnections
• CPC Class Codes: G09G 2310/02 : Addressing, scanning or driving the display screen or processing steps related thereto
• CPC Class Codes: G09G 2310/0254 : Control of polarity reversal in general, other than for liquid crystal displays
• CPC Class Codes: G09G 2310/06 : Details of flat display driving waveforms
• CPC Class Codes: G09G 3/3466 : based on interferometric effect

Abstract

An interference modulator (Imod) incorporates anti-reflection coatings and/or micro-fabricated supplemental lighting sources. An efficient drive scheme is provided for matrix addressed arrays of IMods or other micromechanical devices. An improved color scheme provides greater flexibility. Electronic hardware can be field reconfigured to accommodate different display formats and/or application functions. An IMod'"'"'s electromechanical behavior can be decoupled from its optical behavior. An improved actuation means is provided, some one of which may be hidden from view. An IMod or IMod array is fabricated and used in conjunction with a MEMS switch or switch array. An IMod can be used for optical switching and modulation. Some IMods incorporate 2-D and 3-D photonic structures. A variety of applications for the modulation of light are discussed. A MEMS manufacturing and packaging approach is provided based on a continuous web fed process. IMods can be used as test structures for the evaluation of residual stress in deposited materials.

Claims

1. A method of making a control circuit for a Micro-Electro-Mechanical System (“

MEMS”

), the method comprising;

depositing a silicon layer on a substrate;

patterning the deposited silicon layer;

depositing a structural material on the silicon layer;

patterning the deposited structural material to form a source beam, a drain structure, and a gate structure;

plating a non-corroding metal on the deposited structural material; and

etching away at least some of the silicon layer.

2. The method of claim 1, wherein the deposited structural material comprises an aluminum alloy.

3. The method of claim 1, wherein the non-corroding metal comprises at least one of gold, iridium, or platinum.

4. The method of claim 3, wherein the plated non-corroding material is configured to minimize contact resistance in the control circuit.

5. The method of claim 1, wherein the silicon layer comprises a sacrificial material.

6. A device for controlling a Micro-Electro-Mechanical System (“

MEMS”

), the device comprising;

a silicon layer deposited over a substrate, wherein the silicon layer is patterned and at least some of the silicon layer is etched away;

a structural material deposited over the silicon layer, wherein the structural material comprises a source beam, a drain structure, and a gate structure; and

a non-corroding metal deposited over the structural material, wherein the non-corroding metal is plated.

7. The device of claim 6, wherein the structural material comprises an aluminum alloy.

8. The device of claim 6, wherein the non-corroding metal comprises at least one of gold, iridium or platinum.

9. The device of claim 8, wherein the non-corroding metal is configured to minimize contact resistance.

10. The device of claim 6, further comprising a voltage generator configured to apply a voltage between the source beam and gate structure to deflect the source beam toward the gate structure.

11. The device of claim 8, wherein the source beam is configured to deflect toward the gate structure in a plane parallel to the substrate.

12. The device of claim 8, wherein the source beam is configured to deflect toward the gate structure by a distance that is sufficient to establish electrical contact between the source beam and the drain structure.

13. The device of claim 6, wherein the source beam comprises a switch beam, a contact beam and an insulator material located between the switch beam and the contact beam, and wherein the insulator material is configured to electrically isolate the switch beam from the contact beam.