Integrated mirror array and circuit device with improved electrode configuration

• US 20020110312A1
• Filed: 01/25/2001
• Published: 08/15/2002
• Est. Priority Date: 07/20/2000
• Status: Abandoned Application

• Current Assignee: Nayna Networks, Inc.
• Original Assignee: Nayna Networks, Inc.
• Inventors: Gee, Dale A., Nayak, Anup K., Yang, Xiao
• Application Number:
  US09/771,296
• Publication Number:
  US 20020110312A1
• Time in Patent Office: Days
• US Class Current: 385/18
• CPC Class Codes: B81B 7/04 Networks or arrays of similar microstructural devices
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• 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 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 6/3556 NxM switch, i.e. regular arrays of switches elements of matrix type constellation
• 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 6/359 of the position of the moving element itself during switching, i.e. without monitoring the switched beams
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/003 using switches based on microelectro-mechanical systems [MEMS]

Abstract

An integrated circuit and mirror device and method. The device has a first substrate comprising a plurality of electrode groups, which comprise a plurality of electrodes. The device also has a mirror array formed on a second substrate. Each of the mirrors on the array has a mirror surface being able to pivot about a point in space. Each of the mirrors has a backside surface operably coupled to one of the electrode groups. The device has a capacitance spacer layer disposed between each of the electrode groups and its respective mirror. The mirror is one from the mirror array. A drive circuitry is coupled to each electrode groups. The drive circuitry is configured to apply a drive voltage to any one of the electrodes in each of the electrode groups. The drive circuitry is also disposed in the first substrate and is adapted to pivot each of the mirror faces about the point in space.

Claims

1. An integrated circuit and mirror device, the device comprising:

a first substrate comprising a plurality of electrode groups, each of the groups comprising a plurality of electrodes;

a mirror array formed on a second substrate, each of the mirrors on the array having a mirror surface being able to pivot about a point in space, each of the mirrors having a backside surface operably coupled to one of the electrode groups;

a capacitance spacer layer disposed between each of the electrode groups and its respective mirror, the mirror being one from the mirror array; and

a drive circuitry coupled to each electrode groups, the drive circuitry being configured to apply a drive voltage to any one of the electrodes in each of the electrode groups, the drive circuitry being disposed in the first substrate and being adapted to pivot each of the mirror faces about the point in space.

2. The device of claim 1 wherein the mirror array comprises at least an eight by eight array of mirrors.

3. The apparatus of claim 2 wherein the mirror array comprises at least a 100 by 100 array of mirrors.

4. The device of claim 1 further comprising a sense circuit coupled to each of the electrodes.

5. The device of claim 1 further comprising a multiplexing circuit coupled to the drive circuitry.

6. The device of claim 1 further comprising an input/output circuit coupled to each of the electrodes.

7. The device of claim 1 wherein the capacitance layer comprises a selected thickness to reduce the drive voltage by about 10% and less.

8. The device of claim 1 wherein the capacitance layer comprises a dielectric constant.

9. The device of claim 1 wherein the plurality of electrodes are formed on an upper metal layer.

10. The device of claim 9 wherein the upper metal layer further comprising a plurality of bonding pads.

11. The device of claim 9 wherein the capacitance layer comprising openings to expose a portion of each of the bonding pads.

12. The device of claim 11 wherein the capacitance layer is a patterned layer.

13. The device of claim 12 further comprising a shielding layer disposed between the drive circuitry and the plurality of electrodes.

14. The device of claim 13 wherein the shielding layer prevents a portion of electromagnetic noise from coupling between the drive circuitry and the electrodes.

15. The device of claim 14 wherein the shielding layer is made from a material selected from an aluminum bearing material or a titanium bearing material.

17. The method of claim 16 wherein the shielding layer prevents a portion of electromagnetic noise from coupling between the integrated circuit device layer and the electrodes.

18. The method of claim 16 wherein the capacitance layer comprises a dielectric constant greater than air.

20. The device of claim 19 wherein the shielding layer is selected from an aluminum layer or a titanium layer.

16. A method for manufacturing an integrated mirror array and integrated circuit, the method comprising:

forming an integrated circuit device layer on a first substrate;

forming a dielectric layer overlying the integrated circuit device layer;

forming a shielding layer overlying the dielectric layer;

forming a plurality of electrode groups overlying the shielding layer, each of the electrode groups comprising a plurality of electrodes overlying the shielding layer;

forming a capacitance layer overlying the plurality of electrode groups, the capacitance layer being formed at a predetermined thickness to provide a selected capacitance level; and

joining a second substrate comprising the mirror array to the first substrate, each of the mirrors on the array having a mirror surface being able to pivot about a point in space, each of the mirrors having a backside surface operably coupled to one of the electrode groups.

19. An integrated circuit and mirror device, the device comprising:

a first substrate comprising a plurality of electrode groups, each of the groups comprising a plurality of electrodes;

a mirror array formed on a second substrate, each of the mirrors on the array having a mirror surface being able to pivot about a point in space, each of the mirrors having a backside surface operably coupled to one of the electrode groups;

a capacitance spacer layer disposed between each of the electrode groups and its respective mirror, the mirror being one from the mirror array;

a drive circuitry coupled to each electrode groups, the drive circuitry being configured to apply a drive voltage to any one of the electrodes in each of the electrode groups, the drive circuitry being disposed in the first substrate and being adapted to pivot each of the mirror faces about the point in space; and

a shielding layer disposed between the drive circuitry and electrode groups, the shielding layer preventing a possibility of electromagnetic noise from coupling between the drive circuitry and the electrode groups.

21. A method for operating an actuation of a movable mirror device, the method comprising:

applying a selected voltage to drive electrode coupled to a mirror device to form an electrostatic force to actuate the mirror device, the mirror device being supported by one or more torsion bars that allows the mirror device to move in annular manner about an axis, the axis being parallel to the one or more torsion bars; and

controlling the selected voltage to the drive electrode where the mirror operates within a pull-in range, the pull-in range being dependent upon a spring constant of the torsion bar, an angular position of the mirror device, a permittivity of at least a medium between the drive electrode and the mirror device, and the selected voltage that is applied to the drive electrode.