Methods and configurations for manufacturing hinges for micro-mirror devices

• US 7,746,538 B2
• Filed: 02/12/2008
• Issued: 06/29/2010
• Est. Priority Date: 11/01/2003
• Status: Expired due to Fees

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Silicon Quest Kabushiki-Kaisha
• Inventors: Ishii, Fusao
• Primary Examiner(s): Choi; William C
• Application Number:
  US12/069,837
• Publication Number:
  US 20080180778A1
• Time in Patent Office: 868 Days
• Field of Search: 359/224, 359/290, 359/295, 359/298, 359/318, 359/312, 359/224.1
• US Class Current: 359/290
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

An image display system includes an improved hinge for a micro-mirror device composed of a conductive-doped semiconductor and immune to plastic deformation at typical to extreme temperatures. The hinge is directly connected to the micro-mirror device and facilitates the manufacturing of an optically flat micro-mirror. This eliminates Fraunhofer diffraction due to recesses on the reflective surface of the micro-mirror. In addition, the hinge is hidden from incoming light thus improving contrast and fill-factor. The image display system further includes signal transmission metal traces formed on areas between the doped semiconductor hinges. The signal transmission metal traces are formed either before or after a high temperature crystallization process is applied to the hinges.

Claims

1. A micro-mirror device comprising:

a vertical doped semiconductor hinge comprising a vertical post supported on and extended from a substrate having a cantilever formed as a thin-narrow-plate extended from said vertical post wherein said cantilever further having a mirror supporting platform as a separate segment for supporting a micromirror thereon wherein said doped semiconductor hinge is composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors, and alloy semiconductors.

2. A micro-mirror device comprising:

a plurality of vertical doped semiconductor hinges each including a thin-narrow-plate attached at a top end of a vertical post extended from a substrate, wherein each of the doped semiconductor hinges is composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors, and alloy semiconductors;

a supporting platform coupled to each of the hinges for supporting a mirror plate thereon, wherein the mirror supporting platform is composed of an electrically conductive material; and

each of the vertical doped semiconductor hinges comprising at least a cantilever or a torsion structure or a cantilever combined with a torsion structure.

3. The micromirror device of claim 2 wherein:

the supporting platform is composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors and alloy semiconductors.

4. The micromirror device of claim 2 wherein:

the supporting platform is composed of a material same as the doped semiconductor hinge or the mirror plate.

5. The micromirror device of claim 2 wherein:

the supporting platform is coupled directly to the vertical hinge post of the doped semiconductor hinge.

6. The micromirror device of claim 2 wherein:

the supporting platform has a width substantially same as or wider than a width of the vertical doped semiconductor hinge.

7. The micromirror device of claim 2 further comprising:

a hinge base coupled to and supporting the doped semiconductor hinge wherein the hinge support composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors and alloy semiconductors.

8. The micromirror device of claim 2 further comprising:

a hinge support connecting to the vertical_doped semiconductor hinge extended from said substrate wherein the hinge support composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors and alloy semiconductors.

9. The micromirror device of claim 2 wherein:

said vertical_doped semiconductor hinge is formed by employing a semiconductor formation process selected from a group of semiconductor formation processes consisting of deposition by solid-phase epitaxy, deposition by vapor-phase epitaxy, deposition by liquid-phase epitaxy, deposition by molecular-beam epitaxy, thin film deposition by physical evaporation, thin film deposition by electron-beam evaporation, thin film deposition by filament evaporation, thin film deposition by flash evaporation, thin film deposition by sputtering, thin film deposition by CVD, bulk substrate wafer slice from single crystal ingot, SOS substrate, and SOI substrate.

10. The micromirror device of claim 2 wherein:

said vertical_doped semiconductor hinge is doped with a doping impurity selected from a group doping impurities consisting of group III elements, group IV elements, group V elements, and group VII elements is introduced into said semiconductor.

11. The micromirror device of claim 10 wherein:

said vertical_doped semiconductor hinge is doped with said doping impurity by employing a doping process selected from a group of doping processes consisting of ion-implantation, constant-source diffusion, limited-source diffusion, two-step diffusion, substrate autodoping, substrate out-diffusion, in situ deposition, and in situ crystallization.

12. The micromirror device of claim 2 wherein:

said vertical_doped semiconductor hinge is composed of a material selected from a group of semiconductors consisting of amorphous silicon, polycrystalline silicon, and single crystal silicon.

13. The micromirror device of claim 2 further comprising:

a circuit-comprising a plurality of electrodes on the substrate wherein the vertical doped semiconductor hinge is electrically wired between the circuit and the mirror plate for deflecting the mirror plate.

14. The micromirror device of claim 13 wherein:

a plurality of the vertical_doped semiconductor hinges are connected to and interconnected via the circuit.

15. The projection system of claim 14 wherein:

the supporting platform composed of a same material as the vertical semiconductor hinge or the mirror plate.

16. The projection system of claim 14 wherein:

the vertical semiconductor hinge further includes is a cantilever, having a length shorter than a distance between the substrate and the mirror plate.

17. A micromirror device comprising:

a doped semiconductor hinge including a thin-narrow-plate disposed on a substrate, wherein the doped semiconductor hinge is composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors, and alloy semiconductors; and

a supporting platform coupled to the hinge for supporting a mirror plate thereon, wherein the mirror supporting platform is composed of an electrically conductive material and the supporting platform is a part of the mirror plate, wherein the mirror plate has a concave surface area or a convex surface area.

18. A micromirror device comprising:

a doped semiconductor hinge including a thin-narrow-plate disposed on a substrate, wherein the doped semiconductor hinge is composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors, and alloy semiconductors; and

a supporting platform coupled to the hinge for supporting a mirror plate thereon, wherein the mirror supporting platform is composed of an electrically conductive material; and

wherein the supporting platform has a width substantially same as or narrower than a width of the semiconductor hinge.

19. A micromirror device comprising:

a doped semiconductor hinge including a thin-narrow-plate disposed on a substrate, wherein the doped semiconductor hinge is composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors, and alloy semiconductors;

a supporting platform coupled to the hinge for supporting a mirror plate thereon, wherein the mirror supporting platform is composed of an electrically conductive material; and

a hinge support connecting to the doped semiconductor hinge and substrate, having a first end disposed near the doped semiconductor hinge and a second end disposed near the substrate wherein the first end has a cross sectional area smaller than a cross sectional area of said second end.

20. A micromirror device comprising:

a doped semiconductor hinge including a thin-narrow-plate disposed on a substrate, wherein the doped semiconductor hinge is composed of a material selected from a group of semiconductors consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors, and alloy semiconductors;

a supporting platform coupled to the hinge for supporting a mirror plate thereon, wherein the mirror supporting platform is composed of an electrically conductive material; and

a hinge support, connecting to the doped semiconductor hinge and extended from said substrate wherein the doped semiconductor hinge further includes a cantilever having a length shorter than a distance between the substrate and the mirror plate.

21. The micromirror device of claim 20 wherein:

the length is substantially about half or shorter than the distance between the substrate and the mirror plate.

22. The micromirror device of claim 20 wherein:

the cantilever has a width is substantially the same as or narrower than a width of a cross section of the hinge support.

23. A projection system comprising:

an Illumination light source for projecting an illumination beam impinging to a mirror array disposed on a semiconductor substrate wherein mirrors of said mirror array deflecting the light beam for projecting an image;

each of the mirrors further comprising;

a vertical doped semiconductor hinge, supporting the mirror, wherein the doped semiconductor hinge is composed of a material selected from a group of materials consisting of a single crystal silicon, poly silicon or amorphous silicon and doped with an doping impurity selected from a group doping impurities consisting of group III elements, group IV elements, group V elements, and group VII elements is introduced into the semiconductor hinge;

a supporting platform coupled to the hinge for supporting a mirror thereon, wherein the mirror supporting platform is composed of an electrically conductive material;

each of the vertical doped semiconductor hinges comprising at least a cantilever or a torsion structure or a cantilever combined with a torsion structure; and

a circuit including an electrode disposed on the semiconductor substrate for activating the mirror wherein the mirror is electrically connecting with the circuit through the doped semiconductor hinge.