Methods and configurations for manufacturing hinges for micro-mirror devices

• US 7,375,872 B2
• Filed: 07/23/2005
• Issued: 05/20/2008
• Est. Priority Date: 11/01/2003
• Status: Active Grant

• Current Assignee: Ignite USA (Ignite)
• Original Assignee: Silicon Quest Kabushiki-Kaisha
• Inventors: Ishii, Fusao
• Primary Examiner(s): Mack; Ricky L
• Assistant Examiner(s): Thomas; Brandi N
• Application Number:
  US11/187,248
• Publication Number:
  US 20060018005A1
• Time in Patent Office: 1,032 Days
• Field of Search: 359/290, 359/291, 359/292, 359/295, 359/298, 359/237
• 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 method for manufacturing an image display system with a plurality of micromirrors supported on a plurality of doped semiconductor hinges supported on a substrate comprising:

applying an elevated temperature for crystallizing said semiconductor hinges followed by forming a plurality of metallic lines between said hinges; and

said step of forming a plurality of metallic lines between said hinges further comprising a step of spin coating a photo resist between said hinges by spinning said photo resist as a flow between said hinges with a Reynolds number below 70, representing by 0<

Re<

70.

2. The method of claim 1 wherein:

said step of forming a plurality of metallic lines between said hinges further comprising a step of forming a substantially uniform photo resist layer between said hinges following by applying a photolithographic etching process to form said metallic lines between said hinges.

3. The method of claim 1 wherein:

said step of forming a plurality of metallic lines between said hinges further comprising a step of spin coating a photo resist between said hinges by spinning said photo resist as laminar flow between said hinges.

4. The method of claim 1 wherein:

said step of forming a plurality of metallic lines between said hinges further comprising a step of spray coating a photo resist between said hinges by spraying said photo resist as spray particles to areas between said hinges.

5. The method of claim 1 further comprising:

forming a plurality of reflecting element on top of said hinges after said step of forming a plurality of metallic lines between said hinges.

6. The method of claim 1 further comprising:

forming a plurality of metal oxide semiconductor (MOS) transistors provided for connecting said metallic wires as driving circuit for said micromirrors.

7. An image display system comprising a plurality of micromirrors wherein:

each of said micromirrors supported on a doped semiconductor hinge hidden from an incident light projecting to said micromirrors;

said image display system further includes signal transmission metal traces disposed on areas between said doped semiconductor hinges supporting said micromirrors; and

said signal transmission metal traces are formed prior to an elevated temperature is applied locally to crystallize said hinges by a laser heating process with a laser beam projecting toward said hinges to heat said hinges to a temperature substantially above 600 Celisus.

8. The image display system of claim 7 wherein:

said hinge is a type selected from a group consisting of cantilever hinge, vertical cantilever hinge, torsion hinge, and compound torsion vertical cantilever hinge.

9. The image display system of claim 7 wherein:

said doped semiconductor hinge composed of a semiconductor selected from a group consisting of elemental semiconductors, III-V compound semiconductors, II-VI compound semiconductors, IV compound semiconductors, and alloy semiconductors.

10. The image display system of claim 7 wherein:

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

11. The image display system of claim 7 wherein:

said doped semiconductor hinge composed of a semiconductor doped with a dopant selected from a group consisting of group III elements, group IV elements, group V elements, and group VII elements is introduced into said semiconductor.

12. The image display system of claim 7 wherein:

said doped semiconductor hinge composed of a doped semiconductor formed by a doping process selected from a group of 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.

13. The image display system of claim 7 wherein:

said doped semiconductor hinge composed of a doped semiconductor formed by using a dopant source selected from a group consisting of a solid dopant source, a liquid dopant source;

a vapor dopant source, and a gas dopant source.

14. The image display system of claim 7 wherein:

said doped semiconductor hinge composed of a crystallized doped semiconductor formed by applying a crystallization process selected from a group of crystallization processes consisting of furnace annealing, laser annealing, rapid thermal annealing, lamp annealing, and electrical conduction heating.

15. The image display system of claim 7 wherein:

said doped semiconductor hinge composed of a doped semiconductor formed by using a dopant source selected from a group consisting of PSG, BSG, BPSG, AsSG, SbSG, Arsine, diborane, phosphine, boron trioxide, trimethylborate, boron nitride, boron tribromide, phosphorus pentoxide, ammonium monophosphate, ammonium diphosphate, phosphorus oxychloride, arsenic trioxide, antimony trioxide, antimony pentachloride, silane, dichlorosilane, and stabine.

16. The image display system of claim 7 wherein:

said doped semiconductor hinge is formed by applying a process selected from a group of processes consisting of self-assembly, adhesive bonding, silicon fusion bonding, anodic bonding, and monolithic fabrication.

17. The image display system of claim 7 wherein:

said micromirrors further comprising a reflecting surface for reflecting and projecting an image for display.

18. The image display system of claim 7 wherein:

said doped semiconductor hinge composed of a semiconductor selected from a group consisting of amorphous silicon, polycrystalline silicon, and single crystal silicon.

19. The image display system of claim 7 wherein:

said doped semiconductor hinge composed of a doped semiconductor formed by using a doping a semiconductor layer formed by a process selected from a group of processes consisting of deposition of solid-phase epitaxy, deposition of vapor-phase epitaxy, deposition of liquid-phase epitaxy, deposition of molecular-beam epitaxy, thin film deposition of physical evaporation, thin film deposition of electron-beam evaporation, thin film deposition of filament evaporation, thin film deposition of flash evaporation, sputtering deposition of thin film, CVD thin film deposition, bulk substrate wafer slice from a single crystal ingot, SOS substrate, or SOI substrate.

26. The image display system of claim 7 further comprising:

a layer around said hinge comprising at least two materials with different thermal conductivities.

20. An image display system comprising a plurality of micromirrors wherein:

each of said micromirrors supported on a doped semiconductor hinge hidden from an incident light projecting to said micromirrors;

said image display system further includes signal transmission metal traces disposed on areas between said doped semiconductor hinges supporting said micromirrors; and

said signal transmission metal traces are formed prior to an elevated temperature is applied locally to crystallize said hinges by a laser heating process with a laser beam projecting toward said hinges with an tilted incident angle substantially between 10 to 80 degrees relative to said hinges.

27. The image display system of claim 20 wherein:

a layer around said hinge comprising at least two materials with different thermal conductivities.

21. A method for manufacturing an image display system with a plurality of micromirrors supported on a plurality of doped semiconductor hinges supported on a substrate comprising:

applying a laser beam to each of said hinges for annealing said semiconductor hinges after forming a plurality of metallic lines between said hinges.

22. The method of claim 21 wherein:

said step of applying a laser beam for annealing said hinges comprising a step of applying a laser beam with an tilted incident angle substantially between 10 to 80 degrees relative to said hinges.

23. The method of claim 21 wherein:

said step of applying a laser beam for annealing said hinges comprising a step of applying a laser beam to heat said hinges to a temperature substantially above 600 Celsius.

24. The method of claim 21 further comprising:

forming a plurality of reflecting element on top of said hinges after said step of annealing said hinges.

25. The method of claim 21 further comprising:

forming a plurality of metal oxide semiconductor (MOS) transistors provided for connecting said metallic wires as driving circuit for said micromirrors.