Interference display unit

• US 6,995,890 B2
• Filed: 11/14/2003
• Issued: 02/07/2006
• Est. Priority Date: 04/21/2003
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Prime View International Company Limited (E Ink Holdings Incorporated)
• Inventors: Lin, Wen-Jian
• Primary Examiner(s): Schwartz, Jordan M.
• Assistant Examiner(s): STULTZ, JESSICA T
• Application Number:
  US10/706,923
• Publication Number:
  US 20040207897A1
• Time in Patent Office: 816 Days
• Field of Search: 359/254, 359/242, 359/240, 359/247, 359/252, 359/238, 359/277, 359265- 67, 359288- 91, 359/295, 359/302, 359/315
• US Class Current: 359/254
• CPC Class Codes: B81B 2201/047 Optical MEMS not provided for in B81B2201/042 - B81B2201/045
• CPC Class Codes: B81C 1/00182 Arrangements of deformable or non-deformable structures, e.g. membrane and cavity for use in a transducer
• 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 5/201 in the form of arrays
• CPC Class Codes: G02B 5/284 of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26

Abstract

An interference display unit with a first electrode, a second electrode and posts located between the two electrodes is provided. The characteristic of the interference display unit is that the second electrode'"'"'s stress is released through a thermal process. The position of the second electrode is shifted and the distance between the first electrode and the second electrode is therefore defined. A method for fabricating the structure described as follow. A first electrode and a sacrificial layer are sequentially formed on a substrate and at least two openings are formed in the first electrode and the sacrificial layer. A supporter is formed in the opening and the supporter may have at least one arm on the top portion of the supporter. A second electrode is formed on the sacrificial layer and the supporter and a thermal process is performed. Finally, The sacrificial layer is removed.

Claims

1. An optical interference display unit, at least comprising:

at least two first electrodes located on the substrate and separated with each other;

at least two second electrodes, wherein each of the second electrodes settled in parallel with and above each of the first electrodes correspondingly; and

posts located between the first electrodes and the second electrodes to form a first cavity and a second cavity,

wherein thickness of the two second electrodes is different to provide different stress and after treating the second electrodes by a thermal process, a corresponding length of the first cavity and the second cavity is different.

2. The optical interference display unit of claim 1, wherein the thermal process is baking.

3. The optical interference display unit of claim 1, wherein the thermal process makes the second electrodes able to generate displacement due to stress.

4. The optical interference display unit of claim 1, wherein the second electrodes are a deformable electrode.

5. The optical interference display unit of claim 1, wherein the second electrodes are a movable electrode.

6. The optical interference display unit of claim 1, wherein the material for forming the posts is a photoresist.

7. The optical interference display unit of claim 1, wherein a material for forming the second electrodes is conductive transparent material, metal, conductive opaque material, conductive hemi-transparent material or dielectric material.

8. The optical interference display unit of claim 1, wherein the posts further comprise arms located under the second electrodes.