Method for fabricating an interference display unit

• US 7,016,095 B2
• Filed: 03/03/2005
• Issued: 03/21/2006
• 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:
  US11/069,938
• Publication Number:
  US 20050168849A1
• Time in Patent Office: 383 Days
• Field of Search: 359/254
• 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. A method for manufacturing a matrix color optical interference display unit disposed on a substrate, the method comprising:

forming a first electrode on the substrate;

forming a sacrificial layer on the first electrode;

forming at least four openings in the sacrificial layer and the first electrode to define positions of a first optical interference display unit, a second optical interference display unit, and a third optical interference display unit;

forming a post comprising a support in each of the openings and at least an arm on the sacrificial layer;

forming at least one first electrode layer on the sacrificial layer, the arms and the posts, wherein the first electrode layer forms a second electrode of the first optical interference display unit;

forming at least one second electrode layer on the first electrode layer located only on the second optical interference display unit and the third optical interference display unit, wherein the first and the second electrode layers form a third electrode of the second optical interference display unit;

forming at least one third electrode layer on the second electrode layer located only on the third optical interference display unit, wherein the first, the second and the third electrode layers form a fourth electrode of the third optical interference display unit;

performing a thermal process to make the second, the third and the fourth electrodes able to generate displacement due to stress, thereby various distances between the first electrode and the second, the third and the fourth electrodes are formed; and

removing the sacrificial layer.

2. The method for manufacturing a matrix color optical interference display unit of claim 1, wherein a material for forming the posts is selected from a group consisting of photosensitive materials, non-photosensitive materials and a combination thereof.

3. The method for manufacturing a matrix color optical interference display unit of claim 2, wherein the photosensitive materials are a photoresist.

4. The method for manufacturing a matrix color optical interference display unit of claim 1, wherein the step of forming the post further comprises:

forming a photosensitive material layer to fill the openings and cover the sacrificial layer; and

patterning the photosensitive material layer to form the support in each of the openings and the arm on the support.

5. The method for manufacturing a matrix color optical interference display unit of claim 4, wherein the step of patterning the photosensitive material layer includes a photolithographic process.

6. The method for manufacturing a matrix color optical interference display unit of claim 1, wherein the step for forming the support and the arm further comprises:

forming a non-photosensitive material layer to fill the openings and cover the sacrificial layer; and

patterning the non-photosensitive material layer to form the support in each of the openings and the arm on the support by a photolithographic etch process.

7. The method for manufacturing a matrix color optical interference display unit of claim 1, wherein the thermal process is baking.

8. The method for manufacturing a matrix color optical interference display unit of claim 1, wherein the second, the third and the fourth electrodes are deformable electrodes.

9. The method for manufacturing a matrix color optical interference display unit of claim 1, wherein the second, the third and the fourth electrodes are movable electrodes.

10. The method for manufacturing a matrix color optical interference display unit of claim 1, wherein a material of the first electrode layer is a conductive transparent material, a metal, a conductive opaque material, or a conductive hemi-transparent material.

11. The method for manufacturing a matrix color optical interference display unit of claim 1, wherein a material of the second or third electrode layer is a conductive transparent material, a metal, a conductive opaque material, a conductive hemi-transparent material or a dielectric material.