Method for fabricating an interference display unit

• US 7,198,973 B2
• Filed: 11/13/2003
• Issued: 04/03/2007
• Est. Priority Date: 04/21/2003
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Lin, Wen-Jian, Tsai, Hsiung-Kuang
• Primary Examiner(s): Nguyen; Tuan H.
• Application Number:
  US10/705,824
• Publication Number:
  US 20040209192A1
• Time in Patent Office: 1,237 Days
• Field of Search: 438/48, 438/57, 438/65, 359/254
• US Class Current: 438/48
• 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: G03F 7/0007 Filters, e.g. additive colour filters; Components for display devices

Abstract

A method for fabricating an interference display unit is provided. A first plate and a sacrificial layer are formed in order on a substrate and at least two openings are formed in the first plate and the sacrificial layer. A photoresist layer is spin-coated on the sacrificial layer and fills the openings. A photolithographic process patterns the photoresist layer to define a support with an arm. A second plate is formed on the sacrificial layer and posts. The arm'"'"'s stress is released through a thermal process. The position of the arm is shifted and the distance between the first plate and the second plate is therefore defined. Finally, The sacrificial layer is removed.

Claims

1. A method for manufacturing an 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 two openings in the sacrificial layer and the first electrode to define a position of the optical interference display unit;

forming a support in each of the openings and at least one arm on the support, wherein the support and the at least one arm form a post;

forming a second electrode on the sacrificial layer and the at least one arm;

performing a thermal process to treat the post; and

removing the sacrificial layer.

2. The method for manufacturing an optical interference display unit of claim 1, wherein the post comprises a photoresist.

3. The method for manufacturing an optical interference display unit of claim 1, wherein the post comprises photosensitive or non-photosensitive materials.

4. The method for manufacturing an optical interference display unit of claim 1, wherein the step of forming the post 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 at least one arm on the support, wherein the support and the at least one arm form the post.

5. The method for manufacturing an 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 an optical interference display unit of claims 4 or 5, wherein the photosensitive material layer comprises a photoresist.

7. The method for manufacturing an optical interference display unit of claim 1, wherein the step of forming the support 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 at least one arm on the support by a photolithographic etching process, wherein the support and the at least one arm form the post.

8. The method for manufacturing an optical interference display unit of claim 1, wherein the thermal process comprises baking.

9. The method for manufacturing an optical interference display unit of claim 1, wherein the thermal process results in displacement of at least one arm due to stress.

10. The method for manufacturing an optical interference display unit of claim 1, wherein the first electrode comprises:

the substrate;

an absorption layer; and

a dielectric layer.

11. The method for manufacturing an optical interference display unit of claim 9, wherein the substrate is a transparent material.

12. The method for manufacturing an optical interference display unit of claim 9, wherein the dielectric layer comprises silicon oxide, silicon nitride or metal oxide.

13. The method for manufacturing an optical interference display unit of claim 9, wherein the absorption layer comprises metal.

14. The method for manufacturing an optical interference display unit of claim 9, wherein the substrate comprises ITO glass or IZO glass.

15. The method for manufacturing an optical interference display unit of claim 1, wherein the first electrode and the second electrode are selected from a group consisting of narrowband mirrors, broadband mirrors, non-metal mirrors, metal mirrors and the combination thereof.

16. The method for manufacturing an optical interference display unit of claim 1, wherein the second electrode is a deformable electrode.

17. The method for manufacturing an optical interference display unit of claim 1, wherein the second electrode is a movable electrode.

18. A method for manufacturing an optical interference display unit of claim 1, wherein the second electrode at least comprises opaque materials or semi-transparent materials.

19. The method for manufacturing an optical interference display unit of claim 17, wherein the semi-transparent materials comprises ITO glass or IZO glass.

20. The method for manufacturing an optical interference display unit of claim 1, wherein the supports comprise photosensitive material.