Interference display cell and fabrication method thereof

• US 20060006138A1
• Filed: 09/09/2005
• Published: 01/12/2006
• Est. Priority Date: 08/26/2003
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Lin, Wen-Jian
• Granted Patent: US 7,485,236 B2
• Time in Patent Office: Days
• US Class Current: 216/41
• 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

Abstract

An optical interference display unit with a first electrode, a second electrode and support structures located between the two electrodes is provided. The second electrode has at least a first material layer and a second material layer. At least one material layer of the two is made from conductive material and the second conductive layer is used as a mask while an etching process is performed to etch the first material layer to define the second electrode.

Claims

1. A method for fabricating an optical interference display unit disposed on a transparent substrate, the method comprising:

forming a first electrode on the transparent substrate;

forming a sacrificial layer on the first electrode;

forming at least two openings in the sacrificial layer and the first electrode;

forming support structures in the openings;

forming a first material layer on the sacrificial layer and the support structures;

forming a second material layer on the first material layer;

forming a patterned photoresist layer on the second material layer;

while using the patterned photoresist layer as a mask, etching the second material layer to expose the first material layer;

stripping the patterned photoresist layer;

while using the second material layer as a mask, etching the first material layer to expose the support structures; and

removing the sacrificial layer.

2. The method for fabricating the optical interference display unit of claim 1, wherein the second electrode is a deformable electrode.

3. The method for fabricating the optical interference display unit of claim 1, wherein the second electrode is a movable electrode.

4. The method for fabricating the optical interference display unit of claim 1, wherein the first material layer is made from a conductive material and the second material layer is made from a metal or a dielectric material.

5. The method for fabricating the optical interference display unit of claim 4, wherein the first material layer is made from a metal or a dielectric material and the second material layer is made from a conductive material.

6. The method for fabricating the optical interference display unit of claim 1, wherein a material for forming the first material layer is aluminum, chromium, cobalt, copper, silicon nitride of silicon oxide.

7. The method for fabricating the optical interference display unit of claim 1, wherein a material for forming the second material layer is aluminum, chromium, cobalt, copper, silicon nitride or silicon oxide.

8. The method for fabricating the optical interference display unit of claim 1, wherein a preferred material for forming the second material layer is a material with a higher etching selectivity ratio than that of a material for forming the first material layer.