Method for fabricating a structure for a microelectromechanical systems (MEMS) device

• US 6,794,119 B2
• Filed: 02/12/2002
• Issued: 09/21/2004
• Est. Priority Date: 02/12/2002
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Iridigm Display Corporation (Qualcomm, Inc.)
• Inventors: Miles, Mark W.
• Primary Examiner(s): Ruff, Mark F.
• Assistant Examiner(s): BARRECA, NICOLE M
• APPLICATION: US 20030152872A1
• Time in patent office: 952 Days
• Field of Search: 430/311, 430/313, 430/314, 430/316, 430/317, 430/318, 430/322, 430/394
• US Class Current: 430/313
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81C 1/00396 Mask characterised by its composition, e.g. multilayer masks
• CPC Class Codes: B81C 2201/0109 Sacrificial layers not provided for in B81C2201/0107 - B81C2201/0108
• CPC Class Codes: B81C 2203/0136 Growing or depositing of a covering layer
• 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

The invention provides a microfabrication process which may be used to manufacture a MEMS device. The process comprises depositing one or a stack of layers on a base layer, said one layer or an uppermost layer in said stack of layers being a sacrificial layer; patterning said one or a stack of layers to provide at least one aperture therethrough through which said base layer is exposed; depositing a photosensitive layer over said one or a stack of layers; and passing light through said at least one aperture to expose said photosensitive layer.

Claims

1. A microfabrication process for fabricating a microelectromechanical systems device, comprising:

depositing one or a stack of layers on a substrate;

patterning said one or a stack of layers to form a plurality of longitudinally extending groves therein;

depositing a middle layer on said one or a stack of layers;

patterning the middle layer using said one or a stack of layers as a photomask, wherein said middle layer is exposed to light passed through the groves in the one or a stack of layers; and

developing said middle layer to form longitudinally spaced ridges in the said middle layer disposed in the groves in said one or a stack of layers, said ridges forming a support structure which is part of the microelectromechanical systems device.

2. The method of claim 1, wherein the substrate permits light to pass therethrough.

3. The method of claim 2, wherein the substrate comprises glass.

4. The method of claim 1, further comprising depositing a top layer over said middle layer.

5. The method of claim 4, wherein said top layer comprises nickel and aluminum.

6. The method of claim 4, further comprising patterning said top layer.

7. The method of claim 6, wherein said top layer is patterned to define transversely extending strips which are supported by the longitudinally spaced ridges in the said middle layer.

8. The method of claim 1, wherein said one or an uppermost layer of said stack of layers is a sacrificial layer.

9. The method of claim 1, wherein the said middle layer comprises a negative-acting-photosensitive material.

10. A method for fabricating a microelectromechanical systems device, the method comprising:

a) depositing one or a stack of layers on a base layer, said one layer or an uppermost layer in said stack of layers being a sacrificial layer;

b) patterning said one or a stack of layers to provide at least one aperture therethrough through which said base layer is exposed;

c) depositing a photosensitive layer over said one or a stack of layers;

d) passing light through said at least one aperture to expose said photosensitive layer; and

e) developing said one or a stack of layers to remove unexposed portions of said photosensitive layer and said sacrificial layer to form at least one mechanical support, each support being defined by a portion of said photosensitive layer exposed through an aperture.

11. The method of claim 10, wherein the base layer is a substrate layer.

12. The method of claim 10, wherein said light comprises ultraviolet light.

13. The method of claim 10, wherein said photosensitive layer comprises a negative-acting-photosensitive material.

14. The method of claim 10, further comprising depositing a structural layer over said photosensitive layer.

15. The method of claim 14, wherein said steps (a) to (e) are repeated at least once, wherein for each repetition, the structural layer forms the base layer.