Mems structure preventing stiction

• US 20100258885A1
• Filed: 05/24/2010
• Published: 10/14/2010
• Est. Priority Date: 07/08/2008
• Status: Active Grant

• Current Assignee: PixArt Imaging Incorporated
• Original Assignee: PixArt Imaging Incorporated
• Inventors: Lee, Sheng-Ta, Wang, Chuan-Wei, Hsu, Hsin-Hui
• Granted Patent: US 8,952,463 B2
• Time in Patent Office: Days
• US Class Current: 257/415
• CPC Class Codes: B81B 3/001 Structures having a reduced contact area, e.g. with bumps or with a textured surface

Abstract

A MEMS (Micro-Electro-Mechanical-System) structure preventing stiction, comprising: a substrate; and at least two structural layers above the substrate, wherein at least one of the at least two structural layers is a movable part, and anyone or more of the at least two structural layers is provided with at least one bump to prevent the movable part from sticking to another portion of the MEMS structure.

Claims

1. A MEMS (Micro-Electro-Mechanical-System) structure preventing stiction, comprising:

a substrate; and

at least two structural layers above the substrate, wherein at least one of the at least two structural layers is a movable part, and anyone or more of the at least two structural layers is provided with at least one bump to prevent the movable part from sticking to another portion of the MEMS structure.

2. The MEMS structure of claim 1, wherein the at least one bump is provided above, below, or aside one of the at least two structural layers.

3. The MEMS structure of claim 1, wherein both of the at least two structural layers are provided with the at least one bump.

4. The MEMS structure of claim 1, wherein there are multiple bumps aligned in arrays.

5. The MEMS structure of claim 1, wherein there are multiple bumps arranged irregularly.

6. The MEMS structure of claim 1, wherein each of the at least one bump has a size equal to or smaller than 0.25 μ

m².

7. The MEMS structure of claim 1, wherein the at least one structural layer provided with the bump is a composite layer including at least two layers, and the bump is a single-layer structure.

8. The MEMS structure of claim 1, wherein the at least one structural layer provided with the bump is a composite layer including at least two layers, and the bump is a multi-layer structure.

9. The MEMS structure of claim 1, wherein the at least one structural layer provided with the bump is the movable part.

10. The MEMS structure of claim 1, wherein the at least one structural layer provided with the bump is not the movable part.

11. The MEMS structure of claim 1, wherein the movable part becomes movable after a hydrogen fluoride vapor etch step which creates a space between the at least two structural layers.

12. The MEMS structure of claim 11, wherein oxide sacrificial layers are formed between the at least two structural layers, and wherein the hydrogen fluoride vapor etch step removes the oxide sacrificial layers.