Manufacturing method of suspended microstructure

Abstract

A manufacturing method of a suspended microstructure includes the steps of providing a substrate having a surface; forming a first depositing layer over a part of the surface; forming a second depositing layer over the first depositing layer and another part of the surface wherein an adhesion between the first depositing layer and the substrate is weaker than that between the second depositing layer and the substrate; forming a hole through the second depositing layer to partially expose the surface of the substrate; and filling the hole with an etchant to remove a part of the substrate so as to form a cavity.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:

FIGS. 1A to 1C are schematic views of the conventional manufacturing method of a suspended microstructure using surface micromachining;

FIGS. 2A to 2B are schematic views of the conventional manufacturing method of a suspended microstructure using bulk micromachining;

FIGS. 3A to 3C are additional schematic views of the conventional manufacturing method of a suspended microstructure using bulk micromachining;

FIG. 4 is a flowchart of a manufacturing method of a suspended microstructure according to a first embodiment of the invention;

FIGS. 5A to 5D are schematic views of the manufacturing method of a suspended microstructure according to the first embodiment of the invention;

FIG. 6 is a flowchart of a manufacturing method of a suspended microstructure according to a second embodiment of the invention; and

FIGS. 7A to 7F are schematic views of the manufacturing method of a suspended microstructure according to the second embodiment of the invention.

Claims

1. A manufacturing method of a suspended microstructure, comprising the steps of: providing a substrate having a surface;forming a first depositing layer over a part of the surface;forming a second depositing layer over the first depositing layer and another part of the surface;forming a hole through the second depositing layer to partially expose the surface; andfilling the hole with an etchant to remove a part of the substrate so as to form a cavity.

2. The manufacturing method of claim 1, wherein an adhesion between the first depositing layer and the substrate is weaker than that between the second depositing layer and the substrate.

3. The manufacturing method of claim 1 further comprising the step of removing the first depositing layer.

4. The manufacturing method of claim 3, wherein the first depositing layer is removed by wet etching or isotropic etching.

5. The manufacturing method of claim 1, wherein a thickness of the first depositing layer is smaller than 1000 Å.

6. The manufacturing method of claim 1, wherein the second depositing layer is a microstructure.

7. The manufacturing method of claim 6, wherein the microstructure is a film bulk acoustic resonator (FBAR).

8. The manufacturing method of claim 7, wherein the FBAR is formed by sandwiching a piezoelectric material between two electrodes.

9. The manufacturing method of claim 1, wherein the substrate is made of a single crystal material, a poly crystal material, or an amorphous material.

10. A manufacturing method of a suspended microstructure, comprising the steps of: providing a substrate having a surface;forming a first depositing layer over a part of the surface;forming a second depositing layer over the first depositing layer and another part of the surface;forming a third depositing layer over the second depositing layer;forming a hole through the second depositing layer and the third depositing layer to partially expose the surface; andfilling the hole with an etchant to remove a part of the substrate so as to form a cavity.

11. The manufacturing method of claim 10, wherein an adhesion between the first depositing layer and the substrate is weaker than that between the second depositing layer and the substrate.

12. The manufacturing method of claim 10 further comprising the step of removing the first depositing layer.

13. The manufacturing method of claim 12, wherein the first depositing layer is removed by wet etching or isotropic etching.

14. The manufacturing method of claim 10, wherein the first depositing layer and the second depositing layer both have a thickness smaller than 1000 Å.

15. The manufacturing method of claim 10 further comprising the step of removing the second depositing layer.

16. The manufacturing method of claim 15, wherein the second depositing layer is removed by wet etching or isotropic etching.

17. The manufacturing method of claim 10, wherein the third depositing layer is a microstructure.

18. The manufacturing method of claim 17, wherein the microstructure is a film bulk acoustic resonator (FBAR).

19. The manufacturing method of claim 18, wherein the FBAR is formed by sandwiching a piezoelectric material between two electrodes.