Micro-electro-mechanical device and method of manufacturing the same

• US 7,872,320 B2
• Filed: 11/05/2008
• Issued: 01/18/2011
• Est. Priority Date: 11/07/2007
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Mizoguchi, Takafumi, Tsuchiya, Kaoru
• Primary Examiner(s): Soward; Ida M
• Application Number:
  US12/265,177
• Publication Number:
  US 20090117364A1
• Time in Patent Office: 804 Days
• Field of Search: 257/415, 257417-420, 257/E29.324, 977/724, 977/732, 977/733
• US Class Current: 257/415
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2203/0315 Cavities
• CPC Class Codes: B81B 3/007 For controlling stiffness, e.g. ribs
• CPC Class Codes: Y10S 977/724 Devices having flexible or movable element
• CPC Class Codes: Y10S 977/732 Nanocantilever
• CPC Class Codes: Y10S 977/733 Nanodiaphragm
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]

Abstract

The present invention improves mechanical strength of a micro-electro-mechanical device (MEMS) having a movable portion to improve reliability. In a micro-electro-mechanical device (MEMS) having a movable portion, a portion which has been a hollow portion in the case of a conventional structure is filled with a filler material. As the filler material, a block copolymer that is highly flexible is used, for example. By filling the hollow portion, mechanical strength improves. Besides, warpage of an upper portion of a structure body in the manufacture process is prevented, whereby yield improves. A micro-electro-mechanical device thus manufactured is highly reliable.

Claims

1. A micro-electro-mechanical device comprising:

a microstructure body, the microstructure body comprising;

a lower electrode layer on an insulating surface;

a filler material layer over the lower electrode layer;

an upper electrode layer overlapping with the lower electrode layer with the filler material layer interposed therebetween; and

a structure layer over the upper electrode layer,

wherein the structure layer includes a portion capable of moving, and

wherein the filler material layer comprises an insulating material including plural pores.

2. The device according to claim 1, wherein the plural pores include pores reaching a surface of the filler material layer.

3. The device according to claim 1, wherein percentage of the plural pores included in the filler material layer is greater than or equal to 20 and less than or equal to 80.

4. The device according to claim 1, wherein the filler material layer includes a block copolymer.

5. The device according to claim 4, wherein the block copolymer includes at least one material selected from a group consisting of hydrophobic aromatic hydrocarbon, hydrophobic aliphatic unsaturation hydrocarbon, hydrophilic aliphatic hydrocarbon, hydrophilic aromatic hydrocarbon, hydrophobic siloxane, and metal complex.

6. The device according to claim 4, wherein the block copolymer includes at least one material selected from a group consisting of polymethylmethacrylate, polystyrene, polyfluorene, polybutadiene, polyisoprene, polyvinyl alcohol, polyethylene glycol, polyvinyl pyridine, polystyrene sulfonic acid, poly dimethylsiloxane, and poly ferrocene.

7. The device according to claim 1, wherein the filler material layer has a cylinder structure, a gyroid structure, or a lamellar structure.