MEMS device and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-9230744-B2
Application number	US-201213621982-A
Country	US
Kind code	B2
Filing date	Sep 18, 2012
Priority date	Jan 13, 2012
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

According to one embodiment, a MEMS element comprises a first electrode fixed on a substrate, a second electrode formed above the first electrode to face it, and vertically movable, a first anchor portion formed on the substrate and configured to support the second electrode, and a first spring portion configured to connect the second electrode and the first anchor portion. The first spring portion includes a liner layer includes a brittle material in contact with the second electrode and the first anchor portion, and a base layer formed on the liner layer, includes a brittle material having a composition different from that of the liner layer, and having a film thickness larger than that of the liner layer.

First claim

What is claimed is:

1. A MEMS element comprising:
a first electrode fixed on a substrate;
a second electrode formed above the first electrode to face it, and vertically movable;
a first anchor portion formed on the substrate and configured to support the second electrode; and
a first spring portion configured to connect the second electrode and the first anchor portion, and having a step between the second electrode and the first anchor portion,
wherein the first spring portion includes a liner layer comprising a brittle material in contact with the second electrode and the first anchor portion, and a base layer formed on the liner layer, comprising a brittle material having a composition different from that of the liner layer, and having a film thickness larger than that of the liner layer.

2. The element of claim 1 , wherein the base layer comprises a brittle material having an elastic constant larger than that of the liner layer.

3. The element of claim 2 , wherein the liner layer comprises one of silicon oxide and silicon oxynitride.

4. The element of claim 2 , wherein the base layer comprises one of silicon nitride, silicon oxynitride, polysilicon, silicon, silicon germanium, tungsten, molybdenum, and aluminum titanium.

5. The element of claim 2 , wherein the base layer comprises silicon nitride, and the liner layer comprises silicon oxide.

6. The element of claim 2 , wherein the base layer and the liner layer comprise silicon oxynitride, and a composition ratio of nitrogen in the base layer is higher than that of nitrogen in the liner layer.

7. The element of claim 1 , wherein the second electrode and the first anchor portion comprise a conductive ductile material.

8. The element of claim 7 , wherein the second electrode and the first anchor portion comprise one of aluminum, an alloy containing aluminum as a main component, copper, gold, and platinum.

9. The element of claim 1 , wherein the liner layer is continuously formed from an upper surface to a side surface of the first anchor portion, and from an upper surface to a side surface of the second electrode, and has equal film quality on all the surfaces.

10. The element of claim 1 , further comprising:
a second anchor portion formed on the substrate and configured to support the second electrode; and
a second spring portion configured to connect the second electrode and the second anchor portion, and comprising a ductile material.

11. The element of claim 10 , wherein a spring constant of the first spring portion is larger than that of the second spring portion.

12. The element of claim 10 , wherein the second spring portion comprises one of aluminum, an alloy containing aluminum as a main component, copper, gold, and platinum.

13. The element of claim 1 , wherein the base layer and the liner layer comprise silicon oxynitride, and a composition ratio of nitrogen in the base layer is higher than that of nitrogen in the liner layer.

Assignees

• Watanabe Kei
• Shimooka Yoshiaki
• Saito Tomohiro
• Ikehashi Tamio
• Toshiba Kk

Inventors

• Watanabe Kei
• Shimooka Yoshiaki
• Saito Tomohiro
• Ikehashi Tamio

Classifications

• H01G5/011

  Electrodes · CPC title

• H01G5/16 Primary

  using variation of distance between electrodes · CPC title

• Y10T29/42

  Piezoelectric device making · CPC title