MEMS transducer
First Claim
1. An MEMS transducer comprising:
- a diaphragm having conductivity;
a plate having conductivity;
a support structure for supporting the diaphragm and the plate with a gap layer therebetween, wherein the support structure has an interior wall surrounding the gap layer;
an electrode film having conductivity for covering a contact hole formed in the support structure; and
a protective film which is formed on the support structure externally of the interior wall so as to cover a side surface of the electrode film,wherein an electric signal corresponding to variations of an electrostatic capacitance formed between the diaphragm and the plate is output via the electrode film.
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Accused Products
Abstract
An MEMS transducer is constituted of a diaphragm, a plate, a support structure for supporting the diaphragm and the plate with a gap layer surrounded by an interior wall, an electrode film (e.g. a pad conductive film) for covering a contact hole formed in the support structure, and a protective film (e.g. a pad protective film) which is formed on the support structure externally of the interior wall so as to cover the side surface of the electrode film having low chemical stability. The protective film is formed in the limited area including a part of the surface of the electrode film except for its center portion and the surrounding area of the electrode film. This allows the protective film to use materials having high membrane stress such as silicon nitride or silicon nitride oxide.
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Citations
6 Claims
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1. An MEMS transducer comprising:
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a diaphragm having conductivity; a plate having conductivity; a support structure for supporting the diaphragm and the plate with a gap layer therebetween, wherein the support structure has an interior wall surrounding the gap layer; an electrode film having conductivity for covering a contact hole formed in the support structure; and a protective film which is formed on the support structure externally of the interior wall so as to cover a side surface of the electrode film, wherein an electric signal corresponding to variations of an electrostatic capacitance formed between the diaphragm and the plate is output via the electrode film. - View Dependent Claims (2, 3)
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4. An MEMS transducer comprising:
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a diaphragm having conductivity; a plate having conductivity; an insulating member for insulating the diaphragm from the plate; an electrode film which is composed of a conductive film so as to cover a contact hole formed in the insulating member; and a protective film which is limitedly formed in a part of a surface of the electrode film and a surrounding area of the electrode film on a surface of the insulating member, thus covering a side surface of the electrode film, wherein an electric signal corresponding to variations of electrostatic capacitance formed between the diaphragm and the plate is output from the electrode film. - View Dependent Claims (5, 6)
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Specification