METHOD FOR MANUFACTURING A MEMS SENSOR
First Claim
1. A method for manufacturing a MEMS sensor comprising the steps of:
- forming a recess dug to a halfway point in the thickness direction of a semiconductor substrate by selectively etching the surface layer portion of a sensor region of the semiconductor substrate having the sensor region and a peripheral region surrounding the sensor region, and concurrently, forming a comb-tooth-like fixed electrode and movable electrode that engage with each other via the recess;
forming a sacrifice layer that covers the sensor region and exposes the peripheral region;
forming a protective layer made of a first inorganic material on the semiconductor substrate so that a peripheral edge portion of the protective layer is bonded to the peripheral region and the central portion surrounded by the peripheral edge portion covers the sacrifice layer;
forming a space between the protective layer and the sensor region by removing the sacrifice layer directly below the protective layer; and
forming a cavity by linking the lower portions of the fixed electrode and the movable electrode to each other by isotropic etching by supplying an etching medium into the recess after removing the sacrifice layer.
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Accused Products
Abstract
A capacitance type gyro sensor includes a semiconductor substrate, a first electrode integrally including a first base portion and first comb tooth portions and a second electrode integrally including a second base portion and second comb tooth portions, formed by processing the surface portion of the semiconductor substrate. The first electrode has first drive portions that extend from opposed portions opposed to the respective second comb tooth portions on the first base portion toward the respective second comb tooth portions. The second electrode has second drive portions formed on the tip end portions of the respective second comb tooth portions opposed to the respective first drive portions. The first drive portions and the second drive portions engage with each other at an interval like comb teeth.
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Citations
17 Claims
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1. A method for manufacturing a MEMS sensor comprising the steps of:
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forming a recess dug to a halfway point in the thickness direction of a semiconductor substrate by selectively etching the surface layer portion of a sensor region of the semiconductor substrate having the sensor region and a peripheral region surrounding the sensor region, and concurrently, forming a comb-tooth-like fixed electrode and movable electrode that engage with each other via the recess; forming a sacrifice layer that covers the sensor region and exposes the peripheral region; forming a protective layer made of a first inorganic material on the semiconductor substrate so that a peripheral edge portion of the protective layer is bonded to the peripheral region and the central portion surrounded by the peripheral edge portion covers the sacrifice layer; forming a space between the protective layer and the sensor region by removing the sacrifice layer directly below the protective layer; and forming a cavity by linking the lower portions of the fixed electrode and the movable electrode to each other by isotropic etching by supplying an etching medium into the recess after removing the sacrifice layer. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for manufacturing a MEMS sensor comprising the steps of:
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selectively forming a lower electrode on a semiconductor substrate; laminating an electrode coating film made of a material having etching selectivity to polysilicon on the semiconductor substrate so as to coat the lower electrode; selectively forming a sacrifice polysilicon layer on the electrode coating film; laminating a sacrifice oxide film on the electrode coating film so as to coat the sacrifice polysilicon layer; forming an electrode polysilicon layer on the sacrifice oxide film; forming an upper electrode by selectively etching the electrode polysilicon layer; forming a protective film having etching selectivity to polysilicon so as to cover side walls of the upper electrode; exposing the sacrifice polysilicon layer by removing portions of the sacrifice oxide film; and forming a cavity directly below the upper electrode by removing the exposed sacrifice polysilicon layer. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method for manufacturing a MEMS sensor comprising the steps of:
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forming a base film made of a material having etching selectivity to Si on a Si substrate; forming a polysilicon layer on the base film; forming trenches from the surface of the polysilicon layer to the surface of the Si substrate by selectively etching the polysilicon layer and the base film and concurrently, forming a comb-tooth-like first electrode and second electrode that have a lamination structure including the base film and the polysilicon layer and engage with each other via the trenches; and forming a cavity directly below the base film by etching portions directly below the base film of the Si substrate by isotropic etching by supplying an etching medium into the trenches. - View Dependent Claims (14, 15, 16, 17)
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Specification