Micro-Electro-Mechanical Transducer Having an Insulation Extension
AssigneeKolo Technologies, Inc.
InventorYongli Huang
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Abstract
A micro-electro-mechanical transducer (such as a cMUT) having two electrodes separated by an insulator with an insulation extension is disclosed. The two electrodes define a transducing gap therebetween. The insulator has an insulating support disposed generally between the two electrodes and an insulation extension extending into at least one of two electrodes to increase the effective insulation without having to increase the transducing gap. Methods for fabricating the micro-electro-mechanical transducer are also disclosed. The methods may be used in both conventional membrane-based cMUTs and cMUTs having embedded springs transporting a rigid top plate.
Claims62
An electrostatic transducer comprising:
- a first conductive layer having a top surface;
- a second conductive layer having a bottom surface opposing the top surface of the first layer, the first conducting layer and the second conductive layer defining a transducing gap therebetween;
- an insulating support disposed generally between the first conductive layer and the second conductive layer;
- and
- an insulation extension extending into at least one of the first conducting layer and the second conductive layer.
A micro-electro-mechanical transducer having a movable mechanical part to transform energy, the transducer comprising:
- a substrate;
- a middle spring layer placed over the substrate, the substrate and the middle spring layer defining a cavity therebetween, the cavity being bordered by a sidewall, wherein the middle spring layer extends from the sidewall to cover the cavity;
- an insulating connector on the middle spring layer;
- a top plate placed over the insulating connector, wherein the insulating connected separates the top plate from the middle spring layer to define a transducing gap below the top plate;
- and
- an insulation extension extending beyond the transducing gap.
A capacitive micromachined ultrasonic transducer comprising:
- a lower layer including a substantially static substrate and serving as a bottom electrode;
- a top layer including a membrane and serving as a top electrode, the membrane being adapted for vibrating in relation to the static substrate a transducing excitation, the top layer and the lower layer defining a transducing gap therebetween;
- and
- an insulator having a main portion and an insulation extension, the main portion being generally disposed between and supporting the lower layer and the top layer, and the insulation extension extending into at least one of the lower layer and the top layer.
A method for fabricating a micro-electro-mechanical transducer having two electrodes separated by an insulator with an insulation extension, the method comprising the steps of:
- forming a recess on a major surface of a first conductive layer;
- forming a standing feature of an insulating material over the recess, the standing feature extending from the recess to a free end above the major surface of the first conductive layer;
- and
- placing a second conductive layer over the free end of the standing feature.
A method for fabricating a micro-electro-mechanical transducer having two electrodes separated by an insulator with an insulation extension, the method comprising the steps of:
- forming a patterned trench over a major surface of a substrate by removing material of the substrate, wherein the patterned trench comprises thin lines of unremoved material of the substrate;
- oxidizing the thin lines of unremoved material of the substrate in the patterned trench such that the patterned trench constitutes an insulator;
- patterning and etching the major surface of the substrate such that the insulator has a top end standing above the substrate;
- and
- placing a top conductive layer over the top end of the insulator.
A method for fabricating a micro-electro-mechanical transducer having two electrodes separated by an insulator with an insulation extension, the method comprising the steps of:
- forming a trench over a major surface of a substrate by removing material of the substrate;
- filling the trench with an insulating material;
- patterning and etching the major surface of the substrate such that the insulating material in the trench has a top end standing above the substrate;
- and
- placing a top conductive layer over the top end of the insulator.
A method for fabricating a micro-electro-mechanical transducer having two electrodes separated by an insulator with an insulation extension, the method comprising the steps of:
- providing a top plate, a middle spring layer and a substrate;
- forming a standing feature of an insulating material on a major surface of one of the top plate and the middle spring layer, the standing feature extending from a point below the major surface to a free end beyond the major surface;
- and
- joining the top plate, the middle spring layer and the substrate, such that the top plate and the middle spring layer are connected by the standing feature at the free end thereof, and the middle spring layer is connected to the substrate at an opposing side, wherein the substrate and the middle spring layer define a cavity therebetween, the cavity being bordered by a sidewall, the middle spring layer extending from the sidewall to cover the cavity.
Dependencies are inferred from the claim text.