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US 2014/0213008 A1Published application
Capacitive Sensors and Methods for Forming the Same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsBruce C.S. Chou, Jung-Kuo Tu, Chen-Chih Fan
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Abstract
A device includes a semiconductor substrate, and a capacitive sensor having a back-plate, wherein the back-plate forms a first capacitor plate of the capacitive sensor. The back-plate is a portion of the semiconductor substrate. A conductive membrane is spaced apart from the semiconductor substrate by an air-gap. A capacitance of the capacitive sensor is configured to change in response to a movement of the polysilicon membrane.
Claims20
A method comprising:
- forming a first component comprising:
- forming a first dielectric layer over a first silicon substrate;
- forming a sacrificial layer over the first dielectric layer;
- forming a polysilicon membrane and a first conductive via over the sacrificial layer, wherein the first conductive via is between the first dielectric layer and the polysilicon membrane, and wherein the first conductive via extends into the sacrificial layer;
- forming a first bond layer comprising a portion over the first silicon substrate;
- forming a second component comprising:
- forming a second dielectric layer over a second silicon substrate;
- and
- forming a second bond layer over the second dielectric layer;
- bonding the first component and the second component by bonding the first bond layer to the second bond layer;
- and
- removing portions of the sacrificial layer between the polysilicon membrane and the first dielectric layer to form an air-gap, wherein the polysilicon membrane is configured to move in the air-gap.
9 more elements
A method comprising:
- forming a first sacrificial layer over a semiconductor substrate;
- forming a conductive plate over the first sacrificial layer;
- forming a second sacrificial layer over the conductive plate;
- patterning the first sacrificial layer and the second sacrificial layer to form vias, wherein the conductive plate and the semiconductor substrate are exposed through the vias;
- forming a conductive layer over the second sacrificial layer and filling the vias, wherein the conductive layer comprises a first portion connected to the vias, and a second portion connected to the conductive plate;
- patterning the conductive layer to disconnect the first portion and the second portion of the conductive layer from each other;
- and
- removing the first sacrificial layer to form a capacitor, with the conductive plate and the semiconductor substrate forming two capacitor plates of the capacitor.
5 more elements
A method comprising:
- forming a dielectric layer over a semiconductor substrate;
- forming a sacrificial layer over the dielectric layer;
- patterning the sacrificial layer and the dielectric layer to form vias, wherein the semiconductor substrate is exposed through the vias;
- forming a conductive layer over the sacrificial layer;
- patterning the conductive layer to separate a first portion from a second portion of the conductive layer from each other, wherein the first portion is electrically coupled to the semiconductor substrate;
- and
- removing the sacrificial layer to form an air-gap separating the second portion of the conductive layer from the semiconductor substrate.
4 more elements
Dependencies are inferred from the claim text.