Semiconductor physical quantity sensor
First Claim
1. A semiconductor physical quantity sensor comprising:
- a supporting substrate;
a semiconductor substrate for sensor element supported to the supporting substrate;
a bridge structure formed in the semiconductor substrate for sensor element, the bridge structure having a bridge-like weight part and a moving electrode provided on the weight part;
a cantilever structure formed in the semiconductor substrate for sensor element by being divided from the bridge structure, the cantilever structure having a cantilevered fixed electrode disposed facing the moving electrode;
wherein a width of a root portion of the cantilevered fixed electrode at a fixed end thereof is narrower than a width of the fixed electrode, and a physical quantity is detected on the basis of a displacement of the moving electrode relative to the fixed electrode caused by action of the physical quantity.
1 Assignment
0 Petitions
Accused Products
Abstract
A semiconductor physical quantity sensor from which a stable sensor output can be obtained even when the usage environment changes. A silicon thin film is disposed on an insulating film on a supporting substrate, and a bridge structure having a weight part and moving electrodes and cantilever structures having fixed electrodes are formed as separate sections from this silicon thin film. The moving electrodes provided on the weight part and the cantilevered fixed electrodes are disposed facing each other. Slits are formed at root portions of the cantilevered fixed electrodes at the fixed ends thereof, and the width W1 of the root portions is thereby made narrower than the width W2 of the fixed electrodes proper. As a result, the transmission of warp of the supporting substrate to the cantilevered fixed electrodes is suppressed.
-
Citations
15 Claims
-
1. A semiconductor physical quantity sensor comprising:
-
a supporting substrate;
a semiconductor substrate for sensor element supported to the supporting substrate;
a bridge structure formed in the semiconductor substrate for sensor element, the bridge structure having a bridge-like weight part and a moving electrode provided on the weight part;
a cantilever structure formed in the semiconductor substrate for sensor element by being divided from the bridge structure, the cantilever structure having a cantilevered fixed electrode disposed facing the moving electrode;
wherein a width of a root portion of the cantilevered fixed electrode at a fixed end thereof is narrower than a width of the fixed electrode, and a physical quantity is detected on the basis of a displacement of the moving electrode relative to the fixed electrode caused by action of the physical quantity. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A semiconductor physical quantity sensor comprising:
-
a supporting substrate made of a semiconductor, having an opening of a predetermined shape opening at one side of the supporting substrate;
a moving electrode part supported to the supporting substrate, for displacing over the opening in correspondence with an applied physical quantity;
a first fixed electrode portion defining a first detection capacitance between itself and the moving electrode part; and
a second fixed electrode portion defining a second detection capacitance between itself and the moving electrode part, the applied physical quantity is detected on the basis of the difference between the first detection capacitance and the second detection capacitance when the moving electrode displaces in correspondence with the applied physical quantity, wherein each of the first and second fixed electrode portions includes;
a first facing electrode and a second facing electrode disposed facing the moving electrode over the opening; and
a first interconnection part fixed to the supporting substrate and supports the first facing electrode, and a second interconnection part fixed to the supporting substrate and supports the second facing electrodes, and each of the first and second interconnection parts of each of the first and second fixed electrode portions are electrically independent from each other and disposed facing each other on opposite sides of the opening in the supporting substrate. - View Dependent Claims (8, 9, 10)
the opening is formed in a rectangular;
the moving electrode part is disposed crossing over the opening between one pair of opposite sidewalls of the opening in the supporting substrate; and
the first and second interconnection parts are disposed on the other pair of opposite sides of the opening in the supporting substrate.
-
-
10. A semiconductor physical quantity sensor according to claim 7, wherein:
-
the moving electrode part comprises;
a weight part supported to the opening by its ends in a direction in which the moving electrode displaces on the supporting substrate on opposite sides of the opening; and
first and second projecting parts projecting from this weight part in mutually opposite directions orthogonal to the direction in which the moving electrode displaces, the first projecting parts are made up of parts facing the first facing electrode in the first fixed electrode pair and parts facing the first facing electrode in the second fixed electrode, and the second projecting parts are made up of parts facing the second facing electrode in the first fixed electrode pair and parts facing the second facing electrodes in the second fixed electrode.
-
-
11. A semiconductor physical quantity sensor comprising:
-
a supporting substrate made of a semiconductor, having an opening of a predetermined shape opening at one side of the substrate;
a moving electrode part supported to the supporting substrate, for displacing over the opening in correspondence with an applied physical quantity;
a fixed electrode portion fixed to an edge of the supporting substrate at the opening and disposed facing the moving electrode part, the applied physical quantity is detected on the basis of the difference between the first detection capacitance and the second detection capacitance when the moving electrode displaces in correspondence with the applied physical quantity; and
an interconnection part provided at parts of the fixed electrode part fixed to the edge of the supporting substrate at the opening constitute, the interconnection part for extracting signals to outside, the interconnection part having voids where portions of the interconnection part has been removed so that the supporting substrate is exposed are formed in parts of the interconnection parts overlapping with the supporting substrate. - View Dependent Claims (12)
-
-
13. A semiconductor physical quantity sensor comprising:
-
a supporting substrate made of a semiconductor, having an opening of a predetermined shape opening at one side of the substrate;
a moving electrode part supported by the supporting substrate, for displacing over the opening in correspondence with an applied physical quantity;
a fixed electrode portion fixed to an edge of the supporting substrate at the opening and disposed facing the moving electrode part, the applied physical quantity is detected on the basis of the difference between the first detection capacitance and the second detection capacitance when the moving electrode displaces in correspondence with the applied physical quantity;
a moving electrode pad formed on the supporting substrate on a first side of the opening, for connecting a wire that electrically connects the moving electrode part to an external part; and
a fixed electrode pad formed on the supporting substrate on a second side of the opening facing the first side, for connecting a wire that electrically connects the fixed electrode part to the external part.
-
-
14. A semiconductor physical quantity sensor comprising:
-
a supporting substrate made of a semiconductor, a moving electrode part supported by the supporting substrate, for displacing in correspondence with an applied physical quantity; and
a fixed electrode parts fixed to the supporting substrate and disposed facing the moving electrode part, the applied physical quantity is detected on the basis of the difference between the first detection capacitance and the second detection capacitance when the moving electrode displaces in correspondence with the applied physical quantity;
a moving electrode wire electrically connecting the moving electrode to an external part; and
a fixed electrode wire electrically connecting the fixed electrode to the external part, the fixed electrode wire is apart by a distance of at least 80 μ
m from the moving electrode wires.- View Dependent Claims (15)
-
Specification