JP2018155734A - Semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce potential difference between a piezo resistance part and a shield film.SOLUTION: The semiconductor device includes: a semiconductor substrate formed with a cavity part; a piezo resistance part which is formed in an area of the semiconductor substrate above the cavity part; an insulation film formed above the piezo resistance part; and a conductive shield film formed above the piezo resistance part interposed by the insulation film. The shield film is configured to provide a semiconductor device which is connected to electric potentials different from each other at two different positions. With this, the potential difference between the piezo resistance part and the shield film can be reduced.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a semiconductor device.

  A semiconductor device in which a piezoresistive portion is arranged on a diaphragm formed on a silicon substrate is known. The resistance value of the piezoresistive portion changes due to the distortion of the diaphragm. The amount of change in resistance value is output as an electrical signal. By disposing the shield film above the piezoresistive portion via the insulating film, the influence of electric charges on the piezoresistive portion is reduced.

A configuration is known in which a plurality of piezoresistive portions are covered with a single shield film, and the shield film is applied to a constant reference potential (Patent Document 1). A configuration is also known in which a shield film is individually provided above a plurality of piezoresistive portions (Patent Document 2). In the configuration of Patent Document 2, the shield films formed on each piezoresistive portion connected to the high potential side terminal of the Wheatstone bridge circuit are electrically connected. In addition, the shield films formed on each piezoresistor connected to the low potential side terminal of the Wheatstone bridge circuit are electrically connected. The shield film formed above each piezoresistor connected to the high potential side terminal and the shield film formed above each piezoresistor connected to the low potential side terminal are fixed at different potentials. (Patent Document 2).
[Prior art documents]
[Patent Literature]
[Patent Document 1] JP 2006-329929 A [Patent Document 2] International Publication No. 2012/080811

  When a current flows through the piezoresistive part, the potential varies depending on the position in one piezoresistive part due to a voltage drop, whereas the shield film above the piezoresistive part is fixed at a constant potential regardless of the position. The Therefore, the potential difference between the piezoresistive portion and the shield film varies depending on the position in the piezoresistive portion. The potential difference between the piezoresistive portion and the shield film affects the resistance value and temperature characteristics of the piezoresistive portion. Therefore, in the semiconductor device, it is preferable to reduce the potential difference between the piezoresistive portion and the shield film.

  In a first aspect of the present invention, a semiconductor device is provided. The semiconductor device includes a semiconductor substrate, a piezoresistive portion, an insulating film, and a shield film. The semiconductor substrate may be provided with a cavity. The piezoresistive portion may be provided in a region of the semiconductor substrate above the cavity portion. The insulating film may be provided above the piezoresistive portion. The conductive shield film may be provided above the piezoresistive portion via an insulating film. The shield film may be connected to different potentials at two different locations.

  A potential difference may be applied to the shield film in the same direction as the potential difference generated in the piezoresistive portion.

  The semiconductor device may include a plurality of piezoresistive units that form a Wheatstone bridge circuit. The plurality of piezoresistors may include a first resistor, a second resistor, a third resistor, and a fourth resistor. The first resistor may be electrically connected between the high potential side terminal of the Wheatstone bridge circuit and the first intermediate potential terminal of the Wheatstone bridge circuit. The second resistor may be electrically connected between the first intermediate potential terminal and the low potential side terminal of the Wheatstone bridge circuit. The third resistor may be electrically connected between the high potential side terminal and the second intermediate potential terminal of the Wheatstone bridge circuit. The fourth resistor may be electrically connected between the second intermediate potential terminal and the low potential side terminal. The shield film may be provided above each of the plurality of piezoresistive portions via an insulating film. Two shield films may be connected in series between the high potential side terminal and the low potential side terminal.

  The shield film may include a first shield film, a second shield film, a third shield film, and a fourth shield film. The first shield film, the second shield film, the third shield film, and the fourth shield film may be provided above each of the first resistance, the second resistance, the third resistance, and the fourth resistance. . One end of the first shield film and one end of the third shield film may be electrically connected to the high potential side terminal of the Wheatstone bridge circuit, respectively. One end of the second shield film and one end of the fourth shield film may be electrically connected to the low potential side terminal of the Wheatstone bridge circuit, respectively.

  The other end of the first shield film and the other end of the second shield film may be electrically connected. The other end of the third shield film and the other end of the fourth shield film may be electrically connected.

  The other end of the first shield film and the other end of the fourth shield film may be electrically connected. The other end of the third shield film and the other end of the second shield film may be electrically connected.

  The other end of the first shield film, the other end of the second shield film, the other end of the third shield film, and the other end of the fourth shield film may be electrically connected to each other.

  The other end of the first shield film, the other end of the second shield film, the other end of the third shield film, and the other end of the fourth shield film are electrically connected to the first intermediate potential terminal or the second intermediate potential terminal. May be.

  The semiconductor device may further include a resistance wiring portion. The resistance wiring portion may be a diffused resistor. The resistance wiring portion may be connected to the piezoresistive portion. The semiconductor device may further include a wiring portion. The wiring part may be connected to the shield film. In a plan view, the area of the shield film and the wiring portion may be smaller than that of the piezoresistive portion and the resistance wiring portion.

  The semiconductor device may further include a wiring portion. The wiring part may be connected to the shield film. The wiring part may have a resistance value lower than the resistance value of the shield film. The shield film and the wiring portion may be made of polysilicon that is continuous with each other. The cross-sectional area of the wiring part may be larger than the cross-sectional area of the shield film.

  The semiconductor device may further include a wiring portion. The wiring part may be connected to the shield film. The wiring part may have a resistance value lower than the resistance value of the shield film. The polysilicon constituting the shield film may be thinner than the polysilicon constituting the wiring part.

  The shield film and the wiring portion may be made of polysilicon that is continuous with each other. The doping concentration of the wiring part may be higher than the doping concentration of the shield film.

  The shield film may be made of polysilicon. The wiring part may be made of metal.

  The sheet resistance value of the shield film may be 10Ω / □ or more and 10 kΩ / □ or less.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a figure which shows an example of the circuit structure of the semiconductor pressure sensor 1 in 1st Embodiment. It is a figure which shows the structure of the semiconductor pressure sensor 1 in 1st Embodiment. It is a top view of semiconductor pressure sensor 1 in a 1st embodiment. It is sectional drawing of the semiconductor pressure sensor 1 in 1st Embodiment. It is a top view of the semiconductor pressure sensor 1 in 2nd Embodiment. It is sectional drawing of the semiconductor pressure sensor 1 in 2nd Embodiment. It is a top view of the semiconductor pressure sensor 1 in 3rd Embodiment. It is sectional drawing of the semiconductor pressure sensor 1 in 3rd Embodiment. It is a top view of the semiconductor pressure sensor 1 in 4th Embodiment. It is sectional drawing of the semiconductor pressure sensor 1 in 4th Embodiment. It is a top view of the semiconductor pressure sensor 1 in 5th Embodiment. It is sectional drawing of the semiconductor pressure sensor 1 in 5th Embodiment. It is a figure which shows an example of the circuit structure of the semiconductor pressure sensor 1 in 6th Embodiment. It is a figure which shows an example of the circuit structure of the semiconductor pressure sensor 1 in 7th Embodiment. It is a figure which shows an example of the circuit structure of the semiconductor pressure sensor 1 in 8th Embodiment.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 is a diagram illustrating an example of a circuit configuration of a semiconductor pressure sensor 1 according to the first embodiment. The semiconductor pressure sensor 1 is an example of a semiconductor device. The semiconductor pressure sensor 1 includes a plurality of piezoresistive portions 10 and a shield film 20. The semiconductor pressure sensor 1 includes a plurality of piezoresistive portions 10-1, 10-2, 10-3, and 10-4 (hereinafter, may be collectively referred to as a plurality of piezoresistive portions 10) constituting a Wheatstone bridge circuit. Prepare. In FIG. 1, the plurality of piezoresistors 10 are represented as a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4.

  The piezoresistor 10 may be a diffused resistor formed on the semiconductor substrate. The semiconductor substrate may be a silicon substrate or a compound semiconductor substrate such as silicon carbide (SiC). The piezoresistive portion 10 may be formed by selectively doping a semiconductor substrate with a p-type or n-type dopant and further thermally diffusing.

  The first resistor R1 is electrically connected between the high potential side terminal Vdd of the Wheatstone bridge circuit and the first intermediate potential terminal Vout1 of the Wheatstone bridge circuit. The second resistor R2 is electrically connected between the first intermediate potential terminal Vout1 and the low potential side terminal Vss of the Wheatstone bridge circuit. The third resistor R3 is electrically connected between the high potential side terminal Vdd and the second intermediate potential terminal Vout2 of the Wheatstone bridge circuit. The fourth resistor is electrically connected between the second intermediate potential terminal Vout2 and the low potential side terminal Vss.

  The high potential side terminal Vdd may be a high potential power source. The low potential side terminal Vss may be a ground potential. The first intermediate potential terminal Vout1 and the second intermediate potential terminal Vout2 may be output terminals of the Wheatstone bridge circuit. The first intermediate potential terminal Vout1 and the second intermediate potential terminal Vout2 are each higher than the potential of the low potential side terminal Vss and less than the potential of the high potential side terminal Vdd. The first intermediate potential terminal Vout1 has a potential obtained by dividing the potential difference between the high potential side terminal Vdd and the low potential side terminal Vss by the resistance ratio of the first resistor R1 and the second resistor R2. Similarly, the second intermediate potential terminal Vout2 has a potential obtained by dividing the potential difference between the high potential side terminal Vdd and the low potential side terminal Vss by the resistance ratio of the third resistor R3 and the fourth resistor R4.

  One end of the first resistor R1 and one end of the third resistor R3 may be electrically connected to the high potential side terminal Vdd via the resistor wiring 14. One end of the second resistor R2 and one end of the fourth resistor R4 may be electrically connected to the low potential side terminal Vss via the resistor portion wiring 15. The other end of the first resistor R1 and the other end of the second resistor R2 may be connected to the first intermediate potential terminal Vout1 via the resistor wiring 13. The other end of the third resistor R3 and the other end of the fourth resistor R4 may be connected to the second intermediate potential terminal Vout2 via another resistor portion wiring 13.

  The current flows from the high potential side terminal Vdd through the first resistor R1 and the second resistor R2 to the low potential side terminal Vss. A voltage drop occurs when current flows through the first resistor R1 and the second resistor R2. Therefore, in the first resistor R1, one end connected to the resistor portion wiring 14 has a higher potential than the other end connected to the resistor portion wiring 13. In the second resistor R <b> 2, one end connected to the resistor portion wiring 15 is connected to a lower potential than the other end connected to the resistor portion wiring 13.

  Similarly, current flows from the high potential side terminal Vdd to the low potential side terminal Vss via the third resistor R3 and the fourth resistor R4. A voltage drop occurs when current flows through the third resistor R3 and the fourth resistor R4. Therefore, in the third resistor R 3, one end connected to the resistor portion wiring 14 has a higher potential than the other end connected to the resistor portion wiring 13. In the fourth resistor R4, one end connected to the resistor portion wiring 15 has a lower potential than the other end connected to the resistor portion wiring 13.

  The shield film 20 is provided above each of the plurality of piezoresistive portions 10. The shield film 20 includes a first shield film 20-1, a second shield film 20-2, a third shield film 20-3, and a fourth shield film 20-4. The first shield film 20-1, the second shield film 20-2, the third shield film 20-3, and the fourth shield film 20-4 are connected to the first resistor R1 and the second resistor via an insulating film to be described later. It may be individually provided above each of R2, the third resistor R3, and the fourth resistor R4.

  Each of the plurality of shield films 20 may be made of a conductive material such as polysilicon. Since the shield film 20 of this example is connected to different potentials at two different positions, a current flows in the shield film 20. Therefore, the resistive shield film 20 having a predetermined sheet resistance value is used so that one end and the other end of the shield film 20 are not short-circuited.

  In this example, one end 21 of the first shield film 20-1 and one end 21 of the third shield film 20-3 are electrically connected to the high potential side terminal Vdd of the Wheatstone bridge circuit via the wiring portion 25, respectively. The One end 21 of the second shield film 20-3 and one end 21 of the fourth shield film 20-4 are electrically connected to the low potential side terminal Vss of the Wheatstone bridge circuit via the wiring part 26, respectively.

  In this example, the other end 22 of the first shield film 20-1 and the other end 22 of the second shield film 20-2 are electrically connected. The other end 22 of the third shield film 20-3 and the other end 22 of the fourth shield film 20-4 are electrically connected. Therefore, in this example, the first shield film 20-1 and the second shield film 20-2 are connected in series between the high potential side terminal Vdd and the low potential side terminal Vss as two shield films. Similarly, as the two shield films, the third shield film 20-3 and the fourth shield film 20-4 are connected in series between the high potential side terminal Vdd and the low potential side terminal Vss.

  In this example, the first resistor R1 and the second resistor R2 are electrically connected in series, and the first shield film 20-1 and the second shield film 20-2 provided above these are electrically connected to each other. Connected in series. Similarly, the third resistor R3 and the fourth resistor R4 are electrically connected in series, and the third shield film 20-3 and the fourth shield film 20-4 provided above are electrically connected to each other. Connected in series.

  In this example, current flows in the first shield film 20-1, the second shield film 20-2, the third shield film 20-3, and the fourth shield film 20-4. The current flows from the high potential side terminal Vdd to the low potential side terminal Vss through the first shield film 20-1 and the second shield film 20-2. When current flows through the first shield film 20-1 and the second shield film 20-2, a voltage drop occurs. Therefore, in the first shield film 20-1, one end 21 connected to the wiring portion 25 has a higher potential than the other end 22 connected to the wiring portion 24. In the second shield film 20-2, one end 21 connected to the wiring portion 26 has a lower potential than the other end 22 connected to the wiring portion 24.

  Similarly, the current flows from the high potential side terminal Vdd to the low potential side terminal Vss through the third shield film 20-3 and the fourth shield film 20-4. When current flows through the third shield film 20-3 and the fourth shield film 20-4, a voltage drop occurs. Accordingly, in the third shield film 20-3, one end 21 connected to the wiring portion 25 has a higher potential than the other end 22 connected to the wiring portion 24. In the fourth shield film 20-4, one end 21 connected to the wiring part 26 has a lower potential than the other end 22 connected to the wiring part 24.

  Therefore, the first shield film 20-1 is connected to different potentials at two different positions. Similarly, the second shield film 20-2, the third shield film 20-3, and the fourth shield film 20-4 are respectively connected to different potentials at two different positions.

  A potential difference is applied to the first shield film 20-1 in the same direction as the potential difference generated in the first resistor R1. Similarly, in the second resistor R2, the third resistor R3, and the fourth resistor R4, a potential difference is applied to the corresponding shield film 20 in the same direction as the potential difference generated in each piezoresistor. The resistance portion wiring 14 and the wiring portion 25 may be connected to the high potential side terminal Vdd through the metal wiring 30. Similarly, the resistance portion wiring 15 and the wiring portion 26 may be connected to the low potential side terminal Vss via the metal wiring 32.

  FIG. 2 is a diagram illustrating a configuration of the semiconductor pressure sensor 1 according to the first embodiment. The semiconductor pressure sensor 1 includes a semiconductor substrate 2 provided with a cavity 3. In FIG. 2, the cavity 3 is indicated by a dotted line. In the cavity 3 that is a region surrounded by a dotted line, the thickness of the semiconductor substrate 2 is thinner than the outside of the region surrounded by the dotted line. Since the region of the semiconductor substrate 2 above the cavity 3 is thinner than the outside of the region surrounded by the dotted line, it is easily displaced by pressure. The semiconductor substrate 2 above the cavity 3 functions as a diaphragm.

  The first resistor R 1, the second resistor R 2, the third resistor R 3, and the fourth resistor R 4 that are the plurality of piezoresistive portions 10 may be provided in the region of the semiconductor substrate 2 above the cavity portion 3. In this example, the area of the cavity 3 is polygonal in plan view. In this example, the area of the cavity 3 is octagonal in plan view. The first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4, which are the plurality of piezoresistors 10, may each have a current flowing in the longitudinal direction. The first resistor R1 may be arranged such that the longitudinal direction of the first resistor R1 is along one side adjacent to the first resistor R1 in the cavity 3. Similarly, the fourth resistor R4 may be arranged so that the longitudinal direction of the fourth resistor R4 is along one side of the cavity 3 adjacent to the fourth resistor R4. On the other hand, the second resistor R2 may be arranged so that the longitudinal direction of the second resistor R2 intersects one side of the cavity 3 adjacent to the second resistor R2. The third resistor R3 may be arranged such that the longitudinal direction of the third resistor R3 intersects one side of the cavity 3 adjacent to the third resistor R3. In this example, when the semiconductor substrate 2 functioning as a diaphragm is subjected to pressure, the semiconductor substrate 2 is deformed in the direction intersecting each side around each side of the cavity 3. Therefore, in this example, the first resistor R1 and the fourth resistor R4 are deformed in the short direction (lateral direction) when the diaphragm is deformed. On the other hand, the second resistor R2 and the third resistor R3 are deformed in the longitudinal direction when the diaphragm is deformed. The piezoresistive portion 10 that deforms in the longitudinal direction when the diaphragm deforms and the piezoresistive portion 10 that deforms in the short direction when the diaphragm deforms have different resistance changes when the diaphragm is deformed by pressure. As a result, when the diaphragm is deformed by the pressure, a potential difference is generated between the first intermediate potential terminal Vout1 and the second intermediate potential terminal Vout2, and the pressure can be detected. However, it is only necessary that two or more piezoresistive portions 10 that deform in the longitudinal direction and two or more piezoresistive portions 10 that deform in the short direction when the diaphragm is deformed are provided. Therefore, the shape of the hollow portion 3 and the shape and arrangement of the piezoresistive portion 10 are not limited to the case of FIG.

  The semiconductor substrate 2 may be provided with pads corresponding to the ground potential terminal GND, the first intermediate potential terminal Vout1, and the second intermediate potential terminal Vout2, which are the high potential side terminal Vdd and the low potential side terminal Vss, respectively. In this example, each pad is provided at a corner of the semiconductor substrate 2 constituting the sensor chip. In FIG. 2, wiring to each terminal is schematically shown. As shown in FIG. 1, the piezoresistive portion 10 or the shield film 20 is connected to each potential by each wiring.

  FIG. 3 is a plan view of the semiconductor pressure sensor 1 according to the first embodiment. FIG. 3 shows an enlarged portion of the first resistor R1. The enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4 has substantially the same configuration. However, in FIG. 3, the resistance portion wiring 14 and the wiring portion 25 are connected to the high potential side terminal Vdd through the metal wiring 30, and the resistance portion wiring 13 is connected to the first intermediate potential terminal Vout1. 24 is connected to the shield film on the low potential side, whereas the connection destinations are different in the enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4. FIG. 4 is a cross-sectional view of the semiconductor pressure sensor 1 in the first embodiment. Specifically, FIG. 4 shows a cross section taken along the line AA ′ of FIG.

  The semiconductor pressure sensor 1 includes a piezoresistive portion 10, a resistance portion wiring 13, and a resistance portion wiring 14 as diffusion resistors in a semiconductor substrate 2. As shown in FIG. 4, the diffused resistor is formed on the surface layer in the semiconductor substrate 2. One end 11 on the high potential side in the longitudinal direction of the piezoresistive portion 10 is connected to the resistor portion wiring 14, and the other end 12 on the low potential side in the longitudinal direction of the piezoresistive portion 10 is connected to the resistor portion wiring 13. It is connected. The diffusion resistance may be formed by, for example, selectively doping a semiconductor substrate with a p-type dopant so as to be P +, and further thermally diffusing.

  The resistance portion wiring 13 and the resistance portion wiring 14 have a larger cross-sectional area in the direction perpendicular to the current flow direction than that of the piezoresistive portion 10. In this example, as shown in FIG. 4, the piezoresistive portion 10, the resistance portion wiring 13, and the resistance portion wiring 14 have the same depth from the front surface to the back surface of the semiconductor substrate 2. Therefore, the width of the resistance portion wiring 13 and the resistance portion wiring 14 is wider than the width of the piezoresistive portion 10. The width may mean a width in a direction orthogonal to a direction in which a current flows on a surface parallel to the front surface of the semiconductor substrate 2.

  Due to the difference in cross-sectional area, the electrical resistance of the resistance portion wiring 13 and the electrical resistance of the resistance portion wiring 14 are lower than the electrical resistance of the piezoresistive portion 10. The voltage drop in the resistance portion wiring 13 and the voltage drop in the resistance portion wiring 14 are smaller than the voltage drop in the piezoresistance portion 10. Therefore, according to the semiconductor pressure sensor 1 of this example, it is easy to detect a change in the electrical resistance of the piezoresistive portion 10. In this example, the piezoresistive portion 10, the resistance portion wiring 13, and the resistance portion wiring 14 have the same doping concentration. However, the doping concentration of the resistance portion wiring 13 and the resistance portion wiring 14 may be higher than the doping concentration of the piezoresistance portion 10.

The semiconductor pressure sensor 1 includes an insulating film 4 above the piezoresistive portion 10. In this example, the insulating film 4 is provided in contact with the piezoresistive portion 10. The insulating film 4 may be an oxide film such as silicon oxide (SiO ₂ ), and may be a nitride film or an oxynitride film. The insulating film 4 covers the piezoresistive portion 10. The insulating film 4 may cover the resistance portion wiring 13 and the resistance portion wiring 14.

  The semiconductor pressure sensor 1 has a conductive shield film 20 provided above the piezoresistive portion 10 with an insulating film 4 interposed therebetween. The shield film 20 corresponds to the piezoresistive portion 10. Specifically, the shape of the shield film 20 may be determined according to the shape of the piezoresistive portion 10. The longitudinal direction of the piezoresistive portion 10 and the longitudinal direction of the shield film 20 may be the same. The shield film 20 may be wider than the piezoresistive portion 10 so as to cover the piezoresistive portion 10. In plan view, the outline of the shield film 20 may be provided along the outline of the piezoresistive portion 10.

  The semiconductor pressure sensor 1 includes a wiring part 24 and a wiring part 25 at both ends of the shield film 20. In the first resistor R <b> 1 shown in this example, one end 21 on the high potential side of the shield film 20 is connected to the wiring portion 25. The other end 22 on the low potential side of the shield film 20 is connected to the wiring portion 24. The wiring part 24 and the wiring part 25 have a resistance value lower than the resistance value of the shield film 20.

  The shield film 20, the wiring part 24, and the wiring part 25 may be made of polysilicon that is continuous with each other. In this example, the doping concentration in the shield film 20, the wiring part 24, and the wiring part 25 may be the same. In this example, the wiring part 24 and the wiring part 25 have a larger cross-sectional area in the direction perpendicular to the direction in which the current flows than the shield film 20. In this example, as shown in FIG. 4, the shield film 20, the wiring part 24, and the wiring part 25 have the same thickness in the direction perpendicular to the front surface of the semiconductor substrate 2. Therefore, the width of the wiring part 24 and the width of the wiring part 25 are wider than the width of the shield film 20. The width may mean a width in a direction orthogonal to a direction in which a current flows on a surface parallel to the front surface of the semiconductor substrate 2.

  Due to the difference in cross-sectional area, the electrical resistance of the wiring portion 24 and the wiring portion 25 is lower than the electrical resistance of the shield film 20. The voltage drop at the wiring portion 24 and the wiring portion 25 is smaller than the electrical resistance of the shield film 20. Therefore, according to the semiconductor pressure sensor 1 of this example, a voltage drop can be generated mainly in the portion of the shield film 20, and a potential gradient, that is, a potential difference can be given to the shield film 20.

  The wiring portion 25 and the resistance portion wiring 14 may be electrically connected to the metal wiring 30. In this example, the wiring part 25 is electrically connected to the metal wiring 30 via the contact part 33. The resistance portion wiring 14 is electrically connected to the metal wiring 30 through the contact portion 34. The contact portion 34 may be configured by filling an opening provided in the insulating film 4 with a metal such as aluminum. The metal wiring 30 is connected to the high potential side terminal Vdd of the Wheatstone bridge circuit.

  The resistance portion wiring 13 is electrically connected to the metal wiring 32. In this example, the resistance portion wiring 13 is electrically connected to the metal wiring 32 through the contact portion 35. The metal wiring 32 is connected to the first intermediate potential terminal Vout1 of the Wheatstone bridge circuit. The other end of the wiring portion 24 may extend to the shield film on the low potential side (in this example, the second shield film 20-2). FIG. 3 shows the position of the cavity 3 by a dotted line. Further, the wiring between the first resistor R1, the second resistor R2, the third resistor R3, and the fourth resistor R4 is indicated by a solid line. The metal wiring 30 and the metal wiring 32 may not be provided on the diaphragm which is the semiconductor substrate 2 above the cavity 3 but may be provided on the semiconductor substrate 2 in a region outside the diaphragm. Thereby, it can be prevented that the movement of the diaphragm is inhibited by the metal wiring 30 and the metal wiring 32.

  As shown in FIG. 3, the wiring portion 24 corresponds to the resistance portion wiring 13, and the wiring portion 25 corresponds to the resistance portion wiring 14. Specifically, the shape and size of the wiring portion 24 may be determined so as to cover the resistance portion wiring 13 except for the region where the contact portion 35 is provided. Similarly, the shape and size of the wiring portion 25 may be determined so as to cover the resistance portion wiring 14 except for the region where the contact portion 34 is provided.

  The wiring portion 24 has a first width in the longitudinal direction of the piezoresistive portion 10 and a second width in a direction perpendicular to the longitudinal direction in a plane parallel to the front surface of the semiconductor substrate 2. It may be wider than 13. Similarly, the wiring section 25 may have a first width and a second width wider than the resistance section wiring 14. The position of at least a part of the outline of the wiring part 24 may be determined along the outline of the resistance part wiring 13.

  As described above, in the piezoresistive portion 10 of this example, a potential difference occurs so that the potential at one end 11 is higher than that at the other end 12. On the other hand, the shield film 20 provided above the piezoresistive portion 10 also has one end 21 located on the one end 11 side of the piezoresistive portion 10 having a potential higher than the other end 22 located on the other end 12 side of the piezoresistive portion 10. A potential difference is given so that becomes higher. Therefore, a potential difference is given to the shield film 20 in the same direction as the potential difference generated in the piezoresistive portion 10.

  The shield film 20 may be a resistive film. The sheet resistance value of the shield film 20 may be 10 Ω / □ or more and 10 kΩ / □ or less, more preferably 1 kΩ / □ or more and 10 kΩ / □ or less. If the sheet resistance value of the shield film 20 becomes too low, current consumption in the shield film 20 increases. In addition, it is necessary to increase the thickness of the polysilicon in order to reduce the sheet resistance. Therefore, by setting the sheet resistance value of the shield film 20 to 10Ω / □ or more, it is possible to suppress the current consumption and reduce the thickness of the polysilicon. On the other hand, when the sheet resistance value of the shield film 20 is 10 kΩ / □ or less, the long-term reliability of the doped polysilicon can be improved.

  According to this example, the potential in the shield film 20 is increased above the high potential location in the piezoresistive portion 10, and the potential in the shield film 20 is decreased above the low potential location in the piezoresistive portion 10. In this way, the direction of the potential gradient in the piezoresistive portion 10 is the same as the direction of the potential gradient in the shield film 20. According to this example, the potential distribution in the piezoresistive portion 10 and the potential distribution in the shield film 20 can be matched.

  According to the semiconductor pressure sensor 1 of this example, the potential difference between the shield film 20 and the piezoresistive portion 10 can be reduced as compared with the case where the shield film 20 is fixed at a constant potential. Therefore, it is possible to reduce variations in resistance value or temperature characteristics due to a difference in potential between the shield film 20 and the piezoresistive portion 10 depending on the position on the shield film 20.

  In this example, the cross-sectional area (especially the width) is changed between the shield film 20, the wiring part 24, and the wiring part 25 without changing the doping concentration of the shield film 20, the wiring part 24, and the wiring part 25. Thus, the electrical resistance values of the wiring part 24 and the wiring part 25 can be made smaller than the electrical resistance value of the shield film 20. Therefore, a separate process for changing the doping concentration becomes unnecessary. Since a potential gradient can be generated mainly in the shield film 20 located on the upper portion of the piezoresistive portion 10, a region where a voltage drop is generated between the piezoresistive portion 10 and the shield film 20 can be shared. In addition, the direction of the potential difference generated in the piezoresistive portion 10 and the direction of the potential difference generated in the shield film 20 can be matched. Therefore, the potential distribution generated in the piezoresistive portion 10 and the potential distribution generated in the shield film 20 can be matched.

  FIG. 5 is a plan view of the semiconductor pressure sensor 1 according to the second embodiment. FIG. 5 shows an enlarged portion of the first resistor R1. The enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4 has substantially the same configuration. However, as in FIG. 3, the connection destinations are different in the enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4. FIG. 6 is a cross-sectional view of the semiconductor pressure sensor 1 in the second embodiment. Specifically, FIG. 6 shows a cross section taken along the line BB ′ of FIG.

  In the first embodiment described above, the resistance values of the wiring part 24 and the wiring part 25 are made lower than the resistance value of the shielding film 20 by making the cross-sectional areas of the wiring part 24 and the wiring part 25 larger than those of the shield film 20. Showed the case. On the other hand, in the semiconductor pressure sensor 1 of this example, the resistance values of the wiring part 24 and the wiring part 25 are made to be lower than those of the shielding film 20 by making the doping concentration of the wiring part 24 and the wiring part 25 higher than the doping concentration of the shielding film. The case where it makes lower than resistance value is demonstrated. Since other configurations are the same as those in the first embodiment, repeated description is omitted.

  The semiconductor pressure sensor 1 of this example also includes a piezoresistive portion 10, a resistor portion wiring 13, and a resistor portion wiring 14 as diffusion resistors in the semiconductor substrate 2. The semiconductor pressure sensor 1 has a conductive shield film 20 provided above the piezoresistive portion 10 with an insulating film 4 interposed therebetween. The semiconductor pressure sensor 1 includes a wiring part 24 and a wiring part 25 at both ends of the shield film 20. In this example, the shield film 20, the wiring part 24, and the wiring part 25 may be made of polysilicon that is continuous with each other.

  The cross-sectional area in the direction perpendicular to the direction in which the current flows in the wiring part 24 and the wiring part 25 may not be larger than the cross-sectional area in the direction perpendicular to the direction in which the current flows in the shield film 20. In this example, the cross-sectional areas of the wiring part 24 and the wiring part 25 are smaller than the cross-sectional area of the shield film 20. The doping concentration of the wiring part 24 and the doping concentration of the wiring part 25 are higher than the doping concentration of the shield film.

  Due to the difference in doping concentration, the electrical resistance of the wiring portion 24 and the wiring portion 25 is lower than the electrical resistance of the shield film 20. The voltage drop at the wiring portion 24 and the wiring portion 25 is smaller than the electrical resistance of the shield film 20. Therefore, according to the semiconductor pressure sensor 1 of this example, a voltage drop can be generated mainly in the portion of the shield film 20, and a potential gradient, that is, a potential difference can be given to the shield film 20.

  Also in this example, the potential difference between the shield film 20 and the piezoresistive portion 10 can be reduced as compared with the case where the shield film 20 is fixed at a constant potential. Therefore, it is possible to reduce variations in resistance value or temperature characteristics due to a difference in potential between the shield film 20 and the piezoresistive portion 10 depending on the position on the shield film 20. In this example, the semiconductor pressure sensor 1 includes a piezoresistive portion 10, a resistor portion wiring 13, and a resistor portion wiring 14 as diffusion resistors. The semiconductor pressure sensor 1 includes a shield film 20, a wiring part 24, and a wiring part 25 as polysilicon that are continuous with each other. In the semiconductor pressure sensor 1 of this example, as shown in FIG. 5, the area of the polysilicon is smaller than the area of the diffused resistor in plan view. Specifically, the total area of the shield film 20, the wiring part 24, and the wiring part 25 is smaller than the total area of the piezoresistive part 10, the resistance part wiring 13, and the resistance part wiring 14. According to such a structure, it can reduce that the deformation | transformation according to the pressure of a diaphragm is prevented by the laminated | stacked polysilicon.

  FIG. 7 is a plan view of the semiconductor pressure sensor 1 according to the third embodiment. FIG. 7 shows an enlarged portion of the first resistor R1. The enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4 has substantially the same configuration. However, as in FIG. 3, the connection destinations are different in the enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4. FIG. 8 is a cross-sectional view of the semiconductor pressure sensor 1 according to the third embodiment. Specifically, FIG. 8 shows a cross section taken along the line CC ′ of FIG.

  In the first and second embodiments described above, the case where the shield film 20, the wiring part 24, and the wiring part 25 have the same thickness is shown. On the other hand, in the semiconductor pressure sensor 1 of this example, the polysilicon constituting the shield film 20 is thinner than the polysilicon constituting the wiring portion 24 and the wiring portion 25. The structure of this example may be realized by depositing more polysilicon in the wiring part 24 and the wiring part 25 than in the shielding film 20 part. For example, a first deposition stage in which polysilicon is uniformly deposited on the entire shield film 20, the wiring portion 24, and the wiring portion 25, and a portion of the shielding film 20 is covered with a mask so that only the wiring portion 24 and the wiring portion 25 are polysilicon. The structure of this example may be realized using a second deposition stage that deposits.

  In the example shown in FIG. 8, the thickness of the polysilicon constituting the shield film 20 is T1, and the thickness of the polysilicon constituting the wiring portion 24 and the wiring portion 25 is T2. T2 may be 1.5 times or more of T1, may be 2 times or more of T1, and may be 3 times or more. The polysilicon constituting the shield film 20 is made thinner than the polysilicon constituting the wiring part 24 and the wiring part 25, so that the cross-sectional area of the wiring part 24 and the wiring part 25 is larger than the cross-sectional area of the shield film 20. Become bigger. Therefore, the resistance values of the wiring part 24 and the wiring part 25 can be made lower than the resistance value of the shield film 20. In this example, the doping concentration of the shield film 20 and the doping concentration of the wiring portion 24 and the wiring portion 25 may be the same. However, the doping concentration of the wiring part 24 and the wiring part 25 may be higher than the doping concentration of the shield film.

  Due to the difference in the thickness of the polysilicon, the electrical resistance of the wiring portion 24 and the wiring portion 25 is lower than that of the shield film 20. The voltage drop at the wiring portion 24 and the wiring portion 25 is smaller than the electrical resistance of the shield film 20. Therefore, according to the semiconductor pressure sensor 1 of this example, a voltage drop can be generated mainly in the portion of the shield film 20, and a potential gradient, that is, a potential difference can be given to the shield film 20.

  Also in this example, the potential difference between the shield film 20 and the piezoresistive portion 10 can be reduced as compared with the case where the shield film 20 is fixed at a constant potential. Therefore, it is possible to reduce variations in resistance value or temperature characteristics due to a difference in potential between the shield film 20 and the piezoresistive portion 10 depending on the position on the shield film 20. Also in this example, the area of the polysilicon is smaller than the area of the diffused resistor in plan view. Specifically, the total area of the shield film 20, the wiring part 24, and the wiring part 25 may be smaller than the total area of the piezoresistive part 10, the resistance part wiring 13, and the resistance part wiring 14.

  FIG. 9 is a plan view of the semiconductor pressure sensor 1 according to the fourth embodiment. FIG. 9 is an enlarged view of the first resistor R1. The enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4 has substantially the same configuration. However, as in FIG. 3, the connection destinations are different in the enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4. FIG. 10 is a cross-sectional view of the semiconductor pressure sensor 1 in the fourth embodiment. Specifically, FIG. 10 shows a cross section taken along the line DD ′ of FIG.

  In the first to third embodiments described above, the case where the shield film 20, the wiring part 24, and the wiring part 25 are made of polysilicon that is continuous with each other has been shown. Since the semiconductor substrate 2 above the cavity 3 functions as a diaphragm, it is desirable to use polysilicon or the like having the same thermal expansion coefficient as the semiconductor substrate 2. However, the wiring part 24 and the wiring part 25 may be made of a material different from that of the shield film 20. In this example, the case where the wiring part 24 and the wiring part 25 are comprised with metal materials, such as aluminum, is demonstrated. Since other configurations are the same as those in the first to third embodiments, repeated description will be omitted.

  In the semiconductor substrate 2, a piezoresistive portion 10, a resistance portion wiring 13, and a resistance portion wiring 14 are provided as diffusion resistors. The configuration of the diffused resistor is the same as in the first to third embodiments. The semiconductor pressure sensor 1 has a conductive shield film 20 provided above the piezoresistive portion 10 with an insulating film 4 interposed therebetween. One end 21 on the high potential side of the shield film 20 is connected to the wiring part 40 via the contact part 45. The other end 22 on the low potential side of the shield film 20 is connected to the wiring portion 41 via the contact portion 46.

  The wiring part 40 and the wiring part 41 may be made of a metal such as aluminum or copper. In the wiring portion 40, the contact wiring portion 43 and the shield film wiring portion 44 may be integrally formed of metal. The contact wiring portion 43 is electrically connected to the resistance portion wiring 14 via the contact portion 42. The contact wiring portion 43 may be extended and connected to the high potential side terminal Vdd. The shield film wiring section 44 is connected to the one end 21 on the high potential side of the shield film 20 via the contact section 45. The wiring part 41 is electrically connected to the resistance part wiring 13 via the contact part 46. The other end of the wiring portion 41 may extend to the shield film on the low potential side (in this example, the second shield film 20-2).

  The wiring portion 40 and the wiring portion 41 are made of a metal such as aluminum or copper having a lower resistivity than polysilicon. Moreover, the electrical resistance of the wiring part 40 and the wiring part 41 may be lower than the electrical resistance of the shield film 20 made of polysilicon. The voltage drop at the wiring portion 40 and the wiring portion 41 is smaller than the electrical resistance of the shield film 20. Therefore, according to the semiconductor pressure sensor 1 of this example, a voltage drop can be generated mainly in the portion of the shield film 20, and a potential gradient, that is, a potential difference can be given to the shield film 20.

  Also in this example, the potential difference between the shield film 20 and the piezoresistive portion 10 can be reduced as compared with the case where the shield film 20 is fixed at a constant potential. Therefore, it is possible to reduce variations in resistance value or temperature characteristics due to a difference in potential between the shield film 20 and the piezoresistive portion 10 depending on the position on the shield film 20.

  FIG. 11 is a plan view of the semiconductor pressure sensor 1 according to the fifth embodiment. FIG. 11 is an enlarged view of the first resistor R1. The enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4 has substantially the same configuration. However, as in FIG. 3, the connection destinations are different in the enlarged view of the second resistor R2, the third resistor R3, and the fourth resistor R4. FIG. 12 is a cross-sectional view of the semiconductor pressure sensor 1 in the fifth embodiment. Specifically, FIG. 12 shows a cross section taken along the line EE ′ of FIG.

  In the first to fourth embodiments described above, the outline of the shield film 20 is provided along the outline of the piezoresistive portion 10 in plan view. However, when the piezoresistive portion 10 is partitioned into a complicated shape, the contour of the shield film 20 does not necessarily have to be provided along the contour of the piezoresistive portion 10. One shield film 20 may be connected to different potentials at two different positions so that the potential difference between the piezoresistive portion 10 and the shield film 20 is reduced. In this example, the outline of the shield film 20 is not provided along the outline of the piezoresistive portion 10. Specifically, from the viewpoint of increasing the sensitivity of the sensor, the piezoresistive portion 10 is bent so as to meander.

  One shield film 20 in this example covers the entire meandering piezoresistive portion 10. The semiconductor pressure sensor 1 includes a wiring part 24 and a wiring part 25 at both ends of the shield film 20. In this example, the shield film 20 may be connected to the wiring part 24 on one entire side, and may be connected to the wiring part 25 on the other side facing the one side of the shield film 20.

  The distribution of potential in the piezoresistive portion 10 bent so as to meander and the distribution of potential in the flat shield film 20 are not perfectly matched. However, in general, the piezoresistive portion 10 has a high potential on the side connected to the resistor wiring 14 and a low potential on the side connected to the resistor wiring 13.

  Therefore, in the flat shield film 20, one end 21 on the side close to the resistor wiring 14 side is connected to a high potential, and the other end 22 on the side close to the resistor wiring 13 is connected to a low potential. Compared to the case where the shield film 20 is simply fixed at a constant potential, the potential distribution of the shield film 20 can be made closer to the potential distribution in the piezoresistive portion 10.

  FIG. 13 is a diagram illustrating an example of a circuit configuration of the semiconductor pressure sensor 1 according to the sixth embodiment. In this example, unlike the circuit configuration of the first embodiment described in FIG. 1, the other end 22 of the first shield film 20-1 and the other end 22 of the fourth shield film 20-4 are electrically connected. . The other end 22 of the third shield film 20-3 and the other end 22 of the second shield film 20-2 are electrically connected. Therefore, in this example, the first shield film 20-1 and the fourth shield film 20-4 are connected in series between the high potential side terminal Vdd and the low potential side terminal Vss as two shield films. Similarly, the third shield film 20-3 and the second shield film 20-2 are connected in series between the high potential side terminal Vdd and the low potential side terminal Vss.

  In this example, the first resistor R1 and the second resistor R2 are electrically connected in series, but the first shield film 20-1 and the second shield film 20-2 provided above these are connected in series with each other. Not connected. The third resistor R3 and the fourth resistor R4 are electrically connected in series. The third shield film 20-3 and the fourth shield film 20-4 provided above these are electrically connected in series with each other. Not connected. This point is different from the case of the first to fifth embodiments. Other structures are the same as those in the first to fifth embodiments, and thus the repeated description is omitted. The shield film 20, the wiring part 24, and the wiring part 25 may have the same structure as that described in the first to fifth embodiments.

  Also in this example, a potential difference is applied to the shield film 20 in the same direction as the potential difference generated in each piezoresistive portion 10. By matching the potential distribution in the piezoresistive portion 10 and the potential distribution in the shield film 20, the potential difference between the piezoresistive portion 10 and the shield film 20 can be reduced at each point in the piezoresistive portion 10. Therefore, it is possible to reduce variations in resistance value or temperature characteristics due to a difference in potential between the shield film 20 and the piezoresistive portion 10 depending on the position on the shield film 20.

  FIG. 14 is a diagram illustrating an example of a circuit configuration of the semiconductor pressure sensor 1 according to the seventh embodiment. In this example, at the connection point 29, the other end 22 of the first shield film 20-1, the other end 22 of the second shield film 20-2, the other end 22 of the third shield film 20-3, and the fourth shield film. The other ends 22 of 20-4 are electrically connected to each other. Other structures are the same as those in the first to fifth embodiments, and thus the repeated description is omitted. The shield film 20, the wiring part 24, and the wiring part 25 can employ various configurations described in the first to fifth embodiments.

  Also in this example, a potential difference is applied to the shield film 20 in the same direction as the potential difference generated in each piezoresistive portion 10. By matching the potential distribution in the piezoresistive portion 10 and the potential distribution in the shield film 20, the potential difference between the piezoresistive portion 10 and the shield film 20 can be reduced at each point in the piezoresistive portion 10. Therefore, it is possible to reduce variations in resistance value or temperature characteristics due to a difference in potential between the shield film 20 and the piezoresistive portion 10 depending on the position on the shield film 20.

  FIG. 15 is a diagram illustrating an example of a circuit configuration of the semiconductor pressure sensor 1 according to the eighth embodiment. In this example, in the circuit configuration of the semiconductor pressure sensor 1 in the first embodiment shown in FIG. 1, the other end 22 of the first shield film 20-1 and the other end 22 of the second shield film 20-2 are both first. 1 is electrically connected to the intermediate potential terminal Vout1. Similarly, the other end 22 of the third shield film 20-3 and the other end 22 of the fourth shield film are both electrically connected to the second intermediate potential terminal Vout2.

  In the semiconductor pressure sensor 1 of the sixth embodiment shown in FIG. 13, the other end 22 of the first shield film 20-2 and the other end 22 of the fourth shield film 20-4 are both at the first intermediate potential terminal Vout1. May be electrically connected. Both the other end 22 of the third shield film 20-3 and the other end 22 of the second shield film 20-4 may be electrically connected to the second intermediate potential terminal Vout2. On the other hand, the other end 22 of the first shield film 20-2 and the other end 22 of the fourth shield film 20-4 may both be electrically connected to the second intermediate potential terminal Vout2. Both the other end 22 of the third shield film 20-3 and the other end 22 of the second shield film 20-4 may be electrically connected to the first intermediate potential terminal Vout1.

  In the semiconductor pressure sensor 1 of the seventh embodiment shown in FIG. 14, the connection point 29 may be electrically connected to at least one of the first intermediate potential terminal Vout1 and the second intermediate potential terminal Vout2. As described above, the other end 22 of the first shield film 20-1, the other end 22 of the second shield film 20-2, the other end 22 of the third shield film 20-3, and the fourth shield film 20-4. The other end 22 may be electrically connected to the first intermediate potential terminal Vout1 or the second intermediate potential terminal Vout2. Unlike this example, the other end 22 of the first shield film 20-1, the other end 22 of the second shield film 20-2, the other end 22 of the third shield film 20-3, and the fourth shield film 20- 4 may be connected to a potential other than the first intermediate potential terminal Vout1 and the second intermediate potential terminal Vout2.

  According to the configuration as described above, the first shield film 20-1 and the third shield film 20-3 have the high potential side terminal Vdd and the first intermediate potential terminal Vout1 (or the second intermediate potential terminal) at two different positions. Vout2) is connected to a different potential. Similarly, the second shield film 20-2 and the fourth shield film 20-4 have different potentials of the low potential side terminal Vss and the first intermediate potential terminal Vout1 (or the second intermediate potential terminal Vout2) at two different positions. Connected. Therefore, it is possible to stably give a potential distribution to each shield film 20.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above embodiment. It is apparent from the description of the scope of claims that embodiments with such changes or improvements can be included in the technical scope of the present invention.

1 ..Semiconductor pressure sensor 10 ..Piezoresistor part 11 ..One end 12 ..Other end 13 ..Resistance part wiring 14 ..Resistance part wiring 15 ..Resistance part wiring 20 ..Shield film, 21 ..One end, 22 ..Other end, 24 ..Wiring section, 25 ..Wiring section, 26 ..Wiring section, 29 ..Connection point, 30 ..Metal wiring, 32. Wiring 33 ... Contact part 34 ... Contact part 35 ... Contact part 40 ... Wiring part 41 ... Wiring part 42 ... Contact part 43 ... Contact wiring part 44 ... Shield Wiring part for film, 45 ... Contact part, 46 ... Contact part

Claims (14)

A semiconductor substrate provided with a cavity,
A piezoresistive portion provided in a region of the semiconductor substrate above the cavity;
An insulating film provided above the piezoresistive portion;
A conductive shield film provided above the piezoresistive portion via the insulating film,
The shield film is connected to different potentials at two different positions;
Semiconductor device. A potential difference is given to the shield film in the same direction as the potential difference generated in the piezoresistive portion.
The semiconductor device according to claim 1. It has a plurality of piezoresistive parts that make up the Wheatstone bridge circuit,
Multiple piezoresistive sections
A first resistor electrically connected between a high potential side terminal of the Wheatstone bridge circuit and a first intermediate potential terminal of the Wheatstone bridge circuit;
A second resistor electrically connected between the first intermediate potential terminal and a low potential side terminal of the Wheatstone bridge circuit;
A third resistor electrically connected between the high potential side terminal and the second intermediate potential terminal of the Wheatstone bridge circuit;
A fourth resistor electrically connected between the second intermediate potential terminal and the low potential side terminal;
The shield film is provided above each of the plurality of piezoresistive portions via the insulating film,
The two shield films are connected in series between the high potential side terminal and the low potential side terminal;
The semiconductor device according to claim 1. The shield film includes a first shield film, a second shield film, a third shield film provided above each of the first resistor, the second resistor, the third resistor, and the fourth resistor, And a fourth shield film,
One end of the first shield film and one end of the third shield film are electrically connected to the high potential side terminal of the Wheatstone bridge circuit,
One end of the second shield film and one end of the fourth shield film are electrically connected to the low potential side terminal of the Wheatstone bridge circuit, respectively.
The semiconductor device according to claim 3. The other end of the first shield film and the other end of the second shield film are electrically connected;
The semiconductor device according to claim 4, wherein the other end of the third shield film is electrically connected to the other end of the fourth shield film. The other end of the first shield film and the other end of the fourth shield film are electrically connected;
The semiconductor device according to claim 4, wherein the other end of the third shield film is electrically connected to the other end of the second shield film. The other end of the first shield film, the other end of the second shield film, the other end of the third shield film, and the other end of the fourth shield film are electrically connected to each other. Semiconductor device. The other end of the first shield film, the other end of the second shield film, the other end of the third shield film, and the other end of the fourth shield film are the first intermediate potential terminal or the second intermediate potential. The semiconductor device according to claim 5, wherein the semiconductor device is electrically connected to a terminal. A resistance wiring section as a diffused resistor connected to the piezoresistive section;
A wiring portion connected to the shield film and having a resistance value lower than the resistance value of the shield film;
In plan view, the area of the shield film and the wiring portion is smaller than the piezoresistive portion and the resistance wiring portion,
The semiconductor device according to claim 1. A wiring portion connected to the shield film and having a resistance value lower than the resistance value of the shield film;
The shield film and the wiring portion are made of polysilicon that is continuous with each other,
The semiconductor device according to claim 1, wherein a cross-sectional area of the wiring portion is larger than a cross-sectional area of the shield film. Further comprising a wiring portion connected to the shield film,
The semiconductor device according to claim 1, wherein the polysilicon constituting the shield film is thinner than the polysilicon constituting the wiring portion. A wiring portion connected to the shield film and having a resistance value lower than the resistance value of the shield film;
The shield film and the wiring portion are made of polysilicon that is continuous with each other,
The semiconductor device according to claim 1, wherein a doping concentration of the wiring part is higher than a doping concentration of the shield film. A wiring portion connected to the shield film and having a resistance value lower than the resistance value of the shield film;
The shield film is made of polysilicon,
The semiconductor device according to claim 1, wherein the wiring portion is made of metal. The sheet resistance value of the shield film is 10 Ω / □ or more and 10 kΩ / □ or less,
The semiconductor device according to claim 1.

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