JP5434846B2 - Sensor chip, sensor device, and method of manufacturing sensor chip - Google Patents

Description

  The present invention relates to a sensor chip sensor device capable of outputting a compensation signal for output fluctuation caused by a temperature change of a resistance value, a sensor chip manufacturing method, and the like.

  A sensor chip that detects a change in the resistance value of a piezoresistive element arranged in a flexible portion in order to detect a physical quantity such as pressure or acceleration is known (for example, see Patent Document 1). The resistance value of the piezoresistive element is changed not only by the change of the deflection amount but also by the change of the temperature. For this reason, when using a sensor chip that detects a physical quantity based on a change in the resistance value of the piezoresistive element, it is necessary to perform temperature compensation. Therefore, when packaging the sensor chip, it is also necessary to package the temperature compensating resistance element (see, for example, Patent Document 2).

JP 2006-30159 A JP-A-64-41865

  However, packaging the temperature compensation resistance element in addition to the sensor chip increases the size of the package and increases the cost.

As an embodiment of the present invention, a substrate having a flexible portion and a frame portion, and a sensor circuit which is more formed on the piezoresistive element formed in the flexible portion of the substrate, the frame portion of the substrate A first resistance element formed; a second resistance element connected in series with the first resistance element; formed in the frame portion of the substrate; and having a temperature coefficient different from that of the first resistance element; There is provided a sensor chip including a pad for outputting a potential at a connection point between a resistance element and the second resistance element, and a pad for outputting an output of the sensor circuit.

As another embodiment of the present invention, a sensor device including a sensor chip and a control IC, wherein the sensor chip includes a first substrate having a flexible portion and a frame portion, and the first substrate . a sensor circuit which is more formed on the piezoresistive element formed on the flexible portion, wherein the first resistive element formed in the frame portion of the first substrate, are connected to the first resistor element in series first 1 is formed in the frame portion of the substrate, said second resistance element having a different temperature coefficient to the first resistor element, the pad and the output potential of the connection point between the first resistive element and the second resistive element A sensor device having a pad for outputting an output of the sensor circuit, and the control IC having an amplifier circuit for amplifying the output of the sensor circuit.

As yet another embodiment of the present invention, a sensor circuit is formed on the flexible portion of a substrate having a flexible portion and a frame portion, a first resistance element is formed on the frame portion of the substrate, and the substrate A second resistance element having a temperature coefficient different from that of the first resistance element is formed in the frame portion , the first resistance element and the second resistance element are connected in series, and the first resistance element and the first resistance element Provided is a method for manufacturing a sensor chip, wherein a pad for outputting a potential at a connection point with a two-resistance element and a pad for outputting an output of the sensor circuit are formed on the substrate.

  According to the present invention, when providing a sensor device including a sensor chip, it is not necessary to further package a temperature compensation resistor element, and an increase in the size and cost of the package can be prevented.

It is a side view of the sensor device which packaged the sensor chip concerning one embodiment of the present invention. (A) is an example of an equivalent circuit diagram of the sensor chip according to an embodiment of the present invention, (b) is a diagram showing an equation showing the resistance value of the resistance element Ra and the resistance value of Rb with respect to the temperature T; , shows an equation showing the _{V T,} (c) is a diagram showing one example of a graph of T and _V T / Vdd. It is the upper side figure and side view of an acceleration sensor which are one Example of the sensor chip concerning one embodiment of the present invention. It is an example of the graph which shows the relationship between the diffusion density | concentration of boron, and the temperature coefficient of a piezoresistive element. It is a figure which shows the manufacturing process of the sensor chip which concerns on one Embodiment of this invention. It is an example figure which shows the state by which the pad was formed in the sensor chip which concerns on one Embodiment of this invention. It is an example of the equivalent circuit schematic of the sensor chip concerning one embodiment of the present invention. It is an example figure which shows arrangement | positioning of the area | region in which the 1st resistive element and 2nd resistive element which concern on one Embodiment of this invention are formed. It is a figure which shows the manufacturing process of the sensor chip which concerns on one Embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not construed as being limited to the embodiments described below. Note that in the drawings, the same portions or portions having similar functions are denoted by the same reference numerals, and repeated description thereof may be omitted. In addition, in the case of illustrating the stack, top surface, side surface, and the like of a semiconductor, the width, height, thickness, and the like may be exaggerated.

(Embodiment 1)
FIG. 1 is a side view of a sensor device in which a sensor chip according to an embodiment of the present invention is packaged. In FIG. 1A, a sensor device 100 has a configuration in which a control IC 102 is disposed on a substrate 101 such as a printed circuit board. In addition, the sensor chip 103 according to the embodiment of the present invention is arranged on the control IC. The control IC 102 includes an amplifier circuit that amplifies a signal obtained from the sensor chip 103. The control IC 102 may have a temperature compensation circuit such as temperature compensation. For this purpose, a wiring 105 for connecting the sensor chip 103 and the control IC 102 is provided. Further, a wiring 104 that connects the control IC 102 and the substrate 101 is also provided.

  FIG. 1B is a side view of a sensor device having another configuration. In FIG. 1B, the sensor device 110 has a configuration in which a control IC 112 and a sensor chip 113 are arranged on a substrate 111 such as a printed circuit board. The role of the control IC 112 is the same as that of the control IC 102 in FIG. For this purpose, wirings 114 and 115 are provided between the substrate 111 and the control IC 112 and sensor chip 113. Thereby, a signal from the sensor chip 113 is supplied to the control IC 112. In FIG. 1B, a signal from the sensor chip 113 is supplied to the control IC 112 via the substrate 111. However, as shown in FIG. 1A, wiring for connecting the sensor chip 113 and the control IC 112. The signal from the sensor chip 113 may be directly supplied to the control IC 112.

  As shown in FIG. 1A, by disposing the sensor chip 103 on the control IC 102, the area when the sensor device is viewed from the upper surface can be reduced. Further, by arranging the control IC 112 and the sensor chip 113 in parallel as shown in FIG. 1B, the bottom of the sensor device can be realized.

  1A and 1B, instead of connecting the sensor chips 103 and 113 to the control IC 102 and the substrate 111 using the wirings 105 and 115, the control IC 102 and the substrate are connected via metal bumps or the like. 111 may be connected. Further, the control ICs 102 and 112 and the sensor chips 103 and 113 are sealed with a resin, covered with a lid formed of ceramic or resin, and the lid is fixed to the substrates 101 and 111 with an adhesive or the like. May be.

  FIG. 2A shows an example of an equivalent circuit diagram of a circuit formed on a substrate included in the sensor chip according to the embodiment of the present invention. The substrate included in the sensor chip is, for example, a semiconductor substrate. In FIG. 2A, a voltage and a current are supplied to the sensor circuit 201 using the Vdd terminal and the GND terminal. The sensor circuit 201 is an arbitrary sensor circuit that detects a physical quantity. For example, a Wheatstone bridge circuit using a piezoresistive element for detecting pressure or physical quantity can be included. A signal from the sensor circuit 201, for example, a voltage between resistance elements connected in series in the Wheatstone bridge circuit, is output to an output terminal not shown in the circuit diagram. Further, instead of the piezoresistive element, a capacitive element formed by a fixed electrode and a movable electrode, a piezoelectric element, or the like can be used.

In one embodiment of the present invention, the resistor element Ra and the resistor element Rb are connected in series between the Vdd terminal and the GNG terminal, and the potential at the connection point between the resistor element Ra and the resistor element Rb is set to V _T Output as. Further, the temperature coefficient of the resistance element Ra and the temperature coefficient of the resistance element Rb are different. Thus, the ratio between _{V T} and Vdd is changed by temperature. The reference potential of _{V T} and Vdd, for example, can be set to GND.

FIG. 2B shows an expression indicating resistance values of the resistance element Ra and the resistance element Rb with respect to the temperature _T and an expression indicating VT. In this specification, a symbol indicating a resistance element is also used as a resistance value of the resistance element. The resistance value of the resistance element can be expressed by approximating r (1+ (T−τ) ρ) using the temperature coefficient ρ and the resistance value r at the reference temperature τ. Therefore, for simplicity, τ is set to 0 ° C. (= 273 K), the resistance value of the resistance element Ra is expressed as r _a (1 + Tρ _a ), and the resistance value of the resistance element Rb is expressed as r _b (1 + Tρ _b ). When the resistance element Ra and the resistance element Rb are connected in series and a voltage of Vdd is applied to both ends of the series connection, V _T / Vdd = (r _a (1 + Tρ _a )) / (r _a + r _b + T _{(ρ a r a + ρ b} r b)) to become.

Thus, for example, between the temperature coefficient [rho _a resistive element Ra and temperature coefficient [rho _b of the resistive element Rb, the relationship of ρ _a> ρ _b is satisfied, the temperature T _increases, V T / Vdd increases . That is, a graph of T and V _T / Vdd as shown in FIG. If ρ _a <ρ _b , V _T / Vdd will decrease as temperature T increases.

For example, Ra is 10 ³ Ω at 25 ° C., the temperature coefficient is 0.1% / K, and expressed as Ra = 10 ³ (1 + 10 ⁻³ (T−25 ° C.)) Ω, and Rb is It is 10 ³ Ω at 25 ° C., the temperature coefficient is 0, and Rb = 10 ³ Ω. In this case, when the temperature changes from −35 ° C. to 85 ° C., V _T changes by 90 mV when Vdd = 3V.

From the above, in the control IC, by referring to the V _{T /} Vdd which is the ratio of the Vdd and V _T, it is possible to perform the temperature compensation temperature based around the sensor chip.

If ρ _a = ρ _b , (1 + Tρ _a ) = (1 + Tρ _b ), so that V _T / Vdd = r _a + r _b , and V _T / Vdd does not change even if the temperature changes. Become. That is, temperature compensation cannot be performed with reference to the ratio V _T / Vdd between Vdd and V _T.

Accordingly, the temperature coefficient [rho _a resistive element Ra has a temperature coefficient [rho _b of the resistive element Rb, it is necessary that substantially different. The substantial difference depends on the performance of temperature compensation in a control IC or the like. For example, [rho _b is about 0, the difference between [rho _a and [rho _b refers to that at 1% / K or less 0.1% / K or more. As will be described later, if the difference is 0.1% / K or more and Vdd is 3V, V _T / Vdd will fluctuate by 3% or more when the temperature changes by 50 ° C. Also, when creating a resistive element Ra and the resistive element Rb as piezoresistive element, it is because it is difficult to change the diffusion concentration as the difference between [rho _a and [rho _b exceeds 1% / K.

In order to perform temperature compensation, it is preferable that the change in V _T / Vdd corresponding to the change in temperature T is large. For this purpose, in a normal environment (for example, 25 ° C.) in which the sensor chip is disposed, V _T / Vdd is preferably a value close to 0.5, which is between 0 and 1. That is, Ra and Rb are preferably substantially equal in a normal environment where the sensor chip is disposed.

  FIG. 3 is a plan view and a cross-sectional view of a sensor chip when the sensor chip according to an embodiment of the present invention is an acceleration sensor in which a piezoresistive element is arranged in a flexible part of a silicon film. 3A is a plan view, FIG. 3B is a cross-sectional view along the XX cross-sectional line, and FIG. 3C is a cross-sectional view along the YY cross-sectional line. In FIG. 3, the acceleration sensor has a substantially rectangular parallelepiped shape. The acceleration sensor includes a support substrate 30 such as glass and a sensor body. However, the substrates 101 and 111 may be used instead of the support substrate 30. The sensor body can be formed using an SOI substrate including a support layer, a BOX layer 130, and an active layer. The support layer has a first frame portion 141 and a weight portion 142. The active layer has a second frame part 121 located on the first frame part 141 via a BOX layer, a center part 122, and four flexible parts 123. The center part 122 is connected to the weight part 142 through a part of the BOX layer. When force is applied to the weight part 142 by acceleration, the flexible part 123 bends. Piezoresistive elements Rx to Rz for detecting acceleration in the triaxial (XYZ) direction are formed on the four flexible portions 123. Three Wheatstone bridge circuits can be formed as the sensor circuit 201 by the piezoresistive elements Rx to Rz, and the change in the resistance value of the piezoresistive elements Rx to Rz according to the bending of the four flexible portions 123 can Axial acceleration can be detected.

In addition, as illustrated in FIG. 3A, the resistance element Ra and the resistance element Rb are formed in the second frame portion 121. The resistance element Ra and the resistance element Rb can also be formed on the flexible portion 123. However, when the resistance element Ra and the resistance element Rb are formed as piezoresistive elements, the resistance value of the resistance element Ra and the resistance value of the resistance element Rb are caused by the bending of the flexible portion 123 as described above. since variation, when the resistance elements Ra and the resistance element Rb connected as shown in FIG. 2 (a), there is a case where V _T varies though not temperature changes. Therefore, it is preferable to form and arrange the resistance element Ra and the resistance element Rb at a position where the bending is less than the flexible part 123, for example, the second frame part 121.

  In addition, when a non-negligible bend occurs at the position where the resistor element Ra and the resistor element Rb are arranged, in order to make the change in resistance value due to the bend at the position of the resistor element Ra and the resistor element Rb substantially the same. The resistive element Ra and the resistive element Rb are preferably disposed adjacent to each other.

  The piezoresistive elements Rx to Rz, the resistive element Ra, and the resistive element Rb can be formed by diffusing impurities in the active layer. For example, if the active layer is N-type, a P-type element such as boron is diffused by using an ion implantation method or a thermal diffusion method, and the piezoresistive elements Rx to Rz, the resistive element Ra, and the resistive element Rb Form.

FIG. 4 shows the relationship between the diffusion concentration of boron and the temperature coefficient of the piezoresistive element when piezoresistive elements are formed by diffusing boron into the N-type active layer. As shown in FIG. 4, when the boron diffusion concentration is 10 ¹⁵ atms / cm ³ , the temperature coefficient is about 0.8% / K, and the boron diffusion concentration is monotonous up to about 10 ¹⁹ atms / cm ^3. Decreases to 0, and then increases.

  Therefore, the temperature coefficient of the resistance element Ra and the temperature coefficient of the resistance element Rb can be made different by making the impurity diffusion concentration different when forming the resistance element Ra and the resistance element Rb. Further, when one of the resistance element Ra and the resistance element Rb is formed and the piezoresistance elements Rx to Rz are formed at the same time, and the other one of the resistance element Ra and the resistance element Rb is different. If formed, it is possible to reduce the trouble of forming the piezoresistive element.

The impurity diffusion concentration when forming the resistance element Ra and the resistance element Rb is about 10 ¹⁹ atoms / cm ³ when the resistance element Rb and the piezoresistance elements Rx to Rz are formed simultaneously. For the resistance element Ra, the diffusion concentration of boron, which is an impurity, is about 10 ¹⁵ atms / cm ³ . That is, for example, the impurity diffusion concentration of the resistance element Rb is preferably set to 1000 times or more with respect to the impurity diffusion concentration of the resistance element Ra.

The order of diffusion of impurities for forming the piezoresistive element is such that the boron diffusion concentration is about 10 ¹⁵ atms / at the position where the resistive element Ra, the resistive element Rb, and the piezoresistive elements Rx to Rz are first formed. After making it become cm ³ , the diffusion concentration of boron at the position where the resistance element Rb and the piezoresistive elements Rx to Rz are formed may be about 10 ¹⁹ atms / cm ³ .

FIG. 5 shows a manufacturing process of the sensor chip. FIG. 5A shows a cross section of the semiconductor substrate. The substrate 501 is a semiconductor such as a silicon single crystal substrate or an SOI substrate. If the substrate 501 is an SOI substrate, the lower layer 501-3 is a support layer, the intermediate layer 501-2 is a BOX layer, and the upper layer 501-1 is an active layer. A mask is formed on the upper layer 501-1 of the substrate 501. As a material for the mask, for example, SiO ₂ can be used. These materials are deposited to a uniform thickness on the entire upper layer 501-1 side of the semiconductor substrate 501 by using a CVD (Chemical Vapor Deposition) method or the like to form one layer or a plurality of layers. Thereafter, a photoresist is applied thereon. Then, pattern exposure is performed, and after development processing, etching is performed to transfer the pattern to a mask for patterning. In FIG. 5, it is assumed that the piezoresistive elements Rx to Rz are formed in the region 502 of the upper layer 501-1, and the piezoresistive element Ra and the piezoresistive element Rb are formed in the region 503.

  In FIG. 5B, patterning is performed on the mask on the upper layer 501-1 side of the semiconductor substrate 501, and, for example, openings 506 and 507 for forming the piezoresistive elements Rx to Rz and the piezoresistive element Rb are formed. It is a figure which shows a state. Among the upper layers 501-1 of the semiconductor substrate 501, heat treatment is performed after ion implantation from the upper layer 501-1 side of the semiconductor substrate 501, or the upper layer 501-1 side of the semiconductor substrate 501 is exposed to impurities. Impurities are diffused into the openings 506 and 507.

  FIG. 5C is a diagram showing a state in which the regions 508 and 509 in which impurities are diffused are formed in the openings 506 and 507 of the mask and the mask is removed.

  FIG. 5D shows a state in which the mask material is again deposited on the entire upper layer 501-1 side of the semiconductor substrate 501, etched, transferred to the mask, and patterned, for example, a piezoresistive element. The state where the opening 511 for forming Ra is formed is shown. Then, impurities are diffused into the opening 511 in the upper layer 501-1.

  FIG. 5E shows a state where a region 512 in which impurities are diffused is formed in the opening 511 of the mask and the mask is removed.

  In FIG. 5F, an insulating layer 513 is formed over the entire main surface of the semiconductor substrate 501, and contacts 514, 515, 516, 517, 518, and 519 reaching both ends of the regions 508, 509, and 512 are provided. The formed state is shown.

  FIG. 5G shows a state in which a conductive material such as a metal material is embedded in the contacts 514, 515, 516, 517, 518, and 519 and wirings 520, 521, 522, 523, and 524 are formed. Thereafter, a pad is provided on the substrate 501, and a piezoresistive element, a wiring, a pad, and the like are integrally formed.

  Note that the order of forming the regions 508, 509, and 512 is not necessarily the order shown in FIG. 5, and the region 512 may be formed first, and then the regions 508 and 509 may be formed.

FIG. 6 shows a state in which pads connected to wirings 520, 521, 522, 523, 524 and the like formed on the insulating layer 513 on the upper layer 501-1 are formed on the upper surface of the sensor chip. The pad can be arranged at an arbitrary position of the second frame portion 121. In FIG. 6, pads connected to Vdd, GND, V _T , X1, X2, Y1, Y2, Z1, and Z3 are formed along one side of the second frame portion 121 (in FIG. The connection destination and pad names are the same). By disposing the pad on the second frame portion 121 and as far as possible from the sensor circuit 201, it is possible to prevent the performance of the sensor circuit 201 from being deteriorated due to the disposition of the pad.

FIG. 7 shows an example of a circuit diagram showing the relationship among pads Vdd, GND, V _T , X1, X2, Y1, Y2, Z1, Z2, piezoresistive elements Rx to Rz, resistive element Ra, and resistive element Rb. In FIG. 7, three Wheatstone bridge circuits to which a voltage is applied are formed by the pad Vdd and the pad GND. Each Wheatstone bridge circuit is formed by each set of piezoresistive elements Rx1 to Rx4, Ry1 to Ry4, Rz1 to Rz4, and piezoresistive element Rx1 and piezoresistive element Rx3, piezoresistive element Rx2 and piezoresistive element Rx4, and piezoresistive element. The intermediate points of the resistive element Ry1 and the piezoresistive element Ry3, the piezoresistive element Ry2 and the piezoresistive element Ry4, the piezoresistive element Rz1 and the piezoresistive element Rz3, and the piezoresistive element Rx2 and the piezoresistive element Rx4 are pads X1, X2, and Y1. , Y2, Z1, and Z2. These three Wheatstone bridge circuits correspond to the sensor circuit 201 in FIG.

Further, one end of the resistor element Rb is connected to the pad Vdd, one end of the resistor element Ra is connected to the pad GND, and the other end of the resistor element Rb, the other end of the resistor element Ra, and the pad _VT are connected. In this way, the Wheatstone bridge circuit, the resistance element Ra, and the resistance element Rb are connected in parallel to the pad Vdd and the pad GND, which are pads for supplying the power supply voltage, to supply the power supply voltage. The number of pads can be reduced.

By detecting the voltages of the pads X1, X2, Y1, Y2, Z1, and Z2 by the circuit shown in FIG. 7, the acceleration in the XYZ axis directions can be detected. Further, by detecting the voltage of the pad V _T, the sensor is placed chips can know the temperature of the environment in which, by the temperature compensation of the output signal by the control IC, to detect the exact acceleration Can do.

As described above, the resistance element Rb has a boron diffusion concentration of about 10 ¹⁹ atms / cm ³ and the resistance element Ra has a boron diffusion concentration of about 10 ¹⁵ atms / cm ³ . When the boron diffusion concentration is higher than the boron diffusion concentration of the resistance element Ra, the resistance per length (ie, resistivity) is lower in the resistance element Rb. Therefore, in accordance with the resistivity ratio between the resistive element Ra and the resistive element Rb, for example, as shown in FIG. 8, the resistive element Ra is formed in a region 801, and the resistive element Rb is a region having the same area as the region 801. 802 and the region 803 may be formed, and the regions 801 to 803 may be connected in series. Alternatively, the region 802 and the region 803 may be formed as one region and wired so as to be connected to the region 801 in series.

(Embodiment 2)
In order to lower the connection resistance between the impurity diffusion region of the piezoresistive element and a conductive material such as a metal material used for the wiring, the concentration is further increased near the bottom of the contact reaching both ends of the region where the impurity is diffused or its vicinity. A region in which impurities are diffused may be formed.

  Therefore, after forming regions in which impurities are diffused corresponding to the piezoresistive elements Rx to Rz and, for example, Rb, regions in which impurities are further diffused near the bottoms of contacts formed on these regions A region in which impurities corresponding to Ra are diffused can be formed simultaneously. Thereby, the impurity diffusion concentration of the region in which the impurity corresponding to each of Ra and Rb is diffused can be made different, the temperature characteristics can be made different, and the number of steps for producing both Ra and Rb can be made. Can be prevented from increasing.

  FIG. 9 shows a manufacturing process of the sensor chip according to the present embodiment. FIG. 9A corresponds to FIG.

  FIG. 9B corresponds to FIG. 5B, and patterning is performed on the mask on the upper layer 501-1 side of the semiconductor substrate 501, for example, for forming the piezoresistive elements Rx to Rz and the piezoresistive element Rb. It is a figure which shows the state in which the opening parts 506 and 507 were formed.

  FIG. 9C corresponds to FIG. 5C and shows a state where regions 508 and 509 in which impurities are diffused are formed in the openings 506 and 507 of the mask.

  FIG. 9D shows a case where an opening 901 is formed after a mask 900 having openings 901 to 095 for diffusing impurities at a high concentration in a part of the regions 508 and 509 and forming the piezoresistive element Ra is formed. A state in which a high-concentration impurity diffusion region is formed near the bottom surface of ˜905 is shown.

  In FIG. 9E, the mask 900 is removed, and a wiring is formed on the insulating film 513 in which contacts corresponding to the openings 901 to 094 and contacts to both ends of the impurity diffusion region corresponding to the piezoresistive element Ra are formed. The state which formed 520-524 is shown. That is, it corresponds to FIG.

  As described above, in this embodiment, when the high concentration diffusion region is formed in a part of the impurity diffusion region corresponding to the piezoresistive elements Rx to Rz and, for example, the piezoresistive element Rb, the piezoresistive element Ra is formed. An increase in the number of processes can be prevented. In the present embodiment, the impurity diffusion concentration in the contact bottom of the region corresponding to the piezoresistive elements Rx to Rz and, for example, the piezoresistive element Rb, and the impurity diffusion concentration in the region corresponding to the piezoresistive element Ra are as follows. It becomes substantially the same.

201: Sensor circuit, Ra: Resistance element, Rb: Resistance element, T: Temperature, V _T / Vdd: Voltage value output by sensor chip

Claims (10)

A substrate having a flexible portion and a frame portion;
A sensor circuit which is more formed on the piezoresistive element formed in the flexible portion of the substrate,
A first resistance element formed on the frame portion of the substrate;
A second resistance element connected in series with the first resistance element and formed in the frame portion of the substrate and having a temperature coefficient different from that of the first resistance element;
A pad for outputting a potential at a connection point between the first resistance element and the second resistance element and a pad for outputting an output of the sensor circuit;
Sensor chip with It said first resistive element and said second resistive element is characterized in that the diffusion concentration of each other impurities are piezoresistive elements formed are diffused in different impurities the substrate is different from the conductivity type of the substrate The sensor chip according to claim 1. The impurity diffusion concentration of one of the first resistance element and the second resistance element is substantially the same as the impurity diffusion concentration of the piezoresistive element formed in the flexible portion of the substrate.
Sensor chip according to 請 Motomeko 2. The first resistance element has a high-concentration diffusion region having a higher impurity diffusion concentration than the portion of the first resistance element other than the portion as a portion in contact with the wiring,
4. The sensor chip according to claim 2, wherein an impurity diffusion concentration of the second resistance element is substantially the same as that of the high concentration diffusion region. 5. It has two power pads for supplying power voltage,
The sensor chip according to claim 1, wherein the sensor circuit and the first resistance element and the second resistance element that are directly connected are connected to the two power supply pads in parallel. A sensor device comprising a sensor chip and a control IC,
The sensor chip is
A first substrate having a flexible portion and a frame portion;
A sensor circuit which is more formed on the piezoresistive element formed in the flexible portion of the first substrate,
A first resistance element formed on the frame portion of the first substrate;
A second resistance element connected in series with the first resistance element and formed in the frame portion of the first substrate and having a temperature coefficient different from that of the first resistance element;
A pad for outputting a potential of a connection point between the first resistance element and the second resistance element and a pad for outputting an output of the sensor circuit;
The control IC is
A sensor device having an amplifier circuit for amplifying the output of the sensor circuit.   The sensor device according to claim 6, wherein the control IC is disposed on a second substrate, and the sensor chip is disposed on the control IC.   The sensor device according to claim 6, wherein the control IC and the sensor chip are arranged on the second substrate in parallel. Forming a sensor circuit on the flexible portion of the substrate having the flexible portion and the frame portion ;
Forming a first resistance element on the frame of the substrate;
Forming a second resistance element having a temperature coefficient different from that of the first resistance element on the frame of the substrate;
Connecting the first resistance element and the second resistance element in series;
A method of manufacturing a sensor chip, wherein a pad for outputting a potential at a connection point between the first resistance element and the second resistance element and a pad for outputting an output of the sensor circuit are formed on the substrate. The first resistance element and the second resistance element are piezoresistance elements having different impurity diffusion concentrations,
A high-concentration diffusion region having a higher impurity diffusion concentration than that in the portion of the first resistance element other than the portion is formed in the portion in contact with the wiring of the first resistance element, and the second resistance element is formed. The method of manufacturing a sensor chip according to claim 9.

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