JP2715738B2 - Semiconductor stress detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for improving the characteristics of a semiconductor stress detecting device using a polycrystalline Si piezoresistor.

[0002]

2. Description of the Related Art As a conventional semiconductor stress detecting device, for example, "Micro-Diaphragm Pressure Sensor" Proceedin
gs of the 6th Sensor Symposium, 1986. pp. 23-27 ". FIG. 10 is an example of a semiconductor pressure detecting device as described above, where (a) is a plan view,
(B) is FF 'sectional drawing of (a). In FIG. 10, reference numeral 21 denotes a cavity formed in the Si substrate 26 by etching, and 29 denotes a Si ₃ N ₄ film defining the cavity 21. Reference numeral 22 denotes a diaphragm which is hermetically formed so as to cover the cavity 21, and is composed of Si ₃ N ₄ films 27, 28 and ₃₀ . The diaphragm 22 is formed with p-type polycrystalline Si piezoresistors 23 and 24 sandwiched between Si ₃ N ₄ films 27 and 28. The piezoresistor 23 is formed at the periphery of the diaphragm, and the piezoresistor 24 is formed at the center of the diaphragm. Numeral 25 denotes an etching hole used for etching the cavity 21, and the Si ₃ N ₄ film 30
It is sealed with.

Next, a brief description will be given of a manufacturing method. (10
A Si ₃ N ₄ film is deposited on the Si substrate of the 0) plane by LPCVD, and a window is opened on a portion to be a cavity. Next, a portion to be a cavity is covered with a polycrystalline Si layer (not shown) serving as an etch channel, and a window is formed until the portion reaches the etching hole 25. S constituting the diaphragm 22 thereon
An i ₃ N ₄ film 28 and a polycrystalline Si layer are sequentially formed by LPCVD,
After boron ions are implanted into the polycrystalline Si layer, patterning is performed to form piezoresistors 23 and 24. Next, Si ₃
After covering the piezoresistor with the N ₄ film 27, the etching hole 25 is formed.
And the polycrystalline Si etch channel and the Si below it
The substrate is etched with an anisotropic etchant such as KOH to form a cavity 21. Next, after forming a contact etching and a wiring electrode (not shown), a Si ₃ N ₄ film 30 is deposited by PECVD to seal the cavity.

When pressure is applied to the diaphragm structure as described above, stresses in opposite directions are generated at the center and the end of the diaphragm, and the resistance values of the piezo resistors 23 and 24 change to opposite polarities. By forming a bridge circuit with the resistors 23 and 24, a voltage corresponding to the pressure can be output. In such a surface type pressure sensor, miniaturization is possible because etching from the back side is not used, and the leak current is small because the piezo resistance of the polycrystalline Si film formed on the insulating film is used. There is an advantage that it can be operated even in a high temperature atmosphere.

[0005]

However, in the conventional semiconductor stress detecting device as described above, a bridge circuit is simply constituted by a p-type polycrystalline Si piezoresistor. Since the change in the resistance value (sensitivity) of the p-type polycrystalline Si resistor with respect to the stress has a relatively large temperature coefficient, there is a problem that the sensitivity of the bridge circuit has a large temperature dependency. Also, in order to eliminate the above temperature dependence, it is necessary to provide a compensation circuit,
There is a problem that the configuration becomes complicated and the cost increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object to provide a semiconductor stress detecting device which has a small temperature dependency of sensitivity and does not require a special compensation circuit. And

[0007]

Means for Solving the Problems In order to achieve the above object, the present invention is configured as described in the claims. In other words, according to the first aspect of the present invention, the first p-type polycrystalline Si piezoresistor and the second p-type
Forming a polycrystalline Si piezoresistor;
The crystal Si piezoresistor is applied with the direction of the current flowing through the resistor.
The second direction is arranged so as to be parallel to the applied stress.
The direction of the current flowing through the p-type polycrystalline Si piezoresistor is
Are arranged in a direction perpendicular to the applied stress, and two resistance regions in which the first and second p-type polycrystalline Si piezoresistors are connected in series are used. As a bridge circuit. This configuration corresponds to, for example, an embodiment shown in FIG. 1 described later. The external physical quantity is, for example, acceleration or pressure. In addition, the above-mentioned structural portion has, for example, a cantilever structure or a double-supported beam structure, and is formed of a semiconductor or an insulator. The piezoresistor is generally formed so that a current flows in the longitudinal direction of a rectangle, but is not limited to a rectangle and may be another shape such as a square. In short, it is only necessary that the direction of current flow is parallel or perpendicular to the stress.

Further, in the invention according to claim 2,
A first p-type polycrystalline Si piezoresistor arranged in a direction parallel to the stress and a second p-type polycrystalline Si piezoresistor arranged in a direction perpendicular to the stress are connected in series. A pair of connected resistance regions is provided at each location on the structure where stress is applied in the opposite direction, and a bridge circuit is formed with each pair of resistance regions applied with stress in the same direction. . This configuration corresponds to, for example, an embodiment shown in FIG.

Further, in the invention according to claim 3,
A plurality of first n-type polycrystalline Si piezoresistors arranged in a direction parallel to the stress and a second n-type polycrystalline Si piezoresistor arranged in a direction perpendicular to the stress are formed. A bridge circuit is formed by forming a plurality of the first n-type polycrystalline Si piezoresistors as a pair of opposite sides and using the second n-type polycrystalline Si piezoresistors as another pair of opposite sides. . This configuration corresponds to, for example, an embodiment of FIG. 7 described later.

[0010]

According to the experiments of the present inventors, the resistance formed in the direction parallel to the applied stress and the resistance formed in the direction perpendicular to the stress in the p-type polycrystalline Si resistance and the n-type polycrystalline Si resistance. It was found that there was a large difference in the resistance change rate characteristics with respect to stress. FIGS. 3A and 3B are diagrams showing an example of the above-described resistance change rate characteristics. FIG. 3A shows the characteristics of a p-type polycrystalline Si resistor, and FIG. 3B shows the characteristics of an n-type polycrystalline Si resistor.
As can be seen from FIG. 3A, in the p-type polycrystalline Si resistor, the resistance change rate with respect to the stress is significantly different between the resistance parallel to the stress and the resistance perpendicular to the stress, and the resistance change with respect to the temperature change. The rate of change of the rate is reversed. That is, the temperature dependence of the sensitivity is the opposite sign and the characteristic of the same polarity (the difference from 0 in the rate of change in resistance is, as the temperature decreases, in the negative direction when parallel, in the positive direction when vertical, Both increase). Also, in the n-type polycrystalline Si resistor, the resistance change rate with respect to the stress is significantly different between the resistance parallel to the stress and the resistance perpendicular to the stress, and the temperature dependence of the sensitivity has the opposite sign and the opposite polarity characteristic (resistance The difference from 0 in the rate of change indicates that as the temperature decreases, the rate of change increases in the positive direction for parallel and decreases in the negative direction for vertical).

The present invention has been made based on the above-described novel findings of the present inventors. By appropriately combining a resistance parallel to stress and a resistance perpendicular to stress, a bridge circuit is provided. The dependency is automatically compensated. That is, according to the first aspect of the present invention, the opposite polarity of the temperature dependency between the p-type polycrystalline Si piezoresistor in the direction parallel to the stress and the p-type polycrystalline Si piezoresistor in the direction perpendicular to the stress has the same polarity. The characteristic is utilized. By connecting the two resistors in series, the temperature dependence of the sensitivity of the two resistors is offset and reduced, and two resistor regions connected in series are used. Are formed as a half-bridge circuit with the pair of resistance regions as a pair of opposite sides. Since the resistance change rate with respect to the stress is significantly different between the resistance parallel to the stress and the resistance perpendicular to the stress, a sufficient sensitivity can be obtained even if both resistances are connected in series.

Further, in the invention according to claim 2,
The resistance region in which the temperature dependence of the sensitivity is reduced by connecting in series in the same manner as in the above-mentioned claim 1 is connected to a portion where the stress on the structural portion is applied in the opposite direction (for example, the vicinity of the support portion of the cantilever and the weight portion). (In the vicinity)), and a full bridge circuit is formed by using a pair of opposite sides as resistance regions to which stress is applied in the same direction. For example, a pair of resistance regions provided near the support portion is a pair of opposite sides, and a pair of resistance regions provided near the weight portion is another pair of opposite sides. In this case, the sensitivity can be doubled as compared with the above half bridge circuit.

Further, in the invention according to claim 3,
The n-type polycrystalline Si piezoresistor in the direction parallel to the stress and the n-type polycrystalline Si piezoresistor in the direction perpendicular to the stress are referred to as a pair of resistances in the parallel direction and another pair of resistances in the vertical direction. A full bridge circuit is configured as the opposite side. When connected as described above, as shown in the equivalent circuit diagram of FIG. 8 described later, a series resistor of a parallel direction (eg, 151) and a resistor of a vertical direction (eg, 161) are connected between _Vcc and GND. Although the circuits are connected, the temperature dependence of the sensitivity of the two resistors is opposite in sign and opposite in polarity, so that the temperature dependence of the output of the bridge circuit is offset and reduced. Since the resistance change rate with respect to the stress is significantly different between the resistance parallel to the stress and the resistance perpendicular to the stress, sufficient sensitivity can be obtained even if the connection is made as described above.

[0014]

FIG. 1 is a diagram showing a first embodiment of the present invention.
(A) is a plan view, and (b) is an AA ′ cross-sectional view of (a). In FIG. 1, a weight portion 1, a thin beam portion 2, a gap portion 3 and a support portion 9 constitute a cantilever acceleration sensor. On the insulating film (for example, SiO ₂ film) 7 of the beam 2, p
Form polycrystalline Si piezoresistors 41, 42, 51, 52 are formed. At this time, the p-type polycrystalline Si piezoresistors 41, 42
Are formed parallel to the direction of stress caused by acceleration, the p-type polycrystalline Si piezoresistors 51 and 52 are formed perpendicular to the direction of stress, and 41 and 51 and 42 and 52 are connected in series, respectively. Arrow 100 indicates the direction of the stress generated by the acceleration. In FIG. 1, p-type polycrystalline Si piezoresistors 41 and 5 are shown.
1, 42 and 52 are combined in series, respectively.
The example formed in the character shape is shown. The parallel direction and the vertical direction mean the direction of the current flowing through the resistor. The piezoresistor is generally formed so that a current flows in the longitudinal direction of a rectangle, but the shape is not limited to a rectangle and may be another shape such as a square. In short, it is only necessary that the direction of current flow is parallel or perpendicular to the stress. Further, the polycrystalline Si resistors 61 and 62 are integrated on the supporting portion 9 where no stress is generated. These polycrystalline Si resistors 61 and 62 are p-type polycrystalline Si piezoresistors 4.
It is desirable to use the same shape and the same process as 1, 42, 51 and 52. The p-type polycrystalline Si piezoresistors 41, 42, 51, 52 and the polycrystalline Si resistors 61, 62 are connected by Al lead wires 8 as shown in FIG. The lead 8 may use a diffusion layer.

FIG. 2 is an equivalent circuit diagram of the above configuration.
The circuit shown in FIG. 2 includes p-type polycrystalline Si piezoresistors 41 and 5.
1 and a resistance region in which the p-type polycrystalline Si piezoresistors 42 and 52 are connected in series as a pair of opposite sides, and the fixed resistance polycrystalline Si resistors 61 and 62 are connected to another pair of sides. 2 shows a half-bridge circuit on the opposite side. In FIG. 2, V _cc is the power supply voltage, GND denotes a ground, V _A and V _B are the output terminal voltage, the V _out represents the output voltage.

Next, the operation will be described. In the bridge circuit shown in FIG. 2, the following equation (1) holds.

[0017]

(Equation 1)

R _L : p-type polycrystalline Si piezoresistor 41 parallel to the stress direction
A resistance value R _{T of} 42: a p-type polycrystalline Si piezoresistor 51 perpendicular to the stress direction;
The resistance value of 52 is the resistance value of the polycrystalline Si resistors 61 and 62 where no stress is generated. Here, an acceleration is applied in the acceleration direction indicated by the arrow in FIG. 2 and the p-type polycrystalline Si piezoresistors 41, 42 and 51 are applied. , 52
(Equation 1) becomes the following (Equation 2).

[0019]

(Equation 2)

G _L : p-type polycrystalline Si piezoresistor 41 parallel to the stress direction
42 gauge factor G _T: stress direction perpendicular p-type polycrystalline Si piezoresistive 51,
At this time 52 gage factor of r = R _L + R _T, is set as R _L = R _T, it can be expressed as follows (Equation 3).

[0021]

(Equation 3)

The sensitivity S of this piezo bridge circuit is obtained by differentiating the equation (3) with ε as shown in the following equation (4).

[0023]

(Equation 4)

The temperature characteristic of the sensitivity is as shown in the following equation (5).

[0025]

(Equation 5)

[0026] T: temperature where the gauge factor G _L in the p-type polycrystalline Si resistor 41 and parallel to the stress, the and the gauge factor G _T perpendicular p-type polycrystalline Si resistors 51 and 52 to stress , Below (Equation 6)
There is a relationship as shown in the equation (7). | G _L (positive) |> | G _T (negative) | ... (number 6)

[0027]

(Equation 7)

By substituting the relationship between the above formulas (6) and (7) into the above formulas (4) and (5), it is possible to offset the temperature dependency of the sensitivity while maintaining sufficient sensitivity. It turns out that it is possible. For example, a p-type polycrystalline Si resistor doped with boron at 3 × 10 ¹⁹ cm ³ is represented by the following (Equation 8), (Equation 9)
Has the value shown in the formula. _{G L = 29 G T = -5} ... ( 8)

[0029]

(Equation 9)

By substituting the values of the above equations (8) and (9) into the above equations (4) and (5), the following (10) is obtained.
Equation (11) is obtained. S = 12 (Equation 10)

[0031]

[Equation 11]

As described above, the temperature coefficient can be reduced by about one digit. Further, a p-type polycrystalline Si resistor 41,
The ratio R _L / R of the resistance value R _{L of} 42 to the resistance value R _{T of} 51 and 52.
If _RT is set as shown in the following equation (12), the temperature coefficient can be completely adjusted to zero. Note that, on the right side of the expression (12), dG _T / dT and dG _L
Since the sign of the sign is opposite to that of / dT, the sign is added.

[0033]

(Equation 12)

The polycrystalline Si resistors 61 and 62 provided in portions where no stress is generated are replaced with p-type polycrystalline Si piezo resistors 41 and 4.
With the same process and the same shape as 2, 51 and 52, the output error due to the temperature coefficient of resistance of the polycrystalline Si resistor can be completely canceled. In the past, in order to compensate for the temperature characteristics of the piezo coefficient, it was necessary to change the bridge drive voltage according to the temperature and to correct the output according to the temperature. That would eliminate that need. Therefore, a temperature compensating circuit is not required, and the configuration of the acceleration detecting device whose sensitivity is temperature-compensated can be greatly simplified. Further, in the above embodiment, the example of the cantilever type acceleration sensor has been described. However, the same effect can be obtained by applying this configuration to an acceleration sensor having a plurality of beams, such as a doubly supported type. it can.

Next, FIGS. 4A and 4B are views of a second embodiment of the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a sectional view taken along line BB 'of FIG. This embodiment shows an example in which the present invention is applied to a double-ended beam acceleration sensor. In FIG. 4, p-type polycrystalline Si piezoresistors 41, 42, 51 and 52 are formed at the end of the beam 2 on the weight 1 side, and p-type polycrystalline Si piezoresistors 41 ', 42', 51 'and 52 are formed. ′ Is formed at the end of the beam 2 on the support portion 9 side, and a resistance parallel to the stress and a resistance perpendicular to the stress are connected in series in the same manner as in FIG. 1, and a full bridge circuit is formed as shown in FIG. Configure. That is, one in which a resistance parallel to the stress and a resistance perpendicular to the stress are connected in series is defined as one resistance region, and the resistance regions to which the stress is applied in the same direction (41).
+51 and 42 + 52) as a pair of opposite sides, and the resistive regions (41 '+ 51' and 42 ') in which the stress is in the opposite direction to the above.
+52 ') is used as the other pair of opposite sides to form a bridge circuit. In the case of the above configuration, the direction of the stress is opposite to the direction of the stress between the weight side end of the beam 2 and the support side end, so that a full bridge configuration is possible, and a half bridge configuration as shown in FIG. The sensitivity can be doubled as compared with the case where. In this circuit, the same effect as that shown in the cantilever type example of FIG. 1 can be obtained for the compensation of the temperature characteristic of the sensitivity. Can be greatly simplified.

FIGS. 6A and 6B show a third embodiment of the present invention. FIG. 6A is a plan view, and FIG. 6B is a sectional view taken along the line CC 'of FIG. This embodiment is an example in which the present invention is applied to a pressure sensor. 6, the same reference numerals as those in FIG. 1 denote the same parts. At the end of the diaphragm 10 on the support portion 9 side, p-type polycrystalline Si piezoresistors 41 and 42 are formed parallel to the stress direction, and 51 and 52 are formed perpendicular to the stress direction. Further, the support portion 9 where no stress is generated is provided with a p-type polycrystalline Si.
The polycrystalline Si resistors 61 and 62 having the same shape and the same process as the resistance piezos 41, 42, 51 and 52 are formed.
By wiring as shown in FIG. 2A, a half bridge circuit as shown in FIG. 2 is obtained. When a pressure to be measured is connected to the measuring pipe 11, a stress is generated in the diaphragm 10, and the same effect as described in the first embodiment occurs in the bridge circuit. Hereinafter, the same effects as those of the first embodiment can be obtained, and the configuration of the pressure sensor whose sensitivity is temperature-compensated can be greatly simplified.

FIGS. 7A and 7B show a fourth embodiment of the present invention. FIG. 7A is a plan view, and FIG. 7B is a sectional view taken along the line DD 'of FIG. This embodiment is an example of a semiconductor acceleration sensor using an n-type polycrystalline Si piezoresistor. In FIG. 7, 1
Reference numeral 01 denotes a silicon substrate, and the groove 102, the weight 10
3. The beam portions 104 are formed by forming the silicon substrate 101 by Si etching. Also, n-type polycrystalline Si
The piezo resistors 151 and 152 are formed parallel to the applied stress direction, and the n-type polycrystalline Si piezo resistors 161 and 162 are formed perpendicular to the applied stress direction. These n-type polycrystalline Si piezoresistors are formed by silicon thermal oxide films 108,
9 are formed. The n-type polycrystalline Si piezoresistors 151, 152, 161, and 162 are connected to the metal wiring 11
0 to form a full bridge circuit as shown in FIG. That is, the resistances parallel to the stress (151 and 152) are paired as opposite sides, and the resistances perpendicular to the stress (1
61 and 162) as another pair of opposite sides to form a full bridge circuit. Reference numeral 107 denotes a pedestal of the sensor, and the recess 114 is formed by etching Si similarly to the sensor. For simplicity, peripheral circuits such as a bridge output signal processing unit are not shown.

Next, the operation will be described. When acceleration is applied,
Stress occurs in the beam portion 104, and the n-type polycrystalline Si piezoresistor 1
Resistance of 51,152 R _L and the n-type polycrystalline Si resistance value of the piezoresistive 161 and 162 R _T each R _L (1 + G _L
ε) and R _T (1 + G _T ε). G _L and G _T are the piezoresistive gauge factors of R _L and R _T , respectively, and ε is the strain due to stress. At this time, the output V of the bridge circuit
_OUT is represented by the following equation (13).

[0039]

(Equation 13)

Here, assuming that the distortion ε is sufficiently small, the sensitivity of the bridge circuit output V _{OUT to} the distortion ε is S = R _L G _L
Proportional to the -R _T G _T. For example, when the substrate temperature is 560 ° C., 360
A polycrystalline film is formed to a thickness of 0 °, and phosphorus is applied at 100 keV for 5 ×.
10 ¹⁵ After the ion implanted at a dose of cm ~ ^2, grown oxide film of 600Å by performing oxidation on the polycrystal silicon, n-type which is formed by performing a 30 min annealing further in an N ₂ atmosphere at 900 ° C. the piezoresistive by polycrystalline Si, the temperature coefficient of the rate of change of _{G T TCG T = 90000ppm / K} , G L
It was a TCG _L = -6000ppm / K of. For example, at _{30 ℃, G T = 1.11,} G L = -18.0
Then, the following (Equation 14) is obtained.

[0041]

[Equation 14]

The temperature change of R _T and R _L is from 2000 to 3000
ppm / K, which is much smaller than the above TCG _T and TCG _L , and if neglected, the temperature change of the sensitivity of the bridge circuit output V _OUT is expressed by the following equation (Equation 15).

[0043]

(Equation 15)

In the above equation (15), R _L / R _T = 1
By doing so, it is possible to suppress a temperature change in output sensitivity while maintaining the sensitivity of the bridge circuit output V _OUT . If _{(dG T / dT) ≠ (} dG L / dT) and which was even, the temperature compensation of the output sensitivity by choosing R _L / R _T suitably is possible.

Next, FIGS. 9A and 9B are diagrams showing a fifth embodiment of the present invention, wherein FIG. 9A is a plan view and FIG. 9B is a sectional view taken along line EE 'of FIG. In this embodiment, the present invention is applied to a pressure sensor. In FIG. 9, the diaphragm section 112 is formed by etching the semiconductor substrate 101. The pressure is transmitted from the opening 113 formed in the pedestal 111 to the diaphragm 112. The distortion caused by the stress generated at this time is caused by the n formed on the diaphragm 112.
-Type polycrystalline Si piezoresistors 151, 152, 161, 16
2 by a full bridge circuit. In addition,
n-type polycrystalline Si piezoresistors 151, 152, 161, 1
The direction, connection circuit and operation of 62 are the same as in the embodiment of FIG. In addition, peripheral circuits such as signal processing of a bridge circuit output are not shown.

In the above-described embodiments, an example of a stress detecting device having a thin-walled structure has been described. However, the present invention can be applied to a stress detecting device having no thin-walled structure. Effects can be obtained. Further, in the embodiments described above, the example in which the polycrystalline Si piezoresistor is formed on the semiconductor substrate is shown. However, the present invention is not limited to the semiconductor substrate, and the polycrystalline Si piezoresistor may be formed on an insulating substrate. Similar effects can be obtained.

[0047]

As described above, in the present invention, a bridge circuit is formed by appropriately combining a polycrystalline Si piezoresistor perpendicular to the applied stress direction and a polycrystalline Si piezoresistor parallel to the stress direction. As a result, the polycrystalline S
The temperature dependence of the gauge factor of the piezoresistor can be canceled, and the temperature dependence of the sensitivity of the bridge circuit can be eliminated. This eliminates the need for a temperature compensating circuit and greatly simplifies the configuration of the semiconductor stress detection device, so that a high-performance semiconductor stress detection device can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a plan view and a sectional view of a first embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of the embodiment of FIG.

FIG. 3 is a characteristic diagram showing a relationship between an applied stress and a resistance change rate depending on a direction in which a piezoresistor is formed.

FIG. 4 is a plan view and a cross-sectional view of a second embodiment of the present invention.

FIG. 5 is an equivalent circuit diagram of the embodiment of FIG.

FIG. 6 is a plan view and a sectional view of a third embodiment of the present invention.

FIG. 7 is a plan view and a sectional view of a fourth embodiment of the present invention.

FIG. 8 is an equivalent circuit diagram of the embodiment of FIG. 7;

FIG. 9 is a plan view and a sectional view of a fifth embodiment of the present invention.

FIG. 10 is a plan view and a cross-sectional view of an example of a conventional semiconductor stress detection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Weight part 2 ... Beam part 3 ... Void part 41, 42, 41 ', 42' ... p-type polycrystalline Si piezoresistor 51, 52, 51 ', 52' ... applied stress formed in parallel with the applied stress direction P-type polycrystalline Si piezoresistors 61, 62 formed in a direction perpendicular to the direction 61, p-type polycrystalline Si resistors 7, insulating film 8, lead wire 9, supporting part 10, diaphragm 11, measuring tube 21, cavity 22, diaphragm 23 , 24 ... p-type polycrystalline Si piezoresistive 25 ... etching holes 26 ... Si substrate 27, 28, 29, 30 ... Si ₃ N ₄ film 100 ... arrows 101 indicating the direction of the applied stress ... silicon substrate 102 ... groove 103 ... weight Part 104: Beam part 107: Pedestal 108, 109: Silicon thermal oxide film 110: Metal wiring 112: Diaphragm part 113: Opening part 114: Depression part 151, 152: Formed in parallel with the applied stress direction N-type polycrystalline Si piezoresistive 161 and 162 ... n type was formed perpendicular to the applied stress direction polycrystalline Si piezoresistive

Claims (3)

(57) [Claims] 1. A first p-type polycrystalline Si piezoresistor and a second p-type polycrystalline Si piezoresistor are provided on a structure in which stress is generated in response to the application of an external physical quantity .
forming a p-type polycrystalline Si piezoresistor;
The direction of the current flowing through the polycrystalline Si piezoresistor is marked.
It is arranged so as to be in a direction parallel to the applied stress.
2 p-type polycrystalline Si piezoresistor
Direction is perpendicular to the applied stress.
Is, the first and with two resistance region connecting the second p-type polycrystalline Si piezo resistor in series, the semiconductor stress detection, characterized in that to constitute a bridge circuit each resistive region as a pair of opposite sides apparatus. 2. A first p-type polycrystalline Si piezoresistor and a second p-type polycrystalline Si piezoresistor are formed on a structural part in which stress is generated in response to application of an external physical quantity .
forming a p-type polycrystalline Si piezoresistor;
The direction of the current flowing through the polycrystalline Si piezoresistor is marked.
It is arranged so as to be in a direction parallel to the applied stress.
2 p-type polycrystalline Si piezoresistor
Direction is perpendicular to the applied stress.
And a pair of resistance regions in which the first and second p-type polycrystalline Si piezoresistors are connected in series are provided at locations where the stress is applied in the opposite direction on the structural portion, and the stress is applied in the same direction. A semiconductor stress detection device, wherein a bridge circuit is formed by using each of the applied resistance regions as a pair of opposite sides. 3. A plurality of first p-type polycrystalline Si piezoresistors on a structure where stress is generated in response to application of an external physical quantity.
And a plurality of second p-type polycrystalline Si piezoresistors
The first p-type polycrystalline Si piezoresistor flows through the resistor.
Current direction is parallel to the applied stress
And the second p-type polycrystalline Si piezoresistor is
The direction of the current flowing through the resistor is perpendicular to the applied stress.
Is arranged such that, the first n-type polycrystalline Si piezoresistive comrades a pair of opposing sides, the second n-type polycrystalline Si
A semiconductor stress detection device, wherein a bridge circuit is formed by using piezo resistors together as another pair of opposite sides.