JPH08261853A - Mechanical-quantity sensor element - Google Patents

Abstract

PURPOSE: To provide a mechanical-quantity sensor element which can be operated in a high-temperature region and which comprises a high gage factor G by a method wherein a diamond is used in a specific part. CONSTITUTION: A mechanical-quantity sensor element is constituted of members (a diaphragm 3, a cantilever 4, a support 5 and a cavity body 6) to which a mechanical quantity is applied and of a resistor 1 which is arranged in the prescribed position of the members, which is subjected to the applied mechanical quantity from the members and which is composed of a diamond. Then, when the change in the resistance value of the diamond resistor 1 is measured, respective mechanical quantities are detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical quantity sensor element for detecting mechanical quantities such as strain, stress, pressure and weight.
More specifically, it relates to a mechanical quantity sensor element using diamond in a specific portion.

[0002]

2. Description of the Related Art Measurement of mechanical quantities such as strain, stress, pressure, and weight is important in terms of equipment control and state management. Therefore, until now, mechanical quantity sensor elements of various methods and structures have been developed according to the required measurement range, medium, accuracy and the like. Among them, a mechanical quantity sensor element using a semiconductor is superior to other elements in terms of miniaturization and high accuracy, and has been put to practical use or studied in various application fields.

Generally, a mechanical quantity sensor element using a semiconductor uses silicon (Si) as its material,
Many of them use the piezoresistive effect as the operating principle. The piezoresistive effect is a phenomenon in which the electric resistance value of a semiconductor changes due to strain generated by an external force acting on the semiconductor. Specifically, a strain gauge for detecting a mechanical amount is manufactured by making full use of a process technology such as a microfabrication technique on Si, and the target mechanical amount is measured by the piezoresistive effect of the strain gauge. As an index for evaluating the characteristics of the mechanical quantity sensor element produced by using the piezoresistance effect as described above, the gauge rate G (degree of resistance value change rate per unit strain amount) is generally used. In the case of the mechanical quantity sensor element made of Si, a gauge factor G of about 100 is obtained. Also,
The operating temperature range is up to about 150 ° C.

[0004]

As described above, Si
Although the mechanical quantity sensor element manufactured by the method is excellent in that it can be miniaturized and has high precision, it can be operated at high temperature because the band gap of Si is relatively small. Was impossible. In addition, the gauge factor G was about 100. On the other hand, diamond is chemically inert and has properties such as excellent environmental resistance, and also has properties as a semiconductor,
Since its band gap is as large as about 5.5 eV, it has many advantages such as not losing its characteristics as a semiconductor even at high temperatures. However, until now, a mechanical quantity sensor element using diamond has not been produced.

In order to solve the above-mentioned problems in the prior art, the present invention makes it possible to operate in a high temperature region and to have a high gauge ratio G by using diamond for a specific portion.
An object of the present invention is to provide a mechanical quantity sensor element having

[0006]

In order to achieve the above object, the structure of a sensor element according to the present invention is a mechanical quantity sensor element for detecting an applied mechanical quantity, and a member to which a mechanical quantity is applied, At least a resistor made of diamond, which is arranged at a predetermined position of the member and is subjected to the action of an applied mechanical amount from the member, is provided.

Further, in the above-mentioned constitution of the present invention, it is preferable that the mechanical quantity is one selected from strain quantity, stress, pressure and weight. Further, in the configuration of the present invention,
It is preferable that the resistor made of diamond is formed by a vapor phase synthesis method.

Further, in the above-mentioned structure of the present invention, it is preferable that the resistor made of diamond is one selected from a p-type semiconductor and an n-type semiconductor. Further, in the configuration of the present invention, the resistor made of diamond,
It is preferably polycrystalline.

Further, in the above-mentioned structure of the present invention, the resistance value of the resistor made of diamond is 10 ⁰ Ω or more and 10 or more.
^It is preferably ⁸ Ω or less. Further, in the above-mentioned constitution of the present invention, it is preferable that the resistance value of the resistor made of diamond is 10 ⁻² Ω · cm or more and 10 ⁴ Ω · cm or less.

Further, in the above-mentioned structure of the present invention, it is preferable that the gauge factor of the resistor made of diamond is 100 or more. Further, in the configuration of the present invention,
It is preferable that the surface layer of the resistor made of diamond has conductivity.

Further, in the above-mentioned structure of the present invention, it is preferable that the resistor made of diamond is arranged on the diaphragm. Further, in the configuration of the present invention,
A resistor made of diamond is preferably arranged on the diamond.

[0012]

According to the structure of the present invention, a mechanical quantity sensor element for detecting an applied mechanical quantity, which is a member to which a mechanical quantity is applied, is arranged at a predetermined position of the member, and the mechanical quantity is applied from the member. A resistor made of diamond, which is at least provided with a resistor that is subjected to an amount of quantity, so that when a strain having a semiconductor characteristic is applied by an external force such as stress, pressure, or weight, the resistor made of diamond is introduced. The resistance value of changes due to the piezoresistive effect. And
By measuring the amount of change in the resistance value, the applied mechanical amount can be detected. Further, since diamond is a wide band gap semiconductor, it is possible to realize a mechanical quantity sensor element that can operate in a high temperature region. further,
Since diamond has a large gauge factor G, it is possible to manufacture a mechanical quantity sensor element having highly efficient characteristics.

According to a preferred example of the structure of the present invention in which the diamond resistor is formed by a vapor phase synthesis method, the diamond having the optimum characteristics and structure as the mechanical quantity detecting portion is used. The resistor can be easily formed.

According to a preferred example of the structure of the present invention in which the diamond resistor is one selected from a p-type semiconductor and an n-type semiconductor, the diamond resistor used as the sensing portion is The resistance value can be easily controlled.

According to the preferable example in which the resistor made of diamond is a polycrystalline body in the structure of the present invention, it is very easy to manufacture and the characteristics of the detecting portion of the resistor made of diamond are excellent. Control becomes easy.

Further, in the above-mentioned structure of the present invention, the resistance value of the diamond resistor is 10 ⁰ Ω or more and 10 ⁸ or more.
According to the preferable example of being Ω or less, the resistance value change of the detection portion can be easily measured in practical use.

Further, in the above-mentioned structure of the present invention, the resistance value of the resistor made of diamond is 10 ^-2 Ω · cm.
According to the preferable example of 10 ⁴ Ω · cm or less, it becomes possible to form the sensing portion of the resistor made of diamond having the optimum resistance value.

Further, in the above-mentioned structure of the present invention, according to a preferable example in which the gauge factor of the resistor made of diamond is 100 or more, a mechanical quantity sensor element having higher sensitivity than the conventional one is obtained. Can be realized.

Further, in the above-described structure of the present invention, according to a preferable example in which the surface layer of the resistor made of diamond has conductivity, a resistor which reacts more sensitively to an applied mechanical quantity is formed. Therefore, it is possible to realize a mechanical quantity sensor element having highly efficient characteristics.

Further, in the above-mentioned structure of the present invention, according to the preferable example in which the resistor made of diamond is arranged on the diaphragm, the applied mechanical quantity can efficiently act on the resistor made of diamond. it can.

Further, in the above-mentioned structure of the present invention, according to the preferable example in which the resistor made of diamond is arranged on the diamond, it becomes possible to form a more optimal resistor made of diamond.

[0022]

EXAMPLES The present invention will be described in more detail below with reference to examples. FIG. 1 is a schematic diagram showing a basic configuration example of a mechanical quantity sensor element according to the present invention. As shown in Figure 1,
The present mechanical quantity sensor element has, as its main components, a resistor (hereinafter referred to as “diamond resistor”) 1 made of diamond for detecting an applied mechanical quantity, and a member for causing the applied mechanical quantity to act on the diamond resistor 1 ( 1 (a), a diaphragm 3, a cantilever 4 in FIG. 1 (b), a support 5 in FIG. 1 (c), and a hollow body 6 in FIG. 1 (d). When an external force 2 such as pressure or weight is applied to the mechanical quantity sensor element having the above structure, stress is applied to the region where the diamond resistor 1 is arranged, and strain is introduced into the diamond resistor 1. As a result, the resistance value of the diamond resistor 1 changes due to the piezoresistance effect, and by measuring the amount of change, it is possible to detect mechanical quantities such as strain, stress, pressure, and weight. For example, the mechanical quantity sensor element shown in FIG. 1A has a structure of a pressure sensor element when the mechanical quantity is pressure, and the mechanical quantity sensor element shown in FIG. 1B has a mechanical quantity introduced into the cantilever 4. As a structure of the strain sensor element in the case of the strain amount that is generated, the mechanical sensor element shown in FIG. 1C is a weight sensor element in the case where the mechanical amount is the weight of the object held on the column 5. As a structure, the mechanical quantity sensor element shown in FIG. 1D has a hollow body 6 having an arbitrary mechanical quantity.
It is an example of a structure suitable as a structure of a stress sensor element in the case of a stress acting on. The configuration of the mechanical quantity sensor element is not limited to the four examples described above, and any configuration can be adopted as long as the diamond resistor 1 is arranged in the region where the applied mechanical quantity acts. , May be in the shape. The material used for the member that applies the applied mechanical quantity to the diamond resistor 1 such as the diaphragm 3 and the cantilever 4 is not particularly limited, but from the viewpoint of the characteristics of the mechanical quantity sensor element and the manufacturing viewpoint,
A substrate material or silicon substrate having an insulating diamond layer deposited on the surface is often used.

The diamond resistor 1 may be in the form of a single crystal or a polycrystal, but a polycrystal having an individual grain size of about 0.1 μm to 10 μm is particularly preferable in terms of production. It is optimal from the viewpoint of characteristic control of the detection part. The shape of the detection portion of the diamond resistor 1 is
Any shape such as a linear type, a spiral type, and a lattice type may be used, but the linear type is often used because it is structurally simple. Although its size depends on the size of the entire sensor, the length is generally 10 μm to 1 m.
m, width 1 μm to 100 μm, thickness 1 μm to 50 μm
It is a degree. Further, the resistance value of each diamond resistor 1 is not particularly limited, but it is optimal from the viewpoint of measurement that it is 10 ⁰ Ω or more and 10 ⁸ Ω or less when used as a mechanical sensor element. is there. In order to form such a diamond resistor 1, it is optimum to use diamond having a resistivity value of 10 ^-2 Ω · cm or more and 10 ⁴ Ω · cm or less.

The method for forming the diamond resistor 1 is not particularly limited, but it can usually be easily formed by a vapor phase synthesis method. In this example, the diamond resistor 1 was formed by the microwave plasma CVD method which is a kind of vapor phase synthesis method. Particularly at that time, the diamond resistor 1 having desired characteristics (resistance value, etc.) can be obtained by appropriately selecting the substrate material and growth conditions, and controlling the film thickness, shape, impurity doping amount, etc.
Can be easily formed.

The present invention will be described in more detail with reference to specific examples. <First Embodiment> In this embodiment, as a mechanical quantity sensor element, a p formed on the upper surface of a diaphragm 3 by a microwave plasma CVD method as shown in FIG.
A case will be described in which pressure is detected by using a diamond-shaped resistor 1 having a rectangular shape.

FIG. 2 shows a manufacturing process of the present mechanical quantity sensor element. As substrate material, thickness 20μ on silicon
The substrate 7 having the m insulating diamond film deposited thereon was used (FIG. 2A). After cleaning the substrate 7 by a cleaning process, a p-type diamond layer 8 was formed on the surface thereof (FIG. 2B). The p-type diamond layer 8 was formed by using the microwave plasma CVD method. The microwave plasma CVD method is a method of forming a diamond by applying a microwave to a raw material gas to form a diamond. In this example, carbon monoxide gas (CO) diluted with hydrogen gas (H ₂ ) to about ₂ vol% was used as a source gas, and diborane gas (B
₂ H ₆ ) was added in an amount of about 500 ppm. The gas phase synthesis conditions were a gas pressure of 30 Torr and a substrate temperature of 900 ° C. Formed p-type diamond layer 8
Is a polycrystalline film having a grain size of 2 to 5 μm and a thickness of 1 to 2
μm. When the resistivity of this p-type film was measured,
It was about 100 Ω · cm at room temperature.

Then, using a resistance heating type vapor deposition device,
An aluminum (Al) layer 9 used as a diamond etching mask was vapor-deposited by several μm on the entire surface of the p-type diamond layer 8 (FIG. 2C). Then, an Al mask pattern 17 is formed through a photolithography process and a partial etching process of the Al layer 9 (FIG. 2).
(D)). The Al layer 9 was etched by wet etching using a phosphoric acid-based etching solution.

Then, in order to form the diamond resistor 1 having the desired shape by the p-type diamond layer 8, the patterned Al layer 9 (mask pattern 1) is formed.
The p-type diamond layer 8 was etched using 7) as a mask. The etching was performed by a parallel plate type reactive ion etching apparatus (RIE) using oxygen (O ₂ ) as an etching gas. As a result, the p-type diamond layer 8 not masked by the patterned Al layer 9 (mask pattern 17) was removed by etching, and the shape shown in FIG. 2C was obtained. The detection portion of the formed diamond resistor 1 has a length of 500 μ.
m was a linear type with a width of 50 μm.

Then, after the mask pattern 17 is removed (FIG. 2 (f)), a Si film having a film thickness of about 10 μm is formed on the back surface of the substrate 7 to form a mask for diaphragm formation.
The O ₂ film 10 was formed by the magnetron sputtering method (FIG. 2 (g)). Then, the deposited SiO ₂ film 10
After making a hole pattern with a diameter of 2 mm in the center of the
(H)), the back surface of the substrate 7 was etched. The back surface of the substrate 7 was etched by wet etching using a hydrofluoric nitric acid solution. As a result, the thickness of the etched silicon layer is 100
A diaphragm 3 having a size of about μm was formed (FIG. 2).
(I)).

Finally, the surface p-type diamond resistor 1
Ohmic electrode 11
Was formed (FIG. 2 (j)). The electrode 11 is made of titanium (Ti) / gold (Au) or titanium (T) by the electron beam evaporation method.
A laminated structure of i) / molybdenum (Mo) / gold (Au) was formed. Through the above process, a mechanical quantity sensor element in which the p-type diamond resistor 1 is arranged on the diaphragm 3 was manufactured.

When only the portion of the diaphragm 3 is pressed from the upper surface of the mechanical quantity sensor element manufactured in this way, a compressive stress acts on the diamond resistor 1 and the resistance value of the diamond resistor 1 is zero. It decreased compared with the case of the pressurized state. The degree of change (rate of change) and the applied pressure were in a substantially proportional relationship. That is, the present inventors have confirmed that the applied pressure can be detected by measuring the rate of change of the resistance value of the diamond resistor 1. Further, the characteristics were maintained even at a high temperature of 300 ° C. When the gage rate G of this mechanical quantity (pressure) sensor element was determined, a value of 700 to 1000 was obtained, and a gage rate G that was larger than the conventional one was obtained. This made it possible to realize a highly sensitive mechanical quantity sensor element.

Similar results were obtained in the case of other diamond resistors (n-type film, etc.) manufactured by the same method. Further, in this embodiment, after the p-type diamond layer 8 is formed, no post-treatment is performed, so that the surface layer of the diamond resistor 1 has conductivity. Therefore, a resistor that reacts more sensitively to the applied mechanical amount can be formed, but the surface layer of the diamond resistor 1 is not necessarily limited to one having conductivity. Even when the surface layer of the diamond resistor 1 does not have conductivity, the intended purpose of the present invention can be achieved.

<Second Embodiment> In the present embodiment, as a mechanical quantity sensor element, as shown in FIG. 1 (b), a p type p-type formed at an appropriate position on the cantilever 4 by a microwave plasma CVD method. A case will be described in which the amount of strain introduced into the cantilever 4 is detected by using the one prepared by disposing the diamond resistor 1.

FIG. 3 shows a manufacturing process of the present mechanical quantity sensor element. A silicon substrate 12 was used as the substrate material (FIG. 3A). After cleaning the substrate 12 by a cleaning process, a silicon dioxide layer 13 was formed on the surface thereof (FIG. 3B). This silicon dioxide layer 13 is formed by the diamond plasma layer 14 (FIG. 3D) by the microwave plasma CVD method.
Reference) is used as a mask for selective growth, and the forming method is not particularly limited. In this embodiment, the silicon substrate 12
Formed by thermal oxidation of.

Then, a pattern having the desired shape of the diamond resistor 1 was formed on the silicon dioxide layer 13 through a normal photolithography process (FIG. 3).
(C)). Pattern size is diamond resistor 1
The size of the detection portion of was set to be 50 μm × 5 μm.

The silicon substrate 1 thus prepared
First, an insulative diamond layer 14 was selectively grown on No. 2 (FIG. 3D), and a p-type diamond layer 15 was further formed thereon (FIG. 3E). The insulating diamond layer 14 and the p-type diamond layer 15 are formed by microwave plasma CVD as in the first embodiment.
Method. In this embodiment, carbon monoxide gas diluted with hydrogen gas to about 2 vol% is used as the source gas for forming the insulating diamond layer 14, and p
The shaped diamond layer 15 was formed by further adding about 500 ppm of diborane gas thereto. As a result, the diamond resistor 1 having a shape according to the previously formed pattern was produced on the silicon substrate 12.

Next, the produced diamond resistor 1
The silicon substrate 12 is cut into a cantilever shape so that it will come to an appropriate position (size: length 40 mm, width 5 m.
m), the back surface of the silicon substrate 12 was polished to be thinned (200 μm) to further enhance the sensitivity (FIG. 3).
(F)).

Finally, the p-type diamond resistor 1 on the surface 1
Ohmic electrode 16
Was formed (FIG. 3 (g)). The electrode 16 has a laminated structure of Ti / Au or Ti / Mo / Au formed by the electron beam evaporation method. Through the above process, a mechanical quantity sensor element in which the resistor 1 made of p-type diamond is arranged at an appropriate position of the cantilever 4 made of silicon was manufactured.

Then, as shown in FIG. 1 (b), one end face of the cantilever 4 is fixed, and an external force 2 is applied to the other end of the cantilever 4 from the upper surface to give strain to the diamond resistor 1 by tensile stress. However, the resistance value of the diamond resistor 1 increased as compared with the case of the unstrained state. The degree of change (rate of change) and the amount of strain introduced were in a substantially proportional relationship. That is, the present inventors have confirmed that the strain amount can be detected by measuring the rate of change of the resistance value of the diamond resistor 1. Further, the characteristics were maintained even at a high temperature of 300 ° C. The gage factor G of this mechanical quantity (strain) sensor element was calculated to be 700
A value of up to 1000 can be obtained, and the gauge ratio G is larger than before.
was gotten.

Similar results were obtained in the case of other diamond resistors (n-type film, etc.) manufactured by the same method. Further, in the present embodiment, the mechanical quantity sensor element was manufactured by directly forming the diamond resistor 1 on the cantilever 4 made of silicon. However, the diamond resistor 1 formed in advance is placed on the cantilever 4. The present inventors have confirmed that similar results can be obtained even when a mechanical quantity sensor element is manufactured by firmly adhering.

<Third Embodiment> In the present embodiment, the mechanical quantity sensor element having the structure shown in FIG. 1C is used, and the distortion of the pillar 5 caused by placing an object on the upper part of the pillar 5. The case where the weight is measured by detecting the will be described. In this example, the diamond resistor 1 was used by firmly adhering to the pillar 5 having a diameter of 2 cm.
When an object having a weight of 10 to 50 kg is placed on the upper part of the column 5, stress is generated in the column 5 due to the weight. The stress was detected by measuring the change in the resistance value of the diamond resistor 1 attached to the column 5, and the weight of the object was obtained. The present inventors have confirmed that this allows the weight to be detected in the same manner as in the first and second embodiments.

<Fourth Embodiment> In this embodiment, a mechanical quantity sensor element having a bowl-shaped hollow body 6 as shown in FIG. 1D is used, and the hollow body 6 is subjected to an external force. Two
Is applied to the diamond resistor 1
The case of measurement by will be described. Also in this example, the diamond resistor 1 was firmly bonded to the hollow body 6 and used. The present inventors have confirmed that this makes it possible to detect the stress acting on the hollow body 6 deformed by the external force 2 as in the first and second embodiments.

[0043]

As described above, according to the mechanical quantity sensor element of the present invention, when a diamond having semiconductor characteristics is applied with an external force such as stress, pressure or weight to introduce a strain, the diamond is removed from the diamond. The resistance value of the resistor is changed by the piezoresistive effect. Then, by measuring the amount of change in the resistance value, the applied mechanical amount can be detected. Further, since diamond is a wide band gap semiconductor, it is possible to realize a mechanical quantity sensor element that can operate in a high temperature region. Furthermore, since diamond has a large gauge factor G, it is possible to manufacture a mechanical quantity sensor element having highly efficient characteristics.

According to a preferred example of the above-mentioned structure of the present invention, in which the resistor made of diamond is formed by the vapor phase synthesis method, the diamond having the optimum characteristics and structure as the mechanical quantity detecting portion is used. The resistor can be easily formed.

According to a preferred example of the structure of the present invention in which the diamond resistor is one selected from a p-type semiconductor and an n-type semiconductor, a diamond resistor used as a sensing portion is used. The resistance value can be easily controlled.

According to the preferable example in which the resistor made of diamond is a polycrystalline body in the structure of the present invention, it is very easy to manufacture and the characteristics of the detection portion of the resistor made of diamond are excellent. Control becomes easy.

Further, in the above-mentioned structure of the present invention, the resistance value of the resistor made of diamond is 10 ⁰ Ω or more and 10 ⁸ or more.
According to the preferable example of being Ω or less, the resistance value change of the detection portion can be easily measured in practical use.

Further, in the above-mentioned structure of the present invention, the value of the resistivity of the resistor made of diamond is 10 ^-2 Ω · cm.
According to the preferable example of 10 ⁴ Ω · cm or less, it becomes possible to form the sensing portion of the resistor made of diamond having the optimum resistance value.

Further, according to the preferable example in which the gauge ratio of the resistor made of diamond is 100 or more in the constitution of the present invention, the mechanical quantity sensor having higher sensitivity than the conventional one. The device can be realized.

Further, in the above-mentioned structure of the present invention, according to a preferable example in which the surface layer of the resistor made of diamond has conductivity, a resistor which reacts more sensitively to an applied mechanical quantity is formed. Therefore, it is possible to realize a mechanical quantity sensor element having highly efficient characteristics.

Further, in the above-mentioned structure of the present invention, according to the preferable example in which the resistor made of diamond is arranged on the diaphragm, the applied mechanical quantity can efficiently act on the resistor made of diamond. it can.

Further, in the above-mentioned structure of the present invention, according to the preferable example in which the diamond resistor is arranged on the diamond, it is possible to form a more optimal diamond resistor.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a basic configuration example of a mechanical quantity sensor element according to the present invention.

FIG. 2 is a diagram showing a manufacturing process of an example of the mechanical quantity sensor element according to the present invention.

FIG. 3 is a diagram showing a manufacturing process of another embodiment of the mechanical quantity sensor element according to the present invention.

[Explanation of symbols]

 1 Diamond Resistor 2 External Force 3 Diaphragm Structure 4 Cantilever Structure 5 Pillar Structure 6 Cavity Structure 7 Substrate Material 8 Diamond Layer 9 Aluminum Layer 10 Silicon Oxide Layer 11 Ohmic Electrode 12 Substrate Material 13 Silicon Dioxide Layer 14 Insulating Diamond Layer 15 p-type Diamond Layer 16 Ohmic electrode 17 Mask pattern

Claims (11)

[Claims] 1. A mechanical quantity sensor element for detecting an applied mechanical quantity, comprising: a member to which a mechanical quantity is applied; and a diamond which is arranged at a predetermined position of the member and which receives the action of the applied mechanical quantity from the member. A mechanical quantity sensor element comprising at least a resistor. 2. The mechanical quantity sensor element according to claim 1, wherein the mechanical quantity is one selected from strain quantity, stress, pressure and weight. 3. The mechanical quantity sensor element according to claim 1, wherein the resistor made of diamond is formed by a vapor phase synthesis method. 4. The mechanical quantity sensor element according to claim 1, wherein the resistor made of diamond is one selected from a p-type semiconductor and an n-type semiconductor. 5. The mechanical quantity sensor element according to claim 1, wherein the resistor made of diamond is a polycrystalline body. 6. The mechanical quantity sensor element according to claim 1, wherein the resistance value of the resistor made of diamond is 10 ⁰ Ω or more and 10 ⁸ Ω or less. 7. The mechanical quantity sensor element according to claim 1, wherein the resistance value of the resistor made of diamond is 10 ⁻² Ω · cm or more and 10 ⁴ Ω · cm or less. 8. The mechanical quantity sensor element according to claim 1, wherein the gauge factor of the resistor made of diamond is 100 or more. 9. A surface layer of a resistor made of diamond,
The mechanical quantity sensor element according to claim 1, which has conductivity. 10. The mechanical quantity sensor element according to claim 1, wherein the resistor made of diamond is arranged on the diaphragm. 11. The mechanical quantity sensor element according to claim 1, wherein the resistor made of diamond is arranged on the diamond.