JP2500331B2 - Micro displacement detector - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is highly sensitive to minute displacements.
The present invention relates to a small displacement detector for highly accurate detection.

[0002]

2. Description of the Related Art Recently, with the advent of atomic force microscopes, minute displacements (for example, 0.1
It has become necessary to detect (nm order) with high sensitivity. Of course, to detect such a small displacement,
Atomic force (generally 10 ^-7
It is also possible to detect the order of 10 ^-9 N or less),
At present, the following two devices or methods have been proposed as specific methods for this purpose.

One is a method of combining tunnel electron microscopes as shown in FIG. First, according to the same figure (A),
Describing from the structure of the device, there is a cantilever 31 having one end serving as a fixed end 33 and the other end serving as a free end 34. Near the upper surface of the free end of the cantilever 31, there is a probe provided at the tip of the piezo element 41. The needle 42 faces. When the separation distance δ between the probe 42 and the upper surface of the free end 34 of the cantilever is set to about 1 nm or less and a proper bias voltage V is applied between them, the tunnel current i _t flows through the vacuum barrier. Become. Therefore, the piezo voltage E applied between the pair of electrodes 43 provided at both ends of the piezo element 41 is controlled so that the tunnel current amount is constant, and the piezo element 41 is expanded and contracted. According to this method, as shown in FIG. 9 (B), when the free end 34 by atomic force or the like is displaced by [Delta] y, by controlling the piezo voltage E to a constant tunneling current i _t As a result, the length of the piezo element 41 also changes by Δy. Therefore, conversely, the physical or dimensional displacement Δy can be converted into a change in the amount of electricity to be detected, and in fact, the maximum sensitivity of displacement detection by this method is the same as that of a normal tunnel electron microscope. Accordingly, a good value of about 0.01 nm can be obtained.

Another conventional method for detecting a minute displacement is to use a so-called "optical lever" as shown in FIG. This is to physically amplify and detect the physical displacement amount of a certain point as the movement of the light spot, and the device configuration is as shown in FIG. This is the same as the conventional example in that the cantilever 31 whose one end is the fixed end 33 and the other end is the free end 34 is used. However, since it is desirable to separately provide a light emitting source, which also has particularly good directivity, Requires a laser light source 50 and a light receiving portion 51 thereof. Here, if the laser light from the laser light source 50 irradiates the vicinity of the upper surface of the cantilever free end 34 at the incident angle θ when the cantilever 31 is not displaced, the surface at the irradiated position near the free end of the cantilever. If the smoothness of is kept sufficiently high, the reflected light is naturally emitted in the direction of the emission angle θ which is the same as the incident angle, so that it should be captured at the reference position of the light receiving unit 51. Initialize the measurement system to. After the initial setting, the cantilever 31 moves to the fixed end 3 as shown in FIG.
If a slight displacement Δy is made with 3 as the fulcrum, the incident angle of the irradiation light from the laser light source 50 slightly changes from the previous θ to ψ, and the specular reflected light has an angle change of 2 (ψ−θ). As a result, the light receiving position of the light receiving unit 51 changes by Δx. The amount of change in Δx with respect to the actual displacement Δy increases as the distance L between the reflection position near the free end of the cantilever and the light receiving position of the light receiving unit 51 (light receiving distance) L increases.
It will be geometrically amplified. For example, the length l of the cantilever 31 is 1 mm, and the maximum sensitivity is 0.1 nm.
Considering that the minute displacement Δy up to is detected, the change in the reflection angle of the laser light is estimated to be 1.1 × 10 ⁻⁵ degrees, so that if the light receiving distance L is 1 m, the change Δx in the light receiving position is 10
It becomes about ^-2 mm, which is within the range that can be detected with sufficiently high resolution even with the existing light spot position detection system.

[0005]

As described above, with respect to the conventional method using the combination with the tunnel electron microscope or the conventional method using the optical lever, the sensitivity itself regarding the minute displacement detection of the free end of the cantilever tip can be considered. Can be said to have obtained a satisfactory value. However, each of them has the following drawbacks when considering whether or not they are practical devices.

In the method using a tunnel electron microscope,
It is necessary to bring the probe closer to the position where the tunnel current can be detected, but the device for that is complicated and requires high accuracy, and the device as a whole becomes large,
It is also weak against vibration. The elimination of vibration is one of the essential and most important measurement environmental conditions in principle for this type of minute displacement detection. In addition, in this method, the distance between the cantilever and the probe must be controlled so that the tunnel current is constant at each measurement, so that improvement in work efficiency cannot be expected and operability is extremely poor.

On the other hand, in the method using the optical lever, the biggest problem is that the entire apparatus becomes extremely large in comparison with the method using the tunnel electron microscope. As described with reference to FIG. 10, in order to detect a minute displacement by this method, the separation distance between the cantilever and the light receiver has to be set to be considerably large. Compared to the method using a tunnel electron microscope, the sensitivity is 0.1 nm, which is one order of magnitude lower.
Even if the degree is satisfactory, the distance between the cantilever and the light receiver or the light receiving distance L necessary for that is required.
Is actually 1 m as described above. In order to further increase the geometrical amplification amount of the minute displacement and further improve the detection resolution, it goes without saying from the principle of this method that a longer light receiving distance is required. As a matter of fact, it is almost a difficult technique to isolate the whole of such an extremely large system. Further, in the method utilizing the optical lever, scattering or irregular reflection on the surface of the cantilever which is irradiated with laser light cannot be ignored. In order to achieve a mirror surface on the surface of the cantilever to the extent that is satisfactory for measurement, extremely high processing accuracy is required even with the existing polishing technology that has been considerably advanced.

Further, all of these conventional methods have the drawback that, in addition to the difficulty in vibration isolation of the entire system, it is difficult to use them in combination with an ultrahigh vacuum device or a cryogenic device. Microfabrication performed in an ultra-high vacuum environment (especially in the semiconductor process) and observation of micro-displacement amount based on various phenomena in a cryogenic environment are increasingly required by various technical fields in the future. It must come, but being unable to respond to this is a huge loss. In view of the above situation, the present invention provides a simple and highly accurate micro-displacement detector that can solve all the drawbacks of the above-described conventional example according to a new principle.

[0009]

In order to achieve the above object, the present invention has been described above in that it has a length between a fixed end and a free end and has a cantilever which can be finely displaced with the fixed end as a fulcrum. Even though it is similar to the example, first, the cantilever is made of a semiconductor that is intrinsic or nearly-intrinsic, and then the semiconductor material is attached to one surface of the cantilever.
By doping with appropriate impurities,
As a semiconductor line having conductivity type , we propose a micro-displacement detector having a strip-shaped pattern portion extending from the fixed end to the free end and having a resistance line whose resistance value changes by the piezoresistance effect. As is well known, the intrinsic or near-intrinsic semiconductor used in the present invention has an extremely high specific resistance and can be treated as an insulator.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A shows the essential part of a basic embodiment of a micro displacement detector constructed according to the present invention. First, one end is has a fixed end 3 which is stable and firmly supported by Naru suitable support member 9, the other end has a cantilever (cantilever) 1 which a free end 4 which can be displaced, the material is substantially Intrinsically or almost as an insulator
It is an intrinsic semiconductor. In the case shown, this cantilever 1
Has a rectangular parallelepiped rod shape with a length of 1, a width of b and a thickness of h. However, since the thickness h is actually made extremely thin, a rectangular plate shape is more appropriate. However, in this front and back both principal surfaces of the cantilever 1, which is defined by the length l and width b, and on (the surface if, for example illustrated by that face surface) 5 one aspect, the cantilever
For introducing impurities into the semiconductor material that makes up lever 1
Therefore, the resistance line 2 formed is provided. And
Particularly, in the case of the illustrated embodiment, the resistance line 2 includes a pair of parallel strip-shaped pattern portions 21 and 21 extending between the fixed end side and the free end side of the cantilever 1 and the pair of strip-shaped pattern portions 21 and 21. A folded-back pattern portion 22 for electrically connecting one end portion (in the illustrated case, the end portion on the free end side of the cantilever) of both lengthwise ends of the pattern portion.
And consists of. As a result, in this case, the resistance line 2 has a hairpin shape as a whole, and is located between the pair of open ends of the hairpin on the fixed end side of the cantilever 1, that is, in the illustrated embodiment. It is possible to obtain the required electrical resistance value between the ends marked with 8. Then, as long as the resistance line 2 literally has an electric resistance in a normal sense, a piezoresistive effect is expected in this. Rather, the line 2 formed of a material or substance exhibiting a change rate capable of causing a change in resistance value within a detectable range by a later-described minute displacement detection mechanism is referred to as a resistance line 2 in the present invention. The piezoresistive effect is not recognized, or even if it is present, the electrical property of a material or substance that is in a negligible range compared to that of the resistance line 2 is called insulating property. Therefore, cans
Semiconductor or the like which is the material of the chilever 1 or is close to it
Also in applications of the present invention can be referred to as insulation material.

A specific method of forming the resistance line 2 on one surface of the cantilever 1 will be described later.
In the micro-displacement detector of the present invention configured as shown in FIG. 1 (A), the cantilever 1 that has been flatly extended until then, as shown in FIG. 1 (B) when viewed from the side. When some force F is applied to the free end 4 of the cantilever 1 from the bottom to the top, compressive stress acts on the surface 5 of the cantilever 1 and tensile stress acts on the back surface 6. This stress is due to the resistance line 2 formed on the surface 5 of the cantilever 1 in this embodiment.
Change the resistance value between both ends of. Therefore, if the electrodes 8, 8 provided at both ends of the resistance line 2 are led to an appropriate measurement system (not shown) via an appropriate electric signal line and the minute change in the resistance value is captured, it is applied. The minute displacement Δy generated in the free end 4 of the cantilever 1 by the applied force F can be converted into an electric quantity and detected, and the magnitude of the applied force F can be known. Of course, the direction of the displacement Δy or the direction of the force F can also be detected. Unlike the above, when the applied force F is from top to bottom, the stress applied to the resistance line 2 also changes from compressive stress to tensile stress, so the direction of change in resistance value also changes. is there.

In order to demonstrate the practicality of the micro displacement detector of the present invention based on such a principle, a concrete example of preparation will be examined. Because cantilever 1 in the present invention is made of intrinsic or substantially intrinsic semiconductor, using an existing semiconductor fabrication process, by achieving impurity introduction in accordance with a predetermined pattern on its surface, shown in FIG. 1 (A) the resistance track 2 of planar shape can Komu Ri relatively simple work, such as. If the structural semiconductor of the cantilever 1 is silicon, the resistance line 2 can be formed as a semiconductor line of n-type conductivity by introducing arsenic. Actually, the length l is 200μ
For the surface 5 of the intrinsic silicon cantilever 1 having m, width b of 20 μm and thickness h of 2 μm, the arsenic doping amount is 10
^{Assuming 19} / cm, each length is about 200 μm, which is almost the same as the length of the cantilever, but each line width is 5 μm.
m, and the resistance line 2 having strip-shaped pattern portions 21 and 21 having a depth of 1 μm (thus, the folded pattern portion 22).
Ignoring the length of, the total length of the resistance line 2 is about 40
0 μm), the Young's modulus of the silicon is 11.26 × 10 ¹⁰ N / m ² (Source: AIP Handbook 3rd
ed .. M _c GRAW-HILL), so cantilever free end 4
If, for example, is displaced by 0.18 nm, the lateral compressive strain on the surface of the cantilever provided with the resistance line 2 is about −10 ⁻⁸ . On the other hand, the sensitivity to distortion is -133 in the [100] direction (Source 1: CSSmith, Phy
s. Rev. 94, (1954) 42; Source 2: "Survey and research report 1 on basic sensor technology", Japan Electronic Industry Development Association, 1985
Since it is reported that the resistance change rate of the resistance line 2 at that time is about 10 ⁻⁶ . Therefore, the resistance value of the resistance line 2 measured under the steady state is about 1 KΩ when created under the above conditions, and thus the change in the resistance value due to the above-mentioned compressive strain is also about 1 mΩ. , This is the range that can be sufficiently detected by using the existing electrical measurement system. In other words, the micro-displacement detector of the present invention has sufficient detection capability for micro-displacement on the order of sub-nanometers. The cantilever 1 under the above conditions
The resonant frequency can be calculated to be approximately 36 KHz.

The sensitivity for detecting a small displacement varies depending on the geometrical size and material of the cantilever 1, but generally speaking, the length of the cantilever 1 is made long and the width is made short as much as possible. The smaller the thickness, the higher the sensitivity. Of course, the sensitivity can be improved or adjusted depending on the impurities used to form the resistance line 2 and thus the conductivity of the resistance line 2.

Of course, the fact that a minute displacement can be detected in the above also means that the magnitude of the force F that causes the minute displacement can be measured. For example, in the case of the above specific example, the spring constant is 0.56 N / m, so as described above, when the minute displacement Δy is detected to be 0.18 nm, the force F applied at this time is Size is 1
It can be seen that it is 0 ^-10 N. Therefore, the micro-displacement detector of the present invention can have the ability to detect the micro-force F of this order.

The portion for detecting the force F or the displacement Δy
Is not the free end 4 of the cantilever 1 but
If it is known that the resistance line 2 is limited to a part in the middle of the length direction from the fixed end 3 to the free end 4, the resistance line 2 is folded back in the vicinity of that point, whereby the force F or the displacement Δ.
It is possible to detect y, which can increase the sensitivity. For example, in the case where a warp in the opposite direction may occur between the fixed end side and the free end side with the part where the force F or the displacement Δy is generated as a boundary, the cantilever 1 is almost entirely lengthwise. If there is a resistance line that extends, the change in resistance is canceled out and the effective sensitivity decreases, but there is no fear of this if the formation is limited to the displacement point.

The micro-displacement detector of the present invention can also detect acceleration. For example, it is assumed that a sudden acceleration is applied to the detection system shown in FIG. 1 due to an earthquake or the like. Here, the vibration frequency that causes acceleration is sufficiently larger than the resonance frequency of the present measurement system (36 KHz as described above in the case of the specific examples given above), and the resistance force to acceleration changes in speed. If it is proportional and the proportional coefficient itself is sufficiently large with respect to the period in which acceleration is applied, then the center of gravity G of the cantilever 1 is stationary in space, as shown in FIG. Then, with the center of gravity G as the center, the free end 4 side of the cantilever 1 is displaced by Δy ₁ , and the fixed end 3 side is displaced by Δy ₂ . The resistance value of the resistance line 2 changes with both of these displacements, but since the relationship between the displacement Δy ₁ on the free end side and the displacement Δy ₂ on the fixed end side can be predicted, it is actually abrupt. Δy ₂ displaced by acceleration α
Can also be detected by conversion. Furthermore, if the resistance line 2 is folded back at the center of gravity G, the reason described above will lead to
Without being affected by the displacement Δy ₁ on the free end side, it is possible to detect only the displacement Δy ₂ associated with acceleration, and thus only the acceleration.

Various modifications, such as a structural modification to the basic embodiment of the micro-displacement detector of the present invention and a modification relating to the resistance line pattern shape, will be described below. In the embodiment of the present invention shown in FIG. 1, the resistance line 2 formed on the surface 5 of the cantilever 1 has a hairpin shape, but as shown in FIG. 3, the pattern has a meandering shape as a whole. Can also be That is, in the case of the embodiment shown in FIG. 3, there are a total of six strip-shaped pattern portions 21, ... Which extend between the fixed end 3 and the free end 4 of the cantilever 1 and are parallel to each other. In the order, adjacent ones are alternately electrically connected by the folded pattern portions 22, ... Between the fixed end side and the free end side. By doing so, as a matter of course, not only the resistance value between the pair of both-end electrodes 8, 8 of the resistance line 2 becomes high, but also the change amount of the resistance value due to the stress due to the minute displacement becomes large. Can make a difference. In this case, the number of meanderings can be arbitrarily determined. That is, in general, when n is a number of 3 or more and there are a total of n strip-shaped pattern portions 21, ... When forming the resistance line 2 having a shape, the number of folded pattern portions required is n−1, but the value of n is not limited in principle. It may be a range that can be built on the same cantilever surface as an actual product.

Naturally, the larger the value of n, the higher the sensitivity for detecting the minute displacement. However, conversely, if the problem of sensitivity does not occur, the minute displacement of the present invention is considered. The most basic resistance line shape for a detector is shown in Fig. 1.
It is also understood that the hairpin shape is simpler than the hairpin shape shown in (A), and may be, for example, a shape including only one strip-shaped pattern portion 21. in this case,
In FIG. 1 (A) and FIG. 3, the electrodes 8 provided at both ends of the resistance line 2 are both the fixed end side of the cantilever 1,
In particular, it was formed on the surface of the support member 9, but instead of this, one of them is formed on the free end side. But even so, there is no problem. Wired wiring to the measurement system can be easily done for the electrode provided on the free end side of the cantilever by using the existing fine wiring technology, but this is not the case. It is also possible to provide a probe-shaped electrode which is extremely close to the electrode and establish electrical connection to the resistance line through the presence of a tunnel current. Therefore, even when the pair of electrodes 8 and 8 are both aligned on one end side in the longitudinal direction of the cantilever 1, nothing is aligned on the fixed end 3 side of the cantilever 1 as in the above-described embodiment. It does not need to be sticky and may be aligned on the side of the free end 4 if necessary. For example, Figure 1 (A)
It means that the hairpin shape shown in Fig. 3 and the meandering shape shown in Fig. 3 may be opposite to the direction shown. Further, considering the above comprehensively, even if the meandering shape shown in FIG. 3 is adopted, the number n of the strip-shaped pattern portions 21 ,. This means that even if the electrode 8 of (1) has to be formed at least on the free end side of the cantilever, this is sufficient. First, the electrodes 8 and 8 themselves are descriptive, and it is needless to say that they may be actually formed as, for example, a dot pattern.
As seen in the so-called existing printed circuit board wiring technology, communication with the measurement system at both ends of the resistance line may be achieved via a continuous line pattern portion (not shown) formed on the support member 9.

It should be noted that the portion described as a strip-shaped pattern portion in the above means that it only needs to extend in the lengthwise direction when viewed roughly, and only for a narrow and straight line pattern. It is not limited. It may be undulating in the middle, or thick and thin portions may alternate. In particular, when a displacement part can be predicted, and when it is desired to set the degree of change in resistance value with respect to displacement as the entire length of the resistance line to a desired value by setting an appropriate reference resistance value for that part, It is also effective to change the geometrical and partial pattern shapes (the same purpose can also be satisfied by a local change in the doping amount when the impurities are introduced as described above). Naturally, the folded back pattern portion 22
The same applies to, and any suitable line pattern shape may be used.

Further, the resistance line 2 provided for the cantilever 1 may be plural. For example, as shown in FIG. 4, two hairpin resistance lines 2 and 2 may be arranged in parallel on the surface 5 of the cantilever 1.
Also in this case, the number of juxtapositions is arbitrary, and the overall shape of the individual resistance lines 2 and 2 is also arbitrary, and they do not necessarily have to have the same shape. The number of meandering may be different, or at least one resistance line 2 may be formed only by a strip-shaped pattern portion. In addition, the resistance lines independent of each other may be used electrically independently of each other, or by external wiring, depending on the use or purpose,
They may be connected in series with each other or connected in parallel. It is generally considered that the series connection is for improving the sensitivity and the parallel connection is for increasing the current capacity of the resistance line 2.
It does not prevent other special applications. In some cases, such series connection or parallel connection may work effectively by devising the overall pattern of each resistance line 2 and the direction thereof in order to remove the noise component superimposed on the displacement.

Even if a plurality of resistance lines are provided for one cantilever 1, a perspective view seen from the front surface 5 side of the cantilever 1 is shown in FIG. 5 (A), and a back surface 6 side is shown in FIG. 5 (B). As shown in each of the perspective views seen from above, independent resistance lines 2 and 2 may be provided on each of the front and back surfaces of the cantilever 1, and these can be used independently. FIG. 5 shows an example in which resistance lines having hairpin-shaped patterns similar to those shown in FIG. 1 (A) are formed on the front and back surfaces of the cantilever 1, respectively. The number and the overall shape of the resistance lines 2 formed on each of the side and the back surface 6 are arbitrary. In principle, the plurality of resistance lines may be used independently of each other, and as described above, they may be connected in series or in parallel depending on the purpose. However, if resistance lines that have the same two-dimensional plane pattern and are distributed to the front and back of the cantilever are connected, the direction of change in resistance will be opposite to the displacement, and the absolute value will be the same. In some cases, they cancel each other out. Of course,
I can't think of such a use.

In principle, there are no major restrictions on the two-dimensional or three-dimensional shape of the cantilever 1. For example, in FIG.
As shown in Fig. 3, the wedge shape may be thinner as it goes from the fixed end side to the free end side, or, although not shown, the taper shape may be narrower as it goes to the tip end. If there is a concept of fixed end and free end, almost any planar shape and cross-sectional shape can be allowed (however, with regard to small displacement detection sensitivity, thin and thin and long shapes are acceptable. Excellent, as mentioned above). Further, as shown in FIG. 7, the planar outer contour of the cantilever 1 has a triangular shape, but it may have a hollow frame shape. In such a case, it can be considered that the fixed end 3 is substantially at two places.

Inferring this, the number of fixed ends may be any number. For example, when considering a cantilever having a shape in which two fixed points are orthogonal to each other in the plane and free ends are provided at points at appropriate distances from each other, such a cantilever is formed along two orthogonal directions in the plane. Since the displacement becomes possible, if at least two resistance lines 2 are used and these are arranged so as to be orthogonal to each other, it is possible to detect such a minute displacement in two in-plane directions by monitoring the change in each resistance value. As a result, it becomes possible to detect minute displacements in all directions. Of course, as shown in FIG.
For example, a tip-shaped protrusion 10 or the like may be provided on the back surface 6 of the cantilever 1 and the protrusion 10 may be brought into contact with the object to be displaced so that the displacement can be easily measured.

From a structural and morphological point of view, the free end 4 of the cantilever referred to in the present invention is compared with the fixed end 3 which is intentionally stable and firmly fixed. In, the end portion is configured to allow the displacement intentionally. Therefore, if the free end 4 is mechanically connected to some fixed part by a fragile member, that is, even if it has a shape like a doubly supported beam at first glance, If the structure is designed to allow the displacement of the structure, it is considered that such a structure substantially satisfies the cantilever structure referred to in the present invention, with the part as a part corresponding to the free end. You As described above, when it is developed for displacement detection in the two-dimensional direction, it may be a so-called diaphragm-shaped cantilever in appearance.

[0025]

[0026]

[0027]

[0028]

Minute displacement detector of the present invention exhibits, cantilever and which most are basic fine displacement detection system is composed only of a formed resistance wire path, to the extent that can not be cut further The simple structure is remarkably superior to the above-described conventional example. Naturally, the device configuration can be downsized, and vibration isolation can be facilitated. And cantilever
Is made of intrinsic semiconductor or almost intrinsic semiconductor, resistance wire
The tract is made by doping impurities into it
Therefore, it is necessary to adjust the characteristics required for the detector
The resistance line of any desired pattern with extremely high dimensional accuracy
Can be made relatively easily. Furthermore, satisfactory detection sensitivity can be obtained, and since it has a simple structure, the conversion accuracy into an electric quantity can be improved in the end. Further, in principle, since it can be used in an ultra-high vacuum environment or an extremely low temperature environment, a wide range of application fields can be expected in the future.

[Brief description of drawings]

FIG. 1 is an explanatory view of a structure and an operation of a basic embodiment of a micro displacement detector made according to the present invention.

FIG. 2 is an explanatory view of the operation of the micro displacement detector of the present invention when an acceleration is applied.

FIG. 3 is a schematic configuration diagram of an embodiment of the present invention in which a resistance line is formed in a meandering shape.

FIG. 4 is a schematic configuration diagram of an embodiment of the present invention in which a plurality of resistance lines are formed.

FIG. 5 is a schematic configuration diagram of an embodiment of the present invention in which resistance lines are formed on the front and back surfaces of a cantilever, respectively.

FIG. 6 is a schematic configuration diagram of an embodiment of the present invention in which the cantilever has a wedge shape.

FIG. 7 is a schematic configuration diagram of an embodiment of the present invention in which the cantilever has a triangular frame shape.

FIG. 8 is a schematic configuration diagram of an embodiment of the present invention in which a cantilever is provided with a projecting tip.

FIG. 9 is an explanatory diagram of a configuration and an operation of a conventional example in which a minute displacement is detected by using a tunnel electron microscope.

FIG. 10 is an explanatory diagram of a configuration and an operation of a conventional example in which a minute displacement is detected by using an “optical lever”.

[Explanation of symbols]

 1 cantilever 2 resistance line or insulating material line 3 fixed end 4 free end 5 cantilever front surface 6 cantilever back surface 8 electrode 9 support member

Continuation of front page (56) Reference JP-A-1-253289 (JP, A) JP-A-55-52924 (JP, A) JP-A-54-44562 (JP, A) JP-A-62-73102 (JP , A) JP 62-2101 (JP, A) Actual opening 62-108807 (JP, U) Actual opening 1-67508 (JP, U) Actual opening 2-105108 (JP, U)

Claims (7)

(57) [Claims] 1. Intrinsic or near-intrinsic , which has a length between a fixed end and a free end and can be minutely displaced with the fixed end as a fulcrum.
A cantilever made of a semiconductor material ; provided by doping the cantilever with impurities
Are, on one side of the cantilever has a strip-like pattern portion extending toward said free end from the fixing part, the resistance line for a change in the resistance value by response Ji piezo-resistive stress caused by the minute displacement of the cantilever And a small displacement detector comprising; 2. The micro displacement detector according to claim 1, wherein the resistance line is on one surface of the cantilever,
Two strip-shaped pattern portions that are parallel to each other and extend from the fixed end toward the free end, and both ends of the two strip-shaped pattern portions in the longitudinal direction are electrically connected to each other. A folded displacement pattern portion to be connected; 3. The small displacement detector according to claim 1, wherein the resistance line is on one surface of the cantilever,
Three or more strip-shaped pattern portions that are parallel to each other and extend from the fixed end toward the free end, and the strip-shaped pattern portions of the n strips are sequentially arranged along the arranging direction and one end in the length direction. A total of (n-1) folded-back pattern parts which are electrically connected alternately on the part side and the other end part side; 4. The micro displacement detector according to claim 1, 2, or 3, wherein a plurality of the resistance lines are provided. 5. The small displacement detector according to claim 4, wherein the plurality of resistance lines are provided only on the one surface of the cantilever, and the plurality of resistance lines are provided. And at least some resistance lines are provided on the other surface of the cantilever opposite to the one surface. 6. The micro displacement detector according to claim 4 or 5, wherein at least some of the plurality of resistance lines are electrically connected in series with each other. Displacement detector. 7. The minute displacement detector according to claim 4 or 5, wherein at least some of the plurality of resistance lines are electrically connected in parallel to each other. Displacement detector.