JP2001324375A - Minute weighting detector and minute weighting measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a minute weighting measuring device capable of executing simply measurement of the weight (static weighting) of a minute material or measurement of the weighting (dynamic weighting) by a cantilever. SOLUTION: By using this minute weighting detector 10 composed of a load acceptance part for accepting the weighting, a minute beam part having one end connected to the weighting acceptance part, and a support part for supporting the minute beam part at the other end of the minute beam part, a resistance change of a piezo resister mounted on the minute beam part is acquired s a deflection quantity of the minute beam part, and the magnitude of the load is known from the acquired resistance change (electric signal) and a corresponding relation table prepared beforehand, for showing the correspondence between the deflection quantity and the magnitude of the weighting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an SPM (Scanning Probe M) for observing a minute area (on the order of nanometers) of a sample surface using a sharpened probe.
(microscope).

[0002]

2. Description of the Related Art At present, electronic balances capable of digital display are often used to accurately measure the weight of powders and liquids. In particular, when performing high-precision measurement of several micrograms or less, or weighing extremely light substances having a weight on the order of magnitude, special electronic devices that are subject to expensive and strict measurement atmospheres are required. The balance is being used.

Further, in the field of microscopes for observing minute regions on the order of nanometers, a scanning probe microscope (SPM: SPM) using a cantilever having a probe at the tip is used.
Scanning Probe Microscope
e) is known. The SPM scans the probe of the above-mentioned cantilever along the surface of the sample, and detects an atomic force (attraction or repulsion) generated between the surface of the sample and the probe as an amount of bending of the cantilever. This is for measuring the shape of the surface.

In the SPM, as a method for detecting the amount of bending of the cantilever, an optical lever method and a self-detection method are known. The optical lever method irradiates a laser beam to the cantilever and replaces the change in the reflection angle with the change in the bending of the cantilever. However, this optical lever system requires a detection system separate from the cantilever, such as a laser device or a photodetector that detects reflected light from the cantilever, in order to detect the amount of bending of the cantilever. There is a disadvantage in that fine adjustment of the irradiation angle of the laser beam, the position of the photodetector, and the like is required for each replacement.

On the other hand, the self-detection method uses a cantilever having a piezoresistor formed on its surface, and detects the amount of deflection of the cantilever by measuring a change in the resistance value of the piezoresistor. However, this self-detection method has a disadvantage that the structure of the cantilever is complicated and the cost is higher than that of the cantilever used in the optical lever method.

In any of the methods, the SPM is used to accurately grasp the absolute value of the vertical (Z-axis) displacement between the sample and the probe of the cantilever, that is, the structure of the sample surface in the Z direction. It is necessary to know the spring constant of the cantilever. In particular, during surface observation, since the observation results differ depending on the hardness of the sample, it is important that the force (weight) exerted on the sample by the tip of the probe of the cantilever is known.

At present, this weight is calculated from the above-mentioned spring constant and the amount of pressing the cantilever against the sample. Here, the former spring constant can be calculated from the dimensions of the cantilever as the hardness of the cantilever, and the amount of pressing of the latter cantilever against the sample is determined by the actuator that controls the cantilever or the sample stage in the Z-axis direction. Can be calculated from the control amount.

[0008]

However, it is impossible to measure the weight of a minute substance (or organism) on the order of nanometers exceeding the measurement range of the electronic balance described above. It was impossible to measure a minute substance that could be separated by itself. Therefore, conventionally, in the measurement of the weight of such a minute substance, it is necessary to collect the substances to the extent that they can be measured.

For example, when a single colloid is evaluated for its physical properties, its shape and volume can be observed with an electron microscope or the like, but a means for accurately measuring its weight has not been established. In general, it was not possible to obtain information that can be obtained in the physical property evaluation of other substances such as density.

On the other hand, in the SPM, in order to accurately measure the hardness (rigidity: Stiffness) which is one of the physical properties of the cantilever in order to know the weight on the sample, it is necessary to calculate the above-mentioned dimensions. When the shape of the cantilever is a simple strip, there is no particular difference, but the more complicated the shape, the lower the reliability.

In addition to the method of calculating from these dimensions, a dedicated individual hardness measuring device can be used. However, such a dedicated device is generally expensive and requires a work required for the measurement. Because of the complexity, it was not always a simple means.

Further, the actual weight applied between the sample and the probe can be measured only when the cantilever is attached to the SPM, and such a weight measurement can be performed in real time in the conventional SPM. could not. As a result, the sample may be damaged or crushed for a soft sample, and the tip of the cantilever may be damaged for a hard sample, and it is necessary to accurately predict and verify these situations. Could not.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and measures the weight (static load) of a minute substance which cannot be measured conventionally and the load (dynamic load) by a cantilever.
It is an object of the present invention to provide a micro-weighted detector and a micro-weighted measurement device which can easily perform the measurement of the weight.

[0014]

Means for Solving the Problems To solve the above-mentioned problems,
In order to achieve the object, a minute weight detector according to the invention of claim 1 includes a weight receiving portion receiving a weight, a minute beam portion having one end connected to the weight receiving portion, and the other end of the minute beam portion. A supporting portion for supporting the microbeam portion, wherein the weight is detected by converting a magnitude of the weight given to the weight receiving portion into a bending amount of the microbeam portion. .

According to the first aspect of the present invention, the amount of deflection of the microbeam with the weight receiving portion as a free end is obtained as the magnitude of the weight given to the weight receiving portion, so that the shape of the microbeam is obtained. By selecting various (length, thickness, etc.) and materials, even the minute load, the magnitude of the load can be detected sharply.

According to a second aspect of the present invention, there is provided the micro-weighted detector according to the first aspect, wherein a piezoresistor is provided on the microbeam, and a deflection amount of the microbeam is measured by the piezoresistor. It is characterized in that it is output as a detection signal indicating a change in resistance value.

According to the second aspect of the present invention, the amount of deflection of the minute beam can be obtained as a change in the resistance value of the piezoresistor provided in the minute beam, that is, as an electric signal. It is possible to extract the amount of deflection of the minute beam portion from the minute weight detector itself as a change in the electric signal without preparing a separate required deflection detecting means such as detecting the amount of deflection by detecting the amount.

According to a third aspect of the present invention, there is provided a micro-weight measuring device, comprising: a weight receiving portion receiving the weight; a micro beam portion having one end connected to the weight receiving portion; and a micro beam at the other end of the micro beam portion. A micro-weight detecting means for converting the magnitude of the weight given to the weight receiving portion into a bending amount of the micro-beam portion, and converting the bending amount into an electric signal. A deflection detecting means for outputting; a calculating means for calculating the magnitude of the weight from the electric signal output from the deflection detecting means; and a display means for displaying the magnitude of the weight calculated by the calculating means. It is characterized by having.

According to the third aspect of the present invention, the amount of bending of the minute beam portion bent by the load applied to the weight receiving portion of the minute load detecting means can be obtained as a change in the electric signal by the bending detecting means, The magnitude of the weight is computed from the obtained electric signal by the computing means and the display means, and the result can be displayed.

According to a fourth aspect of the present invention, there is provided a micro-weight measuring apparatus according to the third aspect, wherein the weight is generated in accordance with the weight of the measuring object placed on the weight receiving portion,
The calculating means calculates the weight from the electric signal output from the deflection detecting means, and the display means displays the weight calculated by the calculating means.

According to the fourth aspect of the present invention, when the minute beam portion is bent by the weight of the measuring object placed on the weight receiving portion, the calculating means and the display means determine the amount of bending from the bending amount.
The weight of the measurement object can be calculated and the result can be displayed.

According to a fifth aspect of the present invention, in the micro weight measuring apparatus according to the third aspect, the weight is generated according to a liquid flow or a gas flow given to the weight receiving portion,
The calculation means calculates the flow rate or flow rate of the liquid flow or gas flow from the electric signal output from the deflection detection means, and the display means displays the flow rate or flow rate calculated by the calculation means. Features.

According to the fifth aspect of the present invention, when the minute beam portion is bent by the liquid flow or the gas flow given to the weight receiving portion, the calculating means and the display means determine the amount of bending from the bending amount.
The flow velocity or flow rate of the liquid flow or gas flow can be calculated and the result can be displayed.

According to a sixth aspect of the present invention, in the micro weight measuring apparatus according to the third aspect of the present invention, the weight is generated by an object to be measured pressing the weight receiving portion with a predetermined size, and the calculation is performed. The means calculates the hardness of the measurement object from the electric signal output from the deflection detection means,
The display means displays the hardness calculated by the calculation means.

According to the sixth aspect of the present invention, when the object to be measured presses the weight receiving portion with a predetermined size to bend the minute beam portion, the calculating means and the display means determine the amount of the bending. , The hardness of the measurement object can be calculated and the result can be displayed.

According to a seventh aspect of the present invention, in the micro weight measuring apparatus according to the third aspect of the present invention, the weight receiving portion may
PM (Scanning Probe Microsc)
and SPM support means for fixing the micro-weight detection means to the sample stage of the SPM so as to be a sample to be measured in ope), wherein the weight is such that the cantilever used for the SPM has a predetermined size. The calculation means calculates the hardness of the cantilever from the electric signal output from the deflection detection means, and the display means displays the hardness calculated by the calculation means. It is characterized by.

According to the seventh aspect of the present invention, the minute weight detecting means is fixed to the SPM sample base by the SPM supporting means such that the weight receiving portion becomes the SPM measurement target sample. When the cantilever is pressed against the weight receiving portion with a predetermined size by the conventional SPM operation and the micro beam portion is bent, the calculating means and the display means determine the hardness of the cantilever from the amount of bending. The result can be calculated and displayed.

[0028] Further, the minute weight measuring apparatus according to the invention of claim 8 is the invention according to any one of claims 3 to 7,
The deflection detecting means is provided as a piezoresistor on the microbeam portion of the micro weight detecting means, and converts the amount of deflection into an electric signal indicating a change in the resistance value of the piezoresistor and outputs the electric signal. And

According to the eighth aspect of the present invention, the deflection detecting means is provided integrally with the microbeam as a piezoresistor,
Since the change in the resistance value can be obtained as the amount of deflection of the minute beam portion, the minute load detecting means can be obtained without preparing an independent necessary deflection detecting means such as detecting the amount of deflection by detecting the reflection angle of the laser beam. It becomes possible to extract the amount of deflection of the minute beam portion from itself as an electric signal change.

[0030]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a minute weight detector and a minute weight measuring apparatus according to the present invention. The present invention is not limited by the embodiment. Further, the minute weight measuring device according to the present invention realizes measurement of weight and weight by using the minute weight detector according to the present invention.

(Embodiment 1) First, a micro weight detector and a micro weight measuring apparatus according to Embodiment 1 will be described. In particular, the minute weight detector and the minute weight measurement device according to the first embodiment are characterized in that the weight (static weight) of a minute substance can be measured. FIG. 1 is a block diagram illustrating a schematic configuration of the minute weight measurement device according to the first embodiment.

As shown in FIG. 1, the minute weight measuring device is
Micro-weighted detector 10, measuring head unit 50, arithmetic unit 6
0 and a display unit 70. In FIG. 1, a micro-weight detector 10 detects a weight caused by a micro-substance to be measured being placed, and here, a cantilever (hereinafter, self-detection) used in the above-described self-detection type SPM. (Referred to as a mold cantilever).

FIG. 2 is a schematic diagram for explaining the structure of the micro-weighted detector 10. As shown in FIG. As shown in FIG. 2, the micro weight detector 10 includes a lever unit 11 supported by a support unit 12. In particular, the lever shown in FIG.
It has the simplest strip shape, and has a structure that bends easily with reference to the support point supported by the support portion 12.

Further, the vicinity of the fixed point of the lever portion (support portion 12)
A piezoresistor 13 is formed in the region connected to the piezoresistor. The piezoresistor 13 allows the deflection of the lever 11 to be converted into a change in resistance value, since the shape of the piezoresistor 13 itself is distorted with the deflection of the lever 11. Therefore, this resistance change
By taking out via the electrode wiring 14, it is possible to detect the above-mentioned bending state of the lever portion.

From this, by placing the minute substance to be measured on the weight receiving portion (the portion surrounded by the dotted line 15 in the figure) located on the upper surface near the free end of the lever section 11, the minute substance is placed. The lever portion 11 bends according to the weight of
As a result, a detection signal that changes according to the weight of the minute substance can be obtained through the electrode wiring 14.

FIG. 3 shows the lever 1 when a minute substance is placed thereon.
FIG. 2 is a diagram showing a bent state of the first embodiment. As shown in FIG. 3, when the minute substance 30 is placed near the free end of the lever section 11, the lever section 11 bends in an amount proportional to the weight of the minute substance 30.

In FIG. 1, the measuring head 50
Applies a predetermined voltage to the piezoresistor 13 via the above-described electrode wiring 14, and changes the current supplied as a result of the voltage application, that is, the micro-weighted detector 10
Is a circuit for amplifying the detection signal. The arithmetic unit 60 calculates the weight change amount by using the amplified detection signal output from the measurement head unit 50 and a correspondence table determined by a calibration method described later, by using the actual weight unit and weight. Is a circuit that operates in units of

The weighted change amount calculated by the calculation unit 60 is displayed as a numerical value or a graph on the display unit 70, so that the user can know the physical property value such as the weight of the minute substance to be measured. Will be possible. The above-described functions of the arithmetic unit 60 and the display unit 70 may be realized by a general-purpose computer (CPU, CRT display, or the like).

In addition to the simple strip shape as shown in FIG. 2, the micro-weighted detector 10 is designed so that a micro-substance to be measured can be easily placed on the upper surface near the free end of the lever. The part may be changed to various shapes. FIG.
It is the schematic for demonstrating the structure of another example of a micro weighted detector. As shown in the top view of FIG. 4A, the minute weight detector 20 includes an arc-shaped weight receiving section 2 on the free end side of the lever section 22 supported by the support section 23.
1 are formed, and the minute substance 30 is placed on the weight receiving portion 21.

As shown in the sectional view of the micro weight detector 20 in FIG. 4 (b), the center of the weight receiving portion 21 is depressed, and the minute substance 30 is rolled from the weight receiving portion 21. Prevent from falling and lever part 2
In order that the deflection of No. 2 appears as a displacement only in the Z-axis direction (vertical direction) without including the horizontal twist,
It plays the role of stopping the lever portion 22 on the center line (line from the fixed end to the free end).

The shapes of the lever portion 22 and the weight receiving portion 21 can be arbitrarily designed and manufactured by a conventional semiconductor photo process. In addition to the shapes shown in FIG. Can be changed to various shapes such as a mesh shape.

FIG. 5 is a diagram showing a change in the detection signal of the minute weight detector 10, and particularly shows an example of a form displayed on the display unit 70. As shown in FIG. 5, a signal in a no-load state, that is, a detection signal obtained in a state in which the minute substance 30 is not placed on the lever portion 11 of the minute weight detector 10, and a signal in a loaded state, that is, a minute substance 30 Can be obtained from a detection signal obtained in a state in which the signal is placed on the lever section 11 of the micro-weighted detector 10.

In particular, when the detection results are displayed as a graph as shown in FIG. 5, the detection response can be obtained,
For example, instead of measuring the weight (static load) of the fine substance, as described in a second embodiment described later, the lever 11 may be used.
When it is desired to measure the weight (dynamic weight) applied to the, the weight speed can be measured.

Here, the lever unit 1 of the micro weight detector 10
In order to accurately measure the weight (or weight) of the minute substance placed on the top 1, it is necessary that the correspondence between the change in the resistance value of the piezoresistor 13 and the change in the weight of the minute substance is accurate. Since the change in the resistance value of the piezoresistor 13, that is, the amount of bending of the lever portion 11, varies depending on the hardness of the lever portion 11, the correspondence described above is eventually accurately determined every time the hardness of the lever portion 11 changes. It is necessary to specify in.

Therefore, first, it is required to obtain an accurate hardness of the lever portion 11. FIG. 6 shows the lever 1
FIG. 3 is an explanatory diagram for explaining a method for calculating hardness of No. 1 and particularly shows a hardness reference cantilever. In the top view illustrated in FIG. 6A and the cross-sectional view illustrated in FIG. 6B, the hardness reference cantilever 40 includes a plurality of strip-shaped lever portions 42 to 45 having different longitudinal lengths. 41, and each lever 4
As described above, since the shape of each of Nos. 2 to 45 is simple, an accurate hardness can be theoretically calculated from the dimensions and physical properties of a known material (such as silicon).

The term "hardness" as used herein refers to the degree of deflection of the free end of each lever when a predetermined load is applied to the free end. The larger the amount of deflection, the harder the lever. It is assumed that there is. Therefore, in FIG.
As the length in the longitudinal direction decreases by a predetermined amount in order from the lever portion 42, the hardness increases in order. In this way, by making each hardness known for a plurality of lever portions having a predetermined length, it is possible to easily know the hardness of a lever portion having an arbitrary length. The hardness of each of the lever portions 42 to 45 of the hardness reference cantilever 40 may be obtained in advance by using a dedicated hardness measuring device instead of calculating from the above-described dimensions.

Further, in order to accurately know the above-mentioned correspondence, the traceability of, for example, the National Institute of Standards and Technology (NIST) must be set in advance on the lever 11 of the micro weight detector 10 to be actually used. It is necessary to calibrate the correspondence using the secured reliable reference material.

FIG. 7 is a diagram showing a plurality of standard particles having different particle sizes. In FIG. 7, four standard particles are shown, and the particle sizes of the standard particles belong to, for example, a range from several micrometers to several hundred nanometers.
The weight of each standard particle is known. Therefore, by using such standard particles as the standard material described above,
Calibration of the correspondence described above can be realized.

More specifically, first, standard particles having different weights as shown in FIG. 7 are placed one by one on the lever portion 11 of the micro-weighted detector 10, and as a result, output from the micro-weighted detector 10. (Hereinafter, referred to as a detection value) indicated by a detection signal (which may be a detection signal after various processes have been performed via the measuring head unit 50 and the calculation unit 60).
And so on. Then, a calibration curve indicating the relationship between the detected value and the weight is calculated using the detected values stored and held over the plurality of standard particles and the weight of the standard particle corresponding to each detected value.

FIG. 8 is a graph for explaining a calibration curve showing the relationship between the detected value and the weight. In order to obtain the above-mentioned calibration curve, as shown in FIG. 8, each of the stored and stored detection values is plotted in association with a weight, and a least square method or the like is performed using the plotted values. When an accurate calibration curve cannot be obtained by the least squares method, an approximate curve obtained from the plotted result can be used as the calibration curve.

Since the calibration curve calculated in this way shows the correspondence between the change in the resistance value of the piezoresistor 13 and the change in the weight of the minute substance, the weight of the calibration curve is calculated by using the calibration curve. It is possible to specify the weight from the detection signal obtained for the unknown minute substance.

As described above, according to the minute weight measuring apparatus according to the first embodiment, the minute weight detector 10 having the same structure as the self-detecting cantilever used in the SPM is used, and the minute weight is detected. Lever part 1 of vessel 10
The weight can be measured by placing a minute substance to be measured on 1. That is, since the weight of the minute substance can be obtained as a change in the amount of deflection of the lever portion 11, it is possible to measure the weight of a minute substance that cannot be measured by a conventional electronic balance or the like. Will be possible.

(Second Embodiment) Next, a minute weight detector and a minute weight measuring apparatus according to a second embodiment will be described. The micro weight detector and the micro weight measurement device according to the second embodiment measure the weight or the flow rate of a gas or liquid that changes minutely, whereas the first embodiment enables the weight of a micro substance to be measured. It is characterized by being able to.

FIG. 9 is a block diagram showing a schematic configuration of a minute weight measuring apparatus according to the second embodiment. In FIG. 9, the illustration of the calculation unit 60 and the display unit 70 shown in FIG. 1 is omitted, and the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. . In particular,
The micro-weight measuring device shown in FIG. 9 has a micro-weight detector 10 composed of a lever unit 11 and a support unit 12 attached to a pipe through which a minutely changing flow 92 of gas or liquid is guided. This is different from the configuration of the minute weight measuring device described in the first embodiment.

The method of measuring the flow velocity and the like by the minute weight measuring device is as described below. First, when measuring the flow velocity or the like, as shown in FIG. 9, the lever section 11 of the micro-weighted detector 10 is placed at a position where a change in the flow velocity or the flow rate of the flow 92 appears remarkably or particularly at a position where measurement is desired.
Is fixed so that is positioned.

In particular, the fixing of the support portion 12 is performed by the flow 92.
It is preferable to perform the operation at a position where the surface of the lever portion 11 is perpendicular to the direction. That is, it is required that the lever portion 11 bend most sensitively with respect to the flow 92, whereby the micro-weighted detector 10 replaces the amount of deflection with the flow velocity or flow rate of the flow 92 and outputs it as a detection signal. be able to.

Here, the micro-weighted detector 10 has the same configuration as the self-detecting can lever, and the piezoresistor 13
From the acquisition of the resistance value change (not shown), the measurement head unit 5
0, the signal processing reaching the calculation unit 60 and the display unit 70
It is the same as that described in the first embodiment.

However, in the micro-weight measuring apparatus according to the second embodiment, the correspondence between the change in the resistance value of the piezoresistor 13 and the change in the weight of the minute substance described in the first embodiment is replaced with the piezoresistor. 13 Resistance change and flow 92
It is necessary to know the correspondence between the dynamic weight change applied to the lever portion 11 and the dynamic weight change.

In the past, various flow rate sensors have been used to measure the flow rate and flow rate of a liquid.
In general, the configuration of the apparatus differs depending on whether the object to be measured is a liquid flow or a gas flow. For example, an electromagnetic type or Doppler type sensor is used as a liquid flow velocity sensor, and a windmill counter type or heat dissipation change detection type sensor is used as a gas flow velocity sensor. Among these, the flow rate sensor of the heat-dissipation change detection method focuses on the fact that the heat detection unit is provided before and after the heater, and the distribution of the heat dissipated by the heater changes according to the gas flow. Since the flow rate sensor can be manufactured in a small size by a semiconductor photo process, it can detect a minute change in gas flow.

As described above, in the related art, it is possible to detect the flow velocity and the like by using a dedicated sensor for each measurement object (liquid or gas).
The micro-weighted measuring device according to the above can detect the flow velocity and the like of the object to be measured with a common configuration without distinguishing whether the object is a liquid or a gas.

As described above, according to the minute weight measuring apparatus according to the second embodiment, the minute weight detector 10 having the same structure as the self-sensing cantilever used in the SPM is used, and the minute weight is detected. Lever part 1 of vessel 10
By arranging 1 in the flow 92 of the liquid or gas to be measured, the flow velocity and flow rate of the flow 92 can be measured. That is, since the dynamic load exerted by the flow 92 of the liquid or the gas can be obtained as a change in the amount of deflection of the lever portion 11, it is possible to measure the flow velocity and the flow rate in the same configuration without distinction between the gas and the liquid Will be possible.

(Embodiment 3) Next, a micro weight detector and a micro weight measuring apparatus according to Embodiment 3 will be described. The micro weight detector and the micro weight measurement device according to the third embodiment are different from the first embodiment in that the weight of a micro substance can be measured. It is characterized by being able to measure.

FIG. 10 is an explanatory diagram for explaining an application example of the minute weight measuring apparatus according to the third embodiment. A part of the minute weight measuring apparatus (the minute weight detector 10, the measuring head unit 50, Table 80) and a part of the conventional SPM (cantilever 101, sample table 110, actuator 120). In FIG. 10, the illustration of the calculation unit 60 and the display unit 70 shown in FIG. 1 is omitted, and the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted. .

In particular, the micro-weight detector constituting the micro-weight measuring apparatus according to the third embodiment is characterized in that it can be installed on the sample stage 110 of the SPM in place of a normal sample. Therefore, as shown in the figure, a dedicated support 80 for fixing the micro-weighted detector 10 like a normal sample is used.
Is interposed between the sample stage 110 and the micro-weighted detector 10.

In particular, the surface of the micro-weighted detector 10 near the free end of the lever portion 11 has an SPM cantilever 1
It is necessary to install the probe at a position where it can come into contact with the probe 100 of No. 01. As a result, the SPM can detect the minutely weighted detector 10.
The cantilever 101 can be finely moved in the Z-axis direction (vertical direction) by controlling the actuator 120 in the same manner as in the related art by regarding the lever unit 11 as a sample to be measured.

That is, with the function conventionally provided in the SPM, it is possible to apply a weight to the surface near the free end of the lever portion 11 using the cantilever 101. This means that the micro weight detector 10 can detect the hardness of the cantilever 101. However, in this case, the probe 100 of the cantilever 101
The relationship between the weight given to the predetermined amount of Z-axis displacement finely moved by the actuator 120 and the detection value obtained from the minute weight detector 10 with reference to the position where You need to know. This correspondence can be obtained, for example, by replacing the hardness reference cantilever 40 having a known hardness as shown in FIG. 6 with a cantilever 101 of SPM.

Further, the predetermined Z-axis displacement amount finely moved by the actuator 120, that is, the pressing amount of the cantilever 101, can be easily calculated from the control amount of the actuator 120.
Obtaining a hardness of 01 means that the weight given to the sample can also be obtained.

In the hardness measurement described above, the probe 100 of the cantilever 101 is brought into contact with the surface of the lever portion 11 of the micro-weight detector 10, but if the probe 100 is likely to be damaged, A portion near the free end of the cantilever 101 and where the probe 100 is not provided may be brought into contact with the surface of the lever portion 11.

As described above, according to the minute weight measuring apparatus according to the third embodiment, the minute weight detector 10 having the same structure as the self-detecting cantilever used in the SPM is used, and the minute weight is detected. Lever part 1 of vessel 10
By arranging 1 on the SPM sample stage 110 so as to be a target of SPM sample surface measurement, the hardness of the SPM cantilever 101 can be measured. That is, since the dynamic load exerted by the pressing of the cantilever 101 can be obtained as a change in the amount of deflection of the lever portion 11, the hardness of the cantilever 101 can be easily measured with the cantilever 101 mounted on the SPM. Thereby, the conventional SPM can be used as an ultra-fine part hardness tester such as a nano Vickers hardness tester that can accurately measure hardness.

Further, by grasping the physical properties of the cantilever before observation of the sample in the SPM according to the above procedure, it becomes possible to control the force applied to the sample, thereby reducing damage to a soft sample and protecting the probe in observing a hard sample. Can be easily realized.

In the first to third embodiments, the micro-weighted detector 10 has been described as having the same structure as the self-detecting cantilever. However, the cantilever without the piezoresistor 13 as used in the optical lever system is used. A structure is also possible. However, in this case, in order to detect the amount of bending of the cantilever, a detection system separate from the cantilever, such as a laser device or a photodetector that detects reflected light from the cantilever, is required. Reference numeral 50 is replaced with the photodetector or the like.

[0072]

According to the first and third aspects of the present invention, the amount of deflection of the minute beam portion bent by the weight given to the weight receiving portion of the minute weight detection means (the minute weight detector) is determined by:
It can be obtained as a change in the electric signal by the deflection detecting means, the magnitude of the weight is calculated from the electric signal by the calculating means and the display means, and the result is displayed. An effect is also obtained in which the load can be detected by the bending of the minute beam portion that changes sharply.

According to the second and eighth aspects of the present invention, the piezoresistor is provided in the minute beam portion, and the change in the resistance value is obtained as the amount of deflection of the minute beam portion. Extracting the amount of deflection of the minute beam portion as a change in the electric signal from the minute load detecting means (small weight detector) itself without preparing an independent necessary deflection detecting means such as detecting the amount of deflection by detecting. This makes it possible to simplify the device configuration.

According to the fourth aspect, the amount of bending of the minute beam portion which is bent by placing the object to be measured on the weight receiving portion is calculated as follows.
Since the weight of the object to be measured is calculated and the result is displayed, the weight of the minute substance that could not be measured conventionally can be detected by the sharply changing deflection of the minute beam. To play.

According to the fifth aspect, the flow velocity or the flow rate of the liquid flow or the gas flow is calculated from the amount of bending of the minute beam bent by disposing the weight receiving portion in the liquid flow or the gas flow. Then, since the result is displayed, it is possible to measure the minute flow rate or flow rate in the same configuration without distinguishing whether the fluid is a gas or a liquid.

According to the sixth aspect, the hardness of the measurement object is calculated from the amount of bending of the minute beam portion which is bent by the measurement object pressing the weight receiving portion with a predetermined size. ,
Since the result is displayed, even for a substance in which it has been difficult to accurately measure hardness in the past, there is an effect that the hardness can be detected by the bending of the minute beam portion that changes sharply.

Further, according to the present invention, the minute weight detecting means can be fixed to the sample base of the SPM so that the weight receiving portion becomes a sample to be measured by the SPM. The cantilever presses the weight receiving portion with a predetermined size, and calculates the hardness of the cantilever from the amount of deflection of the minute beam portion bent by this, and displays the result, so the cantilever is mounted on the SPM. In this state, the hardness can be easily measured, and there is an effect that the conventional SPM can be used as an ultra-fine part hardness meter.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a minute weight measurement device according to a first embodiment.

FIG. 2 is a schematic diagram for explaining a structure of a micro-weighted detector according to the first embodiment.

FIG. 3 shows a micro-weighted detector according to the first embodiment;
It is a figure showing the state where the lever part bent when the minute substance was loaded.

FIG. 4 is a schematic diagram for explaining a structure of another example of the micro-weighted detector according to the first embodiment.

FIG. 5 is a diagram showing a change in a detection signal of the micro-weighted detector according to the first embodiment.

FIG. 6 is an explanatory diagram for explaining a method for calculating the hardness of a lever portion of the micro weight detector in the micro weight detection device according to the first embodiment;

FIG. 7 is a diagram showing a plurality of standard particles having different particle diameters in the description of the method of calibrating the micro weight detection device according to the first embodiment.

FIG. 8 is a graph for explaining a calibration curve showing a relationship between a detected value and a weight in the description of the calibration method of the minute weight detection device according to the first embodiment.

FIG. 9 is a block diagram illustrating a schematic configuration of a minute weight measurement device according to a second embodiment;

FIG. 10 is an explanatory diagram for explaining an application example of the minute weight measurement device according to the third embodiment.

[Explanation of symbols]

 10, 20 Micro-weighted detector 11, 22 Lever part 12, 23, 41 Support part 13 Piezoresistor 14 Electrode wiring 30 Micro substance 40 Reference cantilever 50 Measurement head part 60 Calculation part 70 Display part 80 Support base 100 Probe 101 Cantilever 110 Sample stage 120 Actuator

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G01N 13/16 G01N 13/16 C G01P 5/04 G01P 5/04 F G12B 21/02 G12B 1/00 601A (72) Inventor Nobuhiro Shimizu 1-8-8 Nakase, Mihama-ku, Chiba City, Chiba Prefecture Inside Seiko Instruments Inc. (72) Inventor Chiaki Amuro 1-8-8 Nakase, Mihama-ku, Chiba City, Chiba Prefecture Seiko Instruments Inc. F-term (Reference) 2F030 CA04 CC01 CC11 2F049 BA15 2F077 AA25 EE07 VV01

Claims (8)

[Claims] 1. A weight receiving portion receiving a load, a micro beam portion having one end connected to the weight receiving portion, and a support portion supporting the micro beam portion at the other end of the micro beam portion, A small weight detector, wherein the weight is detected by converting a magnitude of the weight given to the weight receiving portion into a deflection amount of the small beam portion. 2. The method according to claim 1, wherein a piezoresistor is provided on the microbeam, and the amount of deflection of the microbeam is output as a detection signal indicating a change in resistance of the piezoresistor. Micro weighted detector. 3. A load receiving device comprising: a load receiving portion receiving a load; a microbeam portion having one end connected to the weight receiving portion; and a support portion supporting the microbeam portion at the other end of the microbeam portion. A small load detecting means for converting the magnitude of the weight given to the receiving portion into a bending amount of the minute beam portion; a bending detecting means for converting the bending amount into an electric signal to output; and an output from the bending detecting means. A minute weight measuring device comprising: a calculating means for calculating the magnitude of the weight from the obtained electric signal; and a display means for displaying the magnitude of the weight calculated by the calculating means. 4. The method according to claim 1, wherein the weight is generated according to a weight of the measurement target placed on the weight receiving unit, and the calculating unit calculates the weight from an electric signal output from the deflection detecting unit. 4. The apparatus according to claim 3, wherein the display unit displays the weight calculated by the calculation unit. 5. The method according to claim 1, wherein the weight is generated according to a liquid flow or a gas flow applied to the weight receiving unit, and the calculating unit calculates the liquid flow or the gas flow from an electric signal output from the deflection detecting unit. The minute weight measuring device according to claim 3, wherein the flow velocity or the flow rate is calculated, and the display unit displays the flow velocity or the flow rate calculated by the calculation unit. 6. The weight is generated when the object to be measured presses the weight receiving portion with a predetermined size, and the calculating means calculates the hardness of the object from the electric signal output from the deflection detecting means. The micro weight measuring apparatus according to claim 3, wherein the hardness is calculated, and the display unit displays the hardness calculated by the calculation unit. 7. The method according to claim 7, wherein the weight receiving unit is an SPM (Scanni).
ng Probe Microscope), comprising: a SPM support means for fixing the micro weight detection means to the sample base of the SPM so as to be a sample to be measured by the SPM. The calculation means calculates the hardness of the cantilever from the electric signal output from the deflection detection means, and the display means displays the hardness calculated by the calculation means. The minute weight measuring device according to claim 3, wherein: 8. The deflection detecting means is provided as a piezoresistor on the micro beam portion of the micro weight detecting means, and converts the amount of deflection into an electric signal indicating a change in the resistance value of the piezoresistor. 8. The method according to claim 3, wherein the output is performed.
The micro weight measurement device according to any one of the above.