JPH10185802A - Surface characteristics evaluation unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the adhesion of the surface of a sample by supporting a spring member at the opposite ends thereof and locating an indenter in the center of the spring member. SOLUTION: The indenter 9 has an end face of accurately defined area and located in the center on the bottom face of a spring 8 so that the end face will be in parallel with the measuring surface 5a of a sample 5 when the spring 8 is fixed to a support 7. The measuring surface 5a is brought into contact with the end face by elevating a stage mounting a sample fixing part 1 or lowering the support 7 and the center of the spring 8 is located by means of a displacement sensor 3. The indenter 9 is then pressed against the sample 5 with a force not causing any plastic deformation of the measuring surface 5a. When the stage is lowered gradually, recovery force of the spring 8 exceeds the adhesion to separate the indenter 9 from the sample 5. The displacement sensor 3 detects displacement of the center of spring 8 and the touching force acting on the end face of the indenter 9 and the measuring surface 5a is calculated based on the flexure and the spring constant of the spring 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a surface characteristic evaluation apparatus. More specifically, the present invention relates to a surface property evaluation device for measuring the adhesive force on the surface of a solid sample.

[0002]

2. Description of the Related Art In a mechanism involving mechanical sliding, such as a gear device or a bearing device, friction caused by an adhesion phenomenon at a contact interface between objects influences the reliability and performance of the device, and furthermore, the life thereof. It is one of the factors to do. For example, the friction of a gear device or a bearing device causes a loss of energy and further wear of the contact surface, thereby shortening the life of the device. Further, the friction between the material and the tool in the plastic working of metal, that is, the adhesion phenomenon, affects the finish of the machined surface. On the other hand, also in a contact mechanism such as a relay device, the adhesive force between the contact surfaces becomes a load during the operation of the relay and also causes deterioration of the contact.

As described above, the adhesion phenomenon is an important factor in all areas of the basic technology, and in recent years, in the advanced technology fields such as a magnetic recording device and a micromachine, the adhesion in a small load or in a small area. Elucidation of the phenomenon is important.

Conventionally, as an apparatus for measuring the adhesion phenomenon between solids, for example, as shown in Japanese Patent Application Laid-Open No. 5-296918, two samples made of a metal material are brought into contact with an appropriate load and then linearly moved. An adhesive force measuring device that slides and calculates an adhesive coefficient from a frictional force and a load at that time has been used.

Japanese Patent Laid-Open Publication No. Hei 3-238342 discloses a surface characteristic evaluation device as a device for measuring a small adhesion force on the order of micronewtons in a minute region. Hereinafter, a conventional surface property evaluation apparatus will be described with reference to the drawings.

FIG. 12 is a perspective view showing the entire structure of a conventional surface characteristic evaluation device. As shown in FIG. 12, the conventional surface characteristic evaluation apparatus has a fixed base 1 on which a sample 105 is placed.
The apparatus includes a sample fixing unit 101 having an indenter 04, an indenter support unit 102 that supports an indenter 107 that comes into contact with a sample 105, and a displacement sensor 103 that measures the displacement of the indenter support unit 102.

In the sample fixing section 101, a sample 105 is placed on a fixing table 104 such that a measurement surface 105a is horizontal. A moving unit (not shown) is provided on the fixed base 104, and can be moved in a direction perpendicular to the measurement surface 105 a of the sample 105.

The indenter supporting portion 102 has a spring 106 whose one end is fixed to a base (not shown) and whose free end is elastically deformed perpendicularly to the measuring surface 105a, and a measuring surface 105 of the spring 106.
and the indenter 107 provided on the surface opposing a. The indenter 107 is formed of diamond in the shape of a pyramid, and has a tip with a radius of the order of submicrons. Note that the indenter 107 is provided so as to be located above the measurement surface 105a.

The displacement sensor 103 is a displacement detecting means for detecting the displacement of the indenter 107 at the free end of the spring 106 in the direction perpendicular to the measurement surface 105a.
Is provided above the free end.

Hereinafter, a method of measuring the adhesive force by the conventional surface characteristic evaluation apparatus will be described.

First, the fixed base 104 is raised to bring the measurement surface 105a of the sample 105 into contact with the indenter 107, and the position of the free end of the spring 106 is detected by the displacement sensor 103. Thereafter, the indenter 107 is pressed against the sample 105 with a force that does not cause plastic deformation on the measurement surface 105a.

Next, the fixing table 104 is gradually lowered. Since the indenter 107 adheres to the sample 105 due to the adhesive force acting between the indenter 107 and the measurement surface 105a, the indenter 107 is moved to the sample 105. From the spring 10
Reference numeral 6 warps toward the measurement surface 105a. When the fixing base 104 is further lowered, the restoring force of the spring 106 exceeds the above-mentioned adhesive force, and the indenter 107 separates from the sample 105. By detecting the displacement of the free end of the spring 106 at this time by the displacement sensor 103, the amount of deflection of the free end of the spring 106 from the position where the indenter 107 comes into contact with the measurement surface 105a to the position where it is separated is measured. The adhesive force acting on the indenter 107 and the measurement surface 105a is calculated from the amount of deflection and the spring constant.

[0013]

However, in the adhesive force measuring device as disclosed in Japanese Patent Application Laid-Open No. 5-296918, the sliding of the sample is performed by a linear reciprocating motion whose amplitude is on the order of millimeters. The contact area also requires a square millimeter order. Therefore, it was not possible to measure the adhesive force in a minute area, and only an averaged adhesive force could be measured even with a sample having a distribution of the adhesive force on the measurement surface.

On the other hand, in the surface characteristic evaluation apparatus disclosed in Japanese Patent Application Laid-Open No. 3-238342, the tip of the indenter is formed to be extremely sharp, so that the adhesion force in a minute area can be measured. Since the indenter is supported and fixed to the free end of the spring, when the indenter is separated from the sample, the indenter gradually tilts with respect to the measurement surface with the deformation of the spring. At this time, since the location where the tip of the indenter contacts the measurement surface changes, the contact area cannot be kept constant, so that the adhesion force could not be measured accurately. Also,
Since the tip of the indenter is conical, the indenter and the measurement surface are in point contact, and it is not possible to know the exact contact area, and the adhesion force per unit contact area required to separate the indenter from the contact with the sample is determined. It could not be evaluated quantitatively.

[0015] For the above reasons, the measured value of the adhesive force is not universal, so that it is impossible to compare the adhesive force when the same sample is measured using different indenters.
Alternatively, even when different samples were measured using the same indenter, the adhesion force could not be compared.

Accordingly, an object of the present invention is to provide a surface characteristic evaluation apparatus capable of measuring the adhesion force with high accuracy.

[0017]

In order to achieve the above object, a surface characteristic evaluation apparatus of the present invention is disposed so as to face a measurement surface of a sample, and is fixed to be elastically deformable in a direction perpendicular to the measurement surface. A spring member, an indenter provided on a surface of the spring member facing the measurement surface, and a displacement characteristic detecting device for detecting displacement of the indenter in a direction perpendicular to the measurement surface. Both ends of the spring member are supported, and the indenter is provided at the center of the spring member.

In the present invention constructed as described above, since the spring member is supported at both ends and the indenter is provided at the center thereof, the indenter always keeps contact with the measurement surface even if the amount of deflection of the spring member changes. It will be provided at the point of maximum deflection that is kept parallel. As a result, even if the spring member is bent, the tip surface of the indenter does not tilt with respect to the measurement surface, and the contact area between the tip surface of the indenter and the measurement surface of the sample is always kept constant.

Further, by forming the distal end surface of the indenter in a plane parallel to the measurement surface, the contact area when the distal end surface is brought into contact with the measurement surface is substantially equal to the area of the distal end surface. For example, even when measuring multiple samples,
The contact area between the tip surface and the measurement surface is kept constant.

Further, by forming the area of the tip end surface of the indenter to a specified area, the area becomes a known value, so that the adhesive force per unit area can be quantitatively and easily measured.

Further, by forming the area to be less than or equal to the square micrometer, the adhesion force can be measured in a minute area of the measurement surface.

By using an optical displacement sensor installed above the spring member as the displacement detecting means, the displacement detecting means does not come into contact with the spring when measuring the amount of deflection of the spring.

Further, by using a piezoelectric thin film provided on the surface of the spring member opposite to the surface on which the indenter is provided as the displacement detection means, a displacement sensor provided above the spring member is provided. Since it becomes unnecessary and the structure disappears from the space above the spring member, observation with a microscope or the like from above the spring member becomes easy.

Further, a piezo element, wherein the spring member is fixed to a support, the sample is mounted on a fixing table, and the support is moved in a direction perpendicular and horizontal to the measurement surface, Alternatively, by having at least one of the piezo elements to move the fixed base in a direction perpendicular to the measurement surface and in a horizontal direction,
By keeping the voltage applied to the piezo element constant, the force with which the indenter is pressed against the sample before starting the measurement becomes constant, so the initial conditions of the measurement become constant, and the piezo element is controlled with nanometer-order accuracy. Therefore, by repeating the minute moving operation, the position where the indenter separates from the sample when the indenter is separated from the sample can be detected more accurately.

[0025]

Next, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a perspective view showing the overall configuration of a first embodiment of the surface characteristic evaluation apparatus of the present invention.

As shown in FIG. 1, the apparatus for evaluating surface properties according to the present embodiment comprises a sample fixing section 1 having a fixing table 4 on which a sample 5 is placed, and an indenter support for supporting an indenter 9 to be brought into contact with the sample 5. It comprises a unit 2 and a displacement sensor 3 which is a displacement detecting means for measuring the displacement of the indenter 9.

The sample fixing section 1 has a structure in which a fixing table 4 is provided on a stage 6 attached to a base (not shown).
Is placed horizontally. The stage 6 is provided with moving means (not shown), and can move in a direction perpendicular to the measuring surface 5a and in a horizontal direction.

The indenter support 2 has a rear end attached to a base (not shown) and a bifurcated spring fixing portion 7 at the end.
a, a spring 8 whose both ends are supported by these two spring fixing portions 7a, and an indenter 9 provided at the center of a surface of the spring 8 facing the measurement surface 5a. It is composed of The support 7 is also provided with a moving means (not shown), and the indenter support 2 is movable in a direction perpendicular to the measurement surface 5a. The indenter 9 is connected to the measurement surface 5
a.

The displacement sensor 3 is provided above the spring 8 so that the detecting portion is located above the center of the spring 8, that is, above the indenter 9. As the displacement sensor 3, it is desirable to use a sensor that can detect displacement without contacting the spring 8, such as an optical displacement sensor.

Next, details of the spring 8 and the indenter 9 will be described with reference to FIGS. FIG. 2 shows the spring 8 shown in FIG.
FIG. 3 is a front view of the spring 8 shown in FIG.

As shown in FIG. 2, the spring 8 used in the present embodiment is provided with two parallel hollow portions 8a in the longitudinal direction, and the indenter 9 is fixed between these hollow portions 8a. Have been. For example, even if an initial stress is generated when the spring 8 is fixed to the spring fixing portion 7a because the bifurcated spring fixing portions 7a of the support 7 are mutually twisted or have a step, the hollow portion 8a is formed. As a result, the initial stress is reduced, so that accurate measurement can be performed as compared with a case where a simple leaf spring without the hollow portion 8a is used.

As shown in FIGS. 2 and 3, the indenter 9 has a tip surface 9a having an area defined accurately.
And is provided at the center of the bottom surface of the spring 8 such that the tip surface 9a is parallel to the measurement surface 5a of the sample 5 when the spring 8 is attached to the support 7. The spring constant of the spring 8 and the area of the tip surface 9a are set according to the adhesion force of the sample 5 to be measured, the required measurement accuracy, the size of the measurement area, and the like. Usually, the spring constant is Newton / meter ( N / m) or less, and the area of the tip surface 9a is set to the order of square micrometers or less.

Hereinafter, a method of measuring the adhesive force by the surface characteristic evaluation apparatus of the present embodiment will be described.

First, the measurement surface 5 is moved by at least one operation of raising the stage 6 or lowering the support 7.
a in contact with the distal end surface 9a of the indenter 9, and the spring 8
Is detected by the displacement sensor 3. afterwards,
The indenter 9 is pressed against the sample 5 with a force that does not cause plastic deformation on the measurement surface 5a. Since the tip surface 9a of the indenter 9 is provided in parallel with the measurement surface 5a, the contact area between the tip surface 9a and the measurement surface 5a is substantially equal to the area of the tip surface 9a formed in a specified area. Become equal.

Next, the stage 6 is gradually lowered.
Since the indenter 9 adheres to the sample 5 by the adhesive force acting between the tip surface 9a of the indenter 9 and the measurement surface 5a, the indenter 9 is lowered from the position where the measurement surface 5a is in contact with the indenter 9. Also, the indenter 9 does not separate from the sample 5, and the spring 8 bends toward the measurement surface 5a as shown in FIG. Here, the indenter 9 is a spring 8
However, since the spring 8 is supported at both ends by the spring fixing portion 7a, the position where the indenter 9 is fixed is the maximum bending point 8b of the spring 8. Since the maximum bending point 8b is always kept parallel to the measurement surface 5a even when the amount of deflection of the spring 8 changes, as a result, the tip surface 9a of the indenter 9 moves to the measurement surface 5a with the deformation of the spring 8. The contact area between the tip end surface 9a and the measurement surface 5a is always kept constant.

When the stage 6 is further lowered, the spring 8
The restoring force exceeds the adhesive force and the indenter 9 separates from the sample 5. By detecting the displacement of the center of the spring 8 by the displacement sensor 3 at this time, the indenter 9 separates from the position where the indenter 9 contacts the sample 5. The amount of deflection of the center of the spring 8 up to the set position is measured, and the adhesive force acting on the distal end surface 9a of the indenter 9 and the measurement surface 5a is calculated from the amount of deflection of the spring 8 and the spring constant.

Further, by repeating the operation of measuring the adhesive force while gradually moving the stage 6 in the horizontal direction to the measuring surface 5a, the distribution of the adhesive force in a minute area of the measuring surface 5a can be measured. .

As described above, since both ends of the spring 8 are supported by the support 7 and the indenter 9 is provided at the center of the spring 8, the tip end surface 9a and the sample 5 are moved in accordance with the deflection of the spring 8.
Since the contact area with the measurement surface 5a does not change,
The adhesive force can be accurately measured.

Further, the tip surface 9a is the measuring surface 5a of the sample 5.
Are provided in parallel with the tip surface 9a and the measurement surface 5a.
Since the contact area is kept constant, for example, even when a plurality of samples are measured, the contact area between the distal end surface 9a and the measurement surface 5a can be kept constant.

Further, since the area of the tip end surface 9a of the indenter 9 is accurately defined and provided, the area has a known value, so that the adhesive force per unit area can be quantitatively and easily measured.

Further, since the area of the tip end face 9a of the indenter 9 is formed to be smaller than the square micrometer, it is possible to measure the adhesion force in a minute area, and the measurement surface 5a
The distribution of the adhesive force in the minute area can be measured.

Since an optical displacement sensor is used as the displacement sensor 3, the displacement sensor 3 does not come into contact with the spring 8 when measuring the amount of deflection of the spring 8. for that reason,
When measuring the amount of deflection of the spring 8, unnecessary external force is not applied to the spring 8, so that the amount of deflection of the spring 8 can be accurately measured.

The material of the spring 8 is preferably stainless steel or the like, but is not limited thereto, and other materials such as metals and silicon materials having high elasticity and easy microfabrication can be used. In particular, when a silicon-based material is used, the spring 8 and the indenter 9 can be integrally formed with extremely small precision with high accuracy by using photolithography technology.

In this embodiment, the indenter 9 has a pyramid whose tip is formed in a plane, but if the area of the tip surface 9a is precisely defined and formed, the shape of the indenter 9 is pyramid. In addition to the shape and the shape of a cone, the shape may be a column such as a cylinder or a prism. Further, the indenter 9 may be formed of any material,
If a thin film of an arbitrary material is formed on the tip surface 9a, the adhesion force can be measured by the indenter 9 formed by combining various substances. it can. In the present embodiment, in order to measure the distribution of the adhesive force in the minute area of the measurement surface 5a, the tip surface 9 is measured.
a is formed in the order of square micrometer or less, but when it is not necessary to measure the distribution of the adhesive force in a minute area, it is not necessary to form the area of the tip end surface 9a minutely. It may be formed on the order of degree.

Further, the surface characteristic evaluation apparatus of the present embodiment
Unlike the method of measuring the surface free energy of a solid from the contact angle by dropping a standard liquid onto the sample surface, since no liquid is used, the adhesive force is measured in a vacuum, in any gas, or even in a liquid. be able to.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 5 is a perspective view showing the overall configuration of the second embodiment of the surface characteristic evaluation device of the present invention.

As shown in FIG. 5, in the present embodiment, a direction perpendicular to the measuring surface 5a in accordance with an applied voltage is applied between the mounting support 10 and the support 7 mounted on a base (not shown). A first piezo element 11 that expands and contracts is provided, and between the stage 6 and the fixed base 4, expands and contracts in a direction perpendicular to the measurement surface 5 a in accordance with the applied voltage, and the upper surface portion 12 a A second piezo element 12 displaced in a horizontal direction is provided. The amount of expansion and contraction and the amount of displacement of these piezo elements 11 and 12 can be controlled with an accuracy on the order of nanometers. The mounting support 10 is provided so as to be movable in a direction perpendicular to the measurement surface 5a of the sample 5. The other configuration is the same as that of the first embodiment, and therefore the description thereof is omitted. In FIG. 5, the same components as those of the first embodiment are denoted by the same reference numerals as those of FIG.

Here, the structure of the second piezo element 12 will be briefly described with reference to FIG.

A piezo element that is displaced in the vertical and horizontal directions, ie, a piezo element that is displaced three-dimensionally, is a scanning tunneling microscope (STM) or an atomic force microscope (AF).
M) and the like, and typical examples thereof include a tripod type and a tube type. In the present embodiment, a tube-type piezo element is used as the second piezo element 12.

As shown in FIG. 6, the second piezo element 12
An X-axis electrode 12b, a Y-axis electrode 12c, and a Z-axis electrode 12d are provided on the outer peripheral surface and the inner peripheral surface. X-axis electrode 1
By controlling the voltage applied to the 2b and Y-axis electrodes 12c, the upper surface portion 12a of the second piezo element 12 can be freely displaced in the XY directions (that is, the direction horizontal to the measurement surface 5a). In addition, by applying a voltage to the Z-axis electrode 12d, the second piezo element 12 can be expanded and contracted in the Z-axis direction (that is, the direction perpendicular to the measurement surface 5a). In this manner, the second piezo element 12 can be expanded and contracted in a direction perpendicular to the measurement surface 5a, and the upper surface portion 12a of the second piezo element 12 can be displaced in a direction horizontal to the measurement surface 5a.

In the measurement of the adhesion force by the surface characteristic evaluation device of the present embodiment, the stage 6 is lifted or the mounting support 1 is
The measurement surface 5a is brought into contact with the distal end surface 9a of the indenter 9 by at least one operation of descending zero. Thereafter, by applying a prescribed voltage to at least one of the first piezo element 11 and the second piezo element 12, the piezo element is extended in a direction perpendicular to the measurement surface 5a, so that the indenter 9 is connected to the sample 5
Pressed with a certain force. Also, each piezo element 1
Since positions 1 and 12 are controlled with an accuracy on the order of nanometers, the position where the indenter 9 separates from the sample 5 when the indenter 9a is separated from the sample 5a can be detected more accurately by repeating a minute moving operation.

As described above, according to the surface characteristic evaluation apparatus of the present embodiment, the force for pressing the indenter 9 against the sample 5 before the start of the measurement is constant, so that the initial condition of the measurement is constant, and The reliability of the comparison result of each measured value when 5 is measured is improved.

Further, as the position where the indenter 9 separates from the sample 5 is more accurately detected, the amount of deflection of the spring 8 is also more accurately measured, so that the adhesion force can be measured more accurately. it can.

Further, the upper surface 1 of the second piezo element 12
By displacing 2a in a direction horizontal to the measurement surface 5a, the sample fixing unit 1 is moved with high precision in a direction horizontal to the measurement surface 5a, so that the distribution of the adhesive force on the measurement surface 5a is measured with high resolution. can do.

In the present embodiment, it is possible to move the sample 5 in the direction perpendicular to the measurement surface 5a and in the horizontal direction only by the second piezo element 12, and to displace the relative position between the sample 5 and the indenter 9. Therefore, the first piezo element 11 may be omitted. If the first piezo element 11 is provided with a function of enabling the support 7 to move in the direction perpendicular to the measurement surface 5a and in the horizontal direction, the second
Of the piezo element 12 can be omitted.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS.
FIG. 7 is a perspective view showing the entire configuration of the third embodiment of the surface characteristic evaluation device of the present invention, and FIG. 8 is a view showing the spring 8 shown in FIG.
9 is a bottom view of the spring 8 shown in FIG. 7, and FIG.
8 is a front view of the spring 8 shown in FIG.

As shown in FIGS. 7 and 8, a piezoelectric thin film 13 is mounted on the upper surface of the spring 8. Piezoelectric thin film 1
Reference numeral 3 indicates that the electric resistance changes in accordance with the amount of strain, and the amount of deflection of the spring 8 is measured by measuring the electric resistance. Therefore, a displacement sensor is unnecessary in the present embodiment. The other configuration is the same as that of the first embodiment, and therefore the description thereof is omitted. In FIGS. 7 to 10, the same components as those of the first embodiment are denoted by the same reference numerals as those of FIG.

Since the piezoelectric thin film 13 has a property that the electric resistance changes according to the amount of distortion when the distortion is generated, the amount of deflection of the spring 8 is measured by measuring the change in the electric resistance. . The adhesive force is obtained from the amount of deflection and the spring constant. The spring constant of the spring 8 in the present embodiment is not a value of the spring 8 alone, but a value of the spring 8 with the piezoelectric thin film 13 mounted. Constants are used.

As described above, the amount of deflection of the spring 8 is
Since the measurement is performed by the piezoelectric thin film 13 mounted on itself, the use of a displacement sensor becomes unnecessary, and the structure in the space above the spring 8 is eliminated, so that observation with a microscope or the like from above becomes easy. Therefore, for example, even when the measurement surface 5a is not a single plane, the measurement position of the adhesive force is determined by microscopic observation, and an operation of bringing the indenter 9 into contact with the measurement surface 5a can be performed under microscopic observation. . This can reduce the possibility that the indenter 9 and the sample 5 may be erroneously damaged during the measurement operation, and can also record an image of the measurement surface 5a.

As shown in FIGS. 8 and 10, the piezoelectric thin film 13 in the present embodiment has a portion where the surface of the spring 8 bends, that is, the entire portion sandwiched by the two hollow portions 8a. However, if the piezoelectric thin film 13 is provided so as to have a correlation with the amount of distortion of the piezoelectric thin film 13 with respect to the amount of deflection of the spring 8, the piezoelectric thin film 13 is provided over the entire portion of the spring 8 where deflection occurs. It is not necessary, and the piezoelectric thin film 13 may be made more compact, or may be provided linearly or the like.

The piezoelectric thin film 13 is made of a material whose electric resistance changes due to distortion, such as silicon.

Further, as shown in FIG.
3 is the piezo element 11, 12 described in the second embodiment.
(See FIG. 5). This makes it possible to measure the adhesive force with high accuracy under microscopic observation. In addition, since the relative position between the sample 5 and the indenter 9 can be displaced by only one of the first piezo element 11 and the second piezo element 12, the first piezo element 11 or the second piezo element 12 One of them may be omitted as described in the second embodiment.

[0064]

Next, an embodiment of the surface characteristic evaluation apparatus shown in FIG. 1 will be described.

The surface characteristic evaluation apparatus of the present embodiment uses stainless steel as the material of the spring 8 and reduces the thickness of the spring 8 to 10 μm.
m, the plate width was 0.2 mm, and the plate length was 4 mm, so that the spring constant of the spring 8 was set to 2 N / m. On the other hand, silicon is used as the material of the indenter 9, the tip surface 9a is set to be the (100) crystal plane, and the area is 0.1%.
It was processed to a thickness of μm ² , and the tip surface 9a was further nitrided. Also,
As the displacement sensor 3, an optical displacement sensor that vertically enters light on the upper surface of the spring 8 and detects displacement based on an interference effect between incident light and reflected light is used.

When the adhesion force of three kinds of samples 5 of silicon, silicon nitride, and silicon oxide was measured using this surface characteristic evaluation apparatus, the adhesion force per unit contact area with the tip surface 9a (silicon nitride) of the indenter 9 was measured. The adhesive force was 1.7 MPa for silicon, 2.4 MPa for silicon nitride, and 7.2 MPa for silicon oxide. Further, no distribution of the adhesive force on the measurement surface 5a was observed. For comparison, a standard liquid was dropped on the surface of silicon, silicon nitride, and silicon oxide, the surface free energy was calculated from the liquid contact angle, and the adhesion energy with silicon nitride calculated using the geometric mean rule. The result is silicon, silicon nitride,
In the order of silicon oxide, the order was larger, and the measurement result of this example was consistent with the result calculated from the surface free energy.

[0067]

As described above, according to the surface characteristic evaluation apparatus of the present invention, both ends of the spring member are supported by the support, and the indenter is provided at the center of the spring member. The contact force can be accurately measured.

Further, by forming the tip surface of the indenter in a plane parallel to the measurement surface, even when a plurality of samples are measured, for example, the contact area between the tip surface and the measurement surface can be kept constant. it can.

Further, by forming the area of the tip end face of the indenter to a specified area, the area has a known value, so that the adhesive force per unit area can be quantitatively and easily measured.

Further, by forming the area of the tip end face of the indenter on the order of a square micrometer or less, it becomes possible to measure the adhesion force in a minute area, and to measure the distribution of the adhesion force in the minute area on the measurement surface. be able to.

By using an optical displacement sensor installed above the spring member as the displacement detecting means, the displacement detecting means does not come into contact with the spring member when measuring the amount of deflection of the spring member. Therefore, no unnecessary external force is applied to the spring member when measuring the amount of deflection of the spring member, so that the amount of deflection of the spring member can be accurately measured.

In addition, by using a piezoelectric thin film provided on the surface of the spring member opposite to the surface on which the indenter is provided as the displacement detecting means, observation with a microscope or the like from above is facilitated, and measurement is performed. It is possible to reduce the possibility that the indenter or the sample is damaged by mistake during the operation, and it is also possible to record an image of the measurement surface.

Further, since the piezo element is provided as a moving means for displacing the relative position between the indenter and the sample, the force with which the indenter is pressed against the sample before the start of the measurement becomes constant. That is, the reliability of the comparison result of each measured value when a plurality of samples are measured is improved. In addition, since the piezo element is controlled with an accuracy of the order of nanometers, the position where the indenter separates from the sample can be detected more accurately, so that the amount of deflection of the spring member is more accurately measured, and the adhesion force is more accurate. Can be measured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a first embodiment of a surface characteristic evaluation device of the present invention.

FIG. 2 is a bottom view of the spring shown in FIG. 1;

FIG. 3 is a front view of the spring shown in FIG. 1;

FIG. 4 is an enlarged front view showing the first embodiment of the surface characteristic evaluation device of the present invention in a state where a spring is bent.

FIG. 5 is a perspective view showing the entire configuration of a second embodiment of the surface characteristic evaluation device of the present invention.

FIG. 6 is a perspective view showing a configuration of a second piezo element shown in FIG.

FIG. 7 is a perspective view showing the overall configuration of a third embodiment of the surface characteristic evaluation device of the present invention.

FIG. 8 is a top view of the spring shown in FIG. 7;

FIG. 9 is a bottom view of the spring shown in FIG. 7;

FIG. 10 is a front view of the spring shown in FIG. 7;

FIG. 11 is a perspective view showing an overall configuration of an application example of the third embodiment of the surface characteristic evaluation device of the present invention.

FIG. 12 is a perspective view showing the entire configuration of a conventional surface characteristic evaluation device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sample fixing part 2 Indenter support part 3 Displacement sensor 4 Fixed table 5 Sample 5a Measurement surface 6 Stage 7 Support body 7a Spring fixing part 8 Spring 8a Cutout part 8b Maximum deflection point 9 Indenter 9a Tip surface 10 Mounting support 11 First Piezo element 12 Second piezo element 12a Upper surface part 12b X-axis electrode 12c Y-axis electrode 12d Z-axis electrode 13 Piezoelectric thin film

Claims (7)

[Claims] 1. A spring member arranged to face a measurement surface of a sample and fixed to be elastically deformable in a direction perpendicular to the measurement surface, and an indenter provided on a surface of the spring member facing the measurement surface. And a displacement detection means for detecting displacement of the indenter in a direction perpendicular to the measurement surface, wherein both ends of the spring member are supported, and the indenter is provided at a center of the spring member. An apparatus for evaluating surface characteristics, comprising: 2. The surface characteristic evaluation device according to claim 1, wherein a tip surface of the indenter is formed in a plane parallel to the measurement surface. 3. The surface characteristic evaluation device according to claim 1, wherein an area of a tip surface of the indenter is formed to a specified area. 4. The surface characteristic evaluation device according to claim 3, wherein the area is formed on the order of square micrometers or less. 5. The apparatus according to claim 1, wherein the displacement detecting means is an optical displacement sensor installed above the spring member.
The surface characteristic evaluation device according to any one of the above. 6. The surface according to claim 1, wherein the displacement detecting means is a piezoelectric thin film provided on a surface of the spring member opposite to a surface on which the indenter is provided. Characteristic evaluation device. 7. A piezo element, wherein the spring member is fixed to a support, the sample is placed on a fixing table, and the support moves the support in a direction perpendicular and horizontal to the measurement surface, or Of the piezo elements for moving the fixed base in a direction perpendicular and horizontal to the measurement surface,
The surface characteristic evaluation device according to any one of claims 1 to 6, further comprising at least one of them.