JPH0549944B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application This invention relates to a device for measuring mechanical properties of fixed surfaces or thin films.

B. Conventional techniques such as vacuum evaporation method, sputtering method, plasma
For thin films of metals, inorganic materials, etc. manufactured by CVD methods, etc., it is necessary to accurately measure the adhesion between the film and the substrate, especially the properties such as friction coefficient, hardness, and surface roughness, which are indicators of this adhesion. required.

The pull-down method is a method for measuring the adhesion of thin films that meets this requirement, but it cannot be applied to thin films that have an adhesion strength above a certain level. For this reason, the indentation method and the scratch method are available for measuring thin film samples with strong adhesion, but these methods are unsuitable for thin film measurements in minute areas.

For this reason, recently a method has been developed in which a vibrating contact needle is brought into contact with the sample surface, the magnitude of vibration corresponding to the frictional force is detected, and the mechanical properties of the surface are measured from the magnitude of this detected value. Proposed.

C. Problems to be Solved by the Invention However, this newly proposed measurement technique involves bringing the contact needle into contact with the sample surface with a constant force using an elastic body such as a leaf spring or a weight.
In particular, it is impossible to improve the accuracy of pressing force, which is a major factor in determining the coefficient of friction, and the reproducibility is poor.

D Means for Solving the Problems The measuring device provided by the present invention includes a contact needle whose tip contacts the sample surface, an excitation mechanism that vibrates the contact needle, and a vibration mechanism that vibrates the contact needle with a predetermined load on the sample surface. a load mechanism brought into contact with the contact needle, a load detection means for measuring the load exerted by the load mechanism on the contact needle, a measurement control section for feedback-controlling the load mechanism according to the output of the load detection means, and an excitation It is equipped with a vibration detection means for detecting the magnitude of vibration of the contact needle against the sample, and the mechanical properties such as the friction coefficient, adhesion force, hardness, etc. of the sample surface are determined based on the load applied to the sample and the output of the vibration detection means. It is characterized by measuring.

E Effect: With the contact needle being pressed against the sample surface by the load mechanism with a predetermined load value, the vibration mechanism vibrates the contact needle in parallel with the sample surface. In this state, the measurement control section maintains the load on the contact needle at a predetermined value by feedback-controlling the load mechanism using the load value detected by the load detection means. Then, mechanical properties such as the friction coefficient, adhesion force, and hardness of the sample surface are measured based on the applied load and the output of the vibration detection means.

F. Embodiments The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 is a diagram schematically showing the entire measuring device according to the present invention in an easy-to-understand manner.
is a measurement control section, and R is a recording section.

First, to explain the structure of the measurement main body part A, 1 is a measurement main body frame, and below there are movable tables 3 and 4 on which samples T and P are placed, which are placed on a lifting table 2. There is. In the upper frame part, a measurement load part L and a vibrating part B, which are the main parts of the present invention, operate while bringing the contact needle 20 into contact with the sample TP via the cartridge 17, and perform measurements, the details of which will be described later. However, this upper frame also contains the measurement result sample.
An optical system K for observing the TP is also installed in parallel.
This S is an eyepiece lens, and T is an objective lens.

Now, as mentioned above, the contact needle 20 is held in the cartridge 17, and this cartridge 17
is vibrated while being biased toward the sample TP side with a constant load by the vibrating part B and the measurement load part L. In this case, the present invention is characterized by the measurement load section L, and the illustrated example shows an electromagnetic force type load mechanism based on the principle of an electronic balance. That is, 6 is an electromagnetic coil fixedly installed on the main body side 1, and 7 is a core (iron core). This iron core 7
is connected to one end of a lever 8 that can freely swing around a fulcrum E, and a load plate 9 is connected to the other end of the lever 8.
are connected. A fixed frame 1 of the vibrating section B is provided below the load plate 9 via a load cell 10.
1 are connected together. Further, this electromagnetic coil 6 is supplied with the required power from the measurement control section C, and the load value from the load cell 10 is output as an electric signal, which is also supplied to the measurement control section C. It is now being entered. This point is also clear from Figure 4.

Therefore, by adjusting the power supply to the coil 6 under feedback control using the output signal from the load cell 10, a constant load can be set, and the load can also be controlled to increase or decrease at a constant speed.

With such a loading mechanism, the contact needle 20 is
The TP is biased while applying a constant load, and the characteristic detection mechanism using the contact needle 20 is as shown in FIGS. 2 and 3.

FIG. 2 schematically shows only the vibration mechanism, and 11 is the load cell 10 as mentioned above.
A cartridge 17 for holding the contact needle 20 is attached to the lower part of the fixed frame 11 via a leaf spring (elastic body) 13.
The upper ends of both leaf springs 13 are connected by a mounting plate 14, and a coil body 16 is connected to this mounting plate 14 via a connecting frame 15. This coil body 16 consists of permanent magnets 1 fixed on both sides of the fixed frame 11.
2, and therefore, when an alternating current is applied to the coil of this coil body 16 from the measurement control unit C, the coil body 16 is vertically mounted on the mounting plate 14 where the coil body 16 is vibrated. The cartridge 17 also vibrates from side to side.

The contact needle 20 is vibrated in this way, and when the contact needle 20 is vibrated while being urged against the sample TP with a constant load, the mechanical properties such as the adhesion force of the thin film on the sample TP are affected. The measurement is performed by a detection mechanism shown in FIG. That is, FIG. 3 is a diagram schematically and perspectively showing the lost end of the cartridge 17. In the figure, 17 is the cartridge, and H is the cartridge 17.
It is a holding rod that removably holds the mounting plate 14.
It is planted in.

The contact needle 20 is held at the tip of a lever 18 that is swingably supported by a support part Z with respect to the cartridge 17. A magnet M is attached to the other end of this lever 18, and the lever 18 is attached to the support part Z.
When the magnet M swings from side to side by swinging around the center, the detection coil 19 detects this and outputs it as an electric signal.

Now, in the above configuration, the frictional characteristics of the surface of the sample TP and the adhesion force of the thin film are measured as follows. The cartridge 17 and the contact needle 20 are vibrated in the direction of the arrow in FIG. 3 by the vibrating mechanism.
In this case, in response to the forced vibration of the cartridge 17, the contact needle 20 is dragged by the sample TP, although it is biased with a constant load.

However, near the point where the vibration amplitude is maximum, the needle 2
0 stops the movement until the restoring force acting in the opposite direction exceeds the frictional force.

On the other hand, since the cartridge 17 continues to be vibrated,
When the needle 20 is stopped or its movement is restricted due to the frictional force with the sample surface, a relative displacement occurs between the lever 18 and the cartridge 17, and this relative displacement is caused by the induced force generated in the coil 19. Detected by electric power. This detection signal is input to the measurement control section C as shown in FIG. 4, and the characteristics are measured based on this signal value. In this case, the load value from the load cell 10 is also an important factor.

Specifically, the friction coefficient and adhesion force are measured in the following manner.

1 Measurement of friction coefficient When the load W pressing the cartridge is gradually increased, the friction force (μW) and the maximum restoring force (kx0) of the lever 18 become balanced at a predetermined load Ws.
A state occurs in which only the cartridge vibrates while the contact needle 20 remains stationary, and in this state, the output voltage of the cartridge is saturated. Therefore, if the load Ws when the output voltage of the cartridge is saturated is known, the friction coefficient can be found as μ=kx ₀ /Ws x ₀ : amplitude of the cartridge k: horizontal spring constant of the holding rod.

2 Measurement of Adhesive Force When this device is used for thin films etc., it is possible to measure the adhesive force. As the load increases, the thin film breaks down, and in this state, a noise-like signal is generated in the output voltage of the cartridge due to fragments of the broken film. The load can be known as the load Wc at the time of peeling.

The Benjamin and Weaver formula is used to determine the adhesion force.

Here, F is adhesion force, H is Brinell hardness, Wc
is the critical load for peeling and R is the radius of the stylus. Although it has been pointed out that adhesion cannot be expressed using a simple formula such as the Benjamin and Weaver formula, this formula is used as a convenience for comparing and examining data from different test conditions.

In the measurement, by displacing the sample TP in the horizontal (Y-axis) direction, changes in frictional force or adhesion force over time can be recorded by the recorder R. In this case, the sample TP is displaced by the Y-axis moving table 4 with respect to the table 3 by the motor 5. That is, the rotation of the motor 5 activates the screw feeding mechanism, and the movable table 3 is displaced in a direction perpendicular to the plane of the paper.
Note that the specific measurement operation is performed according to the flowchart shown in FIG.

Although the features of the present invention are as described above, the present invention is not limited to the above-mentioned and illustrated examples, and includes various modified embodiments. In particular, regarding the loading mechanism, in the illustrated example, a lever 8 is used based on the principle of an electronic balance, and the load is applied using electromagnetic force. A loading method may also be used. For example, an electrostrictive element may be used to generate the load force. Further, although the illustrated example uses a moving coil type vibration mechanism, any other type of vibration mechanism may be used, for example, a type in which the vibration is applied by a speaker supported by an elastic body, or an electrostrictive element may be used. The supporting structure of the contact needle (stylus) and the detection mechanism are also not limited to the illustrated example.

Furthermore, as a loading method, it is possible to use not only a method in which the contact needle is urged from above, but also a method in which the lower movable table can be moved.

The invention encompasses all these variations.

G. Effects of the Invention The surface property measuring device provided by the present invention is as described above in detail, so that the load on the sample by the contact needle can be freely controlled by adopting the loading mechanism.
It has the great feature of being able to measure various characteristics. Further, by adopting a load mechanism, it is possible to improve the accuracy of the load value and improve reproducibility.

[Brief explanation of the drawing]

FIG. 1 is a diagram schematically showing the overall configuration of the measuring device according to the present invention, FIGS. 2 and 3 are enlarged views of some of the components of the measuring device, and FIG. 4 is an electric circuit diagram. FIG. 5 is a flow chart. A...Measurement main unit, C...Measurement control unit, R...
Recording section, B...excitation section, L...measuring load section, E...
...Support part, M...Magnet, 1...Measurement main unit, 3, 4...Moving table, 5...Motor, 6...Coil, 7...Iron core, 8...Lever, 9...Load plate, 10...Load cell, 11...Fixed frame, 12
... Permanent magnet, 13 ... Leaf spring, 17 ... Cartridge, 18 ... Lever, 19 ... Coil, 20
...Contact needle.

Claims (1)

[Claims] 1. A contact needle whose tip contacts the sample surface, an excitation mechanism that excites the contact needle, a load mechanism that brings the contact needle into contact with the sample surface with a predetermined load, and a load mechanism that causes the contact needle to vibrate. load detection means for measuring the load exerted on the sample; a measurement control section for feedback-controlling the load mechanism according to the output of the load detection means; and a vibration detection means for detecting the magnitude of vibration of the contact needle against the sample during vibration. What is claimed is: 1. A surface property measuring device, comprising: means for measuring mechanical properties such as a friction coefficient, adhesion force, hardness, etc. of a sample surface based on a load applied to the sample and an output from the vibration detection means.