Device for synchronously measuring thickness and elastic modulus of thin film

Abstract

The utility model provides a device for synchronously measuring the thickness and the elastic modulus of a film. The device comprises a base, a bearing table and a measuring mechanism, wherein the bearing table and the measuring mechanism are arranged on the base; the measuring mechanism comprises supporting shafts which are located on the two sides of the bearing table and are vertically fixed to the base. The limiting bearing is vertically arranged right above the bearing table and is fixedly connected with the supporting shaft through a cross beam; the measuring rod penetrates through the limiting bearing in the vertical direction and can abut against the upper end face of the bearing table by means of self weight; and a displacement sensor is arranged right above each measuring rod. According to the utility model, when the thickness of the film is measured, the thickness of the film is solved based on Hooke's law by using the internal stress-strain relation in the elastic deformation range of a material line according to the measured deformation, loading force and film thickness data, and the film deformation error caused by a mechanical measurement mode is compensated to a final film thickness measurement result. And finally measured thickness and elasticity modulus results are more accurate.

Description

TECHNICAL FIELD

[0001] The utility model relates to thin film measurement technical field, concretely relates to a device of synchronous measurement thin film thickness and elastic modulus. BACKGROUND

[0002] Thin film technology plays an increasingly important role in various high-tech fields. The research and application of various thin films are increasingly widespread in many departments of modern science and technology. For thin films, film thickness and elastic modulus are important parameters that determine the mechanical properties, electromagnetic properties, photoelectric properties, etc. of the thin films to a certain extent. Therefore, it is very urgent and important to accurately measure the thickness and elastic modulus of the thin films.

[0003] The current thin film thickness testing methods mainly include optical type, electronic type, radiation type and mechanical type, among which the mechanical thin film thickness gauge is popularized due to its simple structure, wide application range and wide measurement range. The principle of the mechanical thin film thickness gauge is to detect the thickness of the film through mechanical induction. Usually, a measurement head is placed above the thin film, and the displacement or pressure change generated after the measurement head contacts the thin film is used to measure the thickness of the thin film. However, when using the mechanical thin film thickness gauge to measure the film thickness, the measurement head will compress the measured thin film under its own weight when it contacts the thin film, causing local deformation of the measured thin film. The local deformation of the test surface causes the thickness measurement result to be seriously inaccurate, resulting in measurement errors. The heavier the weight of the measurement rod, the greater the error.

[0004] The utility model CN204405045U proposes a mechanical film thickness measuring device. When using the device to measure, the measurement head is pressed on the sample, which causes the sample to deform. At this time, the absolute value of the difference between the final position and the initial position of the measurement rod cannot be regarded as the thickness of the sample. In fact, this value is smaller than the actual film thickness. Similarly, the utility model patent CN117824560A proposes a thin film thickness measuring device that can adjust the position of the probe. The device uses a mechanical film thickness measuring method for measurement, but it does not consider that the deformation of the film caused by pressing the probe on the film affects the accuracy of the final measurement result. UTILITY MODEL CONTENTS

[0005] The utility model aims to provide a device for synchronously measuring the thickness and elastic modulus of a thin film to solve the above-mentioned problems of the prior art.

[0006] To achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

[0007] The utility model provides a device for synchronously measuring film thickness and elastic modulus, which comprises a base, a bearing table arranged on the base and a measuring mechanism; the measuring mechanism comprises support shafts fixed vertically on the base on both sides of the bearing table, at least one limiting bearing arranged vertically above the bearing table and fixedly connected with the support shafts through a cross beam, and measuring rods passing through the limiting bearing in the vertical direction and capable of abutting against the upper end surface of the bearing table by gravity; a displacement sensor is further arranged above each measuring rod.

[0008] Further, the bearing table can also be a pressure sensor.

[0009] Further, the measuring rods can be increased in mass by configuring mass rings, which are adsorbed on the base and capable of being directly sleeved on the top of the measuring rods to increase the loading force; when the number of the measuring rods is two or more, the masses of the measuring rod bodies are different from each other.

[0010] Further, the range of the loading force is not greater than the maximum stress at which the film to be measured remains completely elastically deformed.

[0011] According to the above technical solution, the device for synchronously measuring film thickness and elastic modulus can compensate the film deformation error caused by mechanical measurement to the final film thickness measurement result while measuring the film thickness, based on the deformation amount, the loading force and the film thickness data obtained by measurement, and the stress-strain relationship within the linear elastic deformation range of the material based on Hooke's law, so that the thickness and elastic modulus results of the final measurement are more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 FIG. 1 is a structural schematic view of a film thickness measuring device according to an embodiment of the utility model;

[0013] Figure 2 FIG. 2 is a structural schematic view of a film thickness measuring device according to another embodiment of the utility model;

[0014] Figure 3 FIG. 3 is a structural schematic view of a film thickness measuring device according to still another embodiment of the utility model;

[0015] In the drawings: 1, base; 2, bearing table; 3, measuring mechanism; 31, support shaft; 32, cross beam; 33, limiting bearing; 34, measuring rod; 35, displacement sensor; 36, mass ring; 37, elastic pressing block; 38, sensor module; 39, hand screw rod. DETAILED DESCRIPTION

[0016] The preferred embodiment of the utility model will be described in detail below with reference to the drawings.

[0017] Embodiment one:

[0018] As Figure 1 The device for synchronously measuring the thickness and elastic modulus of a film comprises a base 1, a bearing table 2 arranged on the base, and a measuring mechanism 3; the measuring mechanism 3 comprises support shafts 31 fixed vertically on the base 1 on both sides of the bearing table 2, a limiting bearing 33 arranged vertically above the bearing table 2 and fixedly connected with the support shafts 31 through a cross beam 32, and a measuring rod 34 capable of abutting against the upper end surface of the bearing table 2 in the vertical direction by gravity; a displacement sensor 35 is further arranged above the measuring rod 34; in specific operation, the measuring rod 35 can increase the mass by configuring a mass ring 36.

[0019] In specific operation, the mass ring 36 is adsorbed on the base, and when in use, the mass ring 36 can be directly sleeved on the top of the measuring rod to increase the loading force; the range of the loading force is not greater than the maximum stress at which the film to be measured is kept in complete elastic deformation.

[0020] The device for synchronously measuring the thickness and elastic modulus of a film measures the thickness and elastic modulus of a film and comprises the following steps:

[0021] S1, in the initial state, the measuring rod abuts against the upper end surface of the bearing table by gravity;

[0022] S2, the measuring rod is pulled upward to displace upward, and the film to be measured is placed flat on the bearing table;

[0023] S3, the measuring rod is dropped back, the measuring rod is lightly pressed on the film to be measured by gravity, the displacement of the measuring rod is recorded by the displacement sensor, and the loading force on the film to be measured is recorded;

[0024] S4, the mass of the measuring rod is increased by the mass ring, the displacement of the measuring rod is recorded by the displacement sensor again, and the loading force on the film to be measured is recorded;

[0025] S5, the measuring rod is pulled upward to move upward, and the film is taken off from the bearing table;

[0026] S6, the thickness of the film to be measured is calculated according to the parameters obtained in steps S3 and S4;

[0027] Specifically, the specific calculation process of the thickness of the film to be measured comprises:

[0028] Based on the parameters obtained in steps S3 and S4, the following can be obtained according to Hooke's law:

[0029] h1=h0-KF1 (1)

[0030] h2=h0-KF2 (2)

[0031] F1 = m1g (3)

[0032] F2 = (m1 + m2) g (4)

[0033] Simultaneous equations (1) to (4) can be obtained:

[0034]

[0035] In equations (1) to (5): h0 represents the thickness of the measured film; h1 represents the displacement of the measuring rod measured in step S3; F1 represents the loading force measured in step S3; m1 represents the mass of the measuring rod; h2 represents the displacement of the measuring rod measured in step S4; F2 represents the loading force measured in step S4; m2 represents the mass of the ring; g represents the acceleration of gravity; and K represents the elastic coefficient.

[0036] The specific calculation process of the measured elastic modulus of the film includes:

[0037] Within the online elastic deformation, the relationship between stress and strain is represented by the following equation (6):

[0038] σ = E · ε (6)

[0039] The stress on the measured film and the stress on the measured film are represented by the following equations (7) and (8):

[0040]

[0041] Simultaneous equations (6) to (8) can be obtained:

[0042]

[0043] In equations (7) and (9): σ represents the stress on the measured film; E represents the elastic modulus of the measured film; ε represents the stress on the measured film; A represents the cross-sectional area of the loading head, i.e., the measuring rod; F represents the loading force; h represents the displacement of the measuring rod after the loading force F; and h0 represents the calculated film thickness.

[0044] Example Two:

[0045] As Figure 2The device for simultaneously measuring the thickness and elastic modulus of a thin film includes a base 1, a support platform 2 mounted on the base, and a measuring mechanism 3. The measuring mechanism 3 includes support shafts 31 vertically fixed to the base on both sides of the support platform 2, two limiting bearings 33 vertically positioned above the support platform 2 and fixedly connected to the support shafts 31 by a crossbeam 32, and two measuring rods 34 that pass through the limiting bearings 33 vertically and can contact the upper surface of the support platform 2 by their own weight. The measuring rods 34 have different masses, and a displacement sensor 35 is also provided above each measuring rod 34. In specific operation, the mass of the measuring rods 34 can be increased by configuring a mass ring 36.

[0046] In this preferred embodiment, the method for measuring the film thickness and elastic modulus using the aforementioned device is similar to that in Embodiment 1.

[0047] Example 3:

[0048] like Figure 3 The device for simultaneously measuring film thickness and elastic modulus includes a base 1, a support platform 2 mounted on the base 1, and a measuring mechanism. In this embodiment, the measuring mechanism uses a hand-tightening screw in conjunction with a pressure sensor to control the loading force of the measuring rod 34, replacing the variable weight scheme using a mass ring 36 described in Embodiments 1 and 2. Specifically, in this embodiment, the measuring mechanism includes a support shaft 31 vertically mounted on the side of the support platform 2, an elastic pressure block 37 fixedly connected to the support shaft 31 at one end, a sensor module 38 and a measuring rod 34 sequentially mounted on the lower end face of the other end of the elastic pressure block 37, and a hand-tightening screw 39 threadedly connected to the base 1 through the elastic pressure block 37 from top to bottom. The sensor module includes a pressure sensor and a displacement sensor.

[0049] In this preferred embodiment, the method for measuring the film thickness and elastic modulus using the aforementioned apparatus specifically includes the following steps:

[0050] Tighten the hand screw until the pressure sensor displays a loading force of 0.01N. At this point, the lower end of the measuring rod is considered to be in contact with the upper surface of the support platform.

[0051] By turning the hand screw, the measuring rod is lifted and moved upward, so that the film to be tested is placed flat on the support platform;

[0052] Tighten the hand screw back to the measuring rod, allowing the measuring rod to press lightly onto the film to be tested. Record the displacement of the measuring rod as h1 using the displacement sensor, and record the pressure value as F1 using the pressure sensor.

[0053] Continue to screw the hand screw rod, slightly increase the loading force, record the displacement h2 of the measuring rod again through the displacement sensor, and record the pressure value F2 at this time through the pressure sensor;

[0054] The screw hand screw rod pulls the measuring rod to move upward, and the measured film is taken off from the bearing table;

[0055] The remaining data calculation processing steps are the same as those in Embodiment One and Embodiment Two.

[0056] The device for measuring film thickness, according to the deformation, the loading force and the film thickness data obtained through measurement, solves the film thickness based on Hooke's law and the stress-strain relationship within the linear elastic deformation range of the material, compensates the film deformation error caused by the mechanical measurement mode into the final film thickness measurement result, and makes the final measurement result more accurate.

[0057] The above-described embodiments are merely preferred embodiments of the utility model, and do not limit the scope of the utility model. Without departing from the design spirit of the utility model, various modifications and improvements to the technical solutions of the utility model made by those skilled in the art shall fall within the protection scope defined by the claims of the utility model.

Claims

1. An apparatus for simultaneously measuring the thickness and elastic modulus of a thin film, characterized by, The measuring device comprises a base, a bearing table arranged on the base, and a measuring mechanism; The measuring mechanism comprises support shafts fixed vertically on the base on both sides of the bearing table, at least one limiting bearing arranged vertically above the bearing table and fixedly connected with the support shafts through a cross beam, and measuring rods passing through the limiting bearing in the vertical direction and capable of abutting against the upper end surface of the bearing table by gravity; A displacement sensor is further arranged above each measuring rod.

2. The apparatus for simultaneously measuring the thickness and elastic modulus of a thin film according to claim 1, wherein The bearing table can also be a pressure sensor.

3. The apparatus for simultaneously measuring the thickness and elastic modulus of a thin film according to claim 1, wherein The measuring rods can be increased in mass by configuring a mass ring, which is adsorbed on the base and capable of being directly sleeved on the top of the measuring rod to increase the loading force; when the number of the measuring rods is two or more, the masses of the measuring rods are different from each other.

4. The apparatus for simultaneously measuring the thickness and elastic modulus of a thin film according to claim 3, wherein The range of the loading force is not greater than the maximum stress at which the measured film remains completely elastically deformed.

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