KR102402386B1 - Method, apparatus and the system for detecting thickness of an object - Google Patents

Abstract

A method, apparatus, and system for determining thickness are disclosed. The thickness determination system includes: a light source for irradiating light of a wavelength that matches the light absorption characteristics of the object to the object; a sensor disposed to face the light source and generating an image by photographing an object irradiated with light from the light source; and a thickness determination device configured to detect the thickness of the object by using the luminance of the generated image.

Description

Thickness determination method, apparatus and system {Method, apparatus and the system for detecting thickness of an object}

The present invention relates to a thickness determination method, apparatus, and system capable of detecting the thickness of an object in consideration of light absorption characteristics of the object.

In general, in a semiconductor process, a dielectric film, a semiconductor film, or a metal film is formed on a semiconductor substrate such as a semiconductor substrate or glass. As a representative method of forming such a film, a physical vapor deposition (PVD) method such as vacuum evaporation or sputtering, or a chemical vapor deposition method (CVD) using a raw material called a precursor is widely applied.

In particular, these films have various factors in determining the film forming process or quality, but in recent years, in order to increase the degree of integration of semiconductor devices, there is a trend to thin and multi-layered films formed on the substrate. Therefore, the specific gravity for controlling the film thickness has increased.

As a method for measuring the thickness of a film commonly used, there are a mechanical method using a probe, a method using a microscope, and the like.

The mechanical measuring method using a probe is an equipment developed to measure the thickness of a film with a step on the substrate surface. a way to measure However, in this method, the thickness of the metal film as well as the organic film can be easily obtained because the probe is in direct contact with the sample, but there are the following problems.

First, the contact with the probe causes destruction and contamination of the sample, and the thickness measurement speed is slow, and there is a risk of measurement error depending on the subjectivity of the measurer. In addition, since only the thickness of the step can be obtained, it is not possible to measure the thickness of several layers at once, and there is an inconvenience of having to form the step in advance at a place to be measured.

The measurement method using a microscope includes a method of visually measuring using a general optical microscope, and a method of measuring the thickness by obtaining an image at ultra-high magnification using an electron microscope. This method is widely used because the cross section of the sample can be checked with the naked eye, but it has the following problems.

In order to measure the thickness, since the sample must be cut, more time is required compared to the above-described mechanical measuring method, and processing technology for measuring the sample is required. In particular, since this method measures the cross section after forming the film, there is a disadvantage in that the thickness of the film cannot be measured in real time.

An object of the present invention is to provide a thickness determination system and method capable of detecting the thickness of an object in a simple manner without damaging the object.

Another object of the present invention is to provide a thickness determination method, apparatus, and system capable of accurately detecting the thickness of an object in consideration of light absorption characteristics of the object.

According to a first aspect, a thickness determination apparatus and system capable of accurately detecting a thickness of an object in consideration of a light absorption characteristic of the object are provided.

According to a first embodiment, there is provided a light source for irradiating light having a wavelength that matches the light absorption characteristics of the object to the object; a sensor disposed to face the light source and generating an image by photographing an object irradiated with light from the light source; and a thickness determination device configured to detect the thickness of the object by using the luminance of the generated image may be provided.

The thickness determination apparatus may calculate an average luminance of the image and detect the thickness of the object using the calculated average luminance.

The absorbance of the object is calculated using the average luminance and the luminance of the light irradiated to the object, and the thickness of the object can be detected using the calculated absorbance and the extinction coefficient and concentration set in response to the irradiated light have.

When a partial region of the object is photographed by the sensor, the thickness determination apparatus may control the object to be transported by a specified distance.

According to a second embodiment, there is provided a camera, comprising: a sensor for generating an image by photographing an object irradiated with light having a wavelength suitable for absorption characteristics of the object; and a thickness determination module for detecting the thickness of the object by using the luminance of the generated image, wherein the camera may be provided with a camera, characterized in that it is arranged to face the illumination.

The thickness determination module, after detecting the color of the object using an image of the object to which the light is not irradiated, is a light source so that light matching the light absorption characteristics according to the color of the object is irradiated to the object can be output as

According to a third embodiment, there is provided a sensor comprising: a sensing unit configured to acquire an image obtained by photographing an object irradiated with light having a wavelength suitable for absorption characteristics of the object; and a thickness detector configured to detect the thickness of the object by using the luminance of the generated image.

According to a second aspect, there is provided a method capable of accurately detecting a thickness of an object in consideration of a light absorption characteristic of the object.

According to the first embodiment, (a) acquiring an image of an object irradiated with light of a wavelength suitable for the absorption characteristics of the object from a sensor disposed to face the light source; and (b) detecting the thickness of the object by using the luminance of the generated image may be provided.

The step (b) may include calculating the absorbance of the object using the luminance and the luminance of the light irradiated to the object; and detecting the thickness of the object using the calculated absorbance and an extinction coefficient and concentration set in response to the irradiated light.

The sensor performs a line scan of a partial area of the object, but when the partial area is photographed by the sensor, the object is transferred by a specified distance, and then steps (a) and (b) are repeated can do.

According to a second embodiment, there is provided a method for determining a thickness of an object in a camera, the method comprising: generating a first image by photographing the object; determining a color of the object by analyzing the first image; controlling the light of a wavelength matching the light absorption characteristic according to the color of the determined object to be irradiated to the object; generating a second image by photographing the object irradiated with light having a wavelength matching the absorption characteristics; and calculating an average luminance from the second image and detecting a thickness of the object using the calculated average luminance.

By providing the method, apparatus and system for determining thickness of the present invention, it is possible to detect the thickness of an object in a simple manner without damaging the object.

In addition, the present invention can accurately detect the thickness of the object in consideration of the light absorption characteristics of the object.

1 is a diagram schematically showing the configuration of a thickness determination system according to a first embodiment;
2 is a view for explaining a method of determining the thickness of an object according to the first embodiment.
Fig. 3 is a block diagram schematically showing the internal configuration of the thickness determination device according to the first embodiment;
4 is a flowchart illustrating a method for the thickness determination system according to the first embodiment to determine the thickness of the object in consideration of the light absorption characteristics of the object.
5 is a graph showing a result of determining the thickness of an object according to the prior art and the first embodiment;
6 is a block diagram schematically illustrating an internal configuration of a camera capable of determining a thickness of an object in consideration of a light absorption characteristic of the object according to the second embodiment;
7 is a flowchart illustrating a method for a camera to determine a thickness of an object in consideration of a light absorption characteristic of the object according to the second embodiment;

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the present invention, if it is determined that a detailed description of a related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram schematically illustrating the configuration of a thickness determination system according to a first embodiment, and FIG. 2 is a diagram illustrating a method of determining the thickness of an object according to the first embodiment.

Referring to FIG. 1 , the thickness determination system according to the first embodiment includes a light source 110 , a sensor 115 , and a thickness determination device 120 .

The light source 110 is a means for irradiating the light source. For example, the light source 110 may be an LED.

In addition, the light source 110 may selectively irradiate blue light and white light. For example, the light source 110 may selectively irradiate blue light or white light according to a light absorption characteristic of an object under the control of the thickness determination device 120 or a system manager (not shown).

For example, when the object is a yellowish PI film, the light source 110 may irradiate blue light according to the control of the thickness determination device 120 or the system manager, and otherwise may irradiate white light .

The sensor 115 is a means for measuring the intensity of light transmitted through the object.

Since the sensor 115 needs to measure the intensity of light transmitted through the object, it is disposed at a position directly facing the light source 110 .

For example, when the light source 110 is irradiated to the object, a difference in transmittance according to the wavelength of the irradiated light occurs, so that a difference in contrast according to the amount of light occurs on the sensor 115 .

For example, the sensor 115 may be a camera, and more specifically, a line scan camera.

The thickness determination device 120 analyzes the light intensity sensed by the sensor 115 to determine the thickness of the object.

According to Lambert-Beer's law, the thickness of the object can be detected using the absorbance of the object.

The Lambert-Bier's Law is expressed as Equation 1.

는 입사광의 광도(세기)를 나타내고,

는 출사광의 광도(세기)를 나타내며,

는 흡광 계수를 나타내고,

는 농도를 나타내며,

는 두께(즉, 대상물의 두께)를 나타낸다.here,

represents the luminous intensity (intensity) of the incident light,

represents the luminous intensity (intensity) of the emitted light,

represents the extinction coefficient,

represents the concentration,

denotes the thickness (ie, the thickness of the object).

According to Lambert-Bier's law, it can be seen that the thickness of the object can be efficiently detected when light having the correct extinction coefficient of the object is output to the object.

For example, if the object is a yellow PI film, the yellow PI film does not absorb or reflects or transmits all of white light, red light, and green light, while absorbing blue light. That is, when the object is a yellow PI film, it can be seen that blue light is suitable for determining the thickness of the object.

The object may be partially different in thickness. Accordingly, a difference in contrast may occur partially in the image sensed by the sensor 115 .

In other words, the thickness determination apparatus 120 may calculate an average luminance of an image captured by the sensor 115 , and derive absorbance of the object by using the calculated average luminance. Then, the thickness determination apparatus 120 may calculate the thickness of the object by dividing the derived absorbance by the extinction coefficient and the concentration.

Since the thickness determination apparatus 120 can detect the thickness of each part of the object, as a result, the non-uniformity of the object can also be detected.

Depending on the implementation method, the sensor 115 may scan the entire object line by line. However, when the entire object is scanned in line units as described above, a considerable amount of noise may be generated when determining the thickness. For this reason, the sensor 115 may detect the thickness of the object by scanning only a designated partial area.

In FIG. 1 , it is assumed that the thickness determining device 120 is provided as a configuration separate from the sensor 115 , but the thickness determining device 120 may be included as one configuration of the camera depending on the implementation method.

Accordingly, an average luminance may be calculated using an image captured by the camera scanning a designated partial area of the object in line units, and the thickness of the object may be detected using the calculated average luminance. That is, it is natural that the thickness determination device 120 may be included as a component of the camera.

3 is a block diagram schematically illustrating an internal configuration of the thickness determination apparatus according to the first embodiment. The thickness determination apparatus 120 according to the first embodiment is a device that does not include a sensor 115 , and is connected to the sensor 115 to obtain information (image taken of the object) sensed from the sensor 115 to obtain the object. thickness can be determined.

Referring to FIG. 3 , the thickness determination apparatus 120 according to the first embodiment includes a sensing unit 310 , a thickness detection unit 315 , a system management unit 320 , a memory 325 , and a processor 330 . do.

The sensing unit 310 acquires an image of the object from the sensor 115 . As already described above, the sensor 115 is positioned to face the light source 110 with the object interposed therebetween, and the light source 110 according to the light absorption characteristic of the object is irradiated onto the object, and the image is generated by photographing the object. may be output to the sensing unit 310 .

The thickness detection unit 315 analyzes the image input from the sensing unit 310 to calculate the average luminance, and then calculates the thickness of the object by using the calculated average luminance.

Since this is the same as that described above, the overlapping description will be omitted.

The system manager 320 functions to manage a system (not shown) for transferring the light source 110 , the sensor 115 , or an object.

In FIG. 3 , the system management unit 320 is illustrated as a component of the thickness determination apparatus 120 , but the system management unit 320 may be a separate device according to an implementation method.

The memory 325 functions to store various data and algorithms necessary to perform the method for determining the thickness of an object according to the first embodiment.

The processor 330 includes internal components (eg, the sensing unit 310 , the thickness detection unit 315 , the system management unit 320 , the memory 325 , etc.) of the thickness determination apparatus 120 according to the first embodiment. ) to control the

4 is a flowchart illustrating a method for the thickness determination system according to the first embodiment to determine the thickness of an object in consideration of the light absorption characteristics of the object, and FIG. It is a graph.

In step 410, the sensor 115 generates an image by photographing the object irradiated with the light source 110.

As already described above, the light source 110 is disposed at a position facing the sensor 115 with an object interposed therebetween (see FIG. 1 ).

In FIG. 4 , it is assumed that the light source 110 is preset according to the light absorption characteristic of the object.

For example, when the object is a yellow PI film, the light source 110 may be set to irradiate blue light. However, when the object is not a yellow PI film, the light source 110 is set to irradiate white light.

In operation 415 , the thickness determination apparatus 120 calculates an average luminance from the image captured by the sensor 115 .

In step 420 , the thickness determination apparatus 120 calculates the absorbance of the object using the calculated average luminance.

Next, in step 425 , the thickness determination apparatus 120 calculates the thickness of the object using the calculated absorbance, a preset extinction coefficient, and a concentration.

5 shows a graph-shaped result of the thickness of the object calculated by the thickness determination device 120 . Figure 5 (a) is the result of detecting the thickness of the object in consideration of the light absorption characteristics of the object according to the first embodiment, Figure 5 (b) is the detection of the thickness of the object using the conventional X-ray. the results are shown.

As shown in FIG. 5 , the graph of the result of detecting the thickness of the object in consideration of the light absorption characteristic of the object according to the first embodiment includes a narrow error range compared to the result using the conventional X-ray, but the degree of non-uniformity It can be seen that the characteristics appear the same.

The thickness determination system may determine the thickness of the object by scanning an area of the object line by line while transferring the object by a predetermined distance.

6 is a block diagram schematically illustrating an internal configuration of a camera capable of determining a thickness of an object in consideration of a light absorption characteristic of the object according to the second embodiment.

Referring to FIG. 6 , the camera according to the first embodiment is configured to include a sensor 615 and a thickness determination module 620 .

In this case, the camera may be disposed to face the light source 110 with the object interposed therebetween.

The sensor 615 is a means for generating an image by photographing an object.

The sensor 615 may output an image of the object to the thickness determination module 620 .

In addition, before determining the thickness of the first object, the sensor 615 generates a first image by photographing the object in a state in which light in consideration of the absorption characteristics of the object is not irradiated, and may be output to the thickness determination module 620. have. In this case, the first image may be used to determine the color of the object.

Also, the sensor 615 may output a second image obtained by photographing an object irradiated with light according to a light absorption characteristic of the object to the thickness determination module 620 .

The thickness determination module 620 serves to analyze the image of the object input through the sensor 615 to determine the thickness of the object.

For example, the thickness determination module 620 may calculate the average luminance in the image of the object and then calculate the absorbance of the object by using the average luminance. Since this is the same as that described above, the overlapping description will be omitted.

Also, before determining the thickness of the object, the thickness determination module 620 may determine the color of the object by using the first image to initialize the light source setting. For example, after calculating the average color of the first image, the thickness determination module 620 may determine the color of the object using the calculated average color. When the color of the object is determined, the thickness determination module 620 may control the light source 110 to emit light suitable for light absorption characteristics according to the color of the object.

For example, if the object is a yellow PI film, the thickness determination module 620 may control the light source 110 to irradiate blue light to match the absorption characteristics of the yellow PI film.

In addition to this, although not shown in FIG. 6 , the camera 600 may further include a memory and a processor. However, since this is a general configuration, a separate description thereof will be omitted.

In addition, the camera 600 may be connected to an external system to photograph a part of the object to determine the thickness, and then control the object to be transported a certain distance in order to photograph another part of the object.

7 is a flowchart illustrating a method for a camera to determine a thickness of an object in consideration of a light absorption characteristic of the object according to the second embodiment.

In step 710, the camera 600 creates a first image by photographing the object.

In step 715, the camera 600 analyzes the captured first image to determine the color of the object.

For example, the camera 600 may determine the color of the object after calculating the color average of the captured image.

Next, in step 720, the camera 600 controls the light source so that light is irradiated in consideration of absorption characteristics according to the determined color of the object. Accordingly, the light source may irradiate light suitable for absorption characteristics according to the color of the object.

In step 725 , the camera 600 generates a second image by photographing an object irradiated with light matching the light absorption characteristics according to the color of the object from the light source.

In operation 730 , the camera 600 calculates an average luminance from the image captured by the sensor 115 .

In operation 735, the camera 600 calculates the absorbance of the object using the calculated average luminance.

Next, in step 740, the camera 600 calculates the thickness of the object by using the calculated absorbance, the preset extinction coefficient, and the concentration.

Meanwhile, the method for detecting the thickness of a film according to an embodiment of the present invention may be implemented in the form of a program command that can be executed through various electronic information processing means and recorded in a storage medium. The storage medium may include program instructions, data files, data structures, etc. alone or in combination.

Examples of the program instruction include not only machine code such as generated by a compiler, but also a device for electronically processing information using an interpreter or the like, for example, a high-level language code that can be executed by a computer.

The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

Although the above has been described with reference to the preferred embodiment of the present invention, those of ordinary skill in the art may change the present invention in various ways within the scope without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that modifications and variations are possible.

110: light source
115: sensor
120: thickness determination device

Claims (12)

a light source for selectively irradiating any one of blue light and white light to the object according to the light absorption characteristic of the object;
a sensor disposed to face the light source and generating an image by photographing an object irradiated with light from the light source; and
And a thickness determination device for detecting the thickness of the object by using the luminance of the generated image,
The thickness determination device,
After detecting the color of the object using an image of the object to which light is not irradiated, a control signal is provided to the light source so that light matching the absorption characteristics according to the color of the object is irradiated to the object thickness judgment system.
According to claim 1,
The thickness determination device,
The thickness determination system, characterized in that calculating the average luminance of the image, and detecting the thickness of the object using the calculated average luminance.
3. The method of claim 2,
Calculating the absorbance of the object using the average luminance and the luminance of the light irradiated to the object, and detecting the thickness of the object using the calculated absorbance and an extinction coefficient and concentration set in response to the irradiated light Thickness judgment system characterized.
According to claim 1,
When a partial area of the object is photographed by the sensor, the thickness determination apparatus moves the object by a specified distance.
in the camera,
a sensor for generating an image by photographing an object irradiated with light having a wavelength suitable for absorption characteristics of the object; and
And a thickness determination module for detecting the thickness of the object by using the luminance of the generated image,
The thickness determination module controls the light source so that any one of blue light and white light is irradiated according to the light absorption characteristic of the object,
The thickness determination module detects the color of the object using an image obtained by photographing the object to which the light is not irradiated, and then transmits a control signal as a light source so that light matching the light absorption characteristics according to the color of the object is irradiated to the object. output, but
The camera is characterized in that it is arranged to face the light source in front.
delete delete (a) acquiring an image of an object in which any one of blue light and white light is selectively irradiated to the object from a sensor disposed to face the light source according to the absorption characteristics of the object; and
(b) detecting the thickness of the object using the luminance of the obtained image,
Before step (a),
After detecting the color of the object using an image obtained by photographing the object to which the light is not irradiated, a control signal is output as a light source so that light matching the absorption characteristics according to the color of the object is irradiated to the object Thickness determination method in consideration of the light absorption characteristics of the object, characterized in that.
9. The method of claim 8,
The step (b) is,
calculating the absorbance of the object using the luminance and the luminance of light irradiated to the object; and
and detecting the thickness of the object using the calculated absorbance and the extinction coefficient and concentration set in response to the irradiated light.
9. The method of claim 8,
The sensor, but taking a line scan of a partial area of the object,
When the partial area is photographed by the sensor, after the object is transferred by a specified distance, the steps (a) and (b) are repeatedly performed.
delete delete

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