KR102029824B1 - Multi channel optical profiler based on ellipsometry - Google Patents

Abstract

The present invention relates to a multi-channel optical profiler based on ellipsometry.

Description

Ellipsometer-based multi-channel optical measuring instrument {MULTI CHANNEL OPTICAL PROFILER BASED ON ELLIPSOMETRY}

The present invention relates to an ellipsometer-based multichannel optical meter.

Recently, with the miniaturization and high performance of semiconductors, displays, sunlight, and micro sensors, the importance of various types of multilayer thin film structures is increasing. In order to improve the performance of the multilayer thin film structure, researches on various thicknesses and patterns are being conducted, and multilayer thin film structures of more complicated structures are being studied.

Accordingly, in order to manufacture a stable multilayer thin film structure, a technique for analyzing, measuring, and inspecting a thin film structure has attracted much attention. However, in the industry, a thin film structure analysis technology capable of inspecting various measurement areas in more precise and real time is required, but the measurement technology developed so far does not meet this industrial demand.

On the other hand, the ellipsometer is a device for measuring the refractive index of the material and the thickness of the thin film according to the wavelength of the light by checking the change in polarization characteristics of the light. According to the ellipsometer, the structure can be analyzed especially for a thin film and a thin film having a multilayer structure. Of the ellipsometer, the spectroscopic ellipsometer is a device that can analyze the structure of the thin film more accurately by analyzing the information on the polarization state and the wavelength information, including a light source and a spectroscope of a wide wavelength band.

Conventional ellipsometers and spectroscopic ellipsometers include a phase delay device or a phase modulator for changing the degree of phase delay of light. Then, the phase delay degree is changed while rotating the phase delay unit or adjusting the phase modulator.

However, this conventional ellipsometer has a problem that a long measurement time is required because the phase delay must be changed while the phase delay device is rotated or the phase modulator is adjusted.

[Patent Document 1] Korean Patent Publication No. 10-2017-0055661, 2017. 05. 22.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a multi-channel optical meter based on an ellipsometer.

Specifically, the present invention includes a spatial phase delay element (SPR), not a phase delay device or a phase modulator, so that light including a plurality of phase delay information can be generated at one time, thereby significantly reducing measurement time. It is an object of the present invention to provide a multi-channel optical measuring instrument based on an ellipsometer.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood from the following description.

An optical meter according to an embodiment of the present invention for achieving the above object, an optical instrument including a plurality of probes, each of the plurality of probes, a reflection mirror; A sample stage into which light output from the reflective mirror is incident on a surface; And a light input unit spaced apart from the reflection mirror.

In an embodiment, the light output from the reflecting mirror incident on the surface of the sample stage is light reflected from the reflecting surface of the reflecting mirror.

In an embodiment, each of the plurality of probes is provided on a path through which the light output from the sample stage travels, and generates and outputs light including a plurality of phase delay information from the light output from the incident sample stage. It further comprises a spatial phase delay element (SPR).

In an embodiment, the phase delay value of the spatial phase delay element is changed in one direction.

In example embodiments, the spatial phase delay device may include a plurality of unit sections partitioned in one direction, and each unit section may have a constant phase delay value, and each unit section may include a phase delay value of a neighboring unit section. Have different phase delay values.

In example embodiments, each of the plurality of probes may further include a probe main body configured to receive the reflective mirror and the light input unit.

In one embodiment, the light input unit is provided on one side of the inner surface of the probe body and the reflective mirror is provided on the other side of the inner surface of the probe body.

In an embodiment, the optical meter comprises: a light source; And a plurality of light input optical fibers, each end of which is connected to each of the plurality of light input units, the plurality of light input optical fibers transferring light generated by the light source to the light input unit.

In an embodiment, each of the plurality of probes further includes a light output unit to which light output from the sample stage is incident.

In an embodiment, the optical meter may include: a detector configured to sequentially detect lights output from the plurality of light output units; A controller configured to generate an image of an object to be measured from the light detected by the detector; And a plurality of light output optical fibers, one end of which is connected to each of the plurality of light output parts, and the other end of which is spaced apart from a neighboring other end by a predetermined distance, and sequentially outputs the light output from the plurality of light output parts. The optical output device further comprises a plurality of light output optical fibers to the detection unit.

In an embodiment, the detector may further include: a spectrometer configured to spectroscopically input light into the spectroscope as a spectrometer sequentially receiving light output from the plurality of light output units; A detection sensor detecting light output from the spectroscope; And a moving member provided on the surface of the spectroscope and the detection sensor and movable in a predetermined direction under the control of the controller.

In an embodiment, the controller controls the moving member to move the moving member in a predetermined direction so that the light output from the plurality of light output units is sequentially input to the spectrometer.

A probe according to another embodiment of the present invention is a probe for detecting light reflected from an object to be measured, the probe comprising: a reflection mirror; A sample stage on which the object to be measured is placed on a surface, and the light output from the reflection mirror is incident on the surface; And a light input unit spaced apart from the reflection mirror.

In an embodiment, the light output from the reflecting mirror incident on the surface of the sample stage is light reflected from the reflecting surface of the reflecting mirror.

Specific details for achieving the above objects will be apparent with reference to the embodiments to be described below in detail with the accompanying drawings.

However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and the embodiments are provided so that the disclosure of the present invention is complete and the general knowledge in the technical field to which the present invention belongs. It is provided to fully inform the person having the scope of the invention (hereinafter, "the ordinary engineer").

The present invention has the following excellent effects.

First, the optical measuring device according to an embodiment of the present invention includes a spatial phase delay element, not a phase delay device or a phase modulator, so that light including a plurality of phase delay information can be generated at one time, thereby measuring measurement time. There is a significant shortening effect.

In addition, the optical measuring device according to an embodiment of the present invention has an effect of easily photographing a plurality of objects or a plurality of parts of the object including a plurality of probes.

In addition, the optical measuring device according to an embodiment of the present invention includes a detector that is movable in a predetermined direction, so that the plurality of objects or large objects can be easily photographed with minimal movement without requiring the entire system to move. It has one effect.

In addition, the optical measuring device according to an embodiment of the present invention includes a reflecting mirror that reflects the incident light and enters the object to be measured, thereby allowing the light source and the detector to be located on the east side, thereby reducing the volume of the entire system. It is effective.

The effects of the present invention are not limited to the above-described effects, and the tentative effects expected by the technical features of the present invention will be clearly understood from the following description.

1 is a diagram illustrating an ellipsometer-based multi-channel optical meter according to an embodiment of the present invention.
2 illustrates a probe according to an embodiment of the present invention.
3 is a diagram illustrating a spatial phase delay device according to an embodiment of the present invention.
4 is a diagram illustrating a measuring principle of an ellipsometer-based multichannel optical measuring instrument according to an embodiment of the present invention.

The present invention may be modified in various ways and may have various embodiments. Specific embodiments are illustrated in the drawings and described in detail.

Various features of the invention disclosed in the claims may be better understood in view of the drawings and detailed description. The apparatus, methods, recipes, and various embodiments disclosed herein are provided for purposes of illustration. The disclosed structural and functional features are intended to enable those skilled in the art to specifically practice the various embodiments, and are not intended to limit the scope of the invention. The terms and phrases disclosed are intended to explain various features of the disclosed invention in an easy-to-understand manner, and are not intended to limit the scope of the invention.

In the following description of the present invention, if it is determined that the detailed description of the related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, with reference to the accompanying drawings, it will be described in detail with respect to the multi-channel optical meter based on the ellipsometer according to the present invention.

1 is a view showing an ellipsometer-based multi-channel optical meter according to an embodiment of the present invention, Figure 2 is a view showing a probe according to an embodiment of the present invention, Figure 3 is a view of the present invention 4 is a diagram illustrating a spatial phase delay device according to an embodiment, and FIG. 4 is a diagram illustrating a measurement principle of an ellipsometer-based multichannel optical meter according to an embodiment of the present invention.

1 to 4, the optical meter 1 according to the present embodiment includes a light source 10, a light input optical fiber 20, a probe 30, a light output optical fiber 40, a detector 50, and It includes a control unit (not shown).

The light source 10 generates the light necessary for the optical measuring device 1 according to the present embodiment to image the object under test on the surface of the sample stage 34. That is, the light source 10 generates light to be incident on the object to be measured. The light generated by the light source 10 is white light having a wide wavelength band.

Light generated by the light source 10 is transmitted to the probe 30 through the light input optical fiber 20.

The plurality of light input optical fibers 20 are provided. One optical input optical fiber 20 connects one probe 30 of the plurality of probes 30 with the light source 10. More specifically, each light input optical fiber 20 is one end is connected to the light input unit 31 of the probe 30 to be described later, and transmits the light generated by the light source 10 to each probe 30.

A plurality of probes 30 are provided. Each probe 30 includes an optical input unit 31, a reflecting mirror 32, a polarizer 33, a sample stage 34, a spatial phase delay element 35, an optical output unit 36, and a probe body unit 37. It includes.

The light input unit 31, the reflecting mirror 32, the polarizer 33, the spatial phase delay element 35, and the light output unit 36 are accommodated in the probe main body 37, and the sample table 34 is the probe main body. It is provided outside the part 37.

The light input unit 31 is provided on one side of the inner surface of the probe main body 37. The light generated by the light source 31 is input into the probe main body 37 through the light input unit 31. More specifically, the light generated by the light source 10 is input to the light input unit 31 via the light input optical fiber 20, and the light output from the light input unit 31 is reflected inside the probe body 37. It enters into the mirror 32.

The reflective mirror 32 is provided on the other side of the inner surface of the probe main body 37 so as to be spaced apart from the light input unit 31. More specifically, the reflection mirror 32 is provided on the other side of the inner surface of the probe main body 37, but is provided at a position where the light output from the light input unit 31 can be reflected and output to the polarizer 33. . The light input unit 31, the reflecting mirror 32 and the polarizer 33 are thus mutually allowed to allow light output from the light input unit 31 to enter the polarizer 33 via the reflecting mirror 32. It is arranged to satisfy the positional relationship.

The reflecting mirror 32 reflects the light output from the light input unit 31 and enters the polarizer 33. The reflecting mirror 32 includes a reflecting surface that reflects the incident light and outputs the light to the polarizer 33.

The polarizer 33 converts the light reflected from the reflecting mirror 32 into polarized light. Light polarized by the polarizer 33 is incident on the sample stage 34. The angle of incidence of the light incident on the sample stage 34 depends on the specific positional relationship between the light input unit 31 and the reflecting mirror 32. The object to be measured is placed on the surface of the sample table 34, and the light incident on the surface of the sample table 34 is reflected by the object to be measured. Light reflected from the object to be measured and output from the sample stage 34 is incident on the spatial phase delay element 35. On the other hand, the plurality of sample stages 34 included in each probe 30 may be a plurality, or may be one sample stage 34 formed integrally. Therefore, a plurality of objects to be measured may be photographed, and various portions of one object to be measured may be photographed respectively.

The space phase delay element 35 is provided on a path through which the light output from the sample stage 34 travels. The spatial phase delay element 35 generates light including a plurality of phase delay information from the light output from the incident sample stage 34. It demonstrates concretely below.

The spatial phase delay element 35 is an element whose phase delay value changes in one direction (horizontal direction). Specifically, the spatial phase delay element 35 is a device in which the liquid crystals are arranged at a predetermined angle in one direction and thus the refractive index is changed in one direction. Since the liquid crystals are arranged at a predetermined angle along one direction, the refractive index of the spatial phase delay element 35 is also periodically changed along one direction. That is, the phase delay caused by the change of the periodic refractive index is generated in the light incident on the spatial phase delay element 35 and output from the spatial phase delay element 35.

As described above, the spatial phase delay element 35 is arranged in such a way that the liquid crystals are changed at an angle in one direction, so that the spatial phase delay element 35 has a plurality of unit lengths, which are partitioned along one direction. It can be understood as a device including unit intervals. And since each unit section is comprised from the liquid crystal arrange | positioned at a specific angle, each unit section has a fixed phase delay value. On the other hand, the phase delay value of each unit section is different from the phase delay value of the neighboring unit section. In this case, the difference between the phase delay value of each unit section and the phase delay value of the neighboring unit section is not specified, which may be set differently according to an embodiment.

The light output from the sample stage 34 and incident on the spatial phase delay element 35 is incident to the plurality of unit sections included in the spatial phase delay element 35. That is, since the light output from the sample stage 34 and incident on the spatial phase delay element 35 is incident on various unit sections, the phase delay is varied by various values. As described above, since the phase delay value of each unit section is different from the phase delay value of the neighboring unit section, the phase delay is changed to various values. As a result, the light output from the spatial phase delay element 35 becomes light having various phase delay values, that is, a plurality of phase delay information.

As described above, since the conventional ellipsometer uses a phase delay device or a phase modulator to change the phase delay degree of light, a long measurement time is accompanied.

On the other hand, the optical meter 1 according to the present embodiment includes a spatial phase delay element (SPR), not a phase delay device or a phase modulator, so that light including a plurality of phase delay information can be generated at one time. It was. As a result, according to the optical measuring device 1 according to the present embodiment, the measurement time can be significantly shortened as compared with the conventional ellipsometer.

The light output unit 36 includes a detector A and is provided at one side of an inner surface of the probe main body 37 provided with the light input unit 31, and is provided below the light input unit 31. The plurality of polarizations output from the spatial phase delay element 35 are output from the light output unit 36, and are input to the detection unit 50 via the light output optical fiber 40.

A plurality of light output optical fibers 40 are provided. One optical output optical fiber 40 connects one probe 30 of the plurality of probes 30 to the detector 50. More specifically, each light output optical fiber 40 is one end is connected to the light output unit 36 of the probe 30 described above, the other end is provided around the detection unit 50, the output from the light output unit 36 The transferred light to the detection unit 50.

On the other hand, the other end of each light output optical fiber 40 is arranged so as to be spaced apart from the other end of the adjacent light output optical fiber 40 by a predetermined distance. The reason why the other ends are spaced apart from each other is to allow the light output from the plurality of light output units 36 to be sequentially input to the detector 50 without overlapping each other. The separation distance between the other ends is determined according to the minimum moving distance of the moving member (not shown) which will be described later.

As described above, the detector 50 sequentially detects light output from the plurality of light output units 36. The detector 50 includes a spectroscope 51, a detection sensor 52, and a moving member (not shown).

A diffraction grating 51 spectra the input light. It demonstrates more concretely.

The light incident on the spectroscope 51 is light including a plurality of phase delay information generated by the above-described spatial phase delay element 35. As described above, since the spatial phase delay element 35 is an element in which the phase delay value changes in one direction (horizontal direction), phase delay information included in the light incident on the spectroscope 51 is also one direction. Information that depends on the (horizontal direction).

In addition, the spectroscope 51 speculates the input light in the vertical direction, so that light can be easily detected for each wavelength in the detection sensor 52. That is, the spectroscope 51 spectra information on wavelengths of light in the vertical axis direction, so that light can be easily detected for each wavelength in the detection sensor 52.

The detection sensor 52 is a sensor which detects light spectroscopically by the spectroscope 51. The sensing value of the detection sensor 52 is input to the controller.

On the other hand, the spectroscope 51 and the detection sensor 52 are provided on the surface of the moving member. The moving member is provided to be movable in a predetermined direction. The moving member moves in the same direction as the direction in which the other ends of the plurality of light output optical fibers 40 are listed. The moving member moves in a predetermined direction under the control of the controller so that the light output from the plurality of light output optical fibers 40 can be sequentially incident on the spectrometer 51.

The controller generates an image of the object to be measured from the sensing value of the detection sensor 52. As described above, the control unit controls the moving member so that the light output from the plurality of light output optical fibers 40 may be sequentially input to the spectroscope 51, thereby moving the moving member by a predetermined distance by a predetermined distance. Move to. The predetermined distance that the moving member moves, that is, the minimum moving distance of the moving member is equal to the separation distance between the other ends of the light output optical fibers 40 described above.

As described above, the optical measuring device 1 according to the embodiment of the present invention includes a detection unit 50 which is movable in a predetermined direction, so that a plurality of objects to be measured can be measured with minimal movement without the need for the entire system or the sample stage to move. It has the effect of making it easy to photograph water or large objects.

The above descriptions are merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention.

Therefore, the embodiments disclosed herein are not intended to limit the technical spirit of the present invention, but to describe, and the scope of the present invention is not limited by these embodiments.

The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be understood as being included in the scope of the present invention.

1: optical measuring instrument
10: light source 20: light input optical fiber
30: probe 40: optical output optical fiber
50: detector

Claims (10)

An optical instrument comprising a plurality of probes,
Each of the plurality of probes,
Reflective mirror;
A sample stage into which light output from the reflective mirror is incident on a surface;
An optical input unit spaced apart from the reflective mirror; And
A spatial phase delay element (SPR) provided on a path through which the light output from the sample stage travels, and generating and outputting light including a plurality of phase retardation information from the light output from the incident sample stage,
The light output from the reflection mirror incident on the surface of the sample stage is light reflected from the reflection surface of the reflection mirror by the light output from the light input unit,
The spatial phase delay element,
Comprising a plurality of unit intervals partitioned along one direction, each unit section has a constant phase delay value, each unit section has a phase delay value different from the phase delay value of the neighboring unit section,
Optical instrument.
delete delete delete The method of claim 1,
Each of the plurality of probes,
Further comprising a probe body for receiving the reflective mirror and the light input unit,
One side of the inner surface of the probe body portion is provided with the light input unit and the other side of the inner surface of the probe body portion is provided with the reflection mirror,
Optical instrument.
The method of claim 1,
The optical measuring device,
Light source; And
A plurality of light input optical fibers, each end is further connected to each of the plurality of light input units, further comprising the plurality of light input optical fibers for transmitting the light generated in the light source to the light input unit,
Optical instrument.
The method of claim 1,
Each of the plurality of probes,
Further comprising a light output unit to which the light output from the sample stage is incident,
The optical measuring device,
A detector for sequentially detecting lights output from the plurality of light output units;
A controller configured to generate an image of an object to be measured from the light detected by the detector; And
A plurality of optical output optical fibers, each end of which is connected to each of the plurality of optical outputs, the other end is arranged so as to be spaced apart from a neighboring other end by a predetermined distance, the light output from the plurality of optical outputs sequentially the detection unit Further comprising the plurality of light output optical fibers for transmitting to
Optical instrument.
The method of claim 7, wherein
The detection unit,
A spectroscope configured to sequentially input light output from the plurality of light output units, the spectroscope for spectroscopy of light input to the spectroscope;
A detection sensor detecting light output from the spectroscope; And
The spectroscope and the detection sensor is provided on the surface, comprising a moving member movable in a predetermined direction under the control of the controller,
Optical instrument.
The method of claim 8,
The control unit,
To move the moving member in a predetermined direction by controlling the moving member so that the light output from the plurality of light output units are sequentially input to the spectrometer,
Optical instrument.
delete

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