KR20220043475A - Optical System and Method for Measuring Optical information Using The Same - Google Patents

Abstract

The present invention relates to an optical system and an optical information measurement method using the same. According to an embodiment of the present invention, the optical system, which is an optical system detecting optical information of a sample including multi-layered substance film, comprises: a light source block disposed to irradiate light to the sample; a first detection block detecting a second harmonic generation (SHG) component of the reflected light reflected from the sample; and a second detection block detecting a photoluminescence component of the reflected light reflected from the sample.

Description

Optical system and method for measuring optical information using same

The present invention relates to a semiconductor system, and more particularly, to an optical system capable of measuring physical properties of a semiconductor device and a method for measuring optical information using the same.

A write recovery time (twr), a refresh characteristic, and a threshold voltage characteristic that determine the performance of a semiconductor device, particularly a memory device, may be determined by interfacial junction characteristics of materials constituting the memory device.

Accordingly, before packaging the memory device, it is necessary to accurately inspect various factors that determine the interfacial bonding characteristics at the wafer level.

SUMMARY Embodiments of the present invention provide an optical system capable of accurately inspecting properties of a material film and a method of measuring optical information using the same.

An optical system according to an embodiment of the present invention is an optical system for detecting optical information of a sample including a multi-layered material film, comprising: a light source block arranged to irradiate light to the sample; a first detection block for detecting a Second Harmonic Generation (SHG) component of the reflected light reflected from the sample; and a second detection block for detecting a photoluminescence component of reflected light reflected from the sample.

The light source block may include a chirping unit for compensating for a pulse width of the incident light output from the laser source; a beam expander for adjusting the size of the incident light provided from the laser source; a first mirror unit that receives the incident light, transmits incident light of a specific wavelength, and reflects light of other wavelengths; and a first polarizing unit polarizing and outputting the incident light provided by the first mirror unit.

The optical system of the present embodiment may further include an optical block for focusing the incident light provided from the light source block on the sample.

The optical block may include: a scanning unit configured to generate a two-dimensional image in an inspection position portion of the sample by moving the incident light along an x-axis and a y-axis; an alignment unit guiding the incident light output from the scan unit to an inspection position of the sample; and a light condensing unit configured to condense the incident light provided by the alignment unit to an inspection position of the sample.

The optical block may further include a filter unit configured to receive reflected light reflected from the sample, provide a wavelength less than the wavelength of the incident light to the first detection block, and transmit reflected light equal to or greater than the wavelength of the incident light.

The first detection block may include a second polarizer for polarizing the reflected light; an SHG filter unit selectively passing a wavelength corresponding to 1/2 of the wavelength of the incident light among the reflected light provided by the second polarizing unit; a first beam splitter receiving the reflected light filtered by the SHG filter unit and separating the reflected light; a first detector for detecting a characteristic of the sample through a change in the SHG component of a portion of the reflected light separated from the first beam splitter; and a second detector configured to detect a nonlinear characteristic of the sample by imaging the SHG component of the other portion of the reflected light separated from the first beam splitter.

The second detection block may include a second beam splitter that receives the reflected light and separates the photoluminescence of the reflected light; a third detector for detecting a change in photoluminescence of the partial reflected light separated by the second beam splitter; and an optical member that separates the remaining reflected light separated by the second beam splitter for each wavelength and time, and observes a change in photoluminescence according to the wavelength and time. The second detection block is configured to receive the reflected light passing through the scanning unit of the optical block.

A method of measuring optical information according to another embodiment of the present invention is a method of measuring optical information of a sample, the method comprising: irradiating incident light to the sample; detecting the SHG component of the reflected light reflected from the inspection position of the sample; detecting bonding interface characteristics of material layers constituting the sample through the amount of change in the SHG component of the reflected light; detecting a photoluminescence component of the reflected light; and detecting a change amount of a photoluminescence component for each wavelength band of the reflected light and a change amount of a photoluminescence component for each time period of the reflected light to detect characteristics of the material film constituting the sample.

According to the present invention, it is possible to measure not only the defects and properties of the material film constituting the sample, but also the interfacial bonding characteristics between the material films.

1 is a schematic block diagram of an optical system according to an embodiment of the present invention.
2A and 2B are block diagrams showing a detailed configuration of a light source block according to an embodiment of the present invention.
3 is a block diagram showing a detailed configuration of an optical block according to an embodiment of the present invention.
4 is a block diagram showing a detailed configuration of a first detection block according to an embodiment of the present invention.
5 is a block diagram showing a detailed configuration of a second detection block according to an embodiment of the present invention.
6 is a flowchart illustrating a method of detecting optical information using an optical system according to an embodiment of the present invention.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Sizes and relative sizes of layers and regions in the drawings may be exaggerated for clarity of description. Like reference numerals refer to like elements throughout.

1 is a schematic block diagram of an optical system according to an embodiment of the present invention. 2A and 2B are block diagrams showing a detailed configuration of a light source block according to an embodiment of the present invention, and FIG. 3 is a block diagram showing a detailed configuration of an optical block according to an embodiment of the present invention. 4 is a block diagram showing a detailed configuration of a first detection block according to an embodiment of the present invention, and FIG. 5 is a block diagram showing a detailed configuration of a second detection block according to an embodiment of the present invention.

Referring to FIG. 1 , the optical system 100 for detecting optical information of a sample 10 includes a light source block 200 , an optical block 300 , a first detection block 400 , and a second detection block 500 . may include The sample 10 may include a multilayer material film, and optical information of the sample 10 from the optical system 100 , that is, defects on the sample surface as well as bonding interface properties and surface defect properties of the multilayer material film. , and defect properties inside the material film will be detected.

Referring to FIG. 2A , the light source block 200 includes a laser source 210 , a chirping unit 220 , a beam expander 230 , a first mirror unit 250 , and a first polarization unit 260 . include

The laser source 210 may include, for example, a pulse laser. As an example, the pulse laser may be a nanosecond laser, a picosecond laser, a femtosecond laser, or a faster pulsed laser.

The chipping unit 220 may receive the light output from the laser source 210 and perform an operation to compensate. In general, when light is input in the form of a pulse from the laser source 210, a problem of group velocity desperation (GVD) extending beyond a set pulse width may occur, and the chipping unit 220 compensates for this GVD phenomenon. may be provided for.

The beam expander 230 may expand the size of the laser beam (incident light) output from the laser source 210 to a desired size or may average the energy distribution of the incident light.

The first mirror unit 250 may be a dichroic mirror configured to transmit light of a specific wavelength band and reflect light of another wavelength band. When a femtosecond laser is used as a laser source, the first mirror unit 250 may transmit light having a wavelength of 780 nm and reflect a wavelength band longer than 780 nm.

The incident light passing from the first mirror unit 250 extracts light polarized in a specific direction through the first polarization unit 260 and provides it to the optical block 300 .

Also, as shown in FIG. 2B , the light source block 200 may further include a period adjuster 240 between the beam expander 230 and the first mirror unit 250 . In general, when a short pulse laser such as a femtosecond laser is used as the laser source 210 , the incident light may have a very short pulse interval of several to several tens of ns. As described above, when the pulse interval of the incident light is very short, it is difficult to accurately measure the life time of the carrier of the target (a specific material film in the sample) to be measured. There is a need. An acousto-optic modulator (AOM) may be used as the period adjuster 240 of the present embodiment. The AOM is a medium that diffracts only pulses having a specific period, receives and outputs at a specific angle, and blocks other pulses, and can control the period of the pulses.

Referring to FIG. 3 , the optical block 300 may focus the incident light provided from the light source block 200 on the sample 10 . The optical block 300 of the present embodiment may be a confocal microscope capable of generating reflected light while checking an image by a beam scanning method. The reflected light is light output from the sample 10 , and in an embodiment of the present invention, both scattered light and output light may refer to the reflected light.

The optical block 300 of this embodiment may include a scan unit 310 , an alignment unit 320 , a monitoring unit 330 , a light collecting unit 350 , and a filter unit 360 .

The scan unit 310 may generate a two-dimensional image on the sample 10 while moving the incident light provided from the light source block 200 in the X and Y axes. The scan unit 310 may include a scan mirror (not shown) and a driving unit (not shown). In this case, the mirror may use a galvano (Galvano) mirror. The scan mirror may reflect incident light in various directions. The driver may adjust an angle of the mirror to adjust a spot position of light reflected from the sample 10 .

The alignment unit 320 may accurately guide the incident light reflected by the scan unit 310 in a desired direction without spreading. For example, the alignment unit 320 may guide the incident light reflected from the scan unit 310 to be within the incident range of the light collecting unit 350 . The alignment part 320 may be installed between the scanning part 310 and the light collecting part 350 . Accordingly, a space is optically secured, and the shape of the sample 10 can be observed through the monitoring unit 330 using the space. Such an alignment unit 320 may include a scan lens 321 and a tube lens 323 . The scan lens 321 and the tube lens 323 may be spaced apart from each other at a predetermined interval on the path of the incident light.

The monitoring unit 330 may be positioned between the alignment unit 320 and the light collecting unit 350 to monitor the inspection position and shape of the sample 10 on which the incident light is focused. In more detail, the monitoring unit 330 may be positioned between the alignment unit 320 and the filter unit 360 . The monitoring unit 330 may include a camera 331 , a first optical unit 333 , an illumination unit 335 , and a second optical unit 337 .

The camera 331 may include, for example, a charge coupled device (CCD) or a CMOS image sensor (CIS). The camera 331 may observe the shape and measurement position of the sample 10 in real time.

The first optical unit 333 may be positioned on a traveling path of the reflected light reflected from the sample 10 to change the traveling path of the reflected light toward the camera 331 . The first optical unit 333 may include a mirror.

The lighting unit 335 may serve as a light source of the camera 331 . The lighting unit 335 may be, for example, an LED of a white light source. However, the present invention is not limited thereto.

The second optical unit 337 may include an optical element for focusing the light of the illumination unit 335 on the camera 335 . The optical element constituting the second optical unit 337 may include, for example, at least one lens and at least one mirror. The second optical unit 337 provides illumination to the reflected light reflected from the sample 10 so that the camera 331 can finally take an accurate image.

The light collecting unit 350 may focus the incident light induced from the aligning unit 320 to a predetermined position of the sample 10 . The light collecting unit 350 may include an aperture 352 and an objective lens 354 . Incident light may pass through the aperture 352 and be focused on a predetermined portion of the sample 10 by the objective lens 354 . The aperture 352 may be located on a Fourier plane, and should be designed so that various types of openings can enter the corresponding Fourier plane. Through this, light may be incident on the sample 10 at various angles. Also, the image of the Fourier plane may be acquired by a second lens unit 460 and a second detector 470 to be described later.

For example, when a laser having a wavelength of 780 nm is used as a laser source, light having a peak intensity at 780 nm may be incident on the sample 10 . Then, depending on the physical properties of the inspection position of the sample 10 and whether or not there is a defect, electrons and the like are excited to generate reflected light.

The filter unit 360 may receive the reflected light reflected from the sample 10 , and guide the SHG component (signal) of the reflected light to the first detection block 400 . In this embodiment, the filter unit 360 may be, for example, a band pass filter. The filter unit 360 of this embodiment reflects the reflected light of a specific wavelength, for example, a wavelength less than the wavelength of the incident light (eg, 780 nm) to the first detection block 400 , and is larger than the wavelength of the incident light. The reflected light of the wavelength may be transmitted through the traveling path of the reflected light. As is known, since the SHG (Second Harmonic Generation) component has a weaker signal compared to the reflected light, the signal-to-noise ratio should be improved. To this end, the first detection block 400 for detecting the SHG component may be disposed adjacent to the sample 10 so that noise can be minimized.

The reflected light passing through the filter unit 360 of the present embodiment is provided to the light source block 200 through the monitoring unit 330 and the alignment unit 320 of the optical block 300 . The reflected light reaches the first mirror unit 250 of the light source block 200 , and the reflected light of a different specific wavelength is guided to the second detection block 500 . In this case, the first mirror unit 250 is configured to reflect the reflected light having a wavelength greater than that of the incident light.

Referring to FIG. 4 , the first detection block 400 may measure a component of the reflected light (output light) using a non-descan detection (NDD) method for the SHG component of the reflected light. As is known, the SHG component is a phenomenon in which two photons having a frequency ω are incident on the sample 10 and interact with each other, and then one photon having a frequency of 2ω is generated. A defect measurement method using such a SHG component is described in detail in International Patent No. PCT/US2019/029439. In addition, the NDD method is a method of inspecting the characteristics of the sample 10 by receiving the reflected light directly without going through the scan unit 310 in order to reduce the noise characteristics. That is, since the filter unit 360 is positioned between the scan unit 310 and the light collection unit 350 , the filter unit 360 directly filters the reflected light reflected from the sample 10 to filter the first may be provided to the detection block 400 .

The first detection block 400 for measuring the SHG component includes a second polarizer 410 , a SHG filter unit 420 , a beam splitter 430 , a first lens unit 440 , and a first detector 450 . ), a second lens unit 460 and a second detector 470 may be included.

The second polarizer 410 receives the reflected light filtered by the filter unit 360 . The second polarization unit 410 transmits the reflected light having the same or parallel component to its polarization axis.

The SHG filter unit 420 receives the light passing through the second polarization unit 410 . The SHG filter unit 420 may selectively pass a wavelength corresponding to 1/2 of the wavelength of the incident light. For example, when a laser having a wavelength of 780 nm is used as incident light, the SHG filter unit 420 may provide only reflected light having a wavelength of 390 nm to the first beam splitter 430 , and may block reflected light of other wavelength bands.

The first beam splitter 430 may provide a portion of the reflected light provided from the SHG filter unit 420 to the first lens unit 440 .

The first lens unit 440 focuses the reflected light provided from the first beam splitter 430 and provides it to the first detector 450 .

The first detector 450 may receive a portion of the reflected light provided from the first beam splitter 430 , and may detect characteristics of material layers constituting the sample 10 through the SHG component of the reflected light.

As an example, the first detector 450 may detect material properties such as density of interface trap (hereinafter, Dit), charge trap, doping, etc. of the material layer from the SHG component of the reflected light. As another example, the first detector 450 may measure a change in the charge between the silicon layer and the silicon oxide layer or the amount of charge in the silicon oxide layer. As another example, the first detector 450 may detect an oxide charge existing at an interface between a metal constituting the sample 10 and a metal oxide. Also, the first detector 450 may detect information on a depletion region, an accumulation region, and/or an inversion region through a change in the SHG component. The information may be detected by, for example, applying a bias voltage to the sample 10 in a non-contact manner by a corona charging gun or the like. A method of applying a bias voltage in a non-contact manner by a corona charging gun is described in detail in WO2019-210229 filed by some of the inventors of the present application. In addition, the first detector 450 may detect whether the sample 10 is defective by changing the SHG component of the reflected light.

Meanwhile, another portion of the reflected light provided from the SHG filter unit 420 may be provided to the second lens unit 460 by the first beam splitter 430 . The second lens unit 460 is an imaging lens that performs Fourier transform, and although shown as one lens in the drawing, it may include a plurality of lenses. Although not shown in detail, the second lens unit 460 may include a Fourier plane and an aperture therein. The reflected light (SHG signal) incident on the second lens unit 460 is focused through the aperture positioned on the Fourier plane, so that SHG information of the reflected light can be imaged. The intensity of the SHG signal generated by the interaction between the incident light and the sample 10 is a function of the incident angle and the azimuth angle of the incident light. As an example, the intensity of the SHG signal may vary depending on the time when light is irradiated to the sample 10 to cause an interaction. The change in the incident angle and the azimuth angle of the incident light may be adjusted through openings positioned on the Fourier plane, that is, the aperture 352 . For example, when all of the openings of the aperture 352 are open, all the lights incident on the openings at all angles are incident on the sample 10 . Accordingly, various characteristics generated from the sample 10 may be mixed and detected. On the other hand, when the opening of a specific part of the aperture 352 is opened or opened in a specific shape, that is, the crystal state of the sample 10, Dit of the boundary, and the insulating film by changing the open position, size and shape of the opening Information such as bulk trap and surface trap and optimal SHF signal acquisition conditions can be obtained. Conventionally, accuracy is obtained by moving the wafer while the angle of the incident light is fixed, but in this embodiment, the information can be obtained in a simple manner by rotating various openings.

The second detector 470 may detect information imaged by the second lens unit 460 and output it in the form of an image. The second detector 470 may include, for example, an imaging device such as a CCD or a CIS. The second detector 470 may detect the nonlinear characteristic of the sample 10 by the second lens unit 460 . As is known, the non-linear properties may be related to the lattice structure of the sample 10 and the directionality of the pattern. That is, the second detector 470 may detect the characteristics of the sample 10 by changing the incident angle and the azimuth angle of the reflected light. As an example, the second detector 470 may change the lattice structure of the wafer material (eg, Si or its series materials) changed by various process conditions for manufacturing the sample 10, and within various patterns. Changes in the trap status that have occurred can be detected and imaged. In addition, the second detector 470 may collect information on various incident angles and azimuth angles according to the SHG component acquired on the Fourier plane as a single event.

For example, the SHG component exhibits a characteristic that is strongly generated at the bonding interface of different material layers rather than a single material layer. Accordingly, the first detection block 400 may detect an electrical characteristic (Dit) at the bonding interface of the material layer, a passivation characteristic thereof, and defect information at the bonding interface using the SHG component. In addition, when the first detection block 400 is measured on a time basis, it is possible to measure not only the Dit characteristics, but also bulk traps in the material film and trap information on the surface of the material film.

Referring to FIG. 5 , the second detection block 500 may inspect the characteristics of the sample 10 through a photoluminescence component of reflected light reflected from the sample 10 . As is known, the photoluminescence of the reflected light can detect the shape and physical properties of the sample 10 , such as surface defects, concentrations of impurities (or defects), and potentials. In particular, photoluminescence is known to be capable of spectral detection at 900 to 1,400 mm corresponding to the silicon bandgap energy. Such a defect measurement method using photoluminescence is described in detail in US Patent No. 9,354,177.

In general, the photoluminescence signal may be a measure of radiative recombination that occurs when the sample 10 is irradiated with light to excite excess carriers. Since the light irradiated to the sample 10 generates excess carriers in the sample 10, the impurity concentration may vary depending on the defect of the sample 10, the type of impurity, and other recombination mechanisms. Factors may vary the intensity of the photoluminescence component (or signal). In general, photoluminescence intensity is proportional to carrier concentration, so bright areas of photoluminescence may represent higher minority-carrier lifetime regions, and relatively dark areas may represent higher defect concentrations. Such photoluminescence may be a non-contact method. By the incident light irradiated to the sample 10 , various photons may be generated according to defects and other structural shapes of the sample 10 . The photons may move electrons to a conduction band or fall into a valence band due to defects and various physical properties of the sample 10 . This series of operations may cause photoluminescence of various wavelengths. The second detection block 500 of the present embodiment may perform measurement using a nondescan detection (NDD) method. The NDD scheme refers to a case in which both incident light and reflected light pass through the scanning unit 310 . For example, the NDD method is a method generally used in confocal laser scanning microscopy, and is a method of imaging or detecting information of reflected light emitted from the sample 10 by the scan unit 310 . In general, in the case of descan, the optical path is too long, and optical signal loss may occur by various optical systems such as lenses or mirrors positioned on the path. Accordingly, the NDD scheme may be used to prevent optical signal loss.

For example, the second detection block 500 according to the photoluminescence method includes the second beam splitter 510 , the third detector 520 , the third optical unit 530 , the wavelength selector 540 , and imaging. It includes a unit 550 , a near infrared (NIR) detector 560 , and a time-correlated single photon counting (TCSPC) unit 570 .

The second beam splitter 510 may receive reflected light provided through the scan unit 310 of the optical block 300 . In more detail, the reflected light provided through the scan unit 310 of the optical block 300 may proceed to the light source block 200 . The reflected light provided to the light source block 200 may be reflected to the second beam splitter 510 of the second detection block 500 through the second mirror unit 250 of the light source block 200 . The second beam splitter 510 may provide a portion of the photoluminescence component of the reflected light to the third detector 520 and provide the remainder to the third optical unit 530 . As an example, the second beam splitter 510 provides a number to several tens of % of the photoluminescence of the reflected light to the third detector 520 , and the remaining number to several tens of % to the wavelength selector 540 . to provide. For example, various light reflection and transmission ratios may be selected according to the type of the beam splitter.

The third detector 520 may measure the physical properties of the sample 10 by detecting a change in the photoluminescence component of the reflected light distributed by the second beam splitter 510 . The third detector 520 detects a trap density in a material constituting the sample 10, a dangling bond, a concentration of impurities, a surface defect (or a defect energy state) through the photoluminescence component of the reflected light. ) and potential can be detected. For example, although not shown in the drawings, a combination of at least one imaging lens, an aperture, and a polarizer may be positioned at the front end of the third detector 520 . Through this, confocal imaging of photoluminescence components (eg, signals) emitted from the sample 10 of the third detector 520 may be performed. The characteristics of the sample 10 can be observed through the intensity distribution of the photoluminescence component appearing on the image.

The third optical unit 530 may linearly polarize the reflected light provided by the second beam splitter 510 and provide it to the wavelength selector 540 .

The wavelength selector 540 may select the reflected light of a specific wavelength from among the photoluminescence of the reflected light passing through the third optical unit 530 . Such a wavelength selector 540 may be, for example, a monochromator.

The imaging unit 550 is connected to the wavelength selection unit 540 . The imaging unit 550 may detect the intensity of photoluminescence of the reflected light in the wavelength band selected by the wavelength selection unit 540 . As is known, the intensity of photoluminescence for each wavelength band may represent various physical properties of the sample 10 . Therefore, by selecting a specific wavelength by the wavelength selection unit 540 , various physical properties inside the material layer of the sample 10 may be monitored through the imaging unit 550 .

The NIR detector 560 may detect a component corresponding to near IR of the reflected light provided from the wavelength selector 540 . Although the NIR detector 560 has been described as an example in the present embodiment, the present invention is not limited thereto, and a detector that detects visible light photoluminescence or near ultraviolet photoluminescence may be used. The NIR detector 560 absorbs the near-infrared component of the reflected light and emits other components to detect the properties of the material film, for example, a stacking defect.

The TCSPC 570 may count the number of photons of photoluminescence over time. In the TCSPC 570 , for example, the wavelength range of the photoluminescence component may vary according to the physical properties of the sample 10 to be analyzed. Accordingly, a specific wavelength band is extracted by the wavelength selector 540 , and the TCSPC 570 may count the number of photoluminescence photons over time for a physical property to be analyzed. That is, the TSCPC 570 may measure the photoluminescence intensity over time. From this, by measuring the lifetime information of the carriers, it is possible to secure the film quality.

The optical system 100 according to the embodiment of the present invention includes both the first detection block 400 for detecting the SHG component of the reflected light and the second detection block 500 for detecting the photoluminescence component of the reflected light.

The first detection block 400 may measure trap information generated on the surface, inside and/or bonding interface of the films constituting the sample 10 through the SHG component of the reflected light reflected from the sample 10 . .

The second detection block 500 may measure a defect in the film itself constituting the sample 10 through the intensity of photoluminescence of reflected light reflected from the sample 10 . In addition, the second detection block 500 may measure the intensity of photoluminescence for each wavelength band to accurately measure the type of defect. In addition, the second detection block 500 can accurately determine the defect location according to the thickness of the material layer by measuring the amount of light information according to time, and can also accurately measure the type and stacking defect information of the stacked material layer. .

Accordingly, the optical system of this embodiment uses the photoluminescence component and the SHG component, respectively, to analyze the surface of the film quality and the interface between the film qualities, as well as detect the characteristics of reflected light over time to detect internal defects and stacking defects. can be detected at the same time. In addition, the optical system of this embodiment applies a bias voltage to the sample in a non-contact manner by means of a corona gun, and through photoluminescence and SHG changes reflected from the sample, by band banding, that is, the accumulation band ( It is possible to analyze and measure a trap change and a material characteristic change for the entire band, such as accumulation band, flat band, depletion, and inversion.

6 is a flowchart illustrating a method of detecting optical information using an optical system according to an embodiment of the present invention.

Referring to FIG. 6 , the incident light provided from the light source block 200 is irradiated to the inspection position of the sample 10 through the optical block 300 ( S1 ).

The SHG component among the reflected light reflected from the inspection position of the sample 10 is detected to detect the first characteristic of the sample 10 ( S2 ). The first characteristic may include, for example, interfacial electrical characteristics of the material film constituting the sample 10, the degree of charge trapping, doping concentration, change in the amount of charge at the film interface, and the state of the measurement region (eg, depletion region, accumulation region). or whether it is an inversion region). In addition, the first characteristic may include a physical property that varies according to a change in an incident angle and an azimuth angle of the reflected light.

The second characteristic of the sample 10 is detected by detecting a photoluminescence component among the reflected light reflected from the inspection position of the sample 10 ( S3 ). The second characteristic may be different from the first characteristic. The second characteristic may include a surface defect of the sample, impurity concentration, potential, impurity type, majority carrier and minority carrier concentration, and a change in impurity concentration according to depth.

Those skilled in the art will recognize that it is within the skill of the art to use engineering practices to describe devices and/or processes in the manner described herein, and then to incorporate such described devices and/or processes into data processing systems. will recognize that it is common in That is, at least a portion of the devices and/or processes described herein may be incorporated into a data processing system through a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system generally includes a system unit housing, a video display device, memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, operating systems, drivers , graphical user interfaces, and computational entities such as application programs, one or more interactive devices such as a touch pad or screen, and/or feedback loops and control motors (eg, to sense position and/or speed). feedback for; control motors for moving and/or adjusting parts and/or quantities). A typical data processing system may be implemented using any suitable commercially available components, such as those typically found in data computing/communication and/or network computing/communication systems.

Although specific aspects of the subject matter described herein have been described, based on the teachings herein, changes and modifications may be made without departing from the subject matter described herein and its broader aspects. Therefore, it will be apparent to those skilled in the art that the appended claims are intended to cover within the scope all such changes and modifications as come within the true spirit and scope of the subject matter described herein.

Further, while specific embodiments of the invention have been illustrated, various modifications and embodiments of the invention may be made by those skilled in the art without departing from the scope and spirit of the disclosure described above. Accordingly, the scope of the invention should be limited only by the claims appended hereto. It is believed that the present disclosure and many of its attendant advantages will be understood by the foregoing description, in form, construction and arrangement of parts without departing from the disclosed subject matter or sacrificing all of its important advantages. It will be apparent that various changes may be made. The form described is illustrative only, and the intention of the following claims is to embrace and embrace such modifications.

10: sample 100: optical system
100: optical system 200: light source block
210: laser source 220: zipped part
230: beam expansion unit 250: first mirror unit
300: optical block 310: scan unit
320: alignment unit 330: monitoring unit
350: light collecting unit 360: filter unit
400: first detection block 410: second polarization unit
420: SHG filter unit 430: beam splitter
440: first lens unit 450: first detector
460: second lens unit 470: second detector
500: second detection block 510: second beam splitter
520: third detector 530: third optical unit
540: wavelength selector 550: charred part
560: NIR detector 570: TCSPC unit

Claims (18)

An optical system for detecting optical information of a sample including a multi-layered material film, comprising:
a light source block disposed to irradiate light to the sample;
a first detection block for detecting a Second Harmonic Generation (SHG) component of the reflected light reflected from the sample; and
and a second detection block for detecting a photoluminescence component of reflected light reflected from the sample. The method of claim 1,
and the light source block includes a laser source providing a pulsed laser. The method of claim 1,
The light source block comprises a nanosecond laser, a picosecond laser, or a femtosecond laser as a laser source. 3. The method of claim 2,
The light source block,
a chirping unit compensating for a pulse width of the incident light output from the laser source;
a beam expander for adjusting the size of the incident light provided from the laser source;
a first mirror unit that receives the incident light, transmits incident light of a specific wavelength, and reflects light of other wavelengths; and
and a first polarizing unit polarizing and outputting the incident light provided from the first mirror unit. 5. The method of claim 4,
The light source block is positioned between the beam expansion unit and the first mirror unit, the optical system further comprising a period adjusting unit for extending the interval between the pulses of the incident light. The method of claim 1,
The optical system further comprising an optical block for focusing the incident light provided from the light source block on the sample. 7. The method of claim 6,
The optical block is
a scanning unit configured to move the incident light along the x-axis and the y-axis to generate a two-dimensional image on a portion at the inspection position of the sample;
an alignment unit guiding the incident light output from the scan unit to an inspection position of the sample; and
and a light condensing unit configured to condense the incident light provided from the alignment unit to an inspection position of the sample. 8. The method of claim 7,
The aligning unit is an optical system including a scan lens and a tube lens that are spaced apart from each other at regular intervals. 8. The method of claim 7,
The optical block further comprises a monitoring unit positioned between the alignment unit and the light collecting unit to observe the shape of the sample and the inspection position in real time. The method of claim 1,
The optical block further comprises a filter unit configured to receive reflected light reflected from the sample, provide a wavelength less than the wavelength of the incident light to the first detection block, and transmit reflected light equal to or greater than the wavelength of the incident light. 11. The method of claim 10,
The first detection block is
a second polarizer for polarizing the reflected light;
an SHG filter unit selectively passing a wavelength corresponding to 1/2 of the wavelength of the incident light among the reflected light provided by the second polarizing unit;
a first beam splitter receiving the reflected light filtered by the SHG filter unit and separating the reflected light;
a first detector for detecting a characteristic of the sample through a change in the SHG component of a portion of the reflected light separated from the first beam splitter; and
and a second detector configured to detect a nonlinear characteristic of the sample by imaging a SHG component of the reflected light of another portion separated by the first beam splitter. 12. The method of claim 11,
and a lens unit receiving the SHG component of the other portion of the reflected light from the first beam splitter and imaging the SHG component through a Fourier plane. 5. The method of claim 4,
The second detection block is an optical system configured to receive the reflected light passing through the scanning unit of the optical block. The method of claim 1,
The second detection block,
a second beam splitter receiving the reflected light and separating the photoluminescence of the reflected light;
a third detector for detecting a change in photoluminescence of the partial reflected light separated by the second beam splitter; and
and an optical member that separates the remaining reflected light separated by the second beam splitter for each wavelength and time, and observes a change in photoluminescence according to the wavelength and time. 15. The method of claim 14,
The optical member,
a wavelength selection unit that receives the remaining reflected light and selects reflected light of a specific wavelength;
an imaging unit for observing the intensity of photoluminescence of the reflected light of the specific wavelength; and
and a TCSPC time-correlated single photon counting) unit for counting the number of photons according to time change of the reflected light of the specific wavelength. The method of claim 1,
The first detection block is provided in a position closer to the sample than the second detection block. The method of claim 1,
The light source block is a corona gun that applies a bias voltage to the sample in a non-contact manner. A method of measuring optical information in a sample, comprising:
irradiating incident light to the sample;
detecting the SHG component of the reflected light reflected from the inspection position of the sample;
detecting bonding interface characteristics of material layers constituting the sample through the amount of change in the SHG component of the reflected light;
detecting a photoluminescence component of the reflected light; and
and detecting a characteristic of the material film constituting the sample by detecting a change amount of the photoluminescence component for each wavelength band of the reflected light and a change amount of the photoluminescence component for each time period of the reflected light.

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