Device for analyzing defect in sample by using thermoreflectance signal and operating method therefor

Abstract

This device for analyzing a defect in a sample comprises: a laser light source for outputting a laser signal; a signal generator for generating a first signal and a second signal having the same lock-in frequency value; a bias unit for generating a bias signal on the basis of the first signal and applying the bias signal to a sample so that the sample generates heat; a scanning unit for scanning, with the laser signal, the sample heated by the bias signal; a detection unit for detecting a reflected signal reflected from the sample by the scanning, receiving the second signal from the signal generator, and comparing the second signal with the detected reflected signal to acquire a phase delay value of the detected reflected signal; and a control unit for receiving the phase delay value from the detection unit, adjusting the lock-in frequency value, receiving, from the detection unit, the phase delay value at the adjusted lock-in frequency value, and measuring a heating position of the sample on the basis of the phase delay value at each received lock-in frequency value.

Description

Sample defect analysis device using thermal reflection signal and method of operation thereof

[0001] The following embodiments relate to a sample defect analysis device using a thermal reflection signal and a method of operation thereof.

[0002] Conventional Lock-In Thermography (LIT) equipment utilizes infrared cameras to measure internal heat generation in samples (e.g., semiconductor devices with stacked structures) and can detect internal defects based on this heat. However, due to performance limitations of infrared cameras (e.g., camera frame, magnification of the lens), conventional LIT equipment may suffer from low measurement accuracy and spatial resolution, which may result in an inability to accurately detect the location of internal defects.

[0003] The aforementioned background technology is one that the inventor possessed or acquired in the process of deriving the contents of the disclosure of the present application, and it cannot be considered as prior art disclosed to the general public prior to the filing of this application.

[0004] According to one embodiment, a sample defect analysis device capable of detecting internal heat generation and internal defects of a sample (e.g., a semiconductor device with a three-dimensional stacked structure) based on the phase delay between a thermal reflection signal of a visible light wavelength and a reference signal can be provided.

[0005] According to one embodiment, a sample defect analysis device comprises a laser light source that outputs a laser signal, a signal generator that generates a first signal and a second signal having the same lock-in frequency value, a bias unit that generates a bias signal based on the first signal and applies the bias signal to the sample to cause the sample to heat up, a scanning unit that performs scanning with the laser signal on the sample that heats up due to the bias signal, a detection unit that detects a reflected signal reflected from the sample by the scanning, receives the second signal from the signal generator, and obtains a phase delay value of the detected reflected signal by comparing the second signal with the detected reflected signal, and a control unit that receives the phase delay value from the detection unit, adjusts the lock-in frequency value, receives the phase delay value at the adjusted lock-in frequency value from the detection unit, and measures the heat-up location of the sample based on the phase delay value at each received lock-in frequency value. Depending on the adjustment of the lock frequency value, the first signal and the second signal have the adjusted lock frequency value, and the phase delay value at the adjusted lock frequency value may be obtained by comparing the reflected signal reflected from the sample when the lock frequency value is adjusted with the second signal having the adjusted lock frequency value.

[0006] The control unit above performs fitting based on each received phase delay value and can obtain the distance from the surface of the sample to the heat source and the thermal diffusivity of the sample using the result of the fitting.

[0007] The detection unit may include a photodetector that detects the reflected signal and a lock-in amplifier that obtains a phase delay value at each lock frequency value.

[0008] The scanning unit can create a 2D image by scanning the sample with the laser signal through a polarizer, a polarization beam splitter, a λ / 4 wave plate, an XY scanner, and one or more lenses.

[0009] The above sample may include a single-layer sample or a multi-layer sample.

[0010] According to one embodiment, a method of operating a sample defect analysis device comprises the steps of: outputting a laser signal; generating a first signal and a second signal having the same lock-in frequency value through signal branching in a signal generator; generating a bias signal based on the first signal and applying the bias signal to the sample to cause the sample to heat up; performing scanning with the laser signal on the sample that heats up due to the bias signal; detecting a reflected signal reflected from the sample by the scanning; comparing the second signal with the detected reflected signal to obtain a phase delay value of the detected reflected signal; adjusting the lock-in frequency value and obtaining a phase delay value at the adjusted lock-in frequency value; and measuring the heat location of the sample based on the phase delay value at each of the obtained lock-in frequency values. Depending on the adjustment of the lock frequency value, the first signal and the second signal have the adjusted lock frequency value, and the phase delay value at the adjusted lock frequency value may be obtained by comparing the reflected signal reflected from the sample when the lock frequency value is adjusted with the second signal having the adjusted lock frequency value.

[0011] The above measuring step may include a step of performing fitting based on each acquired phase delay value and a step of obtaining the distance from the surface of the sample to the heat source and the thermal diffusivity of the sample using the result of the fitting.

[0012] The above sample may include a single-layer sample or a multi-layer sample.

[0013] FIG. 1 is a block diagram illustrating the configuration of a sample defect analysis device according to one embodiment.

[0014] FIG. 2 is a drawing for explaining an example of the structure of a sample defect analysis device according to one embodiment.

[0015] FIG. 3 is a diagram illustrating the operation of a sample defect analysis device according to one embodiment.

[0016] FIG. 4 is a diagram illustrating a phase delay according to one embodiment.

[0017] FIG. 5 is a diagram illustrating the phase delay according to the locking frequency of a sample defect analysis device according to one embodiment.

[0018] FIG. 6 is a drawing illustrating the fitting results of a sample defect analysis device according to one embodiment.

[0019] FIG. 7 is a flowchart illustrating the operation method of a sample defect analysis device according to one embodiment.

[0020] Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be modified and implemented in various forms. Accordingly, actual implementations are not limited to the specific embodiments disclosed, and the scope of this specification includes modifications, equivalents, or substitutions included in the technical concept described by the embodiments.

[0021] Terms such as "first" or "second" may be used to describe various components, but these terms should be interpreted solely for the purpose of distinguishing one component from another. For example, the first component may be named the second component, and similarly, the second component may be named the first component.

[0022] When it is stated that a component is "connected" to another component, it should be understood that it may be directly connected to or joined to that other component, or that there may be other components in between.

[0023] The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to specify the existence of the described features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0024] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this specification.

[0025] Hereinafter, embodiments will be described in detail with reference to the attached drawings. In the description with reference to the attached drawings, identical components are given the same reference numeral regardless of the drawing number, and redundant descriptions thereof will be omitted.

[0026] FIG. 1 is a block diagram illustrating the configuration of a sample defect analysis device according to one embodiment.

[0027] A sample defect analysis device (100) according to one embodiment can analyze defects in a sample (e.g., a semiconductor device) using a thermoflectance signal. For example, the sample defect analysis device (100) can have sub-micron spatial resolution and can measure or track the location of heat generated inside a sample (e.g., a semiconductor device with a stacked structure) to which a bias signal is applied by using the phase delay (or phase difference) of the thermoflectance signal. Based on these measurement results (or tracking results), the sample defect analysis device (100) can track internal defects in the sample and more accurately determine the location of the internal defects.

[0028] According to an embodiment, the sample may include a single-layer sample (i.e., a sample composed of one layer) (e.g., a material or semiconductor device composed of a single layer) or a multi-layer sample (i.e., a sample composed of multiple layers) (e.g., a semiconductor device composed of multiple layers).

[0029] Referring to FIG. 1, a sample defect analysis device (100) according to one embodiment may include a laser light source (110), a signal generator (120), a bias unit (130), a scanning unit (140), a detection unit (150), and a control unit (160).

[0030] The laser light source (110) can output a laser signal (e.g., a laser signal in the visible light band of short or long wavelength). According to an embodiment, the laser light source (110) may correspond to a light source that outputs a wavelength in the visible light band. By using a laser light source (110) in the visible light band, the sample defect analysis device (100) can have superior spatial resolution compared to a device that detects wavelengths in the mid-infrared region (3 to 8 μm) to generate an image.

[0031] The signal generator (120) can generate a first signal and a second signal having the same frequency (e.g., lock-in frequency) value through signal branching.

[0032] The bias unit (130) can receive a first signal from the signal generator (120). The bias unit (130) can generate a bias signal based on the first signal and can apply or transmit the bias signal to the sample. Heat may be generated in the sample by the bias signal.

[0033] The scanning unit (140) can perform scanning on a sample that is heating up using a laser signal. The laser signal may be reflected from the sample. The signal reflected from the sample by the laser signal is referred to as the reflected signal.

[0034] The detector (150) can detect a reflected signal. The detector (150) may include a light detector and a lock-in amplifier, and can detect a reflected signal through the light detector.

[0035] The detection unit (150) can receive a second signal from the signal generator (120).

[0036] The detection unit (150) can obtain a phase delay value (or phase difference value) of the detected reflection signal by comparing the second signal and the detected reflection signal through a lock-in amplifier.

[0037] The control unit (160) can receive a phase delay value (e.g., the phase delay value of a detected reflected signal) from the detection unit (150).

[0038] The control unit (160) can adjust the lock frequency value. The control unit (160) can control the signal generator (120) so that the signal generator (120) can adjust the lock frequency value.

[0039] The control unit (160) can receive a phase delay value corresponding to the adjusted lock frequency value from the detection unit (150). Here, the phase delay value at the adjusted lock frequency value may be obtained by the detection unit (150) by comparing a reflected signal reflected from the sample when the lock frequency value is adjusted with a second signal having the adjusted lock frequency value. The control unit (160) can measure (or estimate) the heat generation location of the sample based on each received phase delay value. For example, the control unit (160) can perform fitting (e.g., curve fitting) based on each received phase delay value. The control unit (160) can obtain (or calculate or estimate) the distance from the surface of the sample to the heat generation location of the sample using the result of the fitting. Additionally, the control unit (160) can obtain (or calculate or estimate) the thermal diffusivity of the sample using the result of the fitting.

[0040] According to one embodiment, the sample defect analysis device (100) can acquire an image of the sample using a laser light source (110) of a wavelength in the visible light band and a photodetector, thereby having high spatial resolution. In addition, the sample defect analysis device (100) can overcome the frame rate limit of an infrared CCD (charge coupled device) camera through a photodetector and a lock-in amplifier, and can use a high lock frequency, thereby measuring (or estimating) the location of internal heat generation of the sample with high accuracy. The sample defect analysis device (100) can accurately measure the location of internal cracks or internal defects of the sample with high resolution.

[0041] FIG. 2 is a drawing for explaining an example of the structure of a sample defect analysis device according to one embodiment. FIG. 3 is a drawing for explaining the operation of a sample defect analysis device according to one embodiment.

[0042] Referring to FIG. 2, a sample defect analysis device (100) according to one embodiment may include a laser light source (110), a signal generator (120), a bias unit (or bias device) (130), a control unit (160), a polarizer (211) (e.g., a linear polarizer), a polarization beam splitter (PBS) (213), a λ / 4 wave plate (215), an XY scanner (217), lenses (219, 221), an objective lens (223), a pinhole (225), a photodetector (227), a current amplifier (229), and a lock-in amplifier (231).

[0043] In the example illustrated in FIG. 2, a polarizer (211), PBS (213), λ / 4 wave plate (215), XY scanner (217), lenses (219, 221), objective lens (223), and pinhole (225) may be included in the scanning unit (140), and a photodetector (227), current amplifier (229), and lock-in amplifier (231) may be included in the detection unit (150).

[0044] The signal generator (120) can branch the signal to generate a first signal and a second signal having the same frequency value (or the same lock frequency value) (e.g., 100 Hz). The first signal and the second signal may be in the form of sine waves having the same phase. For example, as shown in the example in FIG. 3, the first signal (340) and the second signal (350) may be sine wave signals of 100 Hz. The first signal may be used by the bias unit (130) to generate a bias signal, and the second signal may be used as a reference signal in the lock-in amplifier (231). Although the frequency of each of the first signal and the second signal was previously exemplified as 100 Hz, this is for convenience of explanation only, and the frequency of each of the first signal and the second signal is not limited to 100 Hz.

[0045] The bias unit (130) can generate a bias signal based on a first signal (e.g., a sine wave signal of 100 Hz). The bias unit (130) may include an amplifier and may amplify the first signal through the amplifier. The amplified first signal may correspond to the bias signal. The bias unit (130) may apply the bias signal (e.g., a bias signal of 100 Hz) to the sample (201). The bias signal may have a sine wave form, so the temperature of the sample (201) may repeatedly rise and fall according to the bias signal. The temperature (or heat generation) of the sample (201) may change periodically according to the bias signal.

[0046] The laser light source (110) can output a laser signal (e.g., the laser signal (310) of FIG. 3).

[0047] The scanning unit (140) can scan a sample (201) with an output laser signal through a polarizer (211), a PBS (213), a λ / 4 wave plate (215), an XY scanner (217), and one or more lenses (e.g., lenses (219, 221), an objective lens (223)). For example, the output laser signal can be transmitted to the XY scanner (217) through the polarizer (211), the PBS (213), and the λ / 4 wave plate (215). The XY scanner (217) can perform scanning on the sample (201) through the lenses (219, 221) and the objective lens (223) using the transmitted laser signal. The objective lens (223) may be a high-magnification objective lens (e.g., 10x, 20x, 50x, or 100x, etc.).

[0048] A reflected signal (e.g., the reflected signal (320) of FIG. 3) reflected from a sample (201) can be transmitted to a photodetector (227) through an objective lens (223), lenses (219, 221), an XY scanner (217), a λ / 4 wave plate (215), a PBS (213), and a pinhole (225). The photodetector (227) can detect the reflected signal. Since the sample (201) can heat up due to a bias signal, the reflected signal of the sample (201) may correspond to a thermoreflectance signal. The temperature (or heat) of the sample (201) may change periodically according to the bias signal, and thus a change in the reflectance of the sample (201) may also occur due to the change in heat.

[0049] The photodetector (227) can convert the detected reflected signal into an electrical signal (e.g., a current signal) and can transmit the electrical signal to a current amplifier (229).

[0050] The current amplifier (229) can amplify the electrical signal received from the photodetector (227) and can transmit the amplified electrical signal (e.g., the electrical signal (330) of FIG. 3) to the lock-in amplifier (231).

[0051] The lock-in amplifier (231) can compare the reflected signal of the sample (201) (or the electrical signal amplified by the current amplifier (229)) with a second signal (e.g., a sine wave signal of 100 Hz). As will be described later with reference to FIG. 4, if the heating location is inside the sample (201), a difference may occur between the phase of the second signal and the phase of the reflected signal. Since the second signal may correspond to a reference signal in the lock-in amplifier (231), the reflected signal of the sample (201) can be compared with the reference signal, which is the second signal, to have a phase delay value. The lock-in amplifier (231) can obtain the phase delay value of the reflected signal (e.g., a phase delay value at 100 Hz). In other words, the lock-in amplifier (231) can obtain the phase difference between the phase of the reflected signal and the phase of the second signal.

[0052] The lock-in amplifier (231) can transmit the acquired phase delay value to the control unit (160).

[0053] The control unit (160) can change or adjust the lock frequency value. For example, the control unit (160) can change or adjust the lock frequency value by a predetermined unit. The predetermined unit may include, for example, 100Hz, but the predetermined unit is not limited to the example described above. For convenience of explanation, the lock frequency value being adjusted from 100Hz to 200Hz is given as an example.

[0054] The signal generator (120) can branch the signal to generate a first signal and a second signal having the same lock frequency value (e.g., 200 Hz).

[0055] The bias section (130) can generate a bias signal based on a first signal (e.g., a sine wave signal of 200 Hz) and apply the bias signal to the sample (201).

[0056] The detector (150) can detect the reflected signal of a sample (201) that generates heat by a bias signal having 200 Hz. The detector (150) can compare the reflected signal of the sample (201) with a second signal (e.g., a sine wave signal of 200 Hz) through a lock-in amplifier (231) and can obtain a phase delay value of the reflected signal (e.g., a phase delay value at 200 Hz). The control unit (160) can adjust the lock frequency value multiple times, and the detector (150) can obtain a phase delay value at each of the various lock frequency values.

[0057] The control unit (160) can receive a phase delay value from the detection unit (150) whenever the detection unit (150) acquires a phase delay value. In other words, the control unit (160) can receive a phase delay value at each of the various lock frequency values ​​from the detection unit (150). The control unit (160) can measure the heat generation location of the sample based on each received phase delay value.

[0058] FIG. 4 is a diagram illustrating a phase delay according to one embodiment.

[0059] Referring to FIG. 4, Case 1 may represent a case where heat is generated on the surface of the sample, and Case 2 may represent a case where heat is generated inside the sample.

[0060] In the case of Case 1, there may be no difference between the phase of the reflected signal and the phase of the reference signal (i.e., the second signal).

[0061] In Case 2, a difference may occur between the phase of the reflected signal and the phase of the reference signal. In other words, the phase of the reflected signal may be delayed from the phase of the reference signal. In Case 2, if the lock frequency value is adjusted or changed, the phase delay value may also be changed. The sample defect analysis device (100) can obtain the phase delay value of the reflected signal at each of the different lock frequency values, and can measure or estimate the heat location of the sample (401) (or the distance (Z) between the heat source of the sample (401) and the surface) based on the phase delay value at each of the obtained lock frequency values. The distance (Z) between the heat source of the sample (401) and the surface can be expressed by the following Equation 1.

[0062]

[0063] In the above mathematical formula 1, can represent a phase delay, and can represent the diffusion length. In Equation 1 above, the unit of the phase delay can be radians, and The unit can be m / rad. Heat can propagate from the location where the thermal change occurred, It can represent the distance between the location where a thermal change occurs and the location where the heat propagates and the temperature change can be sufficiently detected. It can be expressed by the following mathematical formula 2.

[0064]

[0065] In the above mathematical formula 2, can represent the thermal conductivity of the sample (401), and can represent the specific heat capacity at constant pressure of the sample (401), and can represent the density of the sample (401).

[0066] The thermal conductivity, constant pressure specific heat capacity, and density of the sample (401) may vary.

[0067] According to Equation 3 below, thermal conductivity, specific heat capacity at constant pressure, and density are thermal diffusivity It can be expressed as.

[0068]

[0069] The thermal penetration depth for the sample (401) can be expressed by the following mathematical formula 4.

[0070]

[0071] In the above mathematical formula 4, It can represent a frequency (e.g., lock frequency).

[0072] FIG. 5 is a diagram illustrating the phase delay according to the locking frequency of a sample defect analysis device according to one embodiment.

[0073] The graph (510) of Fig. 5 shows the thermal diffusivity Is and distance (or depth) is the locking frequency when it is 700um. Changes in phase delay according to can be represented. In the example illustrated in FIG. 5, the unit of phase delay may be degrees.

[0074] In the example illustrated in FIG. 5, the phase delay value for distinguishing a 10 µm interval (e.g., the interval between depth (695 µm) and depth (705 µm)) is the locking frequency When is 1Hz It could be, lock frequency When is 10Hz It can be, lock frequency When is 100Hz It can be. This is a 10um interval Rather than distinguishing by Distinguishing by this may indicate that the location of heat generation within the sample can be located more precisely. In other words, the lock frequency value When it is 100Hz, compared to 1Hz and 10Hz, it can have the effect of distinguishing 10um intervals with a more fine standard.

[0075] FIG. 6 is a drawing illustrating the fitting results of a sample defect analysis device according to one embodiment.

[0076] The reference data in Fig. 6 shows the change in phase delay value according to the lock frequency value when the actual location of the sample's heat generation (or the distance between the actual heat point and the surface) is 600 µm.

[0077] According to one embodiment, the sample defect analysis device (100) has a heat source location (e.g., distance (or depth) of the sample) Phase delay values ​​at each of various lock frequency values ​​can be obtained so as to measure. For example, the sample defect analysis device (100) can obtain phase delay values ​​at each of various lock frequency values ​​through the following mathematical formula 5.

[0078]

[0079] If the above mathematical formula 4 is expressed differently, the above mathematical formula 5 can be obtained.

[0080] In the above mathematical formula 5, can represent a phase delay, and can represent the lock frequency, and can indicate the location of heat generation in the sample (or the distance between the heat point of the sample and the surface), and It can represent the thermal diffusivity of the sample.

[0081] As described above, the sample defect analysis device (100) can obtain the phase delay value of the reflected signal of the sample at each of various lock frequency values. The measurement data illustrated in FIG. 6 may represent the phase delay value of the reflected signal of the sample at each of the lock frequency values ​​(e.g., 100 Hz, 200 Hz, 300 Hz, 400 Hz, 500 Hz, 600 Hz, 700 Hz, 800 Hz, 900 Hz, 1000 Hz). In the example illustrated in FIG. 6, the unit of the phase delay value may be radians.

[0082] The sample defect analysis device (100) and To obtain (or determine) the, fitting (e.g., curve fitting) can be performed based on the measurement data of FIG. 6 (e.g., phase delay values ​​at each lock frequency value). The result of the fitting is shown in FIG. 6. Depending on the fitting, the sample defect analysis device (100) of the sample For example, it can be obtained as 613um, and For example It can be obtained. The sample defect analysis device (100) can accurately measure the location of the heat generation of the sample.

[0083] FIG. 7 is a flowchart illustrating the operation method of a sample defect analysis device according to one embodiment.

[0084] Referring to FIG. 7, in step 710, the sample defect analysis device (100) can output a laser signal.

[0085] In step 720, the sample defect analysis device (100) can generate a first signal and a second signal having the same lock frequency value through signal branching from the signal generator (120).

[0086] In step 730, the sample defect analysis device (100) can generate a bias signal based on the first signal and apply the bias signal to the sample to cause the sample to heat up.

[0087] In step 740, the sample defect analysis device (100) can perform scanning with a laser signal on a sample that is heated by a bias signal.

[0088] In step 750, the sample defect analysis device (100) can detect a reflected signal reflected from the sample.

[0089] In step 760, the sample defect analysis device (100) can obtain a phase delay value of the detected reflection signal by comparing the second signal with the detected reflection signal.

[0090] In step 770, the sample defect analysis device (100) can adjust the lock frequency value and obtain a phase delay value at the adjusted lock frequency value. Here, the phase delay value at the adjusted lock frequency value may be obtained by comparing a reflected signal reflected from the sample when the lock frequency value is adjusted with a second signal having the adjusted lock frequency value.

[0091] In step 780, the sample defect analysis device (100) can measure the heat generation location of the sample based on the phase delay value at each acquired lock frequency value. For example, the control unit (160) of the sample defect analysis device (100) can perform fitting based on each phase delay value. The control unit (160) of Equation 5 Fitting can be performed through this. The control unit (160) can obtain the distance from the surface of the sample to the heat source using the result of the fitting (e.g., the result of the fitting in FIG. 6). In addition, the control unit (160) can obtain the thermal diffusivity of the sample using the result of the fitting.

[0092] The contents described through FIGS. 1 to 6 can be applied to the operation method of the sample defect analysis device (100) of FIG. 7.

[0093] The embodiments described above may be implemented as hardware components, software components, and / or combinations of hardware and software components. For example, the devices, methods, and components described in the embodiments may be implemented using a general-purpose computer or a special-purpose computer, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing unit may execute an operating system (OS) and software applications executed on said operating system. Additionally, the processing unit may access, store, manipulate, process, and generate data in response to the execution of the software. For ease of understanding, the processing unit may be described as being used as a single unit, but those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or one processor and one controller. In addition, other processing configurations, such as parallel processors, are also possible.

[0094] Software may include computer programs, code, instructions, or a combination of one or more of these, and may configure a processing unit to operate as desired or instruct the processing unit independently or collectively. Software and / or data may be stored on any type of machine, component, physical device, virtual equipment, computer storage medium, or device so as to be interpreted by the processing unit or to provide instructions or data to the processing unit. Software may be distributed over networked computer systems and may be stored or executed in a distributed manner. Software and data may be stored on computer-readable recording media.

[0095] The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may store program instructions, data files, data structures, etc., either individually or in combination, and the program instructions recorded on the medium may be those specifically designed and configured for the embodiment or those known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes; optical recording media such as CD-ROMs and DVDs; magneto-optical media such as floptical disks; and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, and flash memory. Examples of program instructions include machine code, such as that generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc.

[0096] The hardware device described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

[0097] Although the embodiments have been described above with reference to the limited drawings, those skilled in the art can apply various technical modifications and variations based thereon. For example, suitable results may be achieved even if the described techniques are performed in a different order than described, and / or if the components of the described system, structure, device, circuit, etc. are combined or assembled in a form different from described, or replaced or substituted by other components or equivalents.

[0098] Therefore, other implementations, other embodiments, and equivalents to the claims also fall within the scope of the claims set forth below.

Claims

1. In a sample defect analysis device, A laser light source that outputs a laser signal; A signal generator that generates a first signal and a second signal having the same lock-in frequency value; A bias unit that generates a bias signal based on the first signal and applies the bias signal to the sample so that the sample heats up; A scanning unit that performs scanning with the laser signal on the sample that generates heat by the above bias signal; A detection unit that detects a reflected signal reflected from the sample by the above scanning, receives the second signal from the signal generator, and obtains a phase delay value of the detected reflected signal by comparing the second signal with the detected reflected signal; and A control unit that receives the phase delay value from the detection unit, adjusts the lock frequency value, receives the phase delay value at the adjusted lock frequency value from the detection unit, and measures the heating location of the sample based on the phase delay value at the received lock frequency value. Includes, According to the adjustment of the lock frequency value, the first signal and the second signal have the adjusted lock frequency value, and the phase delay value at the adjusted lock frequency value is obtained by comparing the reflected signal reflected from the sample when the lock frequency is adjusted with the second signal having the adjusted lock frequency value. Sample defect analysis device.

2. In Paragraph 1, The above control unit is, Performing fitting based on each received phase delay value, and obtaining the distance from the surface of the sample to the heating location using the result of the fitting, Sample defect analysis device.

3. In Paragraph 2, The above control unit is, Obtaining the thermal diffusivity of the sample using the results of the above fitting, Sample defect analysis device.

4. In Paragraph 1, The above detection unit is, A photodetector for detecting the above-mentioned reflection signal; and A lock-in amplifier that obtains phase delay values ​​at each of the above lock frequency values including, Sample defect analysis device.

5. In Paragraph 1, The scanning unit scans the sample with the laser signal through a polarizer, a polarization beam splitter, a λ / 4 wave plate, an XY scanner, and one or more lenses. Sample defect analysis device.

6. In Paragraph 1, The above sample includes a single-layer sample or a multi-layer sample, Sample defect analysis device.

7. In the method of operating a sample defect analysis device, Step of outputting a laser signal; A step of generating a first signal and a second signal having the same lock-in frequency value through signal branching in a signal generator; A step of generating a bias signal based on the first signal and applying the bias signal to the sample so that the sample heats up; A step of performing scanning with the laser signal on the sample that generates heat due to the bias signal; A step of detecting a reflected signal reflected from the sample by the above scanning; A step of obtaining a phase delay value of the detected reflection signal by comparing the second signal and the detected reflection signal; A step of adjusting the lock frequency value and obtaining a phase delay value at the adjusted lock frequency value; and Step of measuring the heating location of the sample based on the phase delay value at each of the above-acquired lock frequency values Includes, According to the adjustment of the lock frequency value, the first signal and the second signal have the adjusted lock frequency value, and the phase delay value at the adjusted lock frequency value is obtained by comparing the reflected signal reflected from the sample when the lock frequency value is adjusted with the second signal having the adjusted lock frequency value. Method of operation of a sample defect analysis device.

8. In Paragraph 7, The above-mentioned measuring step is, A step of performing fitting based on each of the above-mentioned acquired phase delay values; and A step of obtaining the distance from the surface of the sample to the heating location using the result of the above fitting. including, Method of operation of a sample defect analysis device.

9. In Paragraph 8, Step of obtaining the thermal diffusivity of the sample using the results of the above fitting including, Method of operation of a sample defect analysis device.

10. In Paragraph 7, The above sample includes a single-layer sample or a multi-layer sample, Method of operation of a sample defect analysis device.

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