Integrated module type spectroscopic system and method for diagnosing process using the same

Abstract

In an integrated modular spectral system and a method for diagnosing a process using the system, the system includes a spectral module, a detection unit, and a diagnostic unit. The spectral module is configured to receive optical signals emitted from a plasma process. The detection unit is configured to detect the optical signal according to a frequency band based on the optical signal received in the spectral module. The diagnostic unit is configured to determine the state of the plasma process or determine the calibration time of the spectral module based on the detected optical signal. The spectral module includes a first spectrometer and a second spectrometer, the first spectrometer being configured to receive optical signals in a first band via diffraction spectroscopy, and the second spectrometer being configured to receive optical signals in a second band via transmission spectroscopy.

Description

Technical Field

[0001] Exemplary embodiments of the present invention relate to an integrated modular spectroscopic system and a method for diagnostic procedures using the system. More specifically, exemplary embodiments of the present invention relate to an integrated modular spectroscopic system and a method for diagnostic procedures using the system, employing an integrated modular spectroscopic system that integrates a diffraction-based spectrometer and a transmission-based spectrometer to diagnose the progress of various plasma-using processes, process anomalies, spectrometer replacement time, or contamination of the observation port. Prior Technology

[0002] Typically, in semiconductor or display manufacturing processes utilizing plasma, information about changes in the atomic, molecular, ionic, or electronic properties during the manufacturing process can be obtained from optical signals emitted during the process. Furthermore, based on the information obtained in this way, the completion status of the manufacturing process can be determined.

[0003] The optical signals emitted during the manufacturing process are mainly detected using a spectrometer, typically the Czerny-Turner type spectrometer described in Korean Patent Publication No. 10-2023-0058376.

[0004] In other words, using a Czerny-Turner spectrometer, the optical signals emitted during the process are incident on a diffraction spectrometer through an optical fiber, and then diffraction spectral analysis is performed through a grating. The intensity of each wavelength imaged on the CCD array can then be measured.

[0005] However, in the case of this type of diffraction spectrometer, there are limitations to providing the same wavelength resolution across the entire observation wavelength range and to improving sensitivity. Furthermore, the variation in wavelength resolution or sensitivity is limited depending on the arrangement of the individual elements that make up the spectrometer. In particular, there are problems with optical path misalignment due to vibration or temperature variations in the manufacturing facility, or errors due to changes in optical properties. Summary of the Invention

[0006] An exemplary embodiment of the present invention provides an integrated modular spectrometer system that uses an integrated modular spectrometer that integrates a diffraction-based spectrometer and a transmission-based spectrometer to diagnose the progress of various processes using plasma, process anomalies, spectrometer replacement time, or contamination of the observation port.

[0007] Furthermore, exemplary embodiments of the present invention also provide a method for the diagnostic process using the system.

[0008] To achieve the above objectives, the spectral system provided by the present invention includes a spectral module, a detection unit, and a diagnostic unit. The spectral module is configured to receive optical signals emitted from a plasma process. The detection unit is configured to detect optical signals according to frequency bands based on the optical signals received in the spectral module. The diagnostic unit is configured to determine the state of the plasma process or determine the calibration time of the spectral module based on the detected optical signals. The spectral module includes a first spectrometer and a second spectrometer. The first spectrometer is configured to receive optical signals in a first band by diffraction spectroscopy, and the second spectrometer is configured to receive optical signals in a second band by transmission spectroscopy.

[0009] In practice, the optical signals in the first band are optical signals in the ultraviolet (UV), visible light (VIS), and infrared (IR) bands, while the optical signals in the second band are optical signals in the ultraviolet (UV) and visible light (VIS) bands.

[0010] In practice, the diagnostic unit includes a first optical signal detector configured to detect optical signals in the ultraviolet, visible, and infrared bands received from the first spectrometer and optical signals in the ultraviolet and visible bands received from the second spectrometer.

[0011] In practice, the diagnostic unit includes a process determination unit configured to determine the endpoint of the plasma process based on the optical signal detected by the first optical signal detector.

[0012] In practice, the second spectrometer includes a filter configured to selectively transmit wavelengths belonging to specific bands of the ultraviolet (UV) and visible (VIS) light bands.

[0013] In practice, the detection unit includes a second optical signal detector configured to detect whether the optical signals in the ultraviolet and visible light bands received from the first spectrometer have shifted relative to the optical signals in the ultraviolet and visible light bands received from the second spectrometer.

[0014] In practice, the diagnostic unit includes a calibration determination unit configured to determine the alignment calibration point of the first spectrometer based on the motion state of the optical signal detected by the second optical signal detector.

[0015] In practice, the system may also include an observation port located between the processing chamber where plasma processing is performed and the spectral module. Optical signals emitted from the plasma process can be transmitted through the observation port.

[0016] In practice, the detection unit includes a third optical detector configured to detect the transmittance of optical signals in the visible and ultraviolet bands received from the first spectrometer and the transmittance of optical signals in the visible and ultraviolet bands received from the second spectrometer.

[0017] In practice, the diagnostic unit includes a replacement determination unit configured to determine when to replace the observation port based on the transmittance of the optical signal detected by the third optical signal detector.

[0018] In practice, the first spectrometer is configured to receive optical signals via an optical fiber, and the second spectrometer is configured to receive optical signals via the observation port.

[0019] In practice, the replacement time of the optical fiber or the replacement time of the observation port is determined by comparing the difference between the light transmittance of the optical signal received from the first spectrometer and the light transmittance of the optical signal received from the second spectrometer.

[0020] According to another aspect of the invention, the method includes receiving an optical signal emitted from a plasma process using a spectral module, detecting the optical signal according to a frequency band based on the optical signal received in the spectral module, and determining the state of the plasma process or the calibration time of the spectral module based on the detected optical signal. The spectral module includes a first spectrometer and a second spectrometer, the first spectrometer being configured to receive the optical signal in a first band via diffraction spectroscopy.

[0021] In practice, when determining the plasma process, the endpoint of the plasma process is determined based on the optical signal of each band of the detected optical signal.

[0022] During implementation, the detected optical signals are optical signals in the ultraviolet, visible, and infrared bands received from the first spectrometer and optical signals in the ultraviolet and visible bands received from the second spectrometer.

[0023] In practice, when determining the calibration time of the spectral module, the alignment calibration point of the first spectrometer is determined based on the state of movement of the optical signal received from the first spectrometer of the spectral module relative to the optical signal received from the second spectrometer of the spectral module.

[0024] During implementation, the optical signals received from the first spectrometer and the second spectrometer are optical signals in the ultraviolet and visible light bands.

[0025] In practice, optical signals are received through the observation port, and the replacement time of the observation port is determined based on the transmittance of the optical signals received from the first spectrometer and the transmittance of the optical signals received from the second spectrometer.

[0026] In practice, the transmittance of the optical signals received from the first spectrometer and the second spectrometer is the transmittance of the optical signals in the visible light and ultraviolet light bands.

[0027] According to some exemplary embodiments of the present invention, by simultaneously using a first spectrometer that performs diffraction spectroscopy and a second spectrometer that performs transmission spectroscopy, the first spectrometer is used to detect optical signals in the visible light (VIS)-infrared (IR) band, and the second spectrometer is used to detect optical signals in the ultraviolet (UV)-visible light (VIS) band. Therefore, optical signal detection can be performed across the entire frequency band with high sensitivity and reliability.

[0028] Therefore, by overcoming the resolution limitations of the first spectrometer in regions where adjacent optical signals exist (such as the ultraviolet band or metal atom emission signals), the spectrum of optical signals can be detected more accurately and reliably.

[0029] In particular, the second spectrometer includes a filter unit that transmits only wavelengths of a specific band, thereby selectively acquiring optical signals of a specific band to be monitored.

[0030] Therefore, by performing spectral detection of optical signals across the entire band and detecting optical signals in specific bands as described above, the endpoint of the plasma process can be determined more accurately and reliably.

[0031] Furthermore, due to alignment errors in the case of the first spectrometer, wavelengths tend to shift. When the wavelength of the optical signal received by the first spectrometer is significantly shifted relative to a specific band that may be observed jointly by the first and second spectrometers, the calibration time of the first spectrometer is determined, and the calibration of the spectral module can be performed.

[0032] Furthermore, when receiving optical signals emitted by the plasma through the observation port, the transmittance of the received optical signals decreases due to contamination of the observation port. Since the decrease in optical signal transmittance typically occurs in both the first and second spectrometers, it can be monitored to determine when to replace the observation port.

[0033] Therefore, when monitoring plasma processes, in addition to simply and accurately determining the process endpoint, information on the alignment status of the spectral module or the contamination status of the observation port can also be monitored simultaneously. This further improves the accuracy and reliability of determining the process endpoint.

[0034] To further understand the present invention, preferred embodiments are described below, along with drawings and reference numerals, to explain in detail the specific composition of the present invention and the effects it achieves. Simple Explanation of the Diagram

[0035] Figure 1A is a diagram showing the main emission optical signal during the transition process of argon in each energy region, and Figure 1B is a diagram showing the main emission optical signal of tungsten; Figure 2 is a block diagram showing the integrated modular spectral system; Figure 3 is a flowchart illustrating the diagnostic process using the spectral system shown in Figure 2; Figure 4 is a graph showing the optical signal spectrum that can be monitored using the spectral module of Figure 2; Figures 5A and 5B show the results of spectral processing of adjacent wavelength signals using the spectral module of Figure 2; Figures 6A and 6B are state diagrams showing the changes in wavelength signal when the flow rate of silane (SiH4) gas is changed using spectral analysis with the spectral module of Figure 2. Figures 7A and 7B are schematic diagrams used to explain the wavelength shift of the optical signal caused by the alignment error of the first spectrometer in Figure 2; Figure 8A is a graph showing the transmittance of the contamination of the observation port as a function of wavelength according to Figure 2, and Figure 8B is a graph showing the observation port replacement time as a function of the sensitivity of the spectral module in Figure 2. Implementation

[0036] The invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the exemplary embodiments described herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0037] Terms are used only to distinguish one element from another. The terminology used in this application is for describing specific embodiments only and is not intended to limit the invention. Unless the context clearly specifies otherwise, terms without quantity limitation may include single and multiple terms.

[0038] It should be further understood that the terms “comprising” and / or “including” as used in this specification are intended to describe the presence of the stated features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0039] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms, as defined in common dictionaries, shall be interpreted as having the meaning consistent with their meaning in the relevant field context, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0040] The present invention will now be described in detail with reference to the accompanying drawings.

[0041] First, before explaining the exemplary embodiments of the present invention, the required wavelength resolution will be explained by illustrating the frequency band of the optical signal emitted depending on the type of gas or metal used in the semiconductor or display manufacturing process using plasma.

[0042] Figure 1A is a diagram showing the main emission optical signal during the transition process of argon in each energy region, and Figure 1B is a diagram showing the main emission optical signal of tungsten.

[0043] Figure 1A shows the main emission optical signal band of argon (Ar), which is widely used as an inert gas in semiconductor or display manufacturing processes.

[0044] In the case of argon, for optical signals emitted during transitions in a relatively low energy region (2p->1s, where s and p are sublevels) (e.g., 750.4 nm wavelength), there is a band gap of 10 nm or more between the individual optical signals. However, for optical signals emitted during transitions (4p->1s) in a relatively high energy region (e.g., 425.9 nm wavelength), there is a band gap of 1 nm or more between the individual optical signals, thus requiring a relatively very high wavelength resolution.

[0045] Figure 1B shows the main emission optical signal bands of tungsten (W) in metal deposition or etching processes widely used in semiconductor or display manufacturing processes.

[0046] In the case of metals such as tungsten, the outermost electron orbits are d orbitals, and it can be confirmed that there are many energy levels near the energy level of the transitioning electron.

[0047] Furthermore, in terms of the intensity of the optical signal, collisions with high-energy electrons are crucial for generating optical signals with relatively high energy levels in the excited state. However, in typical semiconductor or display manufacturing process plasmas, the probability of the presence of high-energy electrons decreases exponentially. Therefore, relatively high wavelength resolution and high sensitivity are required to measure emitted optical signals in the ultraviolet (UV) band.

[0048] Therefore, in this exemplary embodiment, while selectively detecting optical signals emitted, particularly in the ultraviolet band, other optical signal bands other than the ultraviolet band can also be detected, thereby providing a spectral system with high wavelength resolution and high sensitivity for each detection band.

[0049] In the following sections, exemplary embodiments of the present invention will be described in detail.

[0050] Figure 2 is a block diagram showing the integrated modular spectral system.

[0051] Referring to Figure 2, the integrated modular spectral system 10 (hereinafter referred to as the system) includes a spectral module 100, a detection unit 200, and a diagnostic unit 300. The spectral module 100 includes a first spectrometer 110 and a second spectrometer 120. The detection unit 200 includes first to third optical signal detectors 210, 220, and 230. The diagnostic unit 300 includes a process determination unit 310, a calibration determination unit 320, and a replacement determination unit 330.

[0052] Here, the first spectrometer 110 is a diffraction spectrometer, and the second spectrometer 120 is a transmission spectrometer.

[0053] As described above, system 10 performs spectral analysis on optical signals emitted from processes using plasma (such as semiconductor or display manufacturing processes) (i.e., plasma-emitted optical signals 20) and performs monitoring related to the plasma process. Here, the detailed example processes are not limited to semiconductor or display processes, nor are they limited to various processes in which plasma is used.

[0054] Furthermore, in the case of system 10, the plasma emission optical signal 20 is typically received via an observation port 30 of the processing chamber where the plasma processing is performed, and the observation port 30 may be pre-installed on the processing chamber. Alternatively, system 10 may be installed in the processing chamber.

[0055] In both cases, where the observation port 30 is pre-installed in the processing chamber and installed together with the system 10, the status of the observation port 30 can be monitored by the system 10, as described later.

[0056] Meanwhile, for ease of explanation, the detailed configuration of the system 10 will be described in detail by means of the method used to utilize the diagnostic process of system 10 (described later).

[0057] Figure 3 is a flowchart illustrating the diagnostic process using the spectral system of Figure 2.

[0058] Referring to Figures 2 and 3, in the method of using the diagnostic process of system 10, a plasma emission optical signal 20 is generated during the plasma process (step S10), and the plasma emission light information 20 is provided to system 10 through the observation port 30 (step S20).

[0059] Referring to Figures 2 and 3, the spectral module 100 receives the optical signal 20 provided through the observation port 30 and monitors the optical signal 20 (step S30).

[0060] For example, the spectral module 100 includes a first spectrometer 110 and a second spectrometer 120, and the received optical signal 20 is provided to both the first spectrometer 110 and the second spectrometer 120 (steps S31 and S32).

[0061] The first spectrometer 110 receives the received optical signal 20 by performing diffraction spectroscopy on the optical signal in the first band.

[0062] The first spectrometer 110 is a diffraction spectrometer that receives optical signals via an optical fiber, diffracts them through a grating, and then measures the intensity of each wavelength imaged on a CCD array. In this case, the arrangement or structure of the mirrors, gratings, or CCD array constituting the first spectrometer 110 can be designed in various ways and is not limited to a specific structure, and any diffraction spectrometer in the prior art can be used.

[0063] Here, the optical signal in the first band can be an optical signal in the ultraviolet (UV), visible (VIS), and infrared (IR) bands.

[0064] The first spectrometer 110 receives optical signals in the ultraviolet (UV), visible (VIS), and infrared (IR) bands, which constitute the first band of optical signals (step S32). Simultaneously, the infrared band included in the first band of optical signals may be a near-infrared (NIR) band within a narrow range of 750 nm to 1000 nm.

[0065] In contrast, the second spectrometer 120 receives the received optical signal 20 by performing a transmission spectrum on the optical signal in the second band.

[0066] The second spectrometer 120 is a transmission spectrometer that transmits optical signals only in a specific wavelength band and measures the intensity in that band. In this case, the second spectrometer 120 may include a filter 130 to selectively transmit only optical signals in the specific wavelength band. Furthermore, the filter 130 may be selectively mounted to transmit only specific wavelength bands. The filter 130 includes at least one filter, and each filter selectively transmits only optical signals in the specific wavelength band, thereby selectively transmitting optical signals within the desired wavelength range for the entire filter 130.

[0067] The optical signal in the second band can be, for example, an optical signal in the ultraviolet (UV) and visible (VIS) bands. However, by means of filter 130, optical signals within a specific wavelength range in the ultraviolet (UV) and visible (VIS) bands can be selectively transmitted.

[0068] In other words, the filter 130 of the second spectrometer 120 can be configured to typically transmit only optical signals in the ultraviolet and visible bands, but the filter 130 can be configured to selectively transmit only optical signals in a narrower band.

[0069] As described above, this is to overcome the limitation of wavelength resolution based on adjacent optical signals in the case of a first spectrometer, especially in the ultraviolet band, and to perform spectral analysis of optical signals with high sensitivity.

[0070] Therefore, the second spectrometer 120 can receive optical signals in the ultraviolet (UV) and visible (VIS) bands as optical signals in the second band, or it can receive optical signals in the ultraviolet and visible bands with a narrower selective band (step S34).

[0071] In other words, optical signals in the visible light (VIS) band can also be transmitted simultaneously through the second spectrometer 120 to measure the intensity of the corresponding band (step S34). However, when the second spectrometer 120 transmits optical signals in the visible light (VIS) band together with optical signals in the ultraviolet band, it can be used more effectively to determine the replacement time of the observation port 30, as described later.

[0072] As described above, the spectral module 100 receives optical signals via the first spectrometer 110 and the second spectrometer 120. An example of optical signals received in this manner is described below.

[0073] Figure 4 is a graph showing the optical signal spectrum that can be monitored using the spectral module of Figure 2.

[0074] As shown in Figure 4, with the first spectrometer 110, multiple emitted optical signals can be monitored simultaneously across the entire indicated wavelength band (400nm to 1000nm).

[0075] In contrast, with the second spectrometer 120, it can be confirmed that a small amount of emitted optical signals can be selectively monitored only for specific wavelength bands (approximately 630 nm or approximately 650 nm). Here, in the case of Figure 4, the monitoring characteristics of emitted optical signals are checked only for a specific wavelength range (400 nm to 1000 nm) depending on the type of spectrometer. In fact, as described above, the second spectrometer 120 in this exemplary embodiment primarily monitors emitted optical signals in the visible light (VIS) and ultraviolet (UV) bands, which is the second band.

[0076] Furthermore, when the filter 130 in the second spectrometer 120 includes an ultra-narrowband filter, an effective spectrum with adjacent wavelength signals can be achieved for a narrower band.

[0077] Regarding the above, Figures 5A and 5B show the results of spectralizing adjacent wavelength signals using the spectral module of Figure 2.

[0078] Referring to Figures 5A and 5B, for example, as a result of spectral analysis of the emission optical signals of a plasma in which hydrogen and nitrogen coexist via spectral module 100, it can be confirmed that multiple emission optical signals can be simultaneously monitored across the entire wavelength range (620 nm to 665 nm) by the first spectrometer 110.

[0079] In contrast, in the case of the second spectrometer 120, the filter 130 is applied to transmit only specific wavelengths, thereby allowing selective monitoring of a small number of emitted optical signals only for specific bands (625-635nm band or 655-660nm band).

[0080] However, as shown in Figure 5B, when filter 130 is applied as an ultra-narrowband filter that transmits only the H-α band, it can be confirmed that for the signal in the H-α band (656.4 nm), accurate and effective spectral analysis can be performed using nitrogen (N) signals (654.9 nm and 658.5 nm), which are signals in adjacent bands.

[0081] Therefore, by selecting the filter 130 applied to the second spectrometer 120 to measure only the signal in the target band, effective spectral analysis can be performed even if the signals are very adjacent.

[0082] As described above, the spectrometer module 100 uses both the first spectrometer 110 and the second spectrometer 120 to receive optical signals across the entire wavelength band, while selectively receiving optical signals in a specific wavelength band within a relatively narrow region, thereby performing spectral analysis.

[0083] However, the above description is intended to explain the characteristics of the second spectrometer 120, which, as mentioned above, requires high wavelength resolution and sensitivity to measure emitted optical signals primarily in the ultraviolet band. Therefore, in this exemplary embodiment, optical signals primarily in the ultraviolet band are received and analyzed by the second spectrometer 120. Of course, as previously stated, optical signals in the visible light band can also be received and separated.

[0084] Furthermore, in the case of the second spectrometer 120 in this exemplary embodiment, changes in the intensity of the transmitted signal can be measured relatively accurately.

[0085] Regarding the above, Figures 6A and 6B are graphs showing the changes in wavelength signal when the flow rate of silane (SiH4) gas changes, using spectral analysis with the spectral module of Figure 2.

[0086] In the case of Figure 6A, when the flow rate of silane (SiH4) gas changes, this is the result of measuring the change in the Hα signal according to the variable flow rate of silane gas by the first spectrometer 110.

[0087] Conversely, in the case of Figure 6B, when the flow rate of silane (SiH4) gas changes, this is the result of measuring the change in the Hα signal according to the variable flow rate of silane gas using the second spectrometer 120.

[0088] Referring to Figure 6A, in the case of the first spectrometer 110, since the nitrogen (N2) signal with a fixed flow rate is measured as an overlapping value, it can be confirmed that there is a limitation, namely, that it does not reflect the change in the amount of hydrogen (H) contained in the silane gas with a variable flow rate.

[0089] However, referring to Figure 6B, in the case of the second spectrometer 120, particularly the second spectrometer described above which includes an ultra-narrowband filter that transmits only the H-α band as a filter unit 130, it can be seen that the change in the intensity of the H emission signal, which depends on the flow rate of the H-precursor, can be measured more accurately. That is, it can be seen that the H-alpha signal increases as the flow rate of the precursor increases from 90 sccm to 290 sccm.

[0090] In other words, when spectral analysis is performed by additionally using the second spectrometer 120 as in this exemplary embodiment, spectral analysis between adjacent signals can be performed effectively, thereby clearly measuring the intensity change state of a specific signal.

[0091] As described above, when optical signals of the first and second bands are received by the spectral module 100, optical signals of a specific frequency band are detected by the detection unit 200.

[0092] Referring to Figures 2 and 3, based on the optical signals received in the spectral module 100, the detection unit 200 detects the optical signals according to each frequency band (step S40).

[0093] Here, considering the target identified in the diagnostic unit 300 below, the optical signal detection in the detection unit 200 selectively detects necessary signals or information, which will be described in detail below.

[0094] First, the first optical signal detector 210 of the detection unit 200 detects the optical signals in the ultraviolet, visible and infrared bands received from the first spectrometer 110 and the light in the ultraviolet and visible bands received from the second spectrometer 120 (step S41).

[0095] For all optical signals across all bands detected by the spectral module 100, the first optical signal detector 210 obtains information about the optical signal spectrum, specifically information about the optical signal intensity at each wavelength. Then, the first optical signal detector 210 acquires information about the characteristics of the optical signal itself within the target wavelength range.

[0096] Therefore, the information detected by the first optical signal detector 210 is provided to the process determination unit 310, which will be described later.

[0097] The second optical signal detector 220 of the detection unit 200 detects whether the optical signal in the ultraviolet and visible light bands received from the first spectrometer 100 has shifted relative to the optical signal in the ultraviolet and visible light bands received from the second spectrometer 120, based on the optical signals in the ultraviolet and visible light bands received from the first spectrometer 110 and the optical signals in the ultraviolet and visible light bands received from the second spectrometer 120 (step S42).

[0098] Furthermore, information regarding the movement of optical signals in the ultraviolet and visible bands detected by the second optical signal detector 220 is provided to the calibration determination unit 320, which will be described later.

[0099] In addition, the third optical signal detector 230 of the detection unit 200 detects the brightness of the optical signals in the ultraviolet and visible bands received from the first spectrometer 110, and the brightness of the optical signals in the ultraviolet and visible bands received from the second spectrometer 120 (step S43).

[0100] As previously described, the second spectrometer 120 receives optical signals in the ultraviolet band, but may also optionally receive optical signals in certain visible light bands. Therefore, the visible light band optical signals received in this manner are detected by the third optical signal detector 230.

[0101] Therefore, the optical signal information in the visible light and ultraviolet bands detected by the third optical signal detector 230, that is, the information of the optical signals in the bands jointly acquired by the first spectrometer 110 and the second spectrometer 120, is provided to the replacement determination unit 300.

[0102] As described above, the detection unit 200 selectively detects optical signals in a desired band relative to the optical signals in the band received from the spectral module 100, and provides the detected information to the diagnostic unit 300.

[0103] Then, referring to Figures 2 and 3, the diagnostic unit 300 performs the necessary determination process based on the optical signals of each band detected by the detection unit 200.

[0104] Here, the specific determination process made by the diagnostic unit 300 is explained as follows.

[0105] First, the process determination unit 310 determines the endpoint of the plasma process based on the optical signal detected by the first optical signal detector 210 (step S51).

[0106] In other words, the first optical signal detector 210 detects optical signals in the ultraviolet, visible, and infrared bands received by the first spectrometer 110, and simultaneously detects optical information in the ultraviolet and visible bands received by the second spectrometer 120. Here, in the case of the second spectrometer 120, as described above, optical signals in an ultra-narrowband of a specific frequency band can be detected.

[0107] Therefore, in the process determination unit 310, information on the gas composition contained in the plasma emission optical signal 20 can be confirmed based on the characteristics of the optical signals in the entire band of ultraviolet, visible and infrared light, that is, the characteristics of the optical signal intensity of each wavelength.

[0108] In particular, since the second spectrometer 120 can more accurately obtain the characteristics of the optical signal intensity of each specific wavelength in the high-sensitivity ultraviolet region, the spectral effect between adjacent optical signals is improved, thereby enabling more accurate confirmation of information on the gas composition contained in the plasma emission optical signal 20.

[0109] Therefore, the process determination unit 310 can examine the characteristics such as the gas type and intensity in the currently occurring plasma process based on the characteristics of the optical signal intensity at each wavelength, thereby determining the endpoint of the plasma process.

[0110] Of course, in addition to the endpoint of the plasma process, the process determination unit 310 can also obtain information about the progress of the plasma process, but since the endpoint is an important point in the process, determining the endpoint of the plasma process may be the most important.

[0111] Furthermore, the calibration determination unit 320 determines the alignment calibration point where the first spectrometer 110 needs to be aligned based on information about the motion state of the optical signal detected by the second optical signal detector 220 (step S52).

[0112] Regarding the above, Figures 7A and 7B are schematic diagrams used to explain the wavelength shift of the optical signal caused by the alignment error of the first spectrometer in Figure 2.

[0113] As shown in Figure 7A, when the first spectrometer 110 has an alignment error in at least one of the first to the cooperating manufacturer directions (X, Y and Z), as shown in Figure 7B, there is a problem that the received wavelength shifts relatively significantly in the long wavelength direction and the short wavelength direction.

[0114] Conversely, in the case of the second spectrometer 120, when the incident angle changes due to alignment errors between the lens, transmission filter and detector constituting the second spectrometer 120, the wavelength of the observed optical signal shifts only slightly to a shorter wavelength, as shown in equation (1) below.

[0115] λθ=λ0[1-(n0 / n*)sin2θ]1 / 2

[0116] At this point, λθ is the optical signal wavelength that was incorrectly measured due to alignment error, λ0 is the original optical signal wavelength, n0 is the refractive index of the optical signal transmission medium (air), n* is the refractive index of the bandpass filter, and θ is the alignment error angle.

[0117] In equation (1), assuming that the optical signal with a wavelength of 500 nm has an alignment error of 1 degree, the wavelength shift is only 0.05 nm. It can be confirmed that the wavelength shift caused by the alignment error in the second spectrometer 120 is much smaller than the wavelength shift caused by the alignment error in the first spectrometer 110.

[0118] For the visible and ultraviolet band signals jointly detected by the first spectrometer 110 and the second spectrometer 120, when the wavelength of the optical signal deviates from the wavelength of the optical signal observed at the start of installation, the calibration determination unit 320 can determine that the alignment of the first spectrometer 110 needs to be calibrated.

[0119] This is because the wavelength shift of the optical signal is not generated by the second spectrometer 120, but by the first spectrometer 110.

[0120] Therefore, if the optical signal wavelength shifts beyond a preset shift amount, it is determined that the first spectrometer 110 needs to be aligned and calibrated, and the alignment state of the first spectrometer 110 is calibrated.

[0121] Furthermore, the replacement determination unit 330 determines the time to replace the observation port 30 based on the transmittance of the optical signal detected by the third optical signal detector 230 (step S53).

[0122] The replacement time of the observation port 30 is determined based on the transmittance of the optical signals in the visible and ultraviolet bands received from the first spectrometer 110 and the transmittance of the optical signals in the visible and ultraviolet bands received from the second spectrometer 120.

[0123] As described above, the observation port 30 is the window through which the plasma emission optical signal 20 passes and is provided to the spectral module 100, and must have high transparency in order to effectively provide the emission optical signal 20.

[0124] However, as the plasma process continues, the observation port 30 may become contaminated, and due to this contamination, the transmittance or light intensity of the emitted optical signal 20 provided through the observation port 30 may decrease.

[0125] Regarding the above, Figure 8A is a state curve showing the transmittance of the observation port contamination as a function of wavelength according to Figure 2, and Figure 8B is a curve showing the observation port replacement time as a function of the sensitivity of the spectral module in Figure 2.

[0126] Referring to Figure 8A, it can be seen that as the observation port 30 becomes contaminated, the transmittance changes rapidly within a relatively short wavelength range (200 nm to 500 nm). This is a phenomenon that typically occurs not only in the first spectrometer 110 but also in the second spectrometer 120. Contamination of the observation port 30 occurs when organic or inorganic materials are deposited on the surface of the quartz-made observation port. Therefore, as shown in Figure 8A, it can be confirmed that, due to the rapid change in transmittance within a relatively short wavelength range, there is a trend towards a reduction in long-wavelength signals compared to short-wavelength signals.

[0127] Then, since the transmittance change caused by contamination of the observation window occurs not only in the first spectrometer 110 but also in the second spectrometer 120, it is necessary to obtain the optical signal in the band by the second spectrometer 20. This band includes not only ultraviolet light, i.e., the simple short wavelength range, but also visible light, in order to more accurately obtain the trend of the reduction of long wavelength signal compared with short wavelength signal.

[0128] Therefore, by simultaneously using the transmittance obtained from the first spectrometer 110, which has acquired optical signals from all bands, and the transmittance obtained from the second spectrometer 120, the trend of decreasing long-wavelength signals compared to short-wavelength signals can be more accurately confirmed, as shown in Figure 8A.

[0129] As shown in Figure 8B, the replacement determination unit 330 determines the timing of replacing the observation port 30 based on the contamination status of the observation port 30 by simultaneously monitoring the changes in transmittance in the ultraviolet and visible light bands obtained from the first spectrometer 110 and the changes in transmittance in the ultraviolet and visible light bands obtained from the second spectrometer 120.

[0130] Therefore, when the light transmittance of the observation port 30 becomes lower than the preset standard for the contaminated state, the observation port 30 should be replaced.

[0131] The reception of optical signals from the first spectrometer 110 can be performed via optical fiber, and the reception of optical signals from the second spectrometer 120 can be performed via observation port 30.

[0132] In this case, the time to replace the optical fiber or the time to replace the observation port can be determined by comparing the difference between the transmittance of the optical signal received by the first spectrometer 110 and the transmittance of the optical signal received by the second spectrometer 120 at the start of the measurement.

[0133] Here, if the transmittance of the optical signal received from the first spectrometer 110 is relatively lower than the transmittance of the optical signal received from the second spectrometer 120, it can be determined that the optical fiber needs to be replaced. Conversely, in the opposite case, it can be determined that the observation window needs to be replaced.

[0134] As described above, the diagnostic unit 300 can selectively use the optical signal information detected by the detection unit 200 to determine various states of the plasma process, particularly the end time, the calibration time of the first spectrometer 110, and even the replacement time of the observation port 30. Furthermore, the connection status of the first spectrometer 110 can be considered to determine when to replace the optical fiber.

[0135] According to some exemplary embodiments of the present invention, by simultaneously using a first spectrometer that performs diffraction spectroscopy and a second spectrometer that performs transmission spectroscopy, the first spectrometer is used to detect optical signals in the visible light (VIS)-infrared (IR) band, and the second spectrometer is used to detect optical signals in the ultraviolet (UV)-visible light (VIS) band. Therefore, optical signal detection can be performed across the entire frequency band with high sensitivity and reliability.

[0136] Therefore, by overcoming the resolution limitations of the first spectrometer in regions where adjacent optical signals exist (such as the ultraviolet band or metal atom emission signals), the spectrum of optical signals can be detected more accurately and reliably.

[0137] In particular, the second spectrometer includes a filter unit that transmits only wavelengths of a specific band, thereby selectively acquiring optical signals of a specific band to be monitored.

[0138] Therefore, by performing spectral detection of optical signals across the entire band and detecting optical signals in specific bands as described above, the endpoint of the plasma process can be determined more accurately and reliably.

[0139] Furthermore, due to alignment errors in the case of the first spectrometer, wavelengths tend to shift. When the wavelength of the optical signal received by the first spectrometer is significantly shifted relative to a specific band that may be observed jointly by the first and second spectrometers, the calibration time of the first spectrometer is determined, and the calibration of the spectral module can be performed.

[0140] Furthermore, when receiving optical signals emitted by the plasma through the observation port, the transmittance of the received optical signals decreases due to contamination of the observation port. Since the decrease in optical signal transmittance typically occurs in both the first and second spectrometers, it can be monitored to determine when to replace the observation port.

[0141] Therefore, when monitoring plasma processes, in addition to simply and accurately determining the process endpoint, information on the alignment status of the spectral module or the contamination status of the observation port can also be monitored simultaneously. This further improves the accuracy and reliability of determining the process endpoint.

[0142] The above description describes specific embodiments of the present invention and the technical means used. Many changes and modifications can be derived from the disclosure or teachings herein, which can still be regarded as equivalent changes to the concept of the present invention. The effects produced do not exceed the essential spirit covered by the specification and drawings, and should all be regarded as within the technical scope of the present invention. This is hereby stated.

[0143] In summary, based on the content disclosed above, the present invention can indeed achieve the intended purpose of the invention, providing an integrated modular spectral system and a method for the diagnostic process using the spectral system, which is highly practical and has industrial value. Therefore, an invention patent application is filed in accordance with the law.

[0144] 10: Integrated modular spectral system 20: Plasma emits optical signals 30: Observation Post 100: Spectral Module 110: First Spectrometer 120: Second Spectrometer 130: Filter 200: Detection Unit 210: First optical signal detector 220: Second optical signal detector 230: Third optical signal detector 300: Diagnostic Unit 310: Process Determination Unit 320: Calibration Determination Unit 330: Replace the determining unit

Claims

1. A spectroscopic system, comprising: A spectral module is configured to receive optical signals emitted from a plasma process; A detection unit is configured to detect an optical signal according to a frequency band based on an optical signal received in the spectral module; and a diagnostic unit is configured to determine the state of a plasma process or determine the calibration time of the spectral module based on the detected optical signal; wherein the spectral module includes a first spectrometer and a second spectrometer, the first spectrometer being configured to receive an optical signal in a first band by diffraction spectroscopy, and the second spectrometer being configured to receive an optical signal in a second band by transmission spectroscopy; wherein the detection unit includes a second optical signal detector, the second optical signal detector being configured to detect whether the optical signal received from the first spectrometer has shifted relative to the optical signal received from the second spectrometer.

2. The spectral system as claimed in claim 1, wherein the optical signal in the first band is an optical signal in the ultraviolet (UV), visible (VIS), and infrared (IR) bands, wherein, The optical signals in this second band are optical signals in the ultraviolet (UV) and visible (VIS) bands.

3. The spectral system as claimed in claim 2, wherein the diagnostic unit includes a first optical signal detector configured to detect optical signals in the ultraviolet, visible, and infrared bands received from the first spectrometer and optical signals in the ultraviolet and visible bands received from the second spectrometer.

4. The spectral system as claimed in claim 3, wherein the diagnostic unit includes a process determination unit configured to determine the endpoint of the plasma process based on an optical signal detected by the first optical signal detector.

5. The spectral system as claimed in claim 2, wherein the second spectrometer includes a filter configured to selectively transmit wavelengths belonging to specific bands of the ultraviolet (UV) and visible (VIS) light bands.

6. The spectral system as claimed in claim 2, wherein the second optical signal detector is configured to detect whether the optical signals in the ultraviolet and visible light bands received from the first spectrometer are shifted relative to the optical signals in the ultraviolet and visible light bands received from the second spectrometer.

7. The spectroscopic system as claimed in claim 6, wherein the diagnostic unit includes a calibration determination unit configured to determine the alignment calibration point of the first spectrometer based on the motion state of the optical signal detected by the second optical signal detector.

8. The spectroscopic system as described in claim 2 further includes an observation port disposed between the processing chamber where plasma processing is performed and the spectroscopic module, wherein, Optical signals emitted from the plasma process are transmitted through the observation port.

9. The spectral system as claimed in claim 2, wherein the detection unit includes a third optical detector configured to detect the transmittance of optical signals in the visible and ultraviolet bands received from the first spectrometer and the transmittance of optical signals in the visible and ultraviolet bands received from the second spectrometer.

10. The spectral system as claimed in claim 8, wherein the diagnostic unit includes a replacement determination unit configured to determine when to replace the observation port based on the transmittance of the optical signal detected by the third optical signal detector.

11. The spectroscopic system as claimed in claim 8, wherein the first spectrometer is configured to receive optical signals via an optical fiber, and the second spectrometer is configured to receive optical signals via the observation port.

12. The spectroscopic system as claimed in claim 11, wherein the replacement time of the optical fiber or the replacement time of the observation port is determined by comparing the difference between the light transmittance of the optical signal received from the first spectrometer and the light transmittance of the ground optical signal received from the second spectrometer.

13. A method for a diagnostic process, comprising: The optical signals emitted from the plasma process are received using a spectral module; Based on the optical signal received in the spectral module, the optical signal is detected according to the frequency band; and based on the detected optical signal, the state of the plasma process or the calibration time of the spectral module is determined, wherein the spectral module includes a first spectrometer and a second spectrometer, the first spectrometer being configured to receive the optical signal in a first band by diffraction spectroscopy, and the second spectrometer being configured to receive the optical signal in a second band by transmission spectroscopy; wherein, during the detection of the optical signal, it is detected whether the optical signal received from the first spectrometer has shifted relative to the optical signal received from the second spectrometer.

14. The method as described in claim 13, wherein, in determining the plasma process, the endpoint of the plasma process is determined based on the optical signal of each band of the detected optical signal.

15. The method as claimed in claim 13, wherein the detected optical signals are optical signals in the ultraviolet, visible and infrared bands received from the first spectrometer and optical signals in the ultraviolet and visible bands received from the second spectrometer.

16. The method as described in claim 13, wherein when determining the calibration time of the spectral module, the alignment calibration point of the first spectrometer is determined based on the state of movement of the optical signal received from the first spectrometer of the spectral module relative to the optical signal received from the second spectrometer of the spectral module.

17. The method as described in claim 13, wherein the optical signals received from the first spectrometer and the second spectrometer are optical signals in the ultraviolet and visible light bands.

18. The method as described in claim 13, wherein an optical signal is received via an observation port, and the replacement time of the observation port is determined based on the transmittance of the optical signal received from the first spectrometer and the transmittance of the optical signal received from the second spectrometer.

19. The method as described in claim 18, wherein the transmittance of the optical signals received from the first spectrometer and the second spectrometer is the transmittance of the optical signals in the visible and ultraviolet bands.

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