Spectrum detection light path and adjusting method thereof, film thickness monitoring system and vacuum coating machine

Abstract

The invention relates to a spectrum detection light path and an adjusting method thereof, a film thickness monitoring system and a vacuum coating machine. According to the spectrum detection light path, a transmitting module and a receiving module are arranged on the two opposite side faces of the vacuum cavity respectively, the transmitting module comprises a transmitting collimating mirror, the receiving module comprises a receiving collimating mirror, and the aperture of the transmitting collimating mirror is larger than that of the receiving collimating mirror; the emitting collimating mirror emits a collimated light beam with a preset size, and the receiving collimating mirror receives the collimated light beam to obtain a receiving light spot and sends the receiving light spot to the spectrograph; in the technical scheme, the transmitting collimating mirror and the receiving collimating mirror adopt an asymmetric optical path coupling design, the anti-interference capability is strong, and the optical part is designed outside the vacuum cavity, so that the internal space occupation and mode of the vacuum cavity are reduced, the stability of detection data is ensured, the replacement and maintenance are convenient, and the maintenance difficulty is reduced.

Description

Technical Field

[0001] This application relates to the field of optical thin film manufacturing technology, and in particular to a spectral detection optical path and its adjustment method, a film thickness monitoring system, and a vacuum coating machine. Background Technology

[0002] In the field of high-end optical thin film manufacturing, with the development of modern cutting-edge technology, the number of photons that optical systems are required to collect and process is increasing day by day. The most direct way to achieve this goal is to use optical elements with larger apertures. As the "performance skin" of optical elements, the aperture of the coating must naturally be increased accordingly.

[0003] As the aperture of optical thin-film devices increases, the corresponding thin-film manufacturing equipment will inevitably increase in size. In addition, for optical thin films, product quality is directly proportional to the cleanliness of the cavity. The higher the cleanliness, the higher the product quality, which means fewer components in the cavity and a lower possibility of impurities contaminating the product. Therefore, the entire equipment system has very high requirements for the optical path and it is necessary to avoid placing a large number of monitoring devices inside the cavity.

[0004] After a vacuum chamber is evacuated to a high vacuum, the deformation of the chamber causes the pre-calibrated light to shift. In high-precision optical systems, this will be very noticeable in the detection response. The light shift caused by the deformation of the vacuum chamber may lead to a decrease in spectral energy and a decrease in signal-to-noise ratio, which is extremely detrimental to precise thin-film monitoring. Furthermore, in order to ensure stable acquisition of effective data within a single cycle, as much data as possible needs to be acquired on the smallest possible monitoring substrate. This is to avoid the impact of uniformity issues on the stability of spectral data in the acquired single-cycle data. Current monitoring schemes require the online optical monitoring system to be deployed outside of large-aperture equipment, resulting in long optical path requirements. Atmospheric and vacuum environment-related chamber deformation may also cause optical path collimation and sampling problems, reducing the signal-to-noise ratio. In addition, the requirement to acquire as much data as possible with a small spot size on the smallest possible monitoring substrate places increasingly higher demands on the complexity, accuracy, and stability of the optical path.

[0005] Existing optical monitoring systems employ two main optical path designs for spectral detection. One design uses a bulb-based light source and a coupler mirror, with the bulb inside a vacuum chamber and the coupler outside for light collection. This design cannot meet the requirements for long optical path light collection, and the presence of the light source inside the chamber makes it prone to product contamination and makes uniformity adjustment difficult. Another design involves placing an input port and a receiving port on opposite sides of the vacuum chamber. The light source transmits the light signal through the input port, passes through the monitoring substrate, and is received by the signal receiving structure at the receiving port. However, when applied to large-aperture optical thin film fabrication equipment, the deformation of the vacuum chamber under vacuum conditions can easily lead to light shift, resulting in a reduction in spectral energy and affecting the effectiveness of the spectral energy, thus lowering the signal-to-noise ratio and impacting data acquisition quality. Furthermore, to ensure a sufficiently small monitoring substrate and a large number of monitoring devices, the monitoring spot size must be sufficiently small. However, a small spot size over a long optical path results in limited spectral energy and makes debugging difficult.

[0006] In summary, in large-aperture optical thin film equipment that demands long optical path, small spot size, high energy, and strong anti-interference capabilities, existing spectral detection optical paths cannot ensure the stability and accuracy of the acquired spectral data, severely impacting the precision of coating control. Summary of the Invention

[0007] To address one of the aforementioned deficiencies, this application provides a spectral detection optical path and its adjustment method, a film thickness monitoring system, and a vacuum coating machine.

[0008] A spectral detection optical path, applied to a film thickness monitoring system, includes: a transmitting module and a receiving module respectively disposed on opposite sides of a vacuum cavity; the transmitting module is installed outside a transmitting hole on one side of the vacuum cavity, and the receiving module is installed outside a receiving hole on the other side of the vacuum cavity; The launching module includes a launching collimator, the front end of which is mounted on the launching port; The receiving module includes a receiving collimating lens, the front end of which is mounted on a receiving hole; The aperture of the transmitting collimating lens is larger than the aperture of the receiving collimating lens; The transmitting collimating lens receives the light source signal and emits a collimated beam of a preset size towards the receiving aperture through the transmitting aperture; the collimated beam passes through the monitoring substrate on the orbital disk and then reaches the receiving aperture; The receiving collimating lens receives the collimated beam and obtains a receiving spot, which is then sent to the spectrometer.

[0009] In some embodiments, the launching module further includes a first adjustment frame mounted outside the side of the vacuum chamber, and the launching collimator is connected to the first adjustment frame; The first adjustment bracket is used to adjust the planar position and directional angle of the transmitting collimator; The receiving module also includes a second adjustment frame installed on the outside of the side of the vacuum chamber; The front end of the receiving collimating lens is mounted on the receiving hole, and the receiving collimating lens is connected to the second adjustment bracket; The second adjustment bracket is used to adjust the planar position and directional angle of the receiving collimating mirror.

[0010] In some embodiments, the first adjustment frame includes: a first two-dimensional translation stage and a first angle adjustment stage, wherein the first two-dimensional translation stage is used to adjust the launch collimator to move in a plane, and the first angle adjustment stage is used to adjust the pitch or tilt angle of the launch collimator. The second adjustment frame includes: a second two-dimensional translation stage and a second angle adjustment stage. The second two-dimensional translation stage is used to adjust the plane movement of the receiving collimating lens, and the second angle adjustment stage is used to adjust the pitch or tilt angle of the receiving collimating lens.

[0011] In some embodiments, the first adjusting frame and the second adjusting frame are respectively connected to the control system; The control system is used to output control signals to adjust the first adjustment frame and the second adjustment frame according to the adjustment parameters, control the first two-dimensional translation stage and the second two-dimensional translation stage to perform planar movement, and control the first angle adjustment stage and the second angle adjustment stage to perform angle adjustment, adjust the collimated beam to be concentric with the received light spot, and the collimated beam to be perpendicular to the monitoring substrate.

[0012] In some embodiments, the collimated beam is a parallel beam with a spot diameter of 25 mm; The effective aperture of the receiving collimating lens is 5mm. The diameter of the monitoring substrate is 50mm; The diameter of the transmitting and receiving holes is 50 mm.

[0013] In the above embodiment, a transmitting module and a receiving module are respectively arranged on opposite sides of the vacuum cavity. The transmitting module includes a transmitting collimating lens, and the receiving module includes a receiving collimating lens. The aperture of the transmitting collimating lens is larger than that of the receiving collimating lens. The transmitting collimating lens emits a collimated beam of a preset size, and the receiving collimating lens receives the collimated beam to obtain a received light spot, which is then sent to the spectrometer. In this technical solution, the transmitting collimating lens and the receiving collimating lens adopt an asymmetric optical path coupling design, which has strong anti-interference ability. Moreover, the optical components are designed outside the vacuum cavity, reducing the space occupied inside the vacuum cavity. This method ensures the stability of the detection data, facilitates replacement and maintenance, and reduces maintenance difficulty.

[0014] A method for adjusting a spectral detection optical path, applied to the spectral detection optical path, comprising: (1) Control the transmitting collimator to emit the first test spot, and use the first test spot and the first reflected spot reflected by the mirror at the position of the monitoring substrate to control the first adjustment frame to adjust the transmitting collimator to be perpendicular to the monitoring substrate; (2) Control the receiving collimator to emit a second test spot, and use the second test spot and the second reflected spot reflected by the mirror at the position of the monitoring substrate to control the second adjustment frame to adjust the receiving collimator to be perpendicular to the monitoring substrate; (3) Control the second adjustment frame to adjust the center position of the second reflected light spot to coincide with the center position of the first test light spot, so that the transmitting collimator and the receiving collimator are concentric.

[0015] In some embodiments, step (1) includes: A reflector is placed on one side of the transmitting collimator at the monitoring substrate position, and a first whiteboard is placed near the transmitting collimator position; Place the launching collimator at the initially set plane position and direction angle, and launch the first test spot through the launching collimator; The first adjustment frame is controlled to adjust the plane position and direction angle of the transmitting collimator so that the first test light spot coincides with the first reflected light spot reflected back by the reflector.

[0016] In some embodiments, step (2) includes: A reflector is placed on one side of the receiving collimator at the monitoring substrate position, and a second whiteboard is placed near the receiving collimator. Place the receiving collimator in the initially set plane position and orientation angle, and emit the second test spot through the receiving collimator; The second adjustment frame is controlled to adjust the plane position and direction angle of the receiving collimating mirror so that the second test light spot coincides with the second reflected light spot reflected back by the reflector.

[0017] In some embodiments, step (3) includes: After the first test spot coincides with the first reflected spot reflected back by the mirror, a third whiteboard is placed at the monitoring substrate position, and the first test spot and its center are marked on the third whiteboard. After the second test spot coincides with the second reflected spot reflected back by the reflector, the reflector is removed, and the second test spot illuminates the third white board. The second adjustment frame is controlled to adjust the plane position of the receiving collimating lens so that the center of the second test spot illuminating the third white board coincides with the center of the first test spot marked on the third white board.

[0018] The technical solution of the above embodiment can make the collimated beam and the received light spot concentric by adjusting the planar position and direction angle of the transmitting collimating lens and the receiving collimating lens, so as to ensure that the received light spot is the most representative light signal passing through the central region of the sample, and to ensure that the collimated beam is perpendicular to the monitoring substrate, thereby improving the accuracy of subsequent spectral data.

[0019] A film thickness monitoring system includes: a light source, a rotating disk, a spectrometer, a host computer, and the aforementioned spectral detection optical path; wherein, the light source is connected to the transmitting collimating lens, the spectrometer is connected to the receiving collimating lens, and the spectrometer is connected to the host computer; The light source is used to output an optical signal and couple it to the transmitting collimating lens; The spectrometer is used to convert the optical signal corresponding to the received collimated beam into spectral energy data and send it to the host computer. The host computer is used to calculate the spectral transmission curve of the monitoring substrate based on the spectral energy data.

[0020] In some embodiments, the light source is used to output broadband composite light and transmit it to the transmitting module via optical fiber; The receiving module transmits the composite light to the spectrometer via a receiving optical fiber; The spectrometer uses a grating to spread the composite light according to wavelength to form a spectrum, converts light intensity signals of different wavelengths into corresponding electrical signals, and digitizes the analog electrical signals to obtain spectral energy data.

[0021] A vacuum coating machine includes: a vacuum chamber, a rotating disk, and the aforementioned film thickness monitoring system; The vacuum chamber is used to provide a vacuum environment; The rotating disk is used to place the substrate and the monitoring substrate.

[0022] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0023] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a block diagram of an example optical path for spectral detection; Figure 2 Here is a block diagram of another example of a spectral detection optical path; Figure 3 This is a schematic diagram of an example transmitter module structure; Figure 4 This is a schematic diagram of an example receiving module structure; Figure 5 This is a flowchart of an embodiment of a method for adjusting the optical path of spectral detection; Figure 6 This is a schematic diagram illustrating the vertical monitoring substrate adjustment of an example transmission collimator; Figure 7 This is a schematic diagram illustrating the vertical monitoring substrate adjustment of an example receiving collimator; Figure 8 This is a schematic diagram illustrating the co-centering adjustment of the receiving collimating lens and the receiving collimating lens. Figure 9 This is a block diagram of an example film thickness monitoring system. Figure 10 This is a block diagram of an example vacuum coating machine. Figure 11 This is a top view of an example orbiter; Figure 12 This is a 3D diagram of an example orbital disk. Detailed Implementation

[0024] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0025] Those skilled in the art will understand that, unless otherwise stated, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in this application’s specification means the presence of the stated feature, integer, step, or operation, but does not preclude the presence or addition of one or more other features, integers, steps, or operations.

[0026] This application addresses the scenario of configuring an optical monitoring system on a large-aperture optical thin film fabrication equipment. To ensure that the number of components inside the vacuum cavity is minimized and to avoid the impact of a deviated optical path on the quality of spectral data acquisition, a solution is proposed for a spectral detection optical path and its adjustment method, a film thickness monitoring system, and a vacuum coating machine.

[0027] refer to Figure 1 As shown, Figure 1This is a block diagram of an example optical path for spectral detection, applied to a film thickness monitoring system. It includes: a transmitting module 31 and a receiving module 32 respectively located on opposite sides of a vacuum chamber 01. Here, "sides" refers to any position on the side of the two vacuum chambers 01, such as front / back, left / right, or top / bottom. The transmitting module 31 is mounted outside an emission port on one side of the vacuum chamber 01, and the receiving module 32 is mounted outside a receiving port on the other side of the vacuum chamber 01. The transmitting module 31 emits a collimated beam into the vacuum chamber 01. The collimated beam passes through the monitoring substrate 101 and reaches the receiving port. The emission port and receiving port can be sealed with glass. The monitoring substrate 101 can be mounted on a rotating disk 11 inside the vacuum chamber 01. The receiving module 32 receives the collimated beam through the receiving port on the side of the vacuum chamber 01 to obtain a received light spot, which is then sent to the spectrometer 04.

[0028] The transmitting module 31 in this embodiment may include a transmitting collimating lens 311, the front end of which is mounted on the transmitting aperture; the receiving module 32 includes a receiving collimating lens 321, which is mounted on the receiving aperture; the transmitting collimating lens 311 and the receiving collimating lens 321 are designed asymmetrically, with the aperture of the transmitting collimating lens 311 being larger than that of the receiving collimating lens 321. The transmitting collimating lens 311 ensures that the light spot does not diverge within a certain optical path, thus obtaining a more complete light spot. The receiving collimating lens 321 receives light passing through... The collimated beam of the monitoring substrate 101 receives a light spot of a set size, thereby outputting an optical signal containing the optical information of the monitoring substrate 101 to the spectrometer 04 for analysis. For example, the receiving collimating lens 321 can be connected to the spectrometer 04 via a receiving optical fiber. This technical solution ensures that even when external factors such as vibration of the vacuum chamber or collimating lens adjustment component, or vacuum deformation cause collimation to deteriorate and lead to misalignment, the receiving collimating lens 321 can still receive the light spot of the collimated beam, thereby ensuring the stability and accuracy of the acquired spectral data.

[0029] In some embodiments, such as Figure 2 As shown, Figure 2 Here is another example of a spectral detection optical path structure diagram. The emission module 31 also includes a first adjustment frame 312 mounted on the side of the vacuum chamber 01. The front end of the emission collimating lens 311 is mounted on the emission port. The emission collimating lens 311 is connected to the first adjustment frame 312. The first adjustment frame 312 is used to adjust the planar position and direction angle of the collimated beam emitted by the emission collimating lens 311, and to adjust the four angles of tilt and pitch.

[0030] Correspondingly, the receiving module 32 also includes a second adjustment frame 322 installed on the side of the vacuum chamber 01; the front end of the receiving collimating lens 321 is installed on the receiving hole, and the receiving collimating lens 321 is connected to the second adjustment frame 322; similarly, the second adjustment frame 322 can also be adjusted in planar motion, tilt, and pitch angles; thus, the alignment between the transmitting collimating lens 311 and the receiving collimating lens 321 is adjusted by the first adjustment frame 312 and the second adjustment frame 322 respectively, ensuring the precise alignment between the transmitting collimating lens 311 and the receiving collimating lens 321. The transmitting collimating lens 311 and the receiving collimating lens 321 are perpendicular to the monitoring substrate 101 and are concentric, thus having stronger anti-interference capability.

[0031] In some embodiments, reference Figure 3 As shown, Figure 3 This is a schematic diagram of an example launch module structure; the first adjustment frame 312 may include: a first two-dimensional translation stage 312a and a first angle adjustment stage 312b. The first two-dimensional translation stage 312a is used to adjust the launch collimator 311 for planar movement, for example, x and y plane movement adjustment. The first angle adjustment stage 312b is used to adjust the pitch or tilt angle of the launch collimator 311. Accordingly, refer to... Figure 4 As shown, Figure 4 This is a schematic diagram of an example receiving module structure; the second adjustment frame 322 includes: a second two-dimensional translation stage 322a and a second angle adjustment stage 322b. The second two-dimensional translation stage 322a is used to adjust the receiving collimating lens 321 to move in a plane, and the second angle adjustment stage 322b is used to adjust the pitch or tilt angle of the receiving collimating lens 321.

[0032] As described in the above embodiment, by adjusting the planar position and orientation angle of the transmitting collimating lens 311 and the receiving collimating lens 321, the collimated beam and the receiving spot can be made to be concentric, ensuring that the received spot is the most representative light signal passing through the central region of the sample, and ensuring that the collimated beam is perpendicular to the monitoring substrate, thereby improving the accuracy of subsequent spectral data.

[0033] In some embodiments, such as Figure 2 As shown, the first adjustment frame 312 and the second adjustment frame 322 are respectively connected to the control system 06. The control system 06 is used to output control signals to adjust the first adjustment frame 312 and the second adjustment frame 322 according to the adjustment parameters, control the first two-dimensional translation stage 312a and the second two-dimensional translation stage 322a to perform planar movement, and control the first angle adjustment stage 312b and the second angle adjustment stage 322b to perform angle adjustment, adjust the collimated beam to be concentric with the received light spot, and the collimated beam is perpendicular to the monitoring substrate 101.

[0034] In some embodiments, the diameter of the monitoring substrate 101 in the spectral detection optical path of this application can be 50 mm; the diameter of the emission aperture can be 50 mm, the collimation distance of the emission collimating lens 311 is 1700 mm or more (designed according to the size of the vacuum cavity 01, 1700 mm meets the requirements of large-aperture equipment), and the collimated beam spot emitted by the emission collimating lens 311 is 25 mm, that is, a parallel beam with an emission spot diameter of 25 mm; the diameter of the receiving aperture can be 50 mm, and the receiving spot of the receiving collimating lens 321 is 5 mm; in this technical solution, through the asymmetric design of the receiving aperture smaller than the emission aperture, the receiving collimating lens 321 can efficiently collect the light signal of the collimated beam passing through the sample and transmit it to the spectrometer 04. The small aperture design of the receiving collimating lens 321 helps to limit stray light and improve the signal-to-noise ratio.

[0035] As described in the above embodiment, the optical components are designed outside the vacuum cavity 01. This minimizes the number of components inside the vacuum cavity 01 and avoids damage to the collimating lens caused by high temperatures inside the vacuum cavity 01, ensuring the cleanliness of the film formation space and improving the quality of high-end optical lenses. The asymmetric optical path coupling design ensures maximum coupling efficiency while maintaining the stability of the detection data. It also provides strong anti-interference capabilities against collimation deterioration caused by external factors such as vibration of the vacuum cavity 01 and collimating lens adjustment components, and vacuum deformation. The asymmetric design significantly reduces the difficulty of optical path adjustment during the initial adjustment phase. Furthermore, the components being designed outside the vacuum cavity 01 facilitates replacement and maintenance, greatly reducing maintenance difficulty.

[0036] The following describes an example of a method for adjusting the optical path in spectral detection.

[0037] refer to Figure 5 As shown, Figure 5 This is a flowchart of an adjustment method for the spectral detection optical path in one embodiment, applied to the spectral detection optical path of the aforementioned embodiment, including: (1) Control the transmitting collimator to emit the first test spot, and use the first test spot and the first reflected spot reflected by the mirror at the position of the monitoring substrate to control the first adjustment frame to adjust the transmitting collimator to be perpendicular to the monitoring substrate.

[0038] In this step, the first test light spot can be emitted by the transmitting collimating lens 311 for adjustment. The first test light spot and the first reflected light spot reflected by the mirror at the position of the monitoring substrate 101 are used to control the first adjustment frame 312 to adjust the planar position and direction angle of the transmitting collimating lens 311 so that it is perpendicular to the monitoring substrate 101, thereby ensuring that the collimated beam passes perpendicularly through the monitoring substrate 101.

[0039] (2) Control the receiving collimator to emit a second test spot, and use the second test spot and the second reflected spot reflected by the mirror at the position of the monitoring substrate to control the second adjustment frame to adjust the receiving collimator to be perpendicular to the monitoring substrate.

[0040] (3) Control the second adjustment frame to adjust the center position of the second reflected light spot to coincide with the center position of the first test light spot, so that the transmitting collimator and the receiving collimator are concentric.

[0041] As described in the above embodiments, a precise method for adjusting the spectral detection optical path is provided. To ensure accurate data acquisition, the detection optical path is constructed in a long-distance, non-coplanar optical path, which ensures that the center point of the receiving spot is aligned with the center point of the collimated beam spot, and that the collimated beam is perpendicular to the monitoring substrate, thus ensuring that the receiving spot is the most representative light signal and improving the accuracy of subsequent spectral data.

[0042] In some embodiments, reference Figure 6 As shown, Figure 6 This is an example schematic diagram of vertical monitoring substrate adjustment for a transmission collimator. Step (1) may include the following: (1.1) Place a reflector M on one side of the transmitting collimator 311 at the position of the monitoring substrate 101, and place a first whiteboard K1 near the position of the transmitting collimator 311; for example, the first whiteboard K1 can be placed 10cm in front of the transmitting collimator 311. The whiteboard here can be a cardboard or other material with a certain light transmittance, so that the monitoring substrate 101 can be taken out on the rotary table 11 during adjustment.

[0043] (1.2) Place the emitting collimator 311 at the initially set plane position and direction angle, and emit the first test spot through the emitting collimator 311.

[0044] Specifically, by controlling the first adjustment frame adjustment 312, the transmitting collimating lens 311 is fixed at an initial planar position and direction angle. The transmitting collimating lens 311 is connected to the fiber optic light source. The first test light spot is emitted through the transmitting collimating lens 311. The first test light spot first passes through the first white board K1, and the shape of the first test light spot will be displayed on the first white board K1. After being reflected by the reflector M, it will illuminate the first white board K1 again. Another light spot shape can be obtained on the first white board K1, namely the first reflected light spot.

[0045] (1.3) Control the first adjustment frame 312 to adjust the planar position and direction angle of the transmitting collimating mirror 311 so that the first test light spot coincides with the first reflected light spot reflected back by the reflector M.

[0046] Specifically, the planar position and directional angle of the transmitting collimator 311 are adjusted by controlling the first adjustment frame adjustment 312. By observing the two light spots K1 on the first white board, the first test light spot is made to coincide with the first reflected light spot reflected back by the reflector M, so that the emission direction of the transmitting collimator 311 is perpendicular to the monitoring substrate 101.

[0047] In some embodiments, reference Figure 7 As shown, Figure 7 This is an example schematic diagram of vertical monitoring substrate adjustment using a collimating lens, wherein step (2) includes: (2.1) Place a reflector M on one side of the receiving collimator 321 at the position of the monitoring substrate 101, and place a second whiteboard K2 near the receiving collimator 321.

[0048] (2.2) Place the receiving collimator 321 at the initially set plane position and direction angle, and emit the second test spot through the receiving collimator 321.

[0049] Specifically, by controlling the second adjustment frame adjustment 322, the receiving collimator 321 is fixed at an initial plane position and direction angle. The receiving collimator 321 is connected to the fiber optic light source. The second test light spot is emitted through the receiving collimator 321. The second test light spot first passes through the second white board K2, and the shape of the second test light spot will be displayed on the second white board K2. After being reflected by the reflector M, it will illuminate the second white board K2 again. Another light spot shape can be obtained on the second white board K2, namely the second reflected light spot.

[0050] (2.3) Control the second adjustment frame 322 to adjust the plane position and direction angle of the collimating mirror 321 so that the second test light spot coincides with the second reflected light spot reflected back by the mirror M.

[0051] Specifically, the plane position and direction angle of the receiving collimator 321 are adjusted by controlling the second adjustment frame adjustment 322. By observing the two light spots of the second white board K2, the second test light spot is made to coincide with the second reflected light spot reflected back by the reflector M, so that the receiving direction of the receiving collimator 321 is perpendicular to the monitoring substrate 101.

[0052] In some embodiments, reference Figure 8 As shown, Figure 8 This is a schematic diagram illustrating the co-centering adjustment of the receiving collimating lens and the receiving collimating lens; step (3) may include: (3.1) After the first test spot coincides with the first reflected spot reflected back by the mirror M, place the third white board K3 at the position of the monitoring substrate 101, and mark the first test spot and its center O on the third white board K3.

[0053] (3.2) After the second test spot coincides with the second reflected spot reflected back by the reflector M, the reflector M and the second white board K2 are removed. The second test spot is then irradiated onto the third white board K3. The second adjustment frame 322 is controlled to adjust the plane position of the receiving collimating lens 321 so that the center of the second test spot irradiated onto the third white board K3 coincides with the center of the first test spot marked on the third white board K3.

[0054] Specifically, the center of the collimated beam spot can be determined by the center marked on the third whiteboard K3. After adjusting in the vertical direction, the second adjustment frame 322 is adjusted to adjust the horizontal position, so that the center of the transmitting collimator 311 is aligned with the center of the receiving collimator 321.

[0055] As described in the above embodiment, by using the light spot comparison and adjustment of the reflector and the whiteboard, the emission direction of the transmitting collimator and the receiving direction of the receiving collimator can be accurately perpendicular to the monitoring substrate, and the emission direction of the transmitting collimator and the center of the receiving collimator can be precisely aligned, ensuring that the received light spot is the most representative light signal and improving the accuracy of subsequent spectral data.

[0056] The following describes an embodiment of the film thickness monitoring system.

[0057] like Figure 9 As shown, Figure 9 This is an example block diagram of a film thickness monitoring system, including: a light source 02, a rotating disk 05, a spectrometer 04, a host computer 07, and the spectral detection optical path of any of the aforementioned embodiments; wherein, the light source 02 is connected to the transmitting collimating lens 311, the spectrometer 04 is connected to the receiving collimating lens 321, and the spectrometer 04 is connected to the host computer 07; the light source 02 is used to output an optical signal and couple it to the transmitting collimating lens 311; the spectrometer 04 is used to convert the optical signal corresponding to the received collimated beam into spectral energy data and send it to the host computer 07; the host computer 07 is used to calculate the spectral transmission curve of the monitoring substrate 101 based on the spectral energy data.

[0058] In some embodiments, the light source 02 is used to output broadband composite light and transmit it to the transmitting module 31 through an optical fiber; the receiving module 32 sends the composite light to the spectrometer 04 through a receiving optical fiber; the spectrometer 04 expands the composite light according to wavelength through a grating to form a spectrum, converts light intensity signals of different wavelengths into corresponding electrical signals, and digitizes the analog electrical signals to obtain spectral energy data.

[0059] For example, an optical fiber light source 02 is placed at the bottom of the vacuum chamber 01. The optical fiber light source 02 is connected to the transmitting module 31 at the bottom of the vacuum chamber 01 through an optical fiber with an interface of SMA905. It emits a collimated beam with a collimation distance of 1700mm and a collimated spot size of 25mm. The beam passes through a transmitting hole with a diameter of 5mm. A receiving collimating lens 321 with an effective aperture of 5mm is designed at the top of the vacuum chamber 01 to receive the light signal passing through the monitoring substrate 101. The light signal is transmitted to the spectrometer 04 for photoelectric conversion and analog-to-digital conversion. Finally, the spectral energy data is transmitted to the host computer 07 via USB.

[0060] The film thickness monitoring system of this embodiment forms a complete optical-electronic-data-information link. During the excitation and collimation of the light beam by the light source 02, a high-performance fiber optic light source 02 provides broadband, highly stable composite light. The light source 02 is connected to the armored patch cord fiber via a standard SMA905 interface, ensuring efficient light energy transmission and mechanical stability of the connection. The fiber guides the optical signal to the transmitting module 31 fixed at the bottom of the cavity. The transmitting collimating lens of the transmitting module 31 shapes the divergent beam emitted from the end of the fiber into a high-quality parallel beam with a collimation distance of up to 1700 mm (i.e., the beam hardly diverges within this distance) and a spot diameter of approximately 25 mm, ensuring that the beam maintains a uniform cross-section and energy distribution as it passes through the subsequent sample area. In orbital disk 05, the parallel beam generated by the transmitting module 31 passes vertically upward through a 50mm diameter through-hole in the cavity structure and enters orbital disk 05. This area is specifically designed for placing the substrate to be monitored. The 25mm collimated beam is completely contained within the 50mm through-hole, providing ample space for sample placement and adjustment, while preventing the beam from being blocked by the cavity structure and ensuring the integrity of the measurement area. The beam penetrates the substrate vertically, and its energy is selectively attenuated according to the spectral characteristics of the substrate material (such as absorption and reflection). During signal reception and focusing, the transmitted light carrying sample information continues to propagate upward to the receiving collimating lens. A compact receiving collimating lens 321 is designed here, with an effective aperture of 5mm, which can efficiently collect the light signal passing through the sample and accurately focus it into the receiving optical fiber immediately following it. In spectral analysis and data processing, the receiving optical fiber transmits the converged optical signal to the spectrometer 04, which is a miniature optical fiber. Inside the spectrometer 04, the optical signal undergoes the following processing sequentially: dispersion, where the composite light is spread out according to wavelength by a grating to form a spectrum; photoelectric conversion, where a CCD or CMOS array detector converts light intensity signals of different wavelengths into corresponding electrical signals; and analog-to-digital conversion, where a high-precision ADC circuit digitizes the analog electrical signals to obtain the intensity value of each pixel (corresponding to a specific wavelength). In spectral data processing, the digitized spectral energy data is transmitted in real time to the host computer 07 via a USB interface. The professional software on the computer displays, records, and analyzes the data, and can calculate the intensity ratio of transmitted light to reference light (when there is no sample) to obtain the spectral transmission curve of the monitoring substrate 101, thereby achieving real-time online monitoring and analysis.

[0061] As described in the above embodiment, the 1700mm long-range collimation design is suitable for large cavities or applications requiring long optical paths, ensuring the parallelism of the beam at the sample position. The 5mm small aperture receiver effectively suppresses the influence of ambient stray light and beam edge distortion, improving the accuracy and stability of the measurement. The modular integration and standard fiber optic interfaces such as SMA905 ensure reliable connection of each module (light source 02, transmitting module 31, receiving module 32, spectrometer 04), facilitating maintenance and upgrades. The entire process from light source 02 transmission to data output is completed within a controlled cavity, resulting in strong anti-interference capabilities and high data reliability.

[0062] The following describes an embodiment of a vacuum coating machine.

[0063] like Figure 10 As shown, Figure 10 This is an example structural block diagram of a vacuum coating machine, including: a vacuum chamber 01, a rotating disk 11, a vacuum pump 12, and a film thickness monitoring system of any of the foregoing embodiments; the vacuum chamber 01 is used to provide a vacuum environment; the vacuum pump 12 is used to evacuate the vacuum; the rotating disk 11 is used to place the substrate to be coated and the monitoring substrate 101.

[0064] For the 11th revolution disk, refer to Figure 11 and Figure 12 As shown, Figure 11 This is a top view of an example orbiter. Figure 12 This is a three-dimensional diagram of an example planetary disk. For instance, in a horizontal 4-position planetary disk design within a large-aperture optical coating device, two 50mm diameter holes are drilled on the planetary disk 11 at the positions shown in the diagram. These holes are located at the tangent positions of the two planetary disks. Additionally, by selecting one of these hole positions, two holes of the same size are drilled on the cavity above and below the corresponding hole. Thus, from a top view, when the planetary disk 11 rotates, light can completely pass through the cavity. During use, one of the two holes on the planetary disk 11 is used to place the optical monitoring substrate 101, while the other is left empty, serving as a hollow hole.

[0065] The above description is only a partial embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A spectral detection optical path, applied to a film thickness monitoring system, characterized in that, include: The transmitting module and the receiving module are respectively located on opposite sides of the vacuum cavity; The transmitting module is installed outside the transmitting port on one side of the vacuum cavity, and the receiving module is installed outside the receiving port on the other side of the vacuum cavity; The launching module includes a launching collimator, the front end of which is mounted on the launching port; The receiving module includes a receiving collimating lens, the front end of which is mounted on a receiving hole; The aperture of the transmitting collimating lens is larger than the aperture of the receiving collimating lens; The transmitting collimating lens receives the light source signal and emits a collimated beam of a preset size towards the receiving aperture through the transmitting aperture; the collimated beam passes through the monitoring substrate on the orbital disk and then reaches the receiving aperture; The receiving collimating lens receives the collimated beam and obtains a receiving spot, which is then sent to the spectrometer.

2. The spectral detection optical path according to claim 1, characterized in that, The launch module also includes a first adjustment frame mounted on the side of the vacuum chamber, and the launch collimator is connected to the first adjustment frame; The first adjustment bracket is used to adjust the planar position and directional angle of the transmitting collimator; The receiving module also includes a second adjustment frame installed on the outside of the side of the vacuum chamber; The front end of the receiving collimating lens is mounted on the receiving hole, and the receiving collimating lens is connected to the second adjustment bracket; The second adjustment bracket is used to adjust the planar position and directional angle of the receiving collimating mirror.

3. The spectral detection optical path according to claim 2, characterized in that, The first adjustment frame includes: a first two-dimensional translation stage and a first angle adjustment stage. The first two-dimensional translation stage is used to adjust the launch collimator to move in a plane, and the first angle adjustment stage is used to adjust the pitch or tilt angle of the launch collimator. The second adjustment frame includes: a second two-dimensional translation stage and a second angle adjustment stage. The second two-dimensional translation stage is used to adjust the plane movement of the receiving collimating lens, and the second angle adjustment stage is used to adjust the pitch or tilt angle of the receiving collimating lens.

4. The spectral detection optical path according to claim 3, characterized in that, The first and second adjustment frames are respectively connected to the control system; The control system is used to output control signals to adjust the first adjustment frame and the second adjustment frame according to the adjustment parameters, control the first two-dimensional translation stage and the second two-dimensional translation stage to perform planar movement, and control the first angle adjustment stage and the second angle adjustment stage to perform angle adjustment, adjust the collimated beam to be concentric with the received light spot, and the collimated beam to be perpendicular to the monitoring substrate.

5. The spectral detection optical path according to claim 1, characterized in that, The collimated beam is a parallel beam with a spot diameter of 25 mm; The effective aperture of the receiving collimating lens is 5mm. The diameter of the monitoring substrate is 50mm; The diameter of the transmitting and receiving holes is 50 mm.

6. A method for adjusting the optical path of a spectral detection system, characterized in that, The optical path used in the spectral detection path according to any one of claims 2 to 5 includes: (1) Control the transmitting collimator to emit the first test spot, and use the first test spot and the first reflected spot reflected by the mirror at the position of the monitoring substrate to control the first adjustment frame to adjust the transmitting collimator to be perpendicular to the monitoring substrate; (2) Control the receiving collimator to emit a second test spot, and use the second test spot and the second reflected spot reflected by the mirror at the position of the monitoring substrate to control the second adjustment frame to adjust the receiving collimator to be perpendicular to the monitoring substrate; (3) Control the second adjustment frame to adjust the center position of the second reflected light spot to coincide with the center position of the first test light spot, so that the transmitting collimator and the receiving collimator are concentric.

7. The method for adjusting the optical path of spectral detection according to claim 6, characterized in that, Step (1) includes: A reflector is placed on one side of the transmitting collimator at the monitoring substrate position, and a first whiteboard is placed near the transmitting collimator position; Place the launching collimator at the initially set plane position and direction angle, and launch the first test spot through the launching collimator; The first adjustment frame is controlled to adjust the plane position and direction angle of the transmitting collimating mirror so that the first test light spot coincides with the first reflected light spot reflected back by the reflector; Step (2) includes: A reflector is placed on one side of the receiving collimator at the monitoring substrate position, and a second whiteboard is placed near the receiving collimator. Place the receiving collimator in the initially set plane position and orientation angle, and emit the second test spot through the receiving collimator; The second adjustment frame is controlled to adjust the plane position and direction angle of the receiving collimating mirror so that the second test light spot coincides with the second reflected light spot reflected back by the reflector.

8. The method for adjusting the optical path of spectral detection according to claim 7, characterized in that, Step (3) includes: After the first test spot coincides with the first reflected spot reflected back by the mirror, a third whiteboard is placed at the monitoring substrate position, and the first test spot and its center are marked on the third whiteboard. After the second test spot coincides with the second reflected spot reflected back by the reflector, the reflector is removed, and the second test spot illuminates the third white board. The second adjustment frame is controlled to adjust the plane position of the receiving collimating lens so that the center of the second test spot illuminating the third white board coincides with the center of the first test spot marked on the third white board.

9. A film thickness monitoring system, characterized in that, include: The system comprises a light source, a rotating disk, a spectrometer, a host computer, and a spectral detection optical path as described in any one of claims 1 to 5; wherein the light source is connected to the transmitting collimating lens, the spectrometer is connected to the receiving collimating lens, and the spectrometer is connected to the host computer. The light source is used to output an optical signal and couple it to the transmitting collimating lens; The spectrometer is used to convert the optical signal corresponding to the received collimated beam into spectral energy data and send it to the host computer. The host computer is used to calculate the spectral transmission curve of the monitoring substrate based on the spectral energy data.

10. A vacuum coating machine, characterized in that, include: A vacuum chamber, a rotating disk, and the film thickness monitoring system as described in claim 8 or 9; The vacuum chamber is used to provide a vacuum environment; The rotating disk is used to place the substrate and the monitoring substrate.

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