A vacuum ultraviolet spectrophotometer device

Abstract

This invention discloses a vacuum ultraviolet spectrophotometer device. A vacuum ultraviolet monochromatic spectral system disperses the composite light from a vacuum ultraviolet light source to obtain quasi-monochromatic light output. A vacuum ultraviolet collimation system collimates the quasi-monochromatic light, forming a parallel beam. A vacuum ultraviolet chopper system chops and modulates the vacuum ultraviolet signal, dividing the light into a main optical path and an auxiliary optical path. A vacuum switching mechanism switches the positions of multiple vacuum ultraviolet band filter samples under test. Light conversion is achieved through a vacuum light conversion mechanism, and then received by a vacuum detection component for photoelectric conversion. A comprehensive computing system compares and calculates the spectral transmittance value of the tested sample by comparing the main optical path signal and the auxiliary optical path signal. This invention can meet the requirements for vacuum ultraviolet transmittance testing in the 120nm–200nm wavelength range.

Description

Technical Field

[0001] This invention relates to the field of optical testing technology, and in particular to a vacuum ultraviolet spectrophotometer device. Background Technology

[0002] Vacuum ultraviolet (UV) measurement technology has been widely applied in my country's deep space exploration, long-range precision strike, and lithography machine development fields, serving major national projects such as weather forecasting, military plans, and chip development. A key component in vacuum UV measurement equipment is the vacuum UV filter, whose spectral transmittance characteristics directly affect the performance of the entire measurement system and the accuracy of data retrieval. Therefore, its spectral transmittance parameters need to be calibrated. Calibration of spectral transmittance parameters requires a vacuum UV spectrophotometer. Existing domestic measurement methods cannot meet the requirements for vacuum UV transmittance testing in the 120nm–200nm wavelength range, which is a crucial wavelength range for current and future applications. Therefore, developing a vacuum UV spectrophotometer is of paramount importance. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a vacuum ultraviolet spectrophotometer device, which solves the problem that existing measuring devices cannot meet the requirements for vacuum ultraviolet transmittance testing in the 120nm to 200nm wavelength band.

[0004] To solve the above-mentioned technical problems, the present invention provides a vacuum ultraviolet spectrophotometer device, the technical solution of which is as follows:

[0005] The device includes: a vacuum ultraviolet light source, a vacuum ultraviolet monochromatic spectral system, a vacuum ultraviolet collimation system, a vacuum ultraviolet chopper system, a vacuum ultraviolet light limiting mechanism, a vacuum switching mechanism, a vacuum light conversion mechanism, a vacuum detection component, and a comprehensive computing system.

[0006] The vacuum ultraviolet light source is used to provide spectral energy covering the 120nm to 200nm wavelength range;

[0007] The vacuum ultraviolet monochromatic spectral system utilizes the diffraction effect of a grating to split the composite light from the vacuum ultraviolet light source, thereby obtaining quasi-monochromatic light output.

[0008] The vacuum ultraviolet collimation system collimates the quasi-monochromatic light emitted from the vacuum ultraviolet monochromatic spectral system to form a parallel beam.

[0009] The vacuum ultraviolet chopper system includes a four-blade chopper and a magnetically coupled vacuum transmission assembly. The chopper surface is coated with a vacuum ultraviolet reflective film to achieve chopping modulation of the vacuum ultraviolet signal and split the light into two paths: a main optical path and an auxiliary optical path. The light radiation from the auxiliary optical path is received by the vacuum detection assembly to achieve photoelectric conversion, and the generated electrical signal is collected by the integrated computing system. The magnetic coupler enables the linkage between the vacuum motor outside the vacuum chamber and the chopper shaft inside the vacuum chamber.

[0010] The vacuum ultraviolet limiting mechanism achieves the adjustment of the main optical path beam aperture through a vacuum-sealed adjustable aperture;

[0011] The vacuum switching mechanism enables the switching of positions of multiple vacuum ultraviolet band filter samples to be tested, thereby moving multiple samples into and out of the optical path respectively; the vacuum light conversion mechanism converts the light in the vacuum ultraviolet band into the visible light band. After the vacuum ultraviolet light radiation passes through a sample to be tested in the vacuum switching mechanism, it is converted by the vacuum light conversion mechanism and the optical path is deflected. The deflected light radiation is received by the vacuum detection component to achieve photoelectric conversion, and the generated electrical signal is collected by the integrated computing system.

[0012] The integrated computing system compares and calculates the main optical path signal and the auxiliary optical path signal, eliminates the measurement error introduced by the instability of the light source, and calculates the spectral transmittance value of the sample under test.

[0013] Furthermore, the vacuum ultraviolet monochromatic spectral system includes an entrance slit, a beam splitter grating, and an exit slit. The light from the vacuum ultraviolet light source enters through the entrance slit, is split by the beam splitter grating to form monochromatic light, and exits through the exit slit.

[0014] Furthermore, the vacuum ultraviolet light source includes an energy optimizer and a filter group. First, the energy optimizer focuses the light emitted from the light source's emission point at the entrance slit of the vacuum ultraviolet monochromatic spectral system. Then, the filter group located at the entrance slit filters out light below 120nm and above 200nm through its internal bandpass filter.

[0015] Furthermore, the vacuum ultraviolet collimation system includes two optical lenses, one of which is a plane mirror and the other is an off-axis parabolic mirror. Through double reflection, the focal plane position coincides with the exit slit position of the vacuum ultraviolet monochromatic beam splitter 2.

[0016] Furthermore, the chopper is made of ultra-hard aluminum material, with one side polished to a mirror finish and the other side blackened, and its structure is slightly thicker in the middle than at the edges.

[0017] Furthermore, the vacuum switching mechanism ensures good sealing of the sample holder during adjustment by using a double set of O-ring contact seals.

[0018] Furthermore, the vacuum light conversion mechanism uses a conversion component made of sodium salicylate-coated material to convert light in the vacuum ultraviolet band into light in the visible band.

[0019] Furthermore, it also includes a vacuum dynamic sealing mechanism, which provides a vacuum testing environment and uses O-rings or JO rings to achieve dynamic sealing during the movement of the vacuum switching mechanism and vacuum detection component.

[0020] Furthermore, the angle of the vacuum detection component is adjusted through the vacuum dynamic sealing mechanism until the position of the maximum signal value is the ideal measurement angle.

[0021] Furthermore, the integrated computing system includes a vacuum ultraviolet monochromatic spectrophotometer controller, a vacuum motor controller, two sets of lock-in amplifiers, and a computer.

[0022] The vacuum ultraviolet monochromatic spectroscopy system controller is connected to a computer, receives instructions from the computer, realizes the wavelength setting of the vacuum ultraviolet monochromatic spectroscopy system, and outputs spectral radiation of a certain characteristic wavelength according to the setting requirements;

[0023] The vacuum motor controller is connected to a computer, receives instructions from the computer, and rotates according to a set frequency to drive the chopper to perform chopping.

[0024] The two sets of lock-in amplifiers respectively collect and amplify the signals from the vacuum detection components in the main optical path and the auxiliary optical path, and then transmit the signals to the computer to calculate the spectral transmittance and obtain the spectral transmittance measurement results.

[0025] The vacuum ultraviolet spectrophotometer device of this invention is used to calibrate and test the vacuum ultraviolet filters used in the vacuum ultraviolet measurement system in a ground laboratory. This can promptly identify defects in the design of measurement equipment such as vacuum ultraviolet space payloads and lithography machines, reduce repetitions in the development process, save development costs, shorten the development cycle, and avoid affecting the smooth progress of the overall schedule. At the same time, it effectively ensures the accuracy of data acquired by the vacuum ultraviolet space payload and the precision of semiconductor sample processing, which is of great significance to the development of major vacuum ultraviolet science and technology projects in my country. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a vacuum ultraviolet spectrophotometer device provided in an embodiment of the present invention.

[0027] The above figures include the following reference numerals:

[0028] 1. Vacuum ultraviolet light source; 2. Vacuum ultraviolet monochromatic spectrophotometer system; 3. Vacuum ultraviolet collimation system; 4. Vacuum ultraviolet chopper system; 5. Vacuum ultraviolet light limiting mechanism; 6. Vacuum switching mechanism; 7. Vacuum light conversion mechanism; 8. Vacuum detection component; 9. Vacuum dynamic sealing mechanism; 10. Vacuum pumping system; 11. Vacuum ultraviolet monochromatic spectrophotometer system controller; 12. Vacuum motor controller; 13. Lock-in amplifier; 14. Computer. Detailed Implementation

[0029] The present invention will now be further described with reference to the accompanying drawings.

[0030] As an embodiment of the present invention, a vacuum ultraviolet spectrophotometer device is provided, such as Figure 1 As shown, it includes: a vacuum ultraviolet light source 1, a vacuum ultraviolet monochromatic spectral system 2, a vacuum ultraviolet collimation system 3, a vacuum ultraviolet chopper system 4, a vacuum ultraviolet light limiting mechanism 5, a vacuum switching mechanism 6, a vacuum light conversion mechanism 7, a vacuum detection component 8, a vacuum dynamic sealing mechanism 9, a vacuum pumping system 10, and a comprehensive computing system.

[0031] The vacuum ultraviolet light source 1 is a gas discharge light source with a circular light-emitting point and a cylindrical outer shell. The front window is a magnesium fluoride window, used to provide spectral energy covering the 120nm–200nm wavelength range. It includes an energy optimizer and a filter array to improve energy utilization and eliminate stray light. First, the energy optimizer focuses the light from the light source's emission point onto the entrance slit of the vacuum ultraviolet monochromatic spectrometer 2. Then, the filter array located at the entrance slit filters out light below 120nm and above 200nm through an internal bandpass filter, ensuring spectral purity within the device.

[0032] The vacuum ultraviolet monochromatic spectral system 2 utilizes the diffraction effect of a grating to disperse the composite light from the vacuum ultraviolet light source 1, resulting in quasi-monochromatic light output. The vacuum ultraviolet monochromatic spectral system 2 includes an entrance slit, a beam-splitting grating, and an exit slit. The light from the vacuum ultraviolet light source 1 enters through the entrance slit, is dispersed by the beam-splitting grating to form monochromatic light, and exits through the exit slit. The wavelength accuracy is better than 0.1 nm, and it is adaptable to vacuum levels ≤1×10⁻⁶. -3 Pa's environmental conditions.

[0033] The vacuum ultraviolet collimating system 3 includes two optical lenses, one of which is a plane mirror and the other is an off-axis parabolic mirror. Through double reflection, the focal plane of the vacuum ultraviolet collimating system 3 coincides with the exit slit of the vacuum ultraviolet monochromatic beam splitter 2, thus collimating the quasi-monochromatic light emitted from the vacuum ultraviolet monochromatic beam splitter 2 to form a parallel beam with a diameter of 10mm to 30mm.

[0034] The vacuum ultraviolet chopper system 4 includes a four-piece chopper and a magnetically coupled vacuum transmission assembly. The chopper is made of ultra-hard aluminum, with one side polished to a mirror finish and the other side blackened. To reduce rotational inertia and resist deformation during processing, its structure is slightly thicker in the middle than at the edges. The chopper manufacturing process mainly includes six steps: roughing, finishing, nickel plating, polishing, coating, and inspection. The surface roughness is designed to be Ra = 0.012. A vacuum ultraviolet reflective film is coated on the chopper surface to achieve chopping modulation of the vacuum ultraviolet signal and split the light into two paths: a main optical path and an auxiliary optical path. The light radiation from the auxiliary optical path is received by the vacuum detection assembly 8 for photoelectric conversion, and the generated electrical signal is acquired by the integrated computing system. The magnetic coupler enables the linkage between the vacuum motor outside the vacuum chamber and the chopper shaft inside the vacuum chamber. The modulation frequency of the vacuum ultraviolet chopper system 4 is 50Hz to 200Hz.

[0035] The vacuum ultraviolet limiting mechanism 5 uses a vacuum-sealed adjustable aperture and a two-piece combined aperture assembly to adjust the beam diameter of the main optical path from 0mm to 25mm.

[0036] The vacuum switching mechanism 6 achieves position switching of the three test samples by rotation and lifting, thereby moving the three samples into and out of the optical path respectively. The three test samples are vacuum ultraviolet band filters with an outer diameter of no more than 25 mm and a thickness of no more than 6 mm. The vacuum switching mechanism 6 ensures good sealing of the sample holder during adjustment through a double set of O-ring contact seals.

[0037] The vacuum light conversion mechanism 7 uses a conversion component made of sodium salicylate-coated material to convert light in the vacuum ultraviolet band into light in the visible band for the detector to receive and detect, and to fold the light path by about 45°.

[0038] The vacuum detection component 8 uses a photomultiplier tube with high sensitivity to collect optical signals and output electrical signals.

[0039] The vacuum dynamic sealing mechanism 9 provides a vacuum testing environment and uses O-rings or JO rings to achieve dynamic sealing during the movement of the vacuum switching mechanism 7 and the vacuum detection component 8, ensuring that the vacuum level meets the testing requirements.

[0040] After passing through one of the test samples in the vacuum switching mechanism 6, the vacuum light radiation is received by the vacuum light conversion mechanism 7 and the light path is refracted. The refracted light radiation is received by the vacuum detection component 8 to achieve photoelectric conversion. The generated electrical signal is collected by the integrated computing system. The vacuum dynamic sealing mechanism 9 can realize the angle adjustment of the vacuum detection component 8, and the adjustment is to the position of the maximum signal value as the ideal measurement angle.

[0041] The vacuum system 10 achieves 1×10⁻⁶ vacuum pumping speed through a combination of an oil-free dry pump and a high-speed molecular pump. -3 Vacuum conditions below Pa.

[0042] The integrated computing system includes a vacuum ultraviolet monochromatic spectroscopy system controller 11, a vacuum motor controller 12, two sets of lock-in amplifiers 13, a computer 14, and self-developed software. It realizes the comparison and calculation of the main optical path signal and the auxiliary optical path signal, eliminates the measurement error introduced by the instability of the light source, and calculates the spectral transmittance value of the sample under test.

[0043] The vacuum ultraviolet monochromatic spectrophotometer controller 11 is connected to the computer 14, receives instructions sent by the computer 14, realizes the wavelength setting of the vacuum ultraviolet monochromatic spectrophotometer 2, and outputs spectral radiation of a certain characteristic wavelength according to the setting requirements.

[0044] The vacuum motor controller 12 is connected to the computer 14, receives instructions sent by the computer 14, and rotates according to the set frequency to drive the chopper to perform chopping.

[0045] The two sets of lock-in amplifiers 13 respectively collect and amplify the signals of the vacuum detection components 8 in the main optical path and the auxiliary optical path, and then transmit the signals to the computer 14. The software in the computer 14 calculates the spectral transmittance and obtains the spectral transmittance measurement results.

[0046] The computer 14 controls the vacuum ultraviolet monochromatic spectrophotometer controller 11 and the vacuum motor controller 12 by receiving and sending instructions, collects and processes the signals of the two lock-in amplifiers 13, and calculates the measurement results.

Claims

1. A vacuum ultraviolet spectrophotometer device, characterized in that, The device includes: a vacuum ultraviolet light source (1), a vacuum ultraviolet monochromatic spectral system (2), a vacuum ultraviolet collimation system (3), a vacuum ultraviolet chopper system (4), a vacuum ultraviolet light limiting mechanism (5), a vacuum switching mechanism (6), a vacuum light conversion mechanism (7), a vacuum detection component (8), and a comprehensive computing system. The vacuum ultraviolet light source (1) is used to provide spectral energy covering the 120nm to 200nm wavelength range; The vacuum ultraviolet monochromatic spectral system (2) uses the diffraction effect of the grating to split the composite light of the vacuum ultraviolet light source (1) to obtain quasi-monochromatic light output; The vacuum ultraviolet collimation system (3) collimates the quasi-monochromatic light emitted from the vacuum ultraviolet monochromatic spectral system (2) to form a parallel beam. The vacuum ultraviolet chopper system (4) includes a four-piece chopper and a magnetic coupling vacuum transmission component. The chopper surface is coated with a vacuum ultraviolet reflective film to realize the chopping modulation of the vacuum ultraviolet signal and split the light into two paths, one as the main optical path and the other as the auxiliary optical path. The light radiation of the auxiliary optical path is received by the vacuum detection component (8) to realize photoelectric conversion. The generated electrical signal is collected by the integrated computing system. The magnetic coupler realizes the linkage between the vacuum motor outside the vacuum chamber and the chopper shaft inside the vacuum chamber. The vacuum ultraviolet limiting mechanism (5) adjusts the aperture of the main optical path beam through a vacuum-sealed adjustable aperture; The vacuum switching mechanism (6) enables the switching of positions of multiple vacuum ultraviolet band filter samples to be tested, thereby moving multiple samples into and out of the optical path respectively; the vacuum light conversion mechanism (7) converts the light in the vacuum ultraviolet band into the light in the visible light band. After the vacuum ultraviolet light radiation passes through one of the samples to be tested in the vacuum switching mechanism (6), it is converted by the vacuum light conversion mechanism (7) and the optical path is refracted. The refracted light radiation is received by the vacuum detection component (8) to achieve photoelectric conversion, and the generated electrical signal is collected by the integrated computing system. The integrated computing system compares and calculates the main optical path signal and the auxiliary optical path signal, eliminates the measurement error introduced by the instability of the light source, and calculates the spectral transmittance value of the sample under test.

2. The vacuum ultraviolet spectrophotometer device according to claim 1, characterized in that, The vacuum ultraviolet monochromatic spectral system (2) includes an entrance slit, a beam splitter grating, and an exit slit. The light from the vacuum ultraviolet light source (1) enters through the entrance slit, is split by the beam splitter grating to form monochromatic light, and exits through the exit slit.

3. The vacuum ultraviolet spectrophotometer device according to claim 2, characterized in that, The vacuum ultraviolet light source (1) includes an energy optimizer and a filter group. First, the energy optimizer focuses the light emitted by the light source at the entrance slit of the vacuum ultraviolet monochromatic spectral system (2). Then, the filter group located at the entrance slit filters out light below 120nm and above 200nm through the internal bandpass filter.

4. The vacuum ultraviolet spectrophotometer device according to claim 3, characterized in that, The vacuum ultraviolet collimation system (3) includes two optical lenses, one of which is a plane mirror and the other is an off-axis parabolic mirror. Through double reflection, the focal plane position coincides with the exit slit position of the vacuum ultraviolet monochromatic beam splitting system 2.

5. The vacuum ultraviolet spectrophotometer device according to claim 1, characterized in that, The chopper is made of ultra-hard aluminum material, with one side polished to a mirror finish and the other side blackened. Its structure is slightly thicker in the middle than at the edges.

6. The vacuum ultraviolet spectrophotometer device according to claim 1, characterized in that, The vacuum switching mechanism (6) ensures good sealing of the sample holder during adjustment by using a double set of O-rings for contact sealing.

7. The vacuum ultraviolet spectrophotometer device according to claim 1, characterized in that, The vacuum light conversion mechanism (7) converts light in the vacuum ultraviolet band into light in the visible band using a conversion component made of sodium salicylate coating material.

8. The vacuum ultraviolet spectrophotometer device according to claim 1, characterized in that, It also includes a vacuum dynamic sealing mechanism (9), which provides a vacuum testing environment and uses O-rings or JO rings to achieve dynamic sealing during the movement of the vacuum switching mechanism (7) and the vacuum detection component (8).

9. The vacuum ultraviolet spectrophotometer device according to claim 8, characterized in that, The angle of the vacuum detection component (8) is adjusted by the vacuum dynamic sealing mechanism (9) until the position of the maximum signal value is the ideal measurement angle.

10. The vacuum ultraviolet spectrophotometer device according to claim 1, characterized in that, The integrated computing system includes a vacuum ultraviolet monochromatic spectrometer controller (11), a vacuum motor controller (12), two sets of lock-in amplifiers (13), and a computer (14). The vacuum ultraviolet monochromatic spectroscopy system controller (11) is connected to the computer (14), receives instructions sent by the computer (14), realizes the wavelength setting of the vacuum ultraviolet monochromatic spectroscopy system (2), and outputs spectral radiation of a certain characteristic wavelength according to the setting requirements; The vacuum motor controller (12) is connected to the computer (14), receives instructions sent by the computer (14), rotates according to the set frequency, and drives the chopper to achieve chopping; The two lock-in amplifiers (13) collect and amplify the signals from the vacuum detection components (8) in the main optical path and auxiliary optical path, respectively, and then transmit the signals to the computer (14) to calculate the spectral transmittance and obtain the spectral transmittance measurement results.

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