Multi-wavelength phase modulation scanning measurement system and method

Abstract

The invention provides a multi-wavelength phase modulation scanning measurement system and method, and the system is characterized in that a multi-wavelength light beam generated by a radiation source is subjected to the beam splitting and phase modulation of a first optical system, and then is irradiated to a target structure. Because the response of the light beams with different wavelengths to the target structure is different, the measurement effect can be optimized by adjusting the phase difference. The scattered light beams interfere with each other at the imaging detector to form an interference pattern containing target structure information. The processor analyzes and processes the patterns and extracts related information of the target structure. According to the invention, by introducing a light source with multiple wavelengths and an advanced phase modulation technology, high-precision three-dimensional shape measurement of a target structure is realized.

Description

Technical Field

[0001] The present invention relates to the field of scanning measurement technology, and in particular to a multi-wavelength phase modulation scanning measurement system and method. Background Art

[0002] In the field of modern precision manufacturing and materials science research, the demand for high-precision measurement of microstructures is growing. Traditional optical measurement technology is limited by the wavelength of the light source and the measurement principle, making it difficult to fully characterize complex microstructures. In order to overcome this problem, the present invention proposes a multi-wavelength phase modulation scanning measurement system and method, which aims to achieve high-precision three-dimensional morphology measurement of the target structure by introducing multiple wavelength light sources and advanced phase modulation technology. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a multi-wavelength phase modulation scanning measurement system and method, which is specifically achieved through the following technical solutions:

[0004] The present invention also provides a multi-wavelength phase modulation scanning measurement system, comprising a radiation source, a first optical system, a second optical system, a third optical system and a processor, wherein:

[0005] The radiation source is used to generate a multi-wavelength light beam;

[0006] The first optical system is used to split the light beam generated by the radiation source and apply a phase difference;

[0007] The second optical system is used to guide the light beam to the target structure;

[0008] The third optical system is used to cause the scattered light beams to interfere at the imaging detector;

[0009] The processor is used to analyze the detection signal to determine the property of the target structure.

[0010] Optionally or preferably, the radiation source is a laser capable of stably and continuously generating multi-wavelength light beams.

[0011] Optionally or preferably, the first optical system consists of a beam splitter and a phase modulator; the beam splitter is used to split the incident light beam into two or more beams, each beam of light can be independently phase modulated; the phase modulator can impose one or more phase differences between different light beams by adjusting the parameters of the phase modulator to meet different measurement requirements, thereby achieving precise control of the light beam phase.

[0012] Optionally or preferably, the second optical system comprises a plurality of focusing lenses, and the focusing lenses are used to focus the modulated light beam onto the target structure.

[0013] Optionally or preferably, the third optical system comprises an imaging detector; the imaging detector is used to receive the light beam scattered back from the target structure and cause interference.

[0014] Optionally or preferably, the processor is used to analyze and process the interference pattern captured by the third optical system to extract relevant information of the target structure in real time; the processor calculates the three-dimensional morphology, roughness and refractive index of the target structure by comparing the interference patterns under different phase differences.

[0015] The present invention also provides a multi-wavelength phase modulation scanning measurement method, based on the multi-wavelength phase modulation scanning measurement system as described above, comprising the following steps:

[0016] S1. Generate a multi-wavelength beam using a radiation source;

[0017] S2, splitting and phase modulating the light beam through the first optical system;

[0018] S3, focusing the modulated beam onto the target structure;

[0019] S4, collecting the scattered light beam and interfering it at the imaging detector;

[0020] S5. The processor analyzes and processes the interference pattern to extract relevant information of the target structure.

[0021] Based on the above technical solution, the present invention provides a multi-wavelength phase modulation scanning measurement system method, which can produce the following technical effects:

[0022] (1) Multi-wavelength light source integration: By integrating light sources with multiple wavelengths, the diversification and flexibility of the lithography process are achieved; light sources of different wavelengths can be adjusted and combined according to actual needs to meet the lithography requirements of different materials and structures;

[0023] (2) Beam synthesis technology: Advanced beam synthesis technology is used to improve beam quality and lithography resolution. High-quality lithography patterns are achieved by precisely controlling the energy distribution and phase relationship of each wavelength beam.

[0024] (3) Intelligent control system: The introduction of intelligent control system realizes the automation and precise control of the photolithography process. Through real-time monitoring and feedback mechanism, deviations and errors in the photolithography process can be discovered and corrected in time.

[0025] (4) High compatibility: This system is compatible with existing lithography equipment and technologies without the need for large-scale transformation and upgrading. At the same time, it also reserves sufficient space and interfaces for future technological development;

[0026] (5) Low operating cost: Low long-term operating cost can bring significant improvement in lithography efficiency and increase in output. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0028] Figure 1 It is a schematic diagram of the system structure of the present invention. DETAILED DESCRIPTION

[0029] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Embodiment 1:

[0032] like Figure 1 As shown:

[0033] The present invention also provides a multi-wavelength phase modulation scanning measurement system, comprising a radiation source, a first optical system, a second optical system, a third optical system and a processor, wherein:

[0034] The radiation source is used to generate a multi-wavelength light beam;

[0035] The first optical system is used to split the light beam generated by the radiation source and apply a phase difference;

[0036] The second optical system is used to guide the light beam to the target structure;

[0037] The third optical system is used to cause the scattered light beams to interfere at the imaging detector;

[0038] The processor is used to analyze the detection signal to determine the property of the target structure.

[0039] In this embodiment, the radiation source is a laser that can stably and continuously generate multi-wavelength light beams. Specifically, the laser should have the characteristics of high stability, long life and high efficiency to ensure the reliability and measurement accuracy of the system; further, the laser can be an argon ion laser, a titanium sapphire laser or a fiber laser.

[0040] In this embodiment, the first optical system is composed of a beam splitter and a phase modulator; the beam splitter is used to split the incident light beam into two or more beams, each of which can be independently phase modulated; the phase modulator can apply one or more phase differences between different light beams by adjusting the parameters of the phase modulator to meet different measurement requirements, thereby realizing precise control of the light beam phase; specifically, the beam splitter can be selected from one of a cubic beam splitter, a flat beam splitter or a fiber beam splitter, wherein the cubic beam splitter has the characteristics of high transmittance and low loss, and is suitable for high-precision measurement; the flat beam splitter has the advantages of simple structure and low cost, and is suitable for general measurement; the fiber beam splitter can realize long-distance transmission and flexible layout. When selecting a beam splitter, it is flexibly selected according to factors such as its transmittance, loss, uniformity and stability. Specifically, the phase modulator is selected from one of an electro-optic modulator or an acousto-optic modulator, the electro-optic modulator has the advantages of fast response speed and high modulation efficiency, and is suitable for high-speed modulation; while the acousto-optic modulator has the characteristics of good wavelength selectivity and low insertion loss, and is suitable for modulation of a specific wavelength. When selecting a phase modulator, factors such as modulation speed, modulation efficiency, insertion loss, and stability need to be considered. In order to achieve high-precision phase modulation, a closed-loop control system can be used to precisely control the phase modulator.

[0041] In this embodiment, the second optical system includes a plurality of focusing lenses, which are used to focus the modulated light beam onto the target structure. Furthermore, the plurality of focusing lenses constitute a lens system with variable focal length, which can adapt to different measurement distances and target sizes, and has the characteristics of high transmittance and low aberration to ensure that the light beam maintains high quality during transmission. Furthermore, the lens system is also provided with a non-spherical diffractive optical element, which can reduce aberration and improve imaging quality.

[0042] In this embodiment, the third optical system includes an imaging detector; the imaging detector is used to receive the light beam scattered back from the target structure and make it interfere. Specifically, the imaging detector can use a high-resolution CCD charge-coupled camera or a CMOS complementary metal oxide semiconductor camera to capture subtle changes in the interference pattern; wherein the CCD charge-coupled camera has the characteristics of high image quality and low noise, and is suitable for high-precision measurement; and the CMOS complementary metal oxide semiconductor camera has the advantages of high-speed reading and low power consumption, and is suitable for real-time monitoring. When selecting an imaging detector, factors such as its resolution, sensitivity, dynamic range and reading speed need to be considered. Furthermore, optical elements such as filters or polarizers are also provided in front of the imaging detector, which can improve measurement accuracy and reduce the influence of noise and stray light.

[0043] In this embodiment, the processor is used to analyze and process the interference pattern captured by the third optical system to extract relevant information of the target structure in real time; the processor calculates the three-dimensional morphology, roughness and refractive index of the target structure by comparing the interference patterns under different phase differences. Furthermore, the processor can also generate reports or charts as needed so that users can intuitively understand the measurement results.

[0044] This embodiment also provides a multi-wavelength phase modulation scanning measurement method, which uses the multi-wavelength phase modulation scanning measurement system to perform measurement, including the following steps:

[0045] S1. Generate a multi-wavelength beam using a radiation source;

[0046] S2, splitting and phase modulating the light beam through the first optical system;

[0047] S3, focusing the modulated beam onto the target structure;

[0048] S4, collecting the scattered light beam and interfering it at the imaging detector;

[0049] S5. The processor analyzes and processes the interference pattern to extract relevant information of the target structure.

[0050] The working principle of this embodiment is:

[0051] The system generates a multi-wavelength beam through a radiation source, which is then split and phase modulated by the first optical system and then irradiated onto the target structure. Since beams of different wavelengths respond differently to the target structure, the measurement effect can be optimized by adjusting the phase difference. The scattered beams interfere at the imaging detector to form interference patterns containing information about the target structure. The processor analyzes and processes these patterns to extract relevant information about the target structure.

[0052] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A multi-wavelength phase modulation scanning measurement system, characterized in that: The invention comprises a radiation source, a first optical system, a second optical system, a third optical system and a processor, wherein: The radiation source is used to generate a multi-wavelength light beam; The first optical system is used to split the light beam generated by the radiation source and apply a phase difference; The second optical system is used to guide the light beam to the target structure; The third optical system is used to cause the scattered light beams to interfere at the imaging detector; The processor is used to analyze the detection signal to determine the property of the target structure.

2. The multi-wavelength phase modulation scanning measurement system according to claim 1, characterized in that: The radiation source is a laser that can stably and continuously generate multi-wavelength light beams.

3. The multi-wavelength phase modulation scanning measurement system according to claim 1, characterized in that: The first optical system consists of a beam splitter and a phase modulator; the beam splitter is used to split the incident light beam into two or more beams, each of which can be independently phase modulated; the phase modulator can impose one or more phase differences between different light beams by adjusting the parameters of the phase modulator to meet different measurement requirements, thereby achieving precise control of the light beam phase.

4. The multi-wavelength phase modulation scanning measurement system according to claim 1, characterized in that: The second optical system includes a plurality of focusing lenses, and the focusing lenses are used to focus the modulated light beam onto a target structure.

5. The multi-wavelength phase modulation scanning measurement system according to claim 1, characterized in that: The third optical system includes an imaging detector; the imaging detector is used to receive the light beams scattered back from the target structure and cause interference.

6. The multi-wavelength phase modulation scanning measurement system according to claim 1, characterized in that: The processor is used to analyze and process the interference pattern captured by the third optical system to extract relevant information of the target structure in real time; the processor calculates the three-dimensional morphology, roughness and refractive index of the target structure by comparing the interference patterns under different phase differences.

7. A multi-wavelength phase modulation scanning measurement method, characterized in that: The measurement is performed using the multi-wavelength phase modulation scanning measurement system, including the following steps: S1. Generate a multi-wavelength beam using a radiation source; S2, splitting and phase modulating the light beam through the first optical system; S3, focusing the modulated beam onto the target structure; S4, collecting the scattered light beam and interfering it at the imaging detector; S5. The processor analyzes and processes the interference pattern to extract relevant information of the target structure.

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