Optical field injection calculation method and system of multilayer stacking periodic structure

Abstract

The invention belongs to the related technical field of semiconductor materials, and discloses a light field injection calculation method and system of a multilayer stacking periodic structure. The method comprises the following steps: constructing a three-dimensional geometric model of a metal-dielectric multilayer stacking periodic structure to be measured; calculating the minimum wavelength required to be met when the three-dimensional geometric model excites surface plasmon resonance; an anisotropic homogeneous medium is adopted to be equivalent to different material combinations in the three-dimensional geometric model, and an equivalent model corresponding to the three-dimensional geometric model is obtained; carrying out electromagnetic simulation on the equivalent model by adopting incident light with different wavelengths to obtain a corresponding resonant wavelength when the incident light can permeate into the equivalent model after plasma resonance; and electromagnetic simulation is carried out again by using the incident light with the wavelength to obtain the light field distribution of the cross section of the equivalent model, namely the light field distribution of the cross section of the metal-dielectric multilayer stacking periodic structure to be measured. According to the invention, the optical characteristics of the stacked periodic structure can be expressed quickly, completely and accurately.

Description

Technical Field

[0001] The present invention belongs to the technical field related to semiconductor materials, and more specifically, relates to a method and system for calculating light field injection of a multi-layer stacked periodic structure. Background Art

[0002] With the advent of the digital age, the demand for semiconductor chips in various electronic products continues to increase, driving the rapid development of the semiconductor industry. To meet market demand, the wafer chip manufacturing industry is constantly moving towards higher performance and smaller size. However, with the reduction in size and complexity of semiconductor devices, semiconductor devices in the form of multi-layer stacked structures have become mainstream. Optical detection or characterization of buried features in these high aspect ratio stacked periodic structures has become crucial, including but not limited to 3D NAND, FinFET, DRAM and other stacked structures.

[0003] In these multi-layer opaque stacked structures, since most metals are opaque in the UV-visible-near infrared region and are highly reflective and absorptive materials, traditional optical detection methods often find it difficult to break through their skin limit and achieve deeper feature detection.

[0004] In the prior art, deeper feature detection of multi-layer stacked periodic structures is performed using X-rays or ultrasound with strong penetrating power. The above method cannot detect the light field through ordinary incident light and has the problem of low detection efficiency. Summary of the invention

[0005] In response to the above defects or improvement needs of the prior art, the present invention provides a light field injection calculation method and system for a multi-layer stacked periodic structure, which solves the problem that traditional optical detection cannot inject light fields into multi-layer opaque stacked structures and has low calculation efficiency.

[0006] To achieve the above object, according to one aspect of the present invention, a method for calculating light field injection of a multi-layer stacked periodic structure is provided, the method comprising the following steps:

[0007] Constructing a three-dimensional geometric model of a metal-dielectric multilayer stacked periodic structure to be tested; calculating the minimum wavelength required for the three-dimensional geometric model to excite surface plasmon resonance;

[0008] An anisotropic uniform medium is used to be equivalent to the two materials in the three-dimensional geometric model to obtain an equivalent model corresponding to the three-dimensional geometric model; electromagnetic simulation is performed on the equivalent model using incident light of different wavelengths to obtain the reflectivity curve of the equivalent model under incident light of different wavelengths, and the wavelength λ* corresponding to the strongest resonance of the incident light inside the structure after surface plasmon resonance occurs is obtained from the reflectivity curve, and the light field penetration depth at this wavelength is the deepest.; Electromagnetic simulation is performed again on the equivalent model using incident light of wavelength λ* to obtain the light field distribution of the cross section of the equivalent model, and the light field distribution is the light field distribution of the cross section of the metal-dielectric multilayer stack periodic structure to be measured.

[0009] Further preferably, the minimum wavelength required for the three-dimensional geometric model to excite surface plasmon resonance is calculated according to the following steps:

[0010] Calculate the dielectric constant of the metal in the metal-dielectric multilayer stack periodic structure to be tested at different incident light wavelengths, so as to obtain the wavelength corresponding to when the real part of the dielectric constant of the metal becomes negative;

[0011] The relationship between the angular frequency of the incident light, the dielectric constants of the metal and the dielectric, and the wave vector of the surface plasmon resonance wave is constructed, and the relationship between the wavelength corresponding to when the real part of the dielectric constant of the metal appears negative and the angular frequency of the incident light is combined to calculate the minimum wavelength required for the three-dimensional geometric model to excite the surface plasmon resonance.

[0012] Further preferably, the dielectric constant of the metal in the metal-dielectric multilayer stack periodic structure to be measured at different incident light wavelengths is calculated using the Lorentz-Drude model, and the corresponding relationship is as follows:

[0013] ε(ω)=ε1(ω)+ε2(ω)

[0014]

[0015] Among them, ε(ω) is the dielectric constant of the metal, ε1 is the dielectric constant generated by free electrons, ε2 is the dielectric constant generated by bound electrons, and ω p is the plasma frequency, f0 is the oscillation intensity coefficient, γ0 is the damping coefficient of the zero-order oscillating electron, ω j are the oscillation frequencies of different orders, ω is the angular frequency of the incident light, γ j is the damping coefficient of different orders, j represents the number of oscillating electrons of different orders, k is the total order of oscillating electrons of different orders, and i is an imaginary number.

[0016] Further preferably, the relationship between the incident light angular frequency, the dielectric constants of the metal and the dielectric and the surface plasmon resonance wave vector is as follows:

[0017]

[0018] Among them, k spp is the surface plasmon resonance wave vector, ω is the incident light angular frequency, c is the speed of light in free space, ε m and ε d are the dielectric constants of metal and dielectric respectively.

[0019] Further preferably, the relationship between the corresponding wavelength when the real part of the dielectric constant of the metal becomes negative and the angular frequency of the incident light is as follows:

[0020]

[0021] Where ε(ω) is the dielectric constant of the metal, ω is the angular frequency of the incident light, and ω p is the angular frequency of the incident light when ε(ω) is 0, also known as the plasma frequency of the metal, c is the speed of light in free space, and λ p It is the wavelength at which the real part of the dielectric constant of a metal becomes negative.

[0022] Further preferably, when performing the electromagnetic simulation, it is also necessary to know the dielectric constants of the equivalent model in the horizontal and vertical directions at different incident light wavelengths, and the dielectric constants in the horizontal and vertical directions are calculated in the following manner:

[0023] εh=tm*εm+td*εd

[0024]

[0025] Among them, ε h and ε v are the dielectric constants of the equivalent model in the horizontal and vertical directions, t m and t d are the filling ratios of metal and dielectric in a multilayer period, ε m and ε d are the dielectric constants of metal and dielectric respectively.

[0026] Further preferably, the three-dimensional geometric model is constructed by using the thickness, width, air gap and stacking period of each layer of material in the metal-dielectric multilayer stacking periodic structure to be measured.

[0027] Further preferably, when performing the electromagnetic simulation, the light source is set to vertically incident P-polarized plane waves.

[0028] According to another aspect of the present invention, a calculation system for light field injection into a multi-layer stacked periodic structure is provided. The system includes an actuator for executing the above-mentioned calculation method for light field injection into a multi-layer stacked periodic structure.

[0029] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0030] 1. In the present invention, an anisotropic uniform medium is first used to simplify and equalize the multilayer stacked structure by using the bidirectional anisotropic material in the three-dimensional geometric model. Then, the equivalent model is electromagnetically simulated using the wavelength corresponding to the strongest resonance and deepest penetration of the incident light inside the structure after the surface plasmon resonance of the equivalent model. The incident light of the equivalent model can only irradiate into the metal-dielectric multilayer stacked periodic structure to be tested after the surface plasmon resonance occurs. After the surface plasmon resonance occurs, the wavelength with the smallest light reflectivity is selected for simulation to maximize the depth of the incident light irradiating into the metal-dielectric multilayer stacked periodic structure to be tested. It is not necessary to use X-ray or ultrasound with strong penetrating ability to detect the light field of the structure to be tested. In addition, through the simplified equivalent model, the light field simulation calculation can be quickly performed and the optimized illumination wavelength that can excite the surface plasmon resonance of the multilayer structure can be obtained, which greatly saves the light field simulation time of the actual multilayer stacked structure, thereby improving the efficiency of subsequent optical detection or characterization of these complex multilayer opaque stacked structures.

[0031] 2. Based on the optical properties of the material, the present invention utilizes the hyperbolic dispersion characteristics of the metal-dielectric multilayer film structure, injects P-light light field, and stimulates surface plasmon resonance with the help of momentum matching of the slits in the metal-dielectric multilayer film structure, so that the metal reflection is weakened and the transmission is enhanced, thereby achieving deeper penetration of the light field;

[0032] 3. The present invention uses the Lorentz-Drude model to calculate the dielectric constant, fully considering the behavior of free electrons and bound electrons in the material, and can more accurately describe the complex electromagnetic properties of the material; then the minimum wavelength required to excite the surface plasmon resonance is calculated by combining the relationship between the incident light angular frequency, the dielectric constants of the metal and the dielectric, and the surface plasmon resonance wave vector. This method can obtain the minimum wavelength more accurately and quickly, simplifying the subsequent electromagnetic simulation process;

[0033] 4. The EMT equivalent medium model of the present invention can realize the rapid simulation calculation of the light field of complex metal-dielectric multilayer mode structures, and can express the optical properties of stacked periodic structures more completely and accurately. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1It is a flow chart of a calculation method for light field injection into a multi-layer stacked periodic structure constructed according to a preferred embodiment of the present invention;

[0035] Figure 2a is a schematic structural diagram of a tungsten-silicon dioxide stacked periodic structure constructed according to a preferred embodiment of the present invention;

[0036] Figure 2b It is a structural schematic diagram of an equivalent model of a tungsten-silicon dioxide stacking periodic structure constructed according to a preferred embodiment of the present invention;

[0037] Figure 3a is a graph of the dielectric constant of tungsten metal constructed according to a preferred embodiment of the present invention;

[0038] Figure 3b is a dielectric constant curve diagram of an equivalent model constructed according to a preferred embodiment of the present invention;

[0039] Figure 4 is a reflectivity curve after wavelength scanning of an equivalent model constructed according to a preferred embodiment of the present invention;

[0040] Figure 5a It is a cross-sectional light field penetration diagram of a three-dimensional geometric model without slits when the incident wavelength is 2.76 um constructed according to a preferred embodiment of the present invention;

[0041] Figure 5b It is a cross-sectional light field penetration diagram of a three-dimensional geometric model with a slit when the incident wavelength is 2.76 um constructed according to a preferred embodiment of the present invention;

[0042] Figure 5c It is a cross-sectional light field penetration diagram of an equivalent model constructed according to a preferred embodiment of the present invention when the incident wavelength is 2.76 um;

[0043] Figure 6a It is a cross-sectional light field penetration diagram of a three-dimensional geometric model without slits when the incident wavelength is 3.12 um constructed according to a preferred embodiment of the present invention;

[0044] Figure 6b It is a cross-sectional light field penetration diagram of a three-dimensional geometric model with a slit when the incident wavelength is 3.12 um constructed according to a preferred embodiment of the present invention;

[0045] Figure 6c It is a cross-sectional light field penetration diagram of an equivalent model constructed according to a preferred embodiment of the present invention when the incident wavelength is 3.12 um. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0047] The subwavelength metal-dielectric multilayer stacked periodic structure is essentially a hyperbolic metamaterial, whose properties make deeper detection possible. By studying the electromagnetic properties of hyperbolic metamaterials, it is found that the metal-dielectric multilayer structure has hyperbolic dispersion characteristics and can propagate electromagnetic waves in an unconventional way within a certain frequency range, resulting in the phenomenon of reduced reflection and enhanced transmission, thus breaking the skin limit of metals and providing a non-destructive, non-contact, and fast light field penetration method for optical detection of deeply buried features of multilayer stacked structures.

[0048] The present invention provides a specific example of a metal-dielectric stack periodic structure, including but not limited to tungsten metal-silicon dioxide multilayer film, copper-silicon dioxide multilayer film, germanium-aluminum oxide multilayer film, etc. in 3D NAND, such as Figure 2a As shown, a tungsten metal-silicon dioxide multilayer periodic structure is shown, in which the materials are stacked layer by layer in the vertical direction and arranged in intervals in the horizontal direction.

[0049] like Figure 1 As shown, a method for calculating light field injection into a multi-layer stacked periodic structure includes the following steps:

[0050] S1 builds a three-dimensional geometric model of the multi-layer periodic structure to be tested

[0051] In this embodiment, see Figure 2a , where the thickness t2 of the selected tungsten metal film is 50nm, the thickness t1 of the silicon dioxide film is 50nm, and the thickness t0 of the top silicon dioxide coating layer is 120nm. The silicon dioxide-tungsten metal stacking period is 20 pairs, a total of 40 layers, a total height of 2.12um, the multilayer structure width L1 is 400nm, and the air gap width L2 is 250nm, so the lateral period is L1+L2=650nm, completing the model construction of the multilayer structure.

[0052] S2 calculates the minimum wavelength required to excite surface plasmon resonance in a three-dimensional geometric model.

[0053] (1) Calculate the nodal constants of metals

[0054] In order to obtain the specific dielectric constant of tungsten metal and the dielectric constant of silicon dioxide, the Lorentz-Drude model is used in this specific example to calculate the dielectric constant of tungsten metal, and the model formula is as follows.

[0055] ε(ω)=ε1(ω)+ε2(ω)

[0056]

[0057] In the formula, the dielectric constant is divided into two parts, representing the dielectric constants dominated by free electrons and bound electrons. ε1 represents the dielectric constant generated by free electrons, ε2 represents the dielectric constant generated by bound electrons, and ω p represents the plasma frequency, f0 represents the oscillation intensity coefficient, γ0 is the damping coefficient of the zero-order oscillating electron, ω j is the oscillation frequency of different orders, ω is the angular frequency of the incident light, converted to wavelength, γ j is the damping coefficient of different orders, j represents the number of oscillating electrons of different orders, k is the total order of oscillating electrons of different orders, and i is an imaginary number. The dielectric constant of tungsten metal is calculated using the LD model, where the plasma frequency of tungsten metal is 13.22ev, the oscillation intensity coefficients of different orders are 0.206, 0.062, 0.166, 0.706, and 2.590 respectively; the damping coefficients of different orders are 0.064, 0.530, 1.281, 3.332, and 5.836; the oscillation frequencies of different orders are 1.004, 1.719, 3.580, and 7.569, and the dielectric constant curve of tungsten metal is obtained as follows Figure 3a As shown in Figure 2, when the wavelength is greater than 941nm, the real part of the dielectric constant of tungsten metal becomes negative.

[0058] (2) Using the hyperbolic dispersion characteristics of the metal-dielectric multilayer structure, the minimum wavelength of the band in which surface plasmon resonance can occur between the metal and dielectric surfaces is determined, first satisfying the condition that the real part of the dielectric constant has an opposite sign.

[0059] By solving the Maxwell equations and dispersion relations of the metal-dielectric surface, the relationship between the incident light frequency and the metal-dielectric surface plasmon resonance wave vector is obtained:

[0060]

[0061] In the formula, k spp is the surface plasmon resonance wave vector, ω is the angular frequency of the incident light, c is the speed of light in free space, ε m and ε d Represents the dielectric constant of metals and dielectrics.

[0062]

[0063] The hyperbolic dispersion relation shows that the incident light wave vector in free space is smaller than the surface plasmon resonance wave vector, and under normal circumstances, the incident light cannot excite the metal surface plasmon resonance. Only when ω<ωspp is satisfied and there is an air slit or other coupling medium to produce momentum compensation, so that the incident light wave vector reaches the hyperbolic dispersion region, can surface plasmon resonance occur.

[0064] In this embodiment, the wavelength corresponding to ωspp is calculated to be 2.02 um through the formula, so in order to generate surface plasmon resonance, it is first necessary to be within the infrared band greater than 2.02 um.

[0065] S3 uses an anisotropic uniform medium to be equivalent to the two materials in the three-dimensional geometric model to obtain an equivalent model corresponding to the three-dimensional geometric model.

[0066] The effective dielectric constant of the simplified structure is calculated according to the EMT equivalent dielectric model, and it is found whether the bands with opposite signs of the real parts of the dielectric constants in the horizontal and vertical directions are the same as the bands with opposite signs of the metal-dielectric, so as to verify the accuracy of the equivalent model.

[0067] Specifically, according to the Maxwell-Garnet approximation theory, the calculation formula for the effective dielectric constant of the equivalent homogeneous medium is:

[0068] εh=tm*εm+td*εd

[0069]

[0070] In the formula, ε h and ε v Indicates the horizontal direction (ε x =ε y ) and vertical direction (ε z )’s dielectric constant, ε m and ε d represents the dielectric constant of metal and dielectric, t m and t d It represents the filling ratio of metal and dielectric in a multilayer period, which is the ratio of the single layer thickness of the two materials to the sum of their thicknesses. For example, if the metal thickness is t1 and the dielectric thickness is t2, then t m =(t1 / (t1+t2)).

[0071] Substituting the dielectric constants of the two materials into the calculation, the effective dielectric constant curve of the anisotropic homogeneous medium is obtained as shown in Figure 3b As shown, analysis shows that when the wavelength is greater than 971nm, ε x =ε y <0,ε z > 0, so that the dispersion relation of the equivalent homogeneous structure of tungsten metal-silicon dioxide on the xz cross section is:

[0072]

[0073] The hyperbolic dispersion characteristics of the multilayer stack structure described above correspond one to one, and as Figure 3a and 3b As shown in the figure, the position of the opposite sign of the real part of the dielectric constant and the corresponding wavelength value when the real part of tungsten metal is negative are 971nm and 941nm respectively, which are roughly consistent. It can be seen that the accuracy of the EMT equivalent simplified model is verified. The subsequent model establishment of EMT uses the same parameters as the multilayer stacking structure to ensure good comparison between the two. The height of the EMT material is t3 = 2um. Figure 2b shown.

[0074] S4 uses incident light of different wavelengths to perform electromagnetic simulation on the equivalent model, so as to obtain the reflectivity curve of the equivalent model under incident light of different wavelengths, and obtain the wavelength λ* corresponding to the deepest penetration depth of the incident light after surface plasmon resonance occurs from the reflectivity curve.

[0075] Specifically, the wavelength band that can excite surface plasmon resonance obtained above is at least greater than 2.02um, and the incident light needs to be P-polarized to excite metal surface plasmon resonance. Therefore, the EMT model is rigorously simulated and solved using finite time-domain difference, and the light source is set to be a P-polarized plane wave with vertical incidence, and the wavelength scanning band is 2.02um-4um.

[0076] The wavelength λ* corresponds to the wavelength when the incident light irradiates the equivalent model to excite the surface plasmon resonance of the equivalent model so that the light field can penetrate into the equivalent model. Therefore, this wavelength needs to be greater than the minimum wavelength corresponding to the excitation surface plasmon resonance, and the reflectivity of the incident light is the smallest, at which time the resonance is the strongest.

[0077] like Figure 4 As shown, the reflection spectra at the two locations have absorption peaks, the resonance is the strongest, the light generates electromagnetic waves, and the electric field of the electromagnetic waves can penetrate the structure to the greatest extent. At this time, the wavelengths corresponding to the absorption peaks are 2.76um and 3.12um, that is, λ*=2.76um and 3.12um. Analyzing the penetration distribution of the EZ component in the vertical direction of the cross-sectional electric field, it can be seen that the EZ component has completely penetrated the entire structure at this time, as shown in Figure 5c and Figure 6c shown.

[0078] S5: Perform electromagnetic simulation on the equivalent model again using incident light with a wavelength of λ* to obtain the light field distribution of the cross section of the equivalent model.

[0079] While obtaining the light field distribution of the equivalent model cross-section, in this embodiment, both the three-dimensional geometric model with a slit and the three-dimensional geometric model without a slit were subjected to electromagnetic simulation using the same parameters. For comparison, the three-dimensional geometric model with a slit is the three-dimensional geometric model corresponding to the metal-dielectric multilayer stacked periodic structure to be tested in the present invention, and the three-dimensional geometric model without a slit is obtained by setting the slit in the three-dimensional geometric model with a slit of the present invention to zero.

[0080] The resonance wavelength and EMT model simulation settings obtained by simulating the EMT model are imported into the tungsten metal-silicon dioxide multilayer structures with and without slits for simulation.

[0081] Specifically, the wavelength of the light source is set to 2.76um and 3.12um, and the polarization state is set to P polarization, that is, perpendicular to the slit direction in the model. Then, the light field simulation results of the remaining models are strictly solved by FDTD.

[0082] Comparing the simulation results, it is concluded that when there is no slit, the multilayer structure is Figure 5a and Figure 6a Surface plasmon resonance cannot be excited. When there are slits, the multilayer structure is as follows Figure 5b and Figure 6b and the equivalent EMT model electric field as Figure 5c and Figure 6c The penetration effects are roughly the same, both can penetrate the entire structure, breaking the traditional skin limit of tungsten metal, and the average simulation calculation time for the two is 1min 36secs (multi-layer stacking structure) and 28secs (EMT model), which greatly shortens the simulation calculation time and provides a new method for achieving deeper depth and faster speed 3D NAND buried defect detection.

[0083] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calculating light field injection of a multi-layer stacked periodic structure, characterized in that: The method comprises the following steps: Constructing a three-dimensional geometric model of a metal-dielectric multilayer stacked periodic structure to be tested; calculating the minimum wavelength required for the three-dimensional geometric model to excite surface plasmon resonance; An anisotropic uniform medium is used to be equivalent to the two materials in the three-dimensional geometric model to obtain an equivalent model corresponding to the three-dimensional geometric model; electromagnetic simulation is performed on the equivalent model using incident light of different wavelengths to obtain the reflectivity curve of the equivalent model under incident light of different wavelengths, and the wavelength λ* corresponding to the strongest resonance of the incident light inside the structure after surface plasmon resonance occurs is obtained from the reflectivity curve; electromagnetic simulation is performed again on the equivalent model using incident light of wavelength λ* to obtain the light field distribution of the cross section of the equivalent model, which is the light field distribution of the cross section of the metal-dielectric multilayer stacked periodic structure to be measured.

2. The method for calculating light field injection of a multi-layer stacked periodic structure according to claim 1, characterized in that: The minimum wavelength required for the three-dimensional geometric model to excite surface plasmon resonance is calculated according to the following steps: Calculate the dielectric constant of the metal in the metal-dielectric multilayer stack periodic structure to be tested at different incident light wavelengths, so as to obtain the wavelength corresponding to when the real part of the dielectric constant of the metal becomes negative; The relationship between the angular frequency of the incident light, the dielectric constants of the metal and the dielectric, and the wave vector of the surface plasmon resonance wave is constructed, and the relationship between the wavelength corresponding to when the real part of the dielectric constant of the metal appears negative and the angular frequency of the incident light is combined to calculate the minimum wavelength required for the three-dimensional geometric model to excite the surface plasmon resonance.

3. The method for calculating light field injection of a multi-layer stacked periodic structure according to claim 2, characterized in that: The Lorentz-Drude model is used to calculate the dielectric constant of the metal in the metal-dielectric multilayer stack periodic structure to be tested at different incident light wavelengths, and the corresponding relationship is as follows: ε(ω)=ε1(ω)+ε2(ω) Among them, ε(ω) is the dielectric constant of the metal, ε1 is the dielectric constant generated by free electrons, ε2 is the dielectric constant generated by bound electrons, and ω p is the plasma frequency, f0 is the oscillation intensity coefficient, γ0 is the damping coefficient of the zero-order oscillating electron, ω j are the oscillation frequencies of different orders, ω is the angular frequency of the incident light, γ j is the damping coefficient of different orders, j represents the number of oscillating electrons of different orders, k is the total order of oscillating electrons of different orders, and i is an imaginary number.

4. The method for calculating light field injection of a multi-layer stacked periodic structure according to claim 2, characterized in that: The relationship between the incident light angular frequency, the dielectric constants of the metal and the dielectric and the surface plasmon resonance wave vector is as follows: Among them, k spp is the surface plasmon resonance wave vector, ω is the incident light angular frequency, c is the speed of light in free space, and ε m and ε d are the dielectric constants of metal and dielectric respectively.

5. The method for calculating light field injection of a multi-layer stacked periodic structure according to claim 2, characterized in that: When the real part of the dielectric constant of the metal becomes negative, the relationship between the corresponding wavelength and the angular frequency of the incident light is as follows: Where ε(ω) is the dielectric constant of the metal, ω is the angular frequency of the incident light, and ω p is the angular frequency of the incident light when ε(ω) is 0, also known as the plasma frequency of the metal, c is the speed of light in free space, and λ p It is the wavelength at which the real part of the dielectric constant of a metal becomes negative.

6. A method for calculating light field injection of a multi-layer stacked periodic structure as claimed in claim 1 or 2, characterized in that: When performing the electromagnetic simulation, it is also necessary to know the dielectric constants of the equivalent model in the horizontal and vertical directions at different incident light wavelengths. The dielectric constants in the horizontal and vertical directions are calculated in the following manner: εh=tm*εm+td*εd Among them, ε h and ε v are the dielectric constants of the equivalent model in the horizontal and vertical directions, t m and t d are the filling ratios of metal and dielectric in a multilayer period, ε m and ε d are the dielectric constants of metal and dielectric respectively.

7. A method for calculating light field injection of a multi-layer stacked periodic structure as claimed in claim 1 or 2, characterized in that: The three-dimensional geometric model is constructed by using the thickness, width, air gap and stacking period of each layer of material in the metal-dielectric multilayer stacking periodic structure to be tested.

8. A method for calculating light field injection of a multi-layer stacked periodic structure as claimed in claim 1 or 2, characterized in that: When performing the electromagnetic simulation, the light source is set to vertically incident with a P-polarized plane wave.

9. A computing system for light field injection of a multi-layer stacked periodic structure, characterized in that: The system includes an actuator, which is used to execute the light field injection calculation method for a multi-layer stacked periodic structure as described in any one of claims 1-8.

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