Method for adjusting resonant frequency of terahertz focal plane detector and application thereof

Abstract

The invention discloses a method for adjusting the resonant frequency of a terahertz focal plane detector and application thereof. The terahertz focal plane detector comprises a photosensitive chip and a CMOS readout circuit which are connected in an inverted mode, the photosensitive chip comprises an original substrate and an antenna array arranged on the original substrate, x frequency adjustment compensation plates are arranged on the back face, back to the antenna array, of the original substrate in a laminated mode, and the frequency adjustment compensation plates and the original substrate are made of the same material, and the thickness or the number of the frequency adjustment compensation plates is adjusted, so that the resonant frequency of the terahertz focal plane detector is changed, and the measured value of the resonant frequency corresponding to the resonant peak of the terahertz focal plane detector at the required frequency is close to or equal to the designed theoretical value. According to the terahertz focal plane detector, the period of the response frequency spectrum and the position of the response peak are changed by increasing the frequency adjustment compensation plate and adjusting the thickness of the x frequency compensation adjustment plates, and therefore the resonant frequency of the terahertz focal plane detector is adjusted.

Description

Technical Field

[0001] The present invention particularly relates to a method for adjusting the resonance frequency of a terahertz focal plane detector and application thereof, and belongs to the field of micro-nano manufacturing technology. Background Art

[0002] Terahertz waves (0.3-10THz) have the characteristics of high penetration, low photon energy, high coherence, and fingerprint spectrum. They have broad application prospects in both military and civilian fields. Their core functional materials and component technologies have become the technological commanding heights of international competition and a major strategic need of my country.

[0003] Terahertz imaging sensing technology has the advantages of strong anti-interference ability, high resolution, good timeliness, low photon energy, strong penetration, and rich spectral information. Therefore, it has broad application prospects in deep space detection and remote sensing, target perception and attack and defense, non-destructive testing and hidden target imaging. Among various terahertz detection and perception methods, terahertz focal plane array imaging has the advantages of good real-time imaging and is one of the technical approaches with the best application prospects and the strongest sustainable development potential in terahertz imaging sensing technology. In terahertz information systems, the performance of detectors is the core factor that determines the overall efficiency of the system. The demand for detectors in the new generation of intelligent perception systems is constantly increasing, and they need to have characteristics such as room temperature operation, high responsiveness, multi-function, chip-based and micro-nano-based. The photosensitive chip integrates the detector array with the readout circuit, and has the characteristics of high-resolution detection and large-angle data reception. It has broad application prospects in 6G communications, high-resolution radars, industrial detection, unmanned driving, and biomedicine.

[0004] The typical terahertz focal plane array architecture includes a terahertz microlens array, a focal plane detection array chip, and an intermediate frequency circuit. Figure 1 As shown, the detection array chip is constructed by flip-chip interconnection of a GaN photosensitive chip and a CMOS readout circuit. Each detection unit (pixel) corresponds one-to-one to a different position on the target, and full-field imaging is achieved by independent detection of each pixel.

[0005] In the study of terahertz focal plane detector arrays, the spectral response characteristics are the key factors affecting the detection performance. Traditionally, the response spectrum mainly depends on the geometric structure and material parameters of the antenna. However, when the antennas form an array, the electromagnetic coupling effect between the antennas and the influence of the multi-layer materials after flip-chip interconnection (such as SiC or Si substrate, CMOS circuit, etc.) will cause the resonant frequency to deviate from the design target, significantly affecting the detector performance. Taking the 340GHz focal plane detector as an example, the measured response spectrum (such as Figure 2 The maximum response is obtained near 300 GHz, which is significantly different from the design frequency. This frequency shift will obviously reduce the performance of the detector. Summary of the invention

[0006] The main purpose of the present invention is to provide a method for adjusting the resonant frequency of a terahertz focal plane detector and its application, so as to overcome the deficiencies in the prior art.

[0007] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention includes:

[0008] A first aspect of an embodiment of the present invention provides a method for adjusting the resonant frequency of a terahertz focal plane detector, wherein the terahertz focal plane detector comprises a flip-chip interconnected photosensitive chip and a CMOS readout circuit, wherein the photosensitive chip comprises an original substrate and an antenna array disposed on the original substrate, and the method further comprises:

[0009] x frequency adjustment compensation plates are stacked on the back side of the original substrate facing away from the antenna array, the frequency adjustment compensation plates are made of the same material as the original substrate, and the original substrate and the x frequency adjustment compensation plates are used as a new substrate for the photosensitive chip as a whole, and the thickness or number of the frequency adjustment compensation plates is adjusted to change the resonant frequency of the terahertz focal plane detector, so that the measured value of the resonant frequency corresponding to the resonant peak of the terahertz focal plane detector at the required frequency is close to or equal to the designed theoretical value, x≥1.

[0010] A second aspect of an embodiment of the present invention provides a method for manufacturing a terahertz focal plane detector, comprising: flip-chip interconnecting a photosensitive chip and a CMOS readout circuit to form a terahertz focal plane detector, wherein the photosensitive chip comprises an original substrate and an antenna array disposed on the original substrate;

[0011] Furthermore, x frequency adjustment compensation plates are stacked on the back side of the original substrate facing away from the antenna array, the frequency adjustment compensation plates are made of the same material as the original substrate, and the original substrate and the x frequency adjustment compensation plates are used as a new substrate for the photosensitive chip as a whole, and the thickness or number of the frequency adjustment compensation plates is adjusted to change the resonant frequency of the terahertz focal plane detector, so that the measured value of the resonant frequency corresponding to the resonant peak of the terahertz focal plane detector at the required frequency is close to or equal to the designed theoretical value, and finally the original substrate and the x frequency adjustment compensation plates are combined into one, x≥1.

[0012] Compared with the prior art, the advantages of the present invention include:

[0013] A method for adjusting the resonant frequency of a terahertz focal plane detector provided in an embodiment of the present invention increases a frequency adjustment compensation plate and adjusts the thickness of x frequency compensation adjustment plates to change the period of a response spectrum and the position of a response peak, thereby enhancing the electric field coupling of a specific frequency, overcoming the negative effects of the electromagnetic coupling effect between antenna arrays and the flip-chip interconnection with a CMOS readout circuit on frequency adjustment, and achieving adjustment of the resonant frequency of the terahertz focal plane detector, thereby solving the problem of unpredictable changes in the resonant frequency of the terahertz focal plane detector after the formation of the terahertz focal plane detector.

[0014] A method for adjusting the resonant frequency of a terahertz focal plane detector provided in an embodiment of the present invention can achieve control of the resonant frequency only by adding a frequency adjustment compensation plate and changing the thickness of x frequency adjustment compensation plates. There is no need to change the structure of the terahertz focal plane detector, and no reliance is placed on complex antenna structure adjustment or dynamic tuning elements. The actual value of the resonant frequency of the terahertz focal plane detector is adjusted back to the design target, and the process is simple and the cost is lower. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the structure of a terahertz focal plane detector;

[0016] Figure 2 is the response spectrum of the 340 GHz terahertz focal plane detector;

[0017] Figure 3 is the response spectrum of the 900 GHz terahertz focal plane detector;

[0018] Figure 4 It is a schematic diagram of the principle of adjusting the resonant frequency of a terahertz focal plane detector by increasing the thickness of an original substrate using a frequency adjustment compensation plate provided in a typical implementation case of the present invention;

[0019] Figure 5 This is the response spectrum of the 900GHz terahertz focal plane detector after adding frequency adjustment compensation plates of different thicknesses;

[0020] Figure 6 This is the normalized response spectrum of a 340 GHz terahertz focal plane detector with frequency adjustment compensation plates of different thicknesses added. DETAILED DESCRIPTION

[0021] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0022] A first aspect of an embodiment of the present invention provides a method for adjusting the resonant frequency of a terahertz focal plane detector, wherein the terahertz focal plane detector comprises a flip-chip interconnected photosensitive chip and a CMOS readout circuit, wherein the photosensitive chip comprises an original substrate and an antenna array disposed on the original substrate.

[0023] And, the method includes: stacking x frequency adjustment compensation plates on the back side of the original substrate facing away from the antenna array, the frequency adjustment compensation plates are made of the same material as the original substrate, and the original substrate and the x frequency adjustment compensation plates are used as a new substrate for the photosensitive chip as a whole, and adjusting the thickness or number of the frequency adjustment compensation plates to change the resonant frequency of the terahertz focal plane detector, so that the measured value of the resonant frequency corresponding to the resonant peak of the terahertz focal plane detector at the required frequency is close to or equal to the designed theoretical value, x≥1.

[0024] Furthermore, the method for adjusting the resonant frequency of the terahertz focal plane detector includes: thinning the frequency adjustment compensation plate, or replacing the frequency adjustment compensation plate with a larger thickness value, or increasing the number of the frequency adjustment compensation plates.

[0025] Furthermore, the method for adjusting the resonant frequency of the terahertz focal plane detector includes: arranging x frequency adjustment compensation plates on the original substrate to obtain a new substrate, performing a responsiveness test on the terahertz focal plane detector to obtain an actual response spectrum of the terahertz focal plane detector, and if the measured value of the resonant frequency corresponding to the resonant peak at the required frequency is different from the designed value, adjusting the thickness or number of the frequency adjustment compensation plates until the resonant frequency corresponding to the resonant peak is the required designed value.

[0026] Furthermore, the method for adjusting the resonant frequency of the terahertz focal plane detector specifically includes: determining the thickness adjustment values ​​of the x frequency adjustment compensation plates according to the design value of the resonant frequency of the terahertz focal plane detector, where L is the sum of the thicknesses of the x frequency adjustment compensation plates and the original substrate,

[0027]

[0028] Wherein, f is the design value of the resonance frequency corresponding to the resonance peak of the terahertz focal plane detector at the required frequency, n is the equivalent refractive index of the original substrate when the resonance peak is at the measured value position, and c is the speed of light in vacuum.

[0029] Furthermore, the method for adjusting the resonance frequency of the terahertz focal plane detector specifically includes: adjusting the thickness of the new substrate of the photosensitive chip in multiple times.

[0030] Further, if the measured value of the resonance frequency corresponding to the resonance peak is lower than the design value, the frequency adjustment compensation plate of the new substrate is thinned; if the measured value of the resonance frequency corresponding to the resonance peak is higher than the design value, the frequency adjustment compensation plate with a larger thickness value is replaced or the number of the frequency adjustment plates is increased;

[0031] Furthermore, the k value used for adjusting the thickness of the x frequency adjustment compensation plates multiple times is reduced successively.

[0032] A second aspect of an embodiment of the present invention provides a method for manufacturing a terahertz focal plane detector, which includes: flip-chip interconnecting a photosensitive chip and a CMOS readout circuit to form a terahertz focal plane detector, wherein the photosensitive chip includes an original substrate and an antenna array arranged on the original substrate, and x frequency adjustment compensation plates are stacked on the back side of the original substrate facing away from the antenna array, wherein the frequency adjustment compensation plates are made of the same material as the original substrate, and the original substrate and the x frequency adjustment compensation plates are used as a new substrate for the photosensitive chip as a whole, and the thickness or number of the frequency adjustment compensation plates is adjusted to change the resonant frequency of the terahertz focal plane detector so that the actual measured value of the resonant frequency corresponding to the resonant peak of the terahertz focal plane detector at the required frequency is close to or equal to the designed theoretical value, and finally the original substrate and the x frequency adjustment compensation plates are combined into one, x≥1.

[0033] Furthermore, the manufacturing method of the terahertz focal plane detector includes: thinning the frequency adjustment compensation plate, or replacing the frequency adjustment compensation plate with a larger thickness value, or increasing the number of the frequency adjustment compensation plates.

[0034] Furthermore, the manufacturing method of the terahertz focal plane detector specifically includes:

[0035] X frequency adjustment compensation plates are arranged on the original substrate to obtain a new substrate, and a responsiveness test is performed on the terahertz focal plane detector to obtain an actual response spectrum of the terahertz focal plane detector. If the measured value of the resonance frequency corresponding to the resonance peak at the required frequency is different from the design value, the thickness or number of the frequency adjustment compensation plates is adjusted until the resonance frequency corresponding to the resonance peak is the required design value.

[0036] Furthermore, if the measured value of the resonant frequency corresponding to the resonance peak is lower than the design value, the frequency adjustment compensation plate of the new substrate is thinned; if the measured value of the resonant frequency corresponding to the resonance peak is higher than the design value, the frequency adjustment compensation plate with a larger thickness is replaced or the number of the frequency adjustment plates is increased.

[0037] In a more specific implementation, the method for manufacturing the terahertz focal plane detector specifically includes: determining the thickness adjustment values ​​of the x frequency adjustment compensation plates according to the design value of the resonant frequency of the terahertz focal plane detector, where L is the sum of the thicknesses of the x frequency adjustment compensation plates and the original substrate,

[0038]

[0039] Wherein, f is the design value of the resonance frequency corresponding to the resonance peak of the terahertz focal plane detector at the required frequency, n is the equivalent refractive index of the original substrate when the resonance peak is at the measured value position, and c is the speed of light in vacuum.

[0040] Furthermore, the thickness of the new substrate of the photosensitive chip is adjusted multiple times;

[0041] Furthermore, the k value used for adjusting the thickness of the x frequency adjustment compensation plates multiple times is reduced successively.

[0042] The technical solution, its implementation process and principle will be further explained below in conjunction with the accompanying drawings and specific implementation cases.

[0043] When manufacturing a terahertz focal plane detector, after the antennas form an array, the electromagnetic coupling and edge effects between the antennas cause the overall resonant frequency of the terahertz focal plane detector to shift or change, and adjusting the geometric dimensions of each antenna individually cannot accurately control the resonant frequency of the entire terahertz focal plane detector. In addition, due to the flip-chip interconnection between the terahertz focal plane detector chip and the CMOS readout circuit, as well as the influence of multiple materials such as the original substrate of the terahertz focal plane detector chip (such as SiC substrate, Si substrate), CMOS readout circuit (CMOS) wiring, etc., the electromagnetic environment of the terahertz focal plane detector becomes complex and difficult to predict, resulting in the actual value of the resonant frequency after manufacturing being inconsistent with the design value of the design target.

[0044] The present invention has found that in the existing terahertz focal plane detector, since the wavelength of the incident THz radiation is comparable to or even longer than the thickness of the detector substrate, a very obvious THz wave interference effect will occur at the antenna position, such as Figure 3 As shown in the figure, the response spectrum of the 900GHz focal plane detector shows a periodic interference peak. This substrate cavity interference effect will have a significant impact on the coupling of the signal. Based on this, the present invention has found that, without changing the design of the terahertz focal plane detector, by adding a frequency adjustment compensation plate to the original substrate on the photosensitive chip and changing the thickness of the frequency adjustment compensation plate, the interference condition can be changed, so that the electric field coupling of the antenna at a specific frequency is enhanced, thereby adjusting the resonant frequency back to the design value.

[0045] Specifically, there are two main ways to change the thickness of the frequency adjustment compensation plate. One is to thin the frequency adjustment compensation plate to reduce the thickness of the frequency adjustment compensation plate, or to replace the frequency adjustment compensation plate with a larger thickness value or increase the number of frequency adjustment compensation plates to increase the thickness of x frequency adjustment compensation plates. Since the thinning process after flip-chip is difficult to operate, especially under the premise of ensuring uniformity and consistency of thickness, the precision requirement is very high. The following will mainly change the interference conditions by replacing frequency adjustment compensation plates with different thicknesses, so that the electric field coupling of a specific frequency is enhanced, thereby adjusting the resonant frequency back to the design value as an example, and its specific implementation process will be specifically described.

[0046] In a more specific implementation, a method for adjusting the resonant frequency of a terahertz focal plane detector is performed after a photosensitive chip and a CMOS readout circuit are flip-chip interconnected to form a terahertz focal plane detector, wherein the photosensitive chip includes an original substrate and an antenna array disposed on the original substrate. The specific adjustment method is as follows:

[0047] First, the thickness adjustment value of a single frequency adjustment compensation plate is determined according to the design value of the resonant frequency of the terahertz focal plane detector, where L is the sum of the thickness of the frequency adjustment compensation plate and the original substrate.

[0048]

[0049] Wherein, f is the design value of the resonance frequency corresponding to the resonance peak of the terahertz focal plane detector at the required frequency, n is the equivalent refractive index of the original substrate when the resonance peak is at the measured value position, and c is the speed of light in vacuum.

[0050] It should be noted that although adding a frequency adjustment compensation plate can effectively adjust the resonant frequency, it will cause the detector's response bandwidth to be relatively reduced. Therefore, a smaller "k" value should be selected as much as possible within the range allowed by the process to reduce the impact of adding the frequency adjustment compensation plate on the detector's response bandwidth.

[0051] After determining the thickness adjustment value L that needs to be adjusted, a frequency adjustment compensation plate with a corresponding thickness is manufactured. It should be noted that before the frequency adjustment compensation plate is fixedly combined with the original substrate of the photosensitive chip, the electromagnetic field distribution of the terahertz focal plane detector with the frequency adjustment compensation plate with a corresponding thickness can be simulated using electromagnetic simulation software (such as HFSS, CST, etc.), and the change in the electric field strength at the antenna position is analyzed. Combined with the simulation results, the thickness adjustment value L is further optimized to ensure that the adjusted resonant frequency is more consistent with the design target.

[0052] Then, if Figure 4As shown, the frequency adjustment compensation board is fixedly assembled with the original substrate of the photosensitive chip, and the original substrate is thickened by mounting or other methods. During the assembly process, it should be ensured that the frequency adjustment compensation board is tightly fitted with the original substrate to ensure the consistency of electromagnetic characteristics and reduce the interference effect caused by uneven thickness.

[0053] In order to verify whether the expected effect is achieved by adding the frequency adjustment compensation plate, the terahertz focal plane detector after assembly needs to be retested for responsivity. By testing the responsivity of the terahertz focal plane detector at different frequencies, it is determined whether the addition of the frequency adjustment compensation plate and the adjustment of the thickness of the frequency adjustment compensation plate have successfully adjusted the resonant frequency, and whether the response at the required resonant frequency meets the design target requirements. If the test results show that the resonant frequency has been adjusted to the target range and the responsivity curve is consistent with expectations, the adjustment of the resonant frequency is completed. If the deviation of the actual value of the resonant frequency still does not meet the requirements, the thickness of the frequency adjustment compensation plate is further adjusted according to the test results. Specifically, if the measured value of the resonant frequency corresponding to the resonance peak is lower than the design value, the frequency adjustment compensation plate is thinned to obtain a frequency adjustment compensation plate with a smaller thickness. If the measured value of the resonant frequency corresponding to the resonance peak is higher than the design value, a frequency adjustment compensation plate with a larger thickness value is made and replaced until the design target is achieved.

[0054] In a typical implementation case, the response spectrum of the FPA-900GHz terahertz focal plane detector with frequency adjustment compensation plates of different thicknesses is as follows: Figure 5 As shown, it can be seen that after adding the frequency adjustment compensation plate, there is no significant effect on the responsivity value of the terahertz focal plane detector. Adding the frequency adjustment compensation plate can effectively change the period of the response spectrum and the position of the response peak.

[0055] In a typical implementation case, the present invention also tests the normalized response spectrum of the terahertz focal plane detector after adding frequency adjustment compensation plates of different thicknesses in a 340 GHz terahertz focal plane detector, such as Figure 6 The experiment confirmed that the frequency adjustment compensation plate can effectively adjust the resonant frequency of the terahertz focal plane detector, and frequency adjustment compensation plates of different thicknesses can achieve different degrees of frequency offset compensation.

[0056] A method for adjusting the resonant frequency of a terahertz focal plane detector provided in an embodiment of the present invention introduces a frequency adjustment compensation plate and adjusts the thickness of the frequency adjustment compensation plate to change the period of the response spectrum and the position of the response peak, so that the electric field coupling of a specific frequency is enhanced, and the negative effects of the electromagnetic coupling effect between antenna arrays and the flip-chip interconnection with a CMOS readout circuit on the frequency adjustment are overcome, and the resonant frequency of the terahertz focal plane detector is adjusted, thereby solving the problem of unpredictable changes in the resonant frequency of the terahertz focal plane detector after the formation of the terahertz focal plane detector.

[0057] A method for adjusting the resonant frequency of a terahertz focal plane detector provided in an embodiment of the present invention can achieve control of the resonant frequency only by introducing a frequency adjustment compensation plate and adjusting the thickness of the frequency adjustment compensation plate. There is no need to change the structure of the terahertz focal plane detector, and no reliance on complex antenna structure adjustment or dynamic tuning elements. The actual value of the resonant frequency of the terahertz focal plane detector is adjusted back to the design target, and the process is simple and the cost is lower.

[0058] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for adjusting the resonant frequency of a terahertz focal plane detector, wherein the terahertz focal plane detector comprises a flip-chip interconnected photosensitive chip and a CMOS readout circuit, wherein the photosensitive chip comprises an original substrate and an antenna array disposed on the original substrate, characterized in that: The method further comprises: x frequency adjustment compensation plates are stacked on the back side of the original substrate facing away from the antenna array, the frequency adjustment compensation plates are made of the same material as the original substrate, and the original substrate and the x frequency adjustment compensation plates are used as a new substrate for the photosensitive chip as a whole, and the thickness or number of the frequency adjustment compensation plates is adjusted to change the resonant frequency of the terahertz focal plane detector, so that the measured value of the resonant frequency corresponding to the resonant peak of the terahertz focal plane detector at the required frequency is close to or equal to the designed theoretical value, x≥1.

2. The method for adjusting the resonant frequency of a terahertz focal plane detector according to claim 1, characterized in that: include: The frequency adjustment compensation plate is thinned, or a frequency adjustment compensation plate with a larger thickness is replaced, or the number of the frequency adjustment compensation plates is increased.

3. The method for adjusting the resonant frequency of a terahertz focal plane detector according to claim 1 or 2, characterized in that: include: X frequency adjustment compensation plates are arranged on the original substrate to obtain a new substrate, and a responsiveness test is performed on the terahertz focal plane detector to obtain an actual response spectrum of the terahertz focal plane detector. If the measured value of the resonance frequency corresponding to the resonance peak at the required frequency is different from the design value, the thickness or number of the frequency adjustment compensation plates is adjusted until the resonance frequency corresponding to the resonance peak is the required design value.

4. The method for adjusting the resonant frequency of a terahertz focal plane detector according to claim 3, characterized in that: include: The thickness adjustment values ​​of the x frequency adjustment compensation plates are determined according to the design value of the resonant frequency of the terahertz focal plane detector, where L is the sum of the thicknesses of the x frequency adjustment compensation plates and the original substrate. Wherein, f is the design value of the resonance frequency corresponding to the resonance peak of the terahertz focal plane detector at the required frequency, n is the equivalent refractive index of the original substrate when the resonance peak is at the measured value position, and c is the speed of light in vacuum.

5. The method for adjusting the resonant frequency of a terahertz focal plane detector according to claim 4, characterized in that: adjusting the thickness of the new substrate of the photosensitive chip in multiple times; Preferably, if the measured value of the resonance frequency corresponding to the resonance peak is lower than the design value, the frequency adjustment compensation plate of the new substrate is thinned; if the measured value of the resonance frequency corresponding to the resonance peak is higher than the design value, the frequency adjustment compensation plate with a larger thickness value is replaced or the number of the frequency adjustment plates is increased; Preferably, the k value used for adjusting the thickness of the x frequency adjustment compensation plates multiple times is reduced successively.

6. A method for manufacturing a terahertz focal plane detector, characterized in that: include: A photosensitive chip and a CMOS readout circuit are flip-chip interconnected to form a terahertz focal plane detector, wherein the photosensitive chip includes an original substrate and an antenna array arranged on the original substrate. Furthermore, x frequency adjustment compensation plates are stacked on the back side of the original substrate facing away from the antenna array, the frequency adjustment compensation plates are made of the same material as the original substrate, and the original substrate and the x frequency adjustment compensation plates are used as a new substrate for the photosensitive chip as a whole, and the thickness or number of the frequency adjustment compensation plates is adjusted to change the resonant frequency of the terahertz focal plane detector, so that the measured value of the resonant frequency corresponding to the resonant peak of the terahertz focal plane detector at the required frequency is close to or equal to the designed theoretical value, and finally the original substrate and the x frequency adjustment compensation plates are combined into one, x≥1.

7. The method for manufacturing a terahertz focal plane detector according to claim 6, characterized in that: include: The frequency adjustment compensation plate is thinned, or a frequency adjustment compensation plate with a larger thickness is replaced, or the number of the frequency adjustment compensation plates is increased.

8. The method for manufacturing the terahertz focal plane detector according to claim 6 or 7, characterized in that: include: Arranging x frequency adjustment compensation plates on the original substrate to obtain a new substrate, performing a responsivity test on the terahertz focal plane detector to obtain an actual response spectrum of the terahertz focal plane detector, and if the measured value of the resonance frequency corresponding to the resonance peak at the required frequency is different from the designed value, adjusting the thickness or number of the frequency adjustment compensation plates until the resonance frequency corresponding to the resonance peak is the required designed value; Preferably, if the measured value of the resonant frequency corresponding to the resonance peak is lower than the design value, the frequency adjustment compensation plate of the new substrate is thinned; if the measured value of the resonant frequency corresponding to the resonance peak is higher than the design value, the frequency adjustment compensation plate with a larger thickness is replaced or the number of the frequency adjustment plates is increased.

9. The method for manufacturing the terahertz focal plane detector according to claim 8, characterized in that: include: The thickness adjustment values ​​of the x frequency adjustment compensation plates are determined according to the design value of the resonant frequency of the terahertz focal plane detector, where L is the sum of the thicknesses of the x frequency adjustment compensation plates and the original substrate. Wherein, f is the design value of the resonance frequency corresponding to the resonance peak of the terahertz focal plane detector at the required frequency, n is the equivalent refractive index of the original substrate when the resonance peak is at the measured value position, and c is the speed of light in vacuum.

10. The method for manufacturing the terahertz focal plane detector according to claim 9, characterized in that: adjusting the thickness of the new substrate of the photosensitive chip in multiple times; Preferably, the k value used for adjusting the thickness of the x frequency adjustment compensation plates multiple times is reduced successively.

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