MEMS fabry-perot cavity near-infrared spectrum chip detection method, device, system and medium

Abstract

The application discloses a MEMS Fabry-Perot cavity near-infrared spectrum chip detection method, device, system and medium, and the method comprises the steps of aiming an external near-infrared light source at the center of the chip, acquiring images of the chip under gradually increasing voltages through a microscope system, detecting the circular ring morphology of the first interference ring appearing in the images during the process of gradually increasing voltages, judging whether the first interference ring morphology in the images is qualified, continuously increasing the voltage of the chip whose first interference ring morphology is qualified, and when a second interference ring appears in the chip images and the second interference ring morphology is also qualified, determining that the chip is a qualified product; when the voltage of the chip is increased to the maximum loading voltage, and the number of qualified interference rings is less than 2, determining that the chip is in a state that does not meet the design; and when multiple interference rings appear simultaneously, determining that the chip is in a pull-in state. The application can simply and efficiently realize the rapid screening of spectrum chips, thereby improving the efficiency of chip calibration and the yield of chip packaging.

Description

Technical Field

[0001] This invention relates to the field of Fabry-Perot cavity near-infrared spectroscopy chip technology, and in particular to a MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method, device, system and medium. Background Technology

[0002] Near-infrared spectroscopy (NIRS) technology is characterized by its ease of operation, lack of pollution, and non-destructive nature to sample structure, leading to its widespread application in various fields such as food, chemical, and pharmaceutical industries in recent years. With the development of Micro-Electro-Mechanical Systems (MEMS) technology, MEMS-based Fabry-Perot cavity (PFPC) NIRS chips have been successfully applied to spectral detection equipment, promoting further miniaturization and cost reduction, thereby driving the rapid development of NIRS spectroscopy technology. The basic working principle of the MEMS PFPC chip is based on the Fabry-Perot interference principle. Its structure consists of two flat mirrors with semi-transparent and semi-reflective mirrors, one fixed and the other movable. When a specific voltage is applied to the PFPC, the cavity length changes, allowing incident light to enter and undergo stable multi-beam resonance within the cavity. The light then exits the PFPC with higher energy, while other wavelengths attenuate within the cavity. By driving the PFPC with different voltages through an external circuit, the cavity length can be adjusted, thus achieving filtering effects across different wavelength bands.

[0003] The fabrication process of MEMS Fabry-Perot cavity near-infrared spectroscopy chips involves photolithography, coating, etching, and other processes, exhibiting highly customized characteristics. Existing MEMS fabrication technologies, to some extent, impose limitations and influences on the design and fabrication of MEMS Fabry-Perot cavities. High-performance substrates and thin-film materials used in specific wavelength bands are often difficult to fully integrate into traditional MEMS fabrication lines. During fabrication, the process is affected by various process parameters, methods, and materials. The filtering effect is influenced by factors such as the Fabry-Perot cavity length, mirror tilt, mirror curvature, and mirror cleanliness.

[0004] Currently, traditional Fabry-Perot cavity chip testing methods mostly employ a segmented voltage calibration approach, selecting several characteristic wavelength bands. This involves scanning the voltage within a specific band, and determining the chip's passability when an ideal peak value is observed at the corresponding voltage. This screening method is computationally intensive, inefficient, and requires a high level of expertise, making it unsuitable for large-scale chip screening and widespread application. Therefore, designing an efficient and accurate spectral chip screening method to assist in spectral chip screening and testing, and improve the yield of packaged chips, has become an urgent problem to be solved. Summary of the Invention

[0005] This invention provides a method, apparatus, system, and medium for detecting MEMS Fabry-Perot cavity near-infrared spectroscopy chips to solve the aforementioned problems in the prior art.

[0006] The technical solution adopted in this invention is: to provide a MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method, comprising:

[0007] An external near-infrared light source is aligned with the center of the MEMS Fabry-Perot cavity near-infrared spectroscopy chip, and images of the chip are acquired using a microscope system as the voltage is gradually increased.

[0008] During the process of gradually increasing the voltage, the image of the first interference ring is subjected to ring morphology detection to determine whether the first interference ring in the image is qualified.

[0009] If the voltage is increased further for a chip with a qualified first interference ring, and a second interference ring is detected in the chip image with a qualified second interference ring, then the chip is considered a qualified product. If the number of qualified interference rings is less than 2 when the chip voltage is increased to the maximum load voltage, then the chip is considered to be in a non-design state. If multiple interference rings are detected at the same time, then the chip is considered to be in a pull-in state.

[0010] Furthermore, the method for acquiring images of the chip under progressively increasing voltage using a microscope system includes:

[0011] Data were collected under a microscope from 0V to the maximum applied voltage V. max The voltage increase between chip images includes, but is not limited to, equal step size or incremental step size.

[0012] Furthermore, the method for detecting the ring shape is Hough circle detection or edge detection algorithm.

[0013] Furthermore, after acquiring the image of the chip under gradually increasing voltage using a microscope system, the method further includes correcting the angle and position of the image using a corner detection method.

[0014] Furthermore, the method for correcting the angle and position of the image, specifically the corner detection method, includes:

[0015] The four corner points of the chip are identified, and their coordinates are arranged in ascending order of x-coordinate. The coordinates of the first two corner points (X1, Y1) and (X2, Y2) are extracted. The smallest corner point (X1, Y1) is used as the correction point. The angle θ between the line formed by (X1, Y1) and (X2, Y2) and the x-axis is used as the rotation angle to rotate the image, thereby completing the chip image correction.

[0016]

[0017] The formula for transforming any point P(x,y) in the image into P′(x′,y′) after correction is:

[0018]

[0019] Furthermore, before performing ring morphology detection on the image of the first interference ring, the method further includes: detecting and calibrating the outermost edge ring and stress ring of the chip using a ring morphology detection method.

[0020] Furthermore, the method for determining whether the shape of the first interference ring in the image is acceptable includes:

[0021] When the radius of the first interference ring R∈(R in ,R out When a suspected ring with radius R is identified within the range, edge detection is performed on the ring, and its perimeter L is calculated. A deviation ε is set. If 2πR(1-ε)≤L≤2πR(1+ε), it is considered a qualified interference ring; otherwise, it is considered an unqualified interference ring, indicating an abnormality of incomplete etching on the chip. Where R... in R is the radius of the stress ring. out is the radius of the outermost ring.

[0022] The present invention also provides a MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection device, comprising:

[0023] The image acquisition module is used to acquire near-infrared light projection images of the MEMS Fabry-Perot cavity near-infrared spectroscopy chip in the microscope system under gradually increasing voltage.

[0024] The ring morphology detection module is used to detect the ring morphology of the first interference ring that appears in the image during the process of gradually increasing voltage, and to determine whether the first interference ring in the image is qualified.

[0025] The judgment module is used to determine whether a chip is qualified if, when the voltage is increased further on a chip with a qualified first interference ring, a second interference ring is detected in the chip image and the second interference ring is also qualified; if the number of qualified interference rings is less than 2 when the chip voltage is increased to the maximum load voltage, the chip is determined to be in a non-design state; if multiple interference rings are detected at the same time, the chip is determined to be in a pull-in state.

[0026] The present invention also provides a MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection system, comprising:

[0027] The worktable is used for: placing a Fabry-Perot cavity near-infrared spectroscopy chip, providing incident light to the chip by aligning it with the center of an external near-infrared light source, and continuously supplying power to the chip and providing a gradually increasing voltage.

[0028] The microscope system is used to magnify chip imaging and acquire images of the chip under different voltage conditions through a built-in CCD camera;

[0029] The processor and memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the above-described MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method.

[0030] The present invention also provides a computer-readable storage medium storing computer-executable instructions, which, when called and executed by a processor, cause the processor to implement the above-described MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method.

[0031] The beneficial effects of this invention are: a MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method, which locks the correlation between the differences in the interference ring state of the MEMS near-infrared spectroscopy chip under power and the chip manufacturing process, and proposes a method using intelligent image recognition to achieve fast screening of spectroscopy chips in a simple and efficient manner, thereby improving the efficiency of the spectroscopy chip calibration process and the yield of chip packaging. It plays a positive and effective role in the entire chip process and can greatly promote the industrialization of MEMS near-infrared spectroscopy chips. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method disclosed in Embodiment 1 of the present invention;

[0033] Figure 2 This is a schematic diagram of the state obtained by the MEMS Fabry-Perot cavity near-infrared spectroscopy chip disclosed in Embodiment 1 of the present invention. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be described in further detail below with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0035] Example 1:

[0036] In this embodiment, the response wavelength is 1750nm~2150nm, and the maximum applied voltage V is... max Taking a 36V MEMS Fabry-Perot cavity near-infrared spectroscopy chip (hereinafter referred to as the chip or spectral chip) as an example, the detection method flow of the MEMS Fabry-Perot cavity near-infrared spectroscopy chip is as follows: Figure 1 As shown, the interference ring image at 35V is as follows. Figure 2 As shown.

[0037] Figure 1Image acquisition of the interference ring of the spectral chip is shown in section 101. Specifically, the MEMS near-infrared spectral chip is placed on stage 204, and an external near-infrared light source is aligned with the center of the chip to provide incident light. The power supply is connected to the chip's electrodes via probe 205 to continuously power the chip and also to help fix the chip in place. Finally, images of the chip under different voltage conditions are acquired using a microscope system.

[0038] Figure 1 Angle and position correction of the 102 spectral chip image. Due to the certain margin between the chip and the slots around the stage 204, different chips will have different positions and angles on the stage. To improve the accuracy of the interference ring recognition algorithm, angle and position correction of the chip image is necessary. In this embodiment, corner point detection is used to identify the four corner points of the chip, and the corner point coordinates are arranged in ascending order of x-coordinate. The coordinates of the first two corner points (X1, Y1) and (X2, Y2) are extracted, and the smallest corner point (X1, Y1) is used as the correction point. The angle θ formed by the line formed by (X1, Y1) and (X2, Y2) and the x-axis is used as the rotation angle to rotate the image, thereby completing the chip image correction. Wherein:

[0039]

[0040] The formula for transforming any point P(x,y) in the image into P′(x′,y′) after correction is:

[0041]

[0042] Figure 1 Calibration of the inner and outer rings of the 103 spectral chip image. By detecting the outer ring 202 and the inner ring 203 of the stress surface, the radius of the outer ring 202 can be determined to be R. out The radius of the inner ring 203 of the stress surface is R. in By calibrating the outer and inner rings, the range of subsequent interference ring identification can be defined, reducing computational efficiency and improving identification accuracy.

[0043] Figure 1 The 104th chip is used for interference ring morphology detection. Due to the maximum applied voltage V in this batch of chips... max =36V, the external power supply gradually increases the chip voltage from 0V to 36V, with a loading step size of 0.5V, and simultaneously performs Hough circle detection on the corrected image acquired under a specific voltage. When R∈(R in ,R outWhen a suspected ring of radius R is first identified within the range, edge detection is performed on the ring, and its perimeter L is calculated. A deviation of ε is set. If 2πR(1-ε)≤L≤2πR(1+ε), it is considered a qualified interference ring; otherwise, it is considered an unqualified interference ring, indicating an abnormality of incomplete etching on the chip. Besides Hough circle detection, the morphology of interference rings can also be detected using edge detection algorithms. The detection and judgment of standard interference rings (i.e., interference rings with qualified morphology) includes, but is not limited to, detection of interference rings based on factors such as perimeter, area, and curvature.

[0044] Figure 1 105 is for detecting the number of interference rings in the spectral chip image. After screening by interference ring morphology detection in 104, chips with the first acceptable interference ring morphology are further tested. As voltage is gradually applied, interference rings appear as shown... Figure 2 When a double interference ring is detected as shown in step 206 (the second interference ring also needs to undergo morphological detection as described in step 104), a stop voltage application command is immediately issued, and the current voltage value is output as the reference voltage in the chip calibration process, and the chip is determined to be a qualified product; if more than two interference rings appear immediately after voltage is applied, the chip is determined to be in a pull-in state; if no double interference rings are detected even after the voltage is applied to 36V, the chip is determined to be in a state that does not meet the design standard, is deemed unqualified, and is rejected during chip screening.

[0045] Pull-in state: When the chip is not cleaned properly at the factory and there is a water film, resulting in van der Waals forces, or when the pressure exceeds the Young's modulus of the Fabry-Perot membrane after the chip is powered on, the thin film cannot rebound. In the image, this is presented as a state of multiple dense rings.

[0046] To apply current to the two layers of the Fabry-Perot cavity, two blocking grooves must exist in the bottom layer to block the positive and negative electrodes, resulting in two stress surfaces of different heights and thus interference rings. Therefore, when two standard interference rings appear, we can consider that the product has met the basic performance requirements of the Fabry-Perot cavity chip, namely, good film flatness and good conductivity.

[0047] This embodiment proposes a detection method for MEMS Fabry-Perot cavity near-infrared spectroscopy chips. This method identifies the correlation between the differences in the interference ring states of MEMS near-infrared spectroscopy chips under power and the chip manufacturing process. It proposes a method using intelligent image recognition to achieve fast screening of spectroscopy chips in a simple and efficient manner, thereby improving the efficiency of the spectroscopy chip calibration process and the yield of chip packaging. This method plays a positive and effective role in the entire chip manufacturing process and can greatly promote the industrialization of MEMS near-infrared spectroscopy chips.

[0048] Example 2:

[0049] This embodiment discloses a MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection device, comprising:

[0050] The image acquisition module is used to acquire near-infrared light projection images of the MEMS Fabry-Perot cavity near-infrared spectroscopy chip in the microscope system under gradually increasing voltage.

[0051] The ring morphology detection module is used to detect the ring morphology of the first interference ring that appears in the image during the process of gradually increasing voltage, and to determine whether the first interference ring in the image is qualified.

[0052] The judgment module is used to determine whether a chip is qualified if, when the voltage is increased further on a chip with a qualified first interference ring, a second interference ring is detected in the chip image and the second interference ring is also qualified; if the number of qualified interference rings is less than 2 when the chip voltage is increased to the maximum load voltage, the chip is determined to be in a non-design state; if multiple interference rings are detected at the same time, the chip is determined to be in a pull-in state.

[0053] Example 3:

[0054] This embodiment discloses a MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection system, including:

[0055] The worktable is used for: placing a Fabry-Perot cavity near-infrared spectroscopy chip; aligning an external near-infrared light source with the center of the chip to provide incident light to the chip; and continuously supplying power to the chip with a gradually increasing voltage.

[0056] The microscope system is used to magnify chip imaging and acquire images of the chip under different voltage conditions through a built-in CCD camera;

[0057] The processor and memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method described in Embodiment 1.

[0058] Example 4:

[0059] This embodiment discloses a computer-readable storage medium storing computer-executable instructions. When these instructions are invoked and executed by a processor, they cause the processor to implement the MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method described in Embodiment 1. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for detecting near-infrared spectroscopy chips in MEMS Fabry-Perot cavity, characterized in that, include: An external near-infrared light source is aligned with the center of the MEMS Fabry-Perot cavity near-infrared spectroscopy chip, and images of the chip are acquired using a microscope system as the voltage is gradually increased. During the process of gradually increasing the voltage, the image of the first interference ring is subjected to ring morphology detection to determine whether the first interference ring in the image is qualified. The method for determining whether the shape of the first interference ring in the image is acceptable includes: When the radius of the first interference ring When a suspected ring of radius R is identified within the range, edge detection is performed on the ring, its perimeter L is calculated, and the deviation is set to... ,when If the condition is met, it is determined to be a qualified interference ring; otherwise, it is a defective interference ring, indicating that the chip has an incomplete etching abnormality; where R in R is the radius of the stress ring. out The radius of the outermost ring; If the voltage is increased further for a chip with a qualified first interference ring, and a second interference ring is detected in the chip image with a qualified second interference ring, then the chip is considered a qualified product. If the number of qualified interference rings is less than 2 when the chip voltage is increased to the maximum load voltage, then the chip is considered to be in a non-design state. If multiple interference rings are detected at the same time, then the chip is considered to be in a pull-in state.

2. The MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method according to claim 1, characterized in that, The method for acquiring images of a chip under progressively increasing voltage using a microscope system includes: Collected under a microscope from Up to maximum applied voltage The voltage increase between chip images includes, but is not limited to, equal step size or incremental step size.

3. The MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method according to claim 1, characterized in that, The method for detecting the ring shape is the Hough circle detection or edge detection algorithm.

4. The MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method according to claim 1, characterized in that, After acquiring images of the chip under gradually increasing voltage using a microscope system, the method further includes correcting the angle and position of the images using a corner detection method.

5. The MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method according to claim 4, characterized in that, The method for correcting the angle and position of the image, and the corner detection method include: Identify the four corner points of the chip, arrange the corner point coordinates in ascending order of x-coordinate, and extract the coordinates of the first two corner points, P1. and P2 And with the smallest corner point P1 As the correction point, with P1 and P2 The angle between the straight line formed and the x-axis is the rotation angle. The image is rotated to complete the chip image correction; where: ； any point in the image Corrected The conversion formula is: 。 6. The MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method according to any one of claims 1-5, characterized in that, Before performing ring morphology detection on the image of the first interference ring that appears, the method further includes: detecting and calibrating the outermost edge ring and stress ring of the chip using a ring morphology detection method.

7. A MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection device, characterized in that, include: The image acquisition module is used to acquire near-infrared light projection images of the MEMS Fabry-Perot cavity near-infrared spectroscopy chip in the microscope system under gradually increasing voltage. The ring morphology detection module is used to detect the ring morphology of the first interference ring that appears in the image during the process of gradually increasing voltage, and to determine whether the first interference ring in the image is qualified. The method for determining whether the shape of the first interference ring in the image is acceptable includes: When the radius of the first interference ring When a suspected ring of radius R is identified within the range, edge detection is performed on the ring, its perimeter L is calculated, and the deviation is set to... ,when If the condition is met, it is determined to be a qualified interference ring; otherwise, it is a defective interference ring, indicating that the chip has an incomplete etching abnormality; where R in R is the radius of the stress ring. out The radius of the outermost ring; The judgment module is used to determine whether a chip is qualified if, when the voltage is increased further on a chip with a qualified first interference ring, a second interference ring is detected in the chip image and the second interference ring is also qualified; if the number of qualified interference rings is less than 2 when the chip voltage is increased to the maximum load voltage, the chip is determined to be in a non-design state; if multiple interference rings are detected at the same time, the chip is determined to be in a pull-in state.

8. A MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection system, characterized in that, include: The worktable is used for: placing a Fabry-Perot cavity near-infrared spectroscopy chip, providing incident light to the chip by aligning it with the center of an external near-infrared light source, and continuously supplying power to the chip and providing a gradually increasing voltage. The microscope system is used to magnify chip imaging and acquire images of the chip under different voltage conditions through a built-in CCD camera; The processor and memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement the MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when invoked and executed by a processor, cause the processor to implement the MEMS Fabry-Perot cavity near-infrared spectroscopy chip detection method according to any one of claims 1-6.

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