Indium gallium arsenide linear array detector and detection method based thereon, indium gallium arsenide photosensitive chip

Abstract

The application discloses an indium gallium arsenide linear array detector and a detection method and an indium gallium arsenide photosensitive chip based on the same. The indium gallium arsenide linear array detector comprises the indium gallium arsenide photosensitive chip, and the indium gallium arsenide photosensitive chip comprises at least two rows of equal numbers of picture elements. The picture elements with the same sequence position in each row of picture elements are aligned in the column axis direction. The center distance between two adjacent picture elements in the column axis direction is not less than the center distance between two adjacent picture elements in the row axis direction. The application can realize fast and accurate scanning and fast re-inspection on a detection object by reasonably arranging multiple rows of linear array picture elements and the distance therebetween, thereby significantly improving the efficiency and accuracy of short-wave infrared detection.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and in particular to an indium gallium arsenide linear detector and a detection method based thereon, as well as an indium gallium arsenide photosensitive chip. Background Technology

[0002] The 1-3 μm band is typically divided into short-wave infrared based on the atmospheric window for infrared radiation. Short-wave infrared light is widely present in nature and its reflection properties are very similar to visible light. Indium gallium arsenide (IGaAs) detectors, which operate at high temperatures and offer high reliability, can acquire short-wave infrared signals invisible to the human eye in target scenes, thus enabling short-wave infrared imaging. This imaging technology has significant application value in fields such as aerospace remote sensing, security monitoring, industrial inspection, medical imaging, and environmental monitoring.

[0003] Linear indium gallium arsenide (IGaAs) detectors are widely used in industrial inspection due to their high frame rate and low cost. Applications include product defect detection, product grading, and foreign object identification. However, as industries evolve, the demands for speed and accuracy in infrared detection continue to increase. Current linear detectors can negatively impact system operating speed and increase re-inspection costs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing indium gallium arsenide linear detectors in terms of working speed and accuracy, which cannot meet the detection requirements, and to provide an indium gallium arsenide linear detector, a detection method based thereon, and an indium gallium arsenide photosensitive chip.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] The present invention provides a multi-row indium gallium arsenide (IGaAs) linear detector, the IGaAs linear detector comprising an IGaAs photosensitive chip, the IGaAs photosensitive chip comprising at least two rows of equal number of pixels; the pixels of the same order in each row are aligned in the column axis direction; the center distance between two adjacent pixels along the column axis direction is not less than the center distance between two adjacent pixels along the row axis direction.

[0007] Preferably, the indium gallium arsenide linear detector further includes a readout circuit;

[0008] The readout circuit is electrically connected to the indium gallium arsenide photosensitive chip;

[0009] The readout circuit is used to convert the electrical signals output by the indium gallium arsenide photosensitive chip into imaging data.

[0010] Preferably, the lower surface of the indium gallium arsenide photosensitive chip is a passivation layer;

[0011] The lower surface of the indium gallium arsenide photosensitive chip and the upper surface of the readout circuit are respectively provided with corresponding electrode groups; the indium gallium arsenide photosensitive chip and the readout circuit are electrically connected through the electrode groups.

[0012] Preferably, the indium gallium arsenide linear detector further includes an aperture;

[0013] The aperture is located above the indium gallium arsenide photosensitive chip, and the orthographic projection area of ​​the aperture on the indium gallium arsenide photosensitive chip includes the rectangular area where the pixels of the indium gallium arsenide photosensitive chip are located.

[0014] The aperture is used to limit the imaging range of the indium gallium arsenide linear detector.

[0015] Preferably, the indium gallium arsenide linear detector further includes a window.

[0016] The window is located above the aperture, and the orthographic projection area of ​​the window on the aperture includes the area where the aperture opening is located.

[0017] Preferably, the indium gallium arsenide linear detector further includes a cooler, the upper surface of which is attached to the lower surface of the readout circuit;

[0018] The upper surface of the cooler is not smaller than the lower surface of the readout circuit.

[0019] Preferably, the indium gallium arsenide linear detector further includes a housing; the housing is a cube with an open top.

[0020] The cooler is located at the bottom of the tube shell;

[0021] Both the aperture and the window are mounted on the tube shell.

[0022] Preferably, the indium gallium arsenide linear detector further includes a cover plate disposed at the upper opening of the housing, so that the indium gallium arsenide linear detector forms a closed structure.

[0023] The present invention also provides a detection method based on an indium gallium arsenide linear detector, the detection method comprising the following steps:

[0024] The indium gallium arsenide linear detector described above is used to scan the object to obtain imaging data, which is obtained by converting the pixel readings acquired by the pixels of the indium gallium arsenide linear detector.

[0025] Based on the threshold range, abnormal values ​​in the pixel readings are determined;

[0026] If all the pixels in the same column have abnormal readings, then the position of the detected object and the corresponding pixel is determined to be an abnormal position.

[0027] The present invention also provides an indium gallium arsenide photosensitive chip, the photosensitive chip comprising at least two rows of equal number of pixels; the pixels of the same order in each row are aligned in the column axis direction; the center distance between two adjacent pixels along the column axis direction is not less than the center distance between two adjacent pixels along the row axis direction.

[0028] The positive and progressive effects of this invention are as follows: The indium gallium arsenide linear array detector and the detection method based thereon provided by this invention, and the indium gallium arsenide photosensitive chip, by reasonably setting multiple rows of linear array pixels and their positional relationships, can effectively use multiple pixels located on the same column axis to quickly and accurately scan the detection object, and can realize rapid re-examination of the detection object based on the data of multiple pixels obtained from the scan, thereby significantly improving the efficiency and accuracy of short-wave infrared detection. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the indium gallium arsenide linear detector of Embodiment 1 of the present invention.

[0030] Figure 2 This is a schematic diagram of the planar structure of the 512-element dual-row indium gallium arsenide linear detector of Embodiment 1 of the present invention.

[0031] Figure 3 This is a schematic diagram of the planar structure of the 1024-element three-row indium gallium arsenide linear detector of Embodiment 1 of the present invention.

[0032] Figure 4 This is a flowchart of the detection method based on an indium gallium arsenide linear detector according to Embodiment 2 of the present invention. Detailed Implementation

[0033] The present invention will be further illustrated by way of embodiments below, but the present invention is not limited to the scope of the embodiments described herein.

[0034] Example 1

[0035] See Figure 1 As shown, this embodiment specifically provides an indium gallium arsenide (IGaAs) linear detector 100, which includes an IGaAs photosensitive chip 1. The IGaAs photosensitive chip 1 includes at least two rows of equal numbers of pixels; pixels with the same sequence position in each row are aligned in the column axis direction; the center distance between two adjacent pixels along the column axis direction is not less than the center distance between two adjacent pixels along the row axis direction.

[0036] The center distance between two adjacent pixels along the column axis is at least equal to the center distance between two adjacent pixels along the row axis. At this time, the photosensitive surfaces of the two rows of pixels are the same, which satisfies the basis for the substitutability and verification of the response signals of adjacent pixels in the longitudinal direction, thus ensuring the integrity and independence of the two adjacent rows of pixels.

[0037] If electrical and optical crosstalk between pixels is taken into account, specific isolation structures can be set between adjacent rows of pixels to improve the uniformity and accuracy of pixel response. Of course, in this case, the center distance between two adjacent pixels along the column axis must be greater than the center distance between two adjacent pixels along the row axis.

[0038] The indium gallium arsenide (IGaAs) linear detector 100 is a multi-row detector that can be configured as a dual-row, triple-row, or even more-row pixel structure depending on actual needs. Since at least two aligned pixels along the column axis can be used to scan the object being detected, if one pixel in the same column is damaged, the remaining pixels can serve as backup detectors. Furthermore, the detection results of multiple pixels in the same axis can be cross-checked to ensure the reliability of the detection results.

[0039] In a preferred embodiment, the indium gallium arsenide (IGaAs) linear detector 100 further includes a readout circuit 2, which is electrically connected to the IGaAs photosensitive chip 1 and is used to convert the electrical signals output by the IGaAs photosensitive chip 1 into imaging data. The lower surface of the IGaAs photosensitive chip 1 is a passivation layer; the passivation layer and the upper surface of the readout circuit 2 are respectively provided with a plurality of corresponding electrode groups, and the IGaAs photosensitive chip 1 and the readout circuit 2 are electrically connected through these electrode groups. The passivation layer can reduce surface leakage and provide protection by covering the lower surface material of the IGaAs photosensitive chip 1. The electrodes on the passivation layer are set to a sufficient height to extend from the surface of the passivation layer of the IGaAs photosensitive chip 1 and form electrode groups with corresponding electrodes on the readout circuit 2, thereby realizing the electrical connection between the readout circuit 2 and the IGaAs photosensitive chip 1.

[0040] In a preferred embodiment, the indium gallium arsenide (IGaAs) linear detector also includes an aperture 3 located above the IGaAs photosensitive chip 1. The orthographic projection area of ​​the aperture 3 onto the IGaAs photosensitive chip 1 includes the rectangular area where the pixels of the IGaAs photosensitive chip 1 are located. The aperture 3 is used to limit the imaging range of the IGaAs linear detector. Above the chip, the distance between the aperture 3 and the IGaAs photosensitive chip 1 is preferably 1–10 mm. With the above arrangement, it can be ensured that each pixel of the IGaAs linear detector 100 receives the scanning beam through the aperture 3 during detection, while also effectively limiting the entry of irrelevant beams. For example, for a 512-element double-row IGaAs linear detector, the orthographic projection area of ​​the aperture 3 onto the IGaAs photosensitive chip 1 is larger than the rectangular area formed by the two rows of 512 pixels.

[0041] In a preferred embodiment, the indium gallium arsenide linear detector 100 further includes a window 4; the window 4 is located above the aperture 3, and the orthogonal projection area of ​​the window 4 onto the aperture 3 includes the area where the opening of the aperture 3 is located. Therefore, the window 4 does not block the scanning beam, does not change the optical magnification, and provides protection for the indium gallium arsenide photosensitive chip 1 against dust. The surface of the window 4 can be coated with a filter film of different center wavelengths according to actual needs.

[0042] In a preferred embodiment, the indium gallium arsenide linear detector 100 further includes a cooler 5, the upper surface of which is attached to the lower surface of the readout circuit 2; the upper surface of the cooler 5 is not smaller than the lower surface of the readout circuit 2, thereby ensuring that the cooler 5 provides comprehensive and uniform cooling to the readout circuit 2. Preferably, the cooler 5 can be a thermoelectric cooler, that is, a thermoelectric cooler that utilizes the thermoelectric effect of semiconductors to generate cooling.

[0043] In a preferred embodiment, the indium gallium arsenide linear detector 100 further includes a housing 6 and a cover plate 7; the housing 6 is a cube with an open top; the cooler 5 is located at the bottom of the housing 6; see also Figure 1 As shown, the aperture 3 and the window 4 are both mounted on the housing 6; the cover plate 7 is set at the upper opening of the housing 6 so that the indium gallium arsenide linear detector 100 forms a closed structure. In addition, as those skilled in the art know, the lower part of the housing 6 can be provided with several pins, the upper part of which is electrically interconnected with the metal electrodes around the readout circuit 2 by wire bonding, and the lower part can be connected to an external system for electrical signal transmission by pinhole insertion. After further signal processing, the required imaging results can be obtained.

[0044] As an optional implementation method, see [link to implementation details]. Figure 2 This embodiment shows an indium gallium arsenide linear detector 100 with a 512-element dual-row structure; the indium gallium arsenide linear detector 100 has a size of 512×2 (rows) pixels, a single row pixel center distance of 30μm, and a center distance of 30μm between two adjacent pixels along the column axis.

[0045] The readout circuit 2 measures 15.5 × 1.2 mm; the aperture 3 measures 24.5 mm × 9.5 mm; the center opening measures 16 mm × 1 mm; the window 4 measures 17 mm × 1.5 mm and is made of sapphire; the cover plate 7 measures 24.5 mm × 9.5 mm and has a center opening of 16.8 × 1.2 mm; the housing 6 measures 25 mm × 10 mm × 4.2 mm and is made of ceramic; there are 15 metal pins on each side; and the thermoelectric cooler 5 measures 20 mm × 6 mm × 3 mm.

[0046] As another alternative implementation, see Figure 3This embodiment also illustrates an indium gallium arsenide linear detector 100 with a 1024-element dual-row structure; the size is 1024×3 (rows) pixels, where the center-to-center distance of a single row of pixels is 20μm, and the center-to-center distance between adjacent rows of pixels is 50μm; the readout circuit 2 is 21×1.8mm in size; the aperture 3 is 34.5mm×2mm in size, with a central opening size of 22mm×0.5mm; the window 4 is 23mm×3mm in size and made of sapphire, with two dielectric films deposited on its surface: a 1.38μm filter film covering the left 512×3 pixels, and a 1.64μm filter film covering the right 512×3 pixels. The cover plate 7 is 34.8mm×19.5mm in size; the housing 6 is 35mm×20mm×13mm in size, made of 4J29 alloy, with 19 metal pins on each side; the thermoelectric cooler 5 is 24mm×2mm×3mm in size.

[0047] The indium gallium arsenide linear detector in this embodiment can effectively and quickly scan the detection object by rationally setting multiple rows of linear pixels and their positional relationships. It can also realize rapid re-examination of the detection object based on the data of multiple pixels obtained from the scan, thereby significantly improving the efficiency and accuracy of shortwave infrared detection.

[0048] Example 2

[0049] See Figure 4 As shown, this embodiment specifically provides a detection method based on an indium gallium arsenide linear detector, the detection method including the following steps:

[0050] S1. The object to be detected is scanned to obtain imaging data, which is obtained by converting the pixel readings acquired by the pixels of the indium gallium arsenide linear detector.

[0051] S2. Based on the threshold range, identify outliers in the pixel readings.

[0052] S3. If all the pixel readings obtained by all pixels in the same column are abnormal values, then the position of the detected object and the corresponding pixel is determined to be an abnormal position.

[0053] For step S1, the indium gallium arsenide linear detector 100 in Example 1 can be used to perform a push-broom scan on the object to obtain imaging data and comprehensively acquire the relevant optical characteristics of the object. The threshold range in step S2 is set according to specific needs. If the pixel reading of a certain pixel exceeds the threshold range, the pixel reading is determined to be an abnormal value. For example, when detecting foreign objects, the normal parameter range of known substances in the object can be used as the threshold range for comparison with the detected results. For example, in the detection of foreign objects in grain, spectral testing can be used to judge and identify impurities such as glass and plastic mixed in the grain based on the spectral curve matching degree, thereby greatly improving the sorting efficiency of grain. When applied to product defect detection, the target object is irradiated with short-wave infrared light and the reflected light of the object is obtained by push-broom imaging using the indium gallium arsenide linear detector 100. When the light signal at a certain point exceeds a reasonable range, the object can be considered to have a defect. Furthermore, by statistically analyzing the number of defects within a specific range, product grading can be achieved.

[0054] Step S3 utilizes multi-row structured pixels to achieve rapid verification. For example, the results of multiple rows of pixels in the same column are ANDed. When the calculation result is abnormal, it can be used to characterize the corresponding position of the detected object as abnormal.

[0055] The detection method based on the indium gallium arsenide linear detector in this embodiment can effectively and quickly scan the detection object by reasonably setting multiple rows of linear pixels and their positional relationships. It can also realize rapid re-verification of the detection object based on the data of multiple pixels obtained from the scan, thereby significantly improving the efficiency and accuracy of shortwave infrared detection.

[0056] Example 3

[0057] This embodiment specifically provides an indium gallium arsenide photosensitive chip, including at least two rows of equal number of pixels; pixels with the same sequence position in each row are aligned in the column axis direction; the center distance between two adjacent pixels along the column axis direction is not less than the center distance between two adjacent pixels along the row axis direction.

[0058] As a preferred implementation, the indium gallium arsenide photosensitive chip 1 in Example 1 can be used.

[0059] The indium gallium arsenide (IGaAs) photosensitive chip in this embodiment can effectively utilize multiple pixels located on the same column axis to quickly and accurately scan the detection object by reasonably setting multiple rows and columns of pixels and their positional relationships. It can also realize rapid re-examination of the detection object based on the data of multiple pixels obtained from the scan, thereby significantly improving the efficiency and accuracy of short-wave infrared detection.

[0060] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A detection method based on an indium gallium arsenide linear detector, characterized in that, The detection method includes the following steps: An indium gallium arsenide (IGaAs) linear array detector is used to scan the object to obtain imaging data. The imaging data is obtained by converting the pixel readings acquired by the pixels of the IGaAs linear array detector. The IGaAs linear array detector includes an IGaAs photosensitive chip, which includes at least two rows of pixels with an equal number of pixels. Pixels of the same sequence in each row are aligned in the column axis direction. The center distance between two adjacent pixels along the column axis is not less than the center distance between two adjacent pixels along the row axis. Based on the threshold range, abnormal values ​​in the pixel readings are determined; If all the pixels in the same column have abnormal readings, then the position of the detected object and the corresponding pixel is determined to be an abnormal position.

2. The detection method based on an indium gallium arsenide linear detector as described in claim 1, characterized in that, The indium gallium arsenide linear detector also includes a readout circuit; The readout circuit is electrically connected to the indium gallium arsenide photosensitive chip; The readout circuit is used to convert the electrical signals output by the indium gallium arsenide photosensitive chip into imaging data.

3. The detection method based on an indium gallium arsenide linear detector as described in claim 2, characterized in that, The lower surface of the indium gallium arsenide photosensitive chip is a passivation layer; The lower surface of the indium gallium arsenide photosensitive chip and the upper surface of the readout circuit are respectively provided with corresponding electrode groups; the indium gallium arsenide photosensitive chip and the readout circuit are electrically connected through the electrode groups.

4. The detection method based on an indium gallium arsenide linear detector as described in claim 2, characterized in that, The indium gallium arsenide linear detector also includes an aperture; The aperture is located above the indium gallium arsenide photosensitive chip, and the orthographic projection area of ​​the aperture on the indium gallium arsenide photosensitive chip includes the rectangular area where the pixels of the indium gallium arsenide photosensitive chip are located. The aperture is used to limit the imaging range of the indium gallium arsenide linear detector.

5. The detection method based on an indium gallium arsenide linear detector as described in claim 4, characterized in that, The indium gallium arsenide linear detector also includes a window; The window is located above the aperture, and the orthographic projection area of ​​the window on the aperture includes the area where the aperture opening is located.

6. The detection method based on an indium gallium arsenide linear detector as described in claim 5, characterized in that, The indium gallium arsenide linear detector also includes a cooler, the upper surface of which is attached to the lower surface of the readout circuit; The upper surface of the cooler is not smaller than the lower surface of the readout circuit.

7. The detection method based on an indium gallium arsenide linear detector as described in claim 6, characterized in that, The indium gallium arsenide linear detector also includes a housing; the housing is a cube with an open top. The cooler is located at the bottom of the tube shell; Both the aperture and the window are mounted on the tube shell.

8. The detection method based on an indium gallium arsenide linear detector as described in claim 7, characterized in that, The indium gallium arsenide linear detector also includes a cover plate disposed at the upper opening of the housing, so that the indium gallium arsenide linear detector forms a closed structure.

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