Detector array structure

Abstract

The invention provides a detector array structure which comprises a detector substrate and a photoelectric detection chip arranged on the detector substrate, and the photoelectric detection chip comprises a semiconductor substrate layer and at least one photoelectric detection unit arranged on the semiconductor substrate layer. The photoelectric detection unit comprises two sub-photoelectric detection units which are arranged in a crossed manner, each sub-photoelectric detection unit comprises a conductive electrode, a plurality of conductive leads connected with the conductive electrode and a grating microstructure connected with each conductive lead, and the grating microstructures in the two sub-photoelectric detection units are arranged in a crossed manner. According to the invention, not only can the measurement efficiency be improved, but also the reliability and integration level of differential measurement can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optoelectronics, in particular to a detector array structure. BACKGROUND

[0002] In the field of optoelectronics, the detection of optical signals usually measures the overall light spot, only realizes the conversion of optical signals to electrical signals, and finally outputs a single current or voltage signal. In an optical sensor measurement system, in order to reduce the influence of the change of the light intensity of the detected light spot on the measurement result, it is often necessary to perform differential processing on the signal.

[0003] In order to realize differential processing, the conventional scheme needs to first split the optical signal by means of an optical system, split the measurement optical signal into two optical signals with a certain phase difference, and then detect the two signals by independent detection components to complete the differential measurement process.

[0004] However, the above conventional scheme has obvious defects: the combination of optical splitting and independent detection has a complex structure, and the processing precision of optical elements is extremely high, which not only increases the manufacturing cost, but also greatly increases the difficulty of system integration and debugging; at the same time, the cooperative work of multiple components is easy to introduce signal loss or interference, which reduces the reliability of differential measurement, and it is difficult to meet the development needs of high integration and high efficiency of photoelectric sensors, and it cannot adapt to application scenarios with urgent requirements for structure simplification and performance stability. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a detector array structure which can not only improve the measurement efficiency, but also improve the reliability and integration of differential measurement.

[0006] In a first aspect, an embodiment of the present application provides a detector array structure, comprising: a detector substrate, a photoelectric detection chip arranged on the detector substrate, the photoelectric detection chip comprising a semiconductor substrate layer and at least one photoelectric detection unit arranged on the semiconductor substrate layer, the photoelectric detection unit comprising two sub-photoelectric detection units arranged in cross, each sub-photoelectric detection unit comprising a conductive electrode, a plurality of conductive leads connected to the conductive electrode, and a grating microstructure connected to each conductive lead, wherein the grating microstructures of the two sub-photoelectric detection units are arranged in cross.

[0007] In an optional embodiment, the photoelectric detection chip is provided with a non-photosensitive region and a photosensitive region, the photosensitive region refers to the region of the grating microstructure on the photoelectric detection chip, and the photo-generated carriers generated by the photosensitive region are conducted through the conductive leads and the conductive electrode; the non-photosensitive region refers to the region on the photoelectric detection chip other than the photosensitive region.

[0008] In an alternative embodiment, the grating microstructure in the light-sensitive region is arranged periodically.

[0009] In an alternative embodiment, a plurality of pads are arranged on the detector substrate outside the photodetection chip, and the plurality of pads are used for signal transmission of the detector.

[0010] In an alternative embodiment, a plurality of pads are arranged on the detector substrate close to the conductive electrode in the photodetection chip, and a plurality of pads are arranged on the detector substrate away from the conductive electrode in the photodetection chip, and the number of pads arranged close to the conductive electrode in the photodetection chip is greater than the number of pads arranged away from the conductive electrode in the photodetection chip.

[0011] In an alternative embodiment, the detector array structure adopts a vertical coupling light coupling mode, and the incident light is incident to the photodetection chip through the upper surface of the grating microstructure.

[0012] In an alternative embodiment, each of the photodetection units is isolated from each other.

[0013] In an alternative embodiment, the semiconductor substrate layer adopts a semiconductor material to serve as a common anode or a common cathode of the photodetection chip.

[0014] In an alternative embodiment, the detector substrate is made of ceramic material to provide a stable support base for the photodetection chip.

[0015] In an alternative embodiment, the photodetection chip is glued to the detector substrate by bonding.

[0016] The embodiments of the present application provide a detector array structure, by arranging the crossed sub-photodetection units and corresponding grating microstructures in the photodetection unit, the differential measurement of the optical signal can be directly realized without an additional optical beam splitting system, the difficulty of optical system design and the complexity of integrated debugging are effectively reduced, the optical signal transmission loss is reduced, the measurement efficiency is improved, the overall structure is simplified, and the reliability and integration of the differential measurement are improved.

[0017] In order to make the above objectives, characteristics and advantages of the present application more apparent, clear and easy to understand, the following preferred embodiments are specifically described below, and the accompanying drawings are referred to as follows. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as limiting the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0019] Figure 1 A structural schematic diagram of a detector array structure provided by an embodiment of the present application; Figure 2 A structural schematic diagram of an optical detection unit provided by an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, every other embodiment obtained by those skilled in the art without creative labor is within the scope of the present application.

[0021] In the specification, the words "one", "an", "the", and "said" are used to represent one or more elements / components / etc.; the words "include" and "have" are used to represent an open-ended inclusion in the meaning of comprising in addition to the listed elements / components / etc. there can be additional elements / components / etc.; the words "first" and "second" are used only as labels, not as a quantity limitation of their objects.

[0022] It should be understood that in the embodiments of the present application, "at least one" means one or more, and "multiple" means two or more than two. "And / or" is only a description of the relationship between the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. The character " / " generally represents an "or" relationship between the front and rear associated objects. "Including A, B and / or C" means including any 1 or any 2 or 3 of A, B and C.

[0023] It should be understood that, in the embodiments of the present application, “B corresponding to A”, “B corresponding to A”, “A corresponding to B” or “B corresponding to A” means that B is associated with A, and B can be determined according to A. Determining B according to A does not mean that B is determined only according to A, but also can be determined according to A and / or other information.

[0024] In addition, the described embodiments are only part of the embodiments of the present application, not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but only represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] It is found through research that, in order to realize differential processing, the conventional scheme needs to first split the optical signal by means of an optical system, split the measurement optical signal into two optical signals with a certain phase difference, and then detect the two signals by independent detection components, so as to complete the differential measurement process.

[0026] However, the above conventional scheme has obvious defects: the combination structure of optical splitting and independent detection is complex, and the machining precision of optical elements is extremely high, which not only increases the manufacturing cost, but also greatly increases the difficulty of system integration and debugging; at the same time, the cooperative work of multiple components is easy to introduce signal loss or interference, which reduces the reliability of differential measurement, and it is difficult to meet the development needs of high integration and high efficiency of photoelectric sensors, and it cannot adapt to the application scenarios with urgent requirements for structure simplification and performance stability.

[0027] Based on this, the embodiments of the present application provide a detector array structure, which can not only improve the measurement efficiency, but also improve the reliability and integration of differential measurement.

[0028] As shown in Figure 1 and Figure 2 The embodiments of the present application provide a detector array structure, which includes a detector substrate 10, a photoelectric detection chip 20 arranged on the detector substrate 10, the photoelectric detection chip 20 including a semiconductor substrate layer (not shown in the figure) and at least one photoelectric detection unit 30 arranged on the semiconductor substrate layer, the photoelectric detection unit 30 including two sub-photoelectric detection units arranged in cross, each sub-photoelectric detection unit including a conductive electrode 301, a plurality of conductive leads 302 connected with the conductive electrode 301, and a grating microstructure 303 connected with each conductive lead 302, wherein the grating microstructures 303 in the two sub-photoelectric detection units are arranged in cross.

[0029] Here, the detector substrate 10 refers to the basic component for carrying the photodetection chip 20 and realizing signal transmission and structural support. Among them, the detector substrate 10 can have stable mechanical properties and suitable electrical properties to ensure that the photodetection chip 20 is stable after installation, and to avoid interference in the signal transmission process.

[0030] In an optional embodiment, the material selection of the detector substrate 10 can be combined with the environmental requirements of the application scene, and materials with mechanical strength and insulation are preferred to avoid external interference affecting signal transmission.

[0031] For example, the detector substrate is made of ceramic material, which provides a stable support base for the photodetection chip 20. The ceramic material itself has high mechanical strength, low thermal expansion coefficient, environmental resistance, such as corrosion resistance, high temperature resistance and other characteristics, which can avoid the deformation of the substrate caused by external environmental changes, and thus ensure the position of the photodetection chip 20 glued on the substrate is fixed, the structure is complete, and the relative positions of the key functional components such as the grating microstructure 303 and the conductive electrode 301 on the chip are unchanged, providing structural protection for the accuracy of subsequent optical signal differential measurement.

[0032] In an optional embodiment, the detector substrate can be made of zirconia ceramic material, which has a bending strength of 1500MPa, a thermal expansion coefficient close to that of a semiconductor substrate layer (such as silicon), about , which can reduce the stress of the chip caused by the difference between thermal expansion and cold contraction due to temperature changes, and protect the structural integrity of the photodetection unit 30. For example, for optical signal detection scenes in industrial environments, an alumina ceramic material is selected to make the detector substrate 10, which has high temperature resistance and corrosion resistance, which can adapt to harsh environments, and good insulation performance to isolate external electrical interference.

[0033] In this way, the high rigidity and low thermal expansion coefficient of the ceramic material in the embodiment of the application can effectively resist deformation and vibration, ensure the position stability of the photodetection chip 20 and the surface functional components, avoid the deviation of the received optical signal caused by structural deviation, and lay the foundation for the accuracy of differential measurement. And in industrial detection, outdoor sensing and other scenes, the detector needs to withstand high temperature, humidity or corrosive environment, and ordinary substrate is easy to age and fail. The ceramic material (such as zirconia ceramic) has excellent corrosion resistance and high temperature resistance, which can resist the erosion of harsh environment for a long time, and avoid the decline of support ability caused by substrate aging. This makes the detector array structure can run stably for a long time in multiple scenes, reduces the equipment failure caused by substrate damage, and improves the overall service life and use reliability.

[0034] In addition, the ceramic substrate is compatible with traditional semiconductor photolithography, bonding and other processes, and can be assembled with the photoelectric detection chip 20 without introducing special processing equipment. The compactness of the ceramic material does not interfere with the photoelectric conversion process of the chip. At the same time, the miniaturized design of the ceramic substrate can be efficiently combined with the detector substrate 10, the pad 60 and other components, without occupying too much space, providing favorable conditions for the high integration of the detector array.

[0035] In an optional embodiment, the size of the detector substrate 10 can be designed according to the specifications and detection requirements of the photoelectric detection chip 20, to ensure that the chip can be completely carried and sufficient space can be reserved for the auxiliary structure. For example, if the size of the photoelectric detection chip 20 is 5mm x 5mm, the detector substrate 10 can be designed as 8mm x 8mm, and the reserved edge area can be used to set the subsequent pad 60 structure.

[0036] Further, the photoelectric detection chip 20 is arranged on the detector substrate 10, and the photoelectric detection chip 20 includes a semiconductor substrate layer and at least one photoelectric detection unit 30 arranged on the semiconductor substrate layer, and the photoelectric detection unit 30 includes two sub-photoelectric detection units arranged in cross.

[0037] Among them, the photoelectric detection chip 20 is the core component for realizing the reception and photoelectric conversion of optical signals, and its function is to convert the incident optical signal into a measurable electrical signal; the semiconductor substrate layer is the basic support layer of the photoelectric detection chip 20, and participates in the carrier transport in the photoelectric conversion process; the photoelectric detection unit 30 is an independent unit for realizing the detection of optical signals in a specific area, and multiple photoelectric detection units 30 can be arranged in one photoelectric detection chip 20 according to the measurement requirements, to realize the simultaneous detection of multiple areas; the sub-photoelectric detection unit is a subdivision of the photoelectric detection unit 30, and the purpose of cross arrangement of the two sub-photoelectric detection units is to receive the same measurement light spot in zones, to provide two independent optical signals for subsequent differential calculation.

[0038] Optionally, the photoelectric detection chip 20 can be closely attached to the detector substrate 10 to ensure the stability of the structure and the efficiency of signal transmission, and the semiconductor substrate layer thereof can be selected according to the detection requirements. For example, the photoelectric detection chip 20 is glued to the detector substrate 10 by adhesion.

[0039] Specifically, the photoelectric detection chip 20 and the detector substrate 10 are fixedly connected by using an adhesive with specific properties, such as low stress, high bonding strength, and adaptation to the semiconductor process. This assembly method can ensure that the photoelectric detection chip 20 and the detector substrate 10 are closely attached, which not only guarantees the stability of the structural connection and avoids loosening or displacement of the photoelectric detection chip 20 in use, but also adapts to the photoelectric conversion function of the photoelectric detection chip 20, such as the adhesive needing to have insulation to avoid electrical interference, having certain thermal conductivity to assist in heat dissipation of the photoelectric detection chip 20, and being compatible with subsequent pad 60 wiring, signal transmission, and other structural designs, which is a key assembly link for realizing the integration of the detector array structure.

[0040] The present embodiment realizes high connection strength through adhesive bonding, such as selecting an epoxy resin adhesive, and the shear strength after curing is ≥15MPa, which can ensure that the photoelectric detection chip 20 and the detector substrate 10 are closely attached for a long time, avoiding measurement errors caused by displacement, and providing protection for the structural stability of differential measurement. Among them, the adhesive bonding process is simple to operate and can be completed through conventional steps such as dispensing and curing, without the need for a high-temperature environment, which can avoid damage to the functional layer of the chip, such as the semiconductor substrate layer and the grating microstructure 303, due to high temperature. At the same time, this process is compatible with the semiconductor mass production process, without the need to introduce complex equipment, thereby reducing the manufacturing and integration difficulty of the detector array.

[0041] In this way, in industrial detection, outdoor sensing, and other scenarios, the detector needs to withstand temperature fluctuations, slight impact, and other environmental conditions. The adhesive used for adhesive bonding, such as modified epoxy resin, can have wide temperature range stability and impact resistance, which can buffer the influence of external impact on the photoelectric detection chip 20, and at the same time avoid the structural stress caused by the difference in thermal expansion and contraction of the photoelectric detection chip 20 and the detector substrate 10 due to temperature changes. This makes the detector array work stably in multiple environments, improves the overall environmental adaptability, and indirectly guarantees the long-term measurement efficiency.

[0042] Alternatively, the semiconductor substrate layer is made of a semiconductor material to serve as a common anode or common cathode of the photoelectric detection chip 20. Among them, the semiconductor substrate layer as a common electrode can realize the unified connection of the common electrodes of all sub-photoelectric detection units, without the need to set a common electrode for each unit separately, simplifying the electrode layout of the chip; the selection of the common anode or common cathode needs to match the polarity of the conductive electrode 301 to form a complete conductive loop.

[0043] Here, the semiconductor substrate layer not only bears the basic support function of the photoelectric detection chip 20, but also is endowed with the electrode function, and can be directly used as the common anode or common cathode of the photoelectric detection chip 20, that is, the anodes of all sub photoelectric detection units are uniformly connected to the substrate layer (common anode design), or the cathodes of all sub photoelectric detection units are uniformly connected to the substrate layer (common cathode design), without the need to separately design and set a common electrode for each sub photoelectric detection unit. Through the integrated design of the support layer and the common electrode, the chip structure and electrode layout can be simplified, and the transmission requirement of the photo-generated carriers in the photoelectric conversion process can be met.

[0044] For example, if it is necessary to adapt to a high-sensitivity light detection scene, an N-type semiconductor can be selected as the substrate layer. The N-type semiconductor has a high free electron concentration, which is beneficial to the rapid transmission of photo-generated carriers and improves the photoelectric conversion speed.

[0045] Since the traditional detector needs to separately design a semiconductor substrate layer (only for support) and an independent common electrode, the two need to be connected through an additional conductive structure, which increases the complexity of the chip structure and the processing steps such as photoetching and welding. In the embodiment of the present application, the semiconductor substrate layer is directly used as the common anode or common cathode, thereby omitting the design and manufacturing process of the independent common electrode, reducing the electrode lead-out and connection processes; and the processing of the semiconductor substrate layer is compatible with the semiconductor photoetching process of the photoelectric detection chip 20, without the need to introduce additional equipment, thereby reducing the manufacturing difficulty and cost.

[0046] In addition, the connection part of the independent common electrode and the substrate layer of the traditional detector is prone to signal loss due to contact resistance, and may also introduce interference due to loose connection, thereby affecting the differential measurement accuracy. In the embodiment of the present application, the semiconductor substrate layer and the photoelectric conversion region (such as the light sensing region 40) of the chip are both of semiconductor material, and are combined closely and have continuous conductive paths, thereby greatly reducing the contact resistance and reducing the signal attenuation in the process of transmitting the photo-generated carriers to the common electrode; at the same time, without additional connection structure, the signal interference caused by problems such as looseness and oxidation is avoided, the stability of the two differential signals is ensured, and the accuracy of the differential measurement result is indirectly improved.

[0047] In addition, through the integrated design of the substrate layer and the common electrode, the support and electrode functions are integrated without increasing the overall size of the chip, the space occupied by the independent common electrode is saved, the conditions for setting more photoelectric detection units 30 on the photoelectric detection chip 20 to realize multi-channel differential measurement are provided, and the multi-spot simultaneous detection scene can be adapted, thereby improving the measurement efficiency and the sensor integration.

[0048] In an optional embodiment, the thickness of the semiconductor substrate layer can be controlled within a reasonable range. If the thickness is too large, the carrier transmission path will be increased and the conversion efficiency will be reduced. If the thickness is too small, the structural strength will be affected. Generally, the thickness can be set to 10-50 microns. For example, for a detection scene in the visible light band, an N-type silicon semiconductor with a thickness of 20 microns is selected as the substrate layer, which can ensure fast carrier transmission and meet the structural support requirements.

[0049] Further, the number of photodetection units 30 can be determined according to the channel requirements of the actual measurement scene. The plurality of photodetection units 30 need to be arranged in order on the semiconductor substrate layer and maintain a certain distance between each other to avoid signal crosstalk. Specifically, each photodetection unit 30 is isolated from each other. For example, in an optical sensing system that needs to simultaneously detect 3 light signals, 3 independent photodetection units 30 can be arranged on the photodetection chip 20, and each unit is spaced apart by 50 microns to ensure that the detection signals of each unit do not interfere with each other.

[0050] Specifically, each photodetection unit 30 is isolated from each other. The photodetection chip 20 can set multiple independent photodetection units 30 according to the measurement requirements, and form a physical and electrical separation between adjacent photodetection units 30 through specific structural design, such as an isolation layer and a groove in the semiconductor process. In this way, the signal independence is directly ensured from the hardware level, and the external circuit does not need to additionally process the crosstalk signal, but only needs to perform a regular differential calculation on the independent signals output by each unit. This simplifies the signal processing process, reduces the design complexity of the external circuit, and reduces the workload of system integration and debugging.

[0051] This isolation design not only prevents the migration or interference of photo-generated carriers and electrical signals generated by different detection units during operation, but also ensures that each photodetection unit 30 can independently receive and process the light signals of the corresponding region, avoiding measurement errors caused by signal crosstalk between units, and providing a structural basis for multi-channel differential measurement.

[0052] In this way, the embodiments of the present application block the migration of carriers across units through isolation design, so that each unit only outputs the light signal detected by itself, ensuring the purity of the signal used for differential calculation and avoiding measurement deviation caused by crosstalk. The isolation between units is the premise of realizing multi-channel parallel measurement, and each isolated photodetection unit 30 can independently undertake a differential detection task of a light spot without the need for sequential queuing measurement. For example, when 3 isolated photodetection units 30 are arranged on the chip, 3 light signals can be simultaneously subjected to differential detection, and the measurement efficiency can be improved to 3 times compared with single-unit serial measurement.

[0053] Further, the two sub-photodetecting units can be cross-shaped, and the light-sensitive areas of the two sub-photodetecting units are equal, so as to ensure uniform detection of the same light spot and the accuracy of the subsequent differential result. For example, the single photodetecting unit 30 is designed as a square with a side length of 100 microns, and the single photodetecting unit 30 is divided into two sub-photodetecting units with a light-sensitive area of 5000 microns by cross-shaped division, so that the light signals received by the two sub-photodetecting units only have a phase difference and no light intensity deviation.

[0054] Optionally, each sub-photodetecting unit comprises a conductive electrode 301, a plurality of conductive leads 302 connected with the conductive electrode 301, and a grating microstructure 303 connected with each conductive lead 302, wherein the grating microstructures 303 in the two sub-photodetecting units are cross-shaped.

[0055] The conductive electrode 301 is a component for collecting photo-generated carriers generated by the sub-photodetecting unit and guiding the photo-generated carriers out as an electrical signal; the conductive lead 302 is a conductive channel connecting the conductive electrode 301 and the grating microstructure 303, and is used for transmitting photo-generated carriers generated in the grating microstructure 303 region to the conductive electrode 301; and the grating microstructure 303 is a structure for splitting light and receiving a light signal, and the periodic arrangement of the grating microstructure 303 can realize selective reception of a specific wavelength light signal, and the cross-shaped arrangement can realize isolation of two light signals.

[0056] Specifically, the conductive electrode 301 can be made of a metal material with excellent conductivity to reduce signal loss in the process of collecting carriers, and gold, aluminum and the like can be used. For example, a gold electrode with a thickness of 200 nanometers is made on the edge of the sub-photodetecting unit by an evaporation process. The low resistivity of the gold electrode can quickly collect photo-generated carriers and reduce the attenuation in the signal transmission process.

[0057] Specifically, the conductive lead 302 can be connected with each period unit of the grating microstructure 303, so as to ensure that the photo-generated carriers generated in each region of the grating microstructure 303 can be effectively transmitted. The width of the conductive lead 302 needs to be designed according to the current size to avoid burning of the lead due to excessive current, and the conductive leads 302 need to be uniformly distributed in the grating microstructure 303 region to ensure uniform collection of carriers. For example, an aluminum conductive lead 302 with a width of 2 microns is designed, and each lead is connected with a period unit of the grating microstructure 303, so as to ensure that the photo-generated carriers can be uniformly and quickly transmitted to the conductive electrode 301.

[0058] Here, the period size of the grating microstructure 303 can be determined according to the wavelength of the probe light signal, and is usually 1 / 2 to 1 times the probe wavelength to achieve efficient light coupling and light splitting. The intersection angle of the grating microstructure 303 of the two sub-optical detection units needs to match the sub-unit intersection mode to ensure the partition coverage of the light spot. For example, for near-infrared light detection with a wavelength of 850 nanometers, the period of the grating microstructure 303 is set to 425 nanometers, and the grating microstructure 303 of the two sub-optical detection units is arranged in the horizontal and vertical directions, respectively, to realize the partitioned reception of the horizontal and vertical direction light signals of the same light spot, and to provide two independent signals for differential measurement.

[0059] In an optional embodiment, the photoelectric detection chip 20 is provided with a non-photosensitive region 50 and a photosensitive region 40. The photosensitive region 40 refers to the region of the grating microstructure 303 on the photoelectric detection chip 20, and the photo-generated carriers generated by the photosensitive region 40 are conducted through the conductive lead 302 and the conductive electrode 301. The non-photosensitive region 50 refers to the region of the photoelectric detection chip 20 other than the photosensitive region 40.

[0060] The photosensitive region 40 refers to the core region of light signal reception and photoelectric conversion, and the presence of the grating microstructure 303 enables the region to selectively absorb incident light of a specific wavelength and generate photo-generated carriers. The non-photosensitive region 50 is mainly used to set the conductive electrode 301, lead and isolation structure, and does not participate in light signal reception to avoid stray light interference.

[0061] Specifically, the area of the photosensitive region 40 can be designed according to the size of the light spot to ensure that the light spot can completely cover the photosensitive region 40 and avoid waste of light signals. For example, if the measurement light spot diameter is 0.8 mm, the photosensitive region 40 can be designed as a circular shape with a diameter of 1 mm, and the grating microstructure 303 fills the circular region. The non-photosensitive region 50 is the region of the chip edge and the electrode, and the width can be set to 0.2 mm to effectively isolate stray light.

[0062] The embodiments of the present application realize the partition design, so that the photosensitive region 40 only focuses on light signal absorption and carrier generation, and the non-photosensitive region 50 focuses on carrier export and structure arrangement. The conductive lead 302 can directly connect the grating microstructure 303 and the conductive electrode 301, shorten the transmission path, reduce the attenuation of the carriers in the transmission process, improve the efficiency of the electrical signal transmission, and provide a clear and stable signal source for subsequent differential measurement.

[0063] The non-photosensitive region 50 has no grating microstructure 303 and will not absorb stray light to generate additional photo-generated carriers, thereby avoiding invalid electrical signals caused by stray light from mixing into normal measurement signals. At the same time, the non-photosensitive region 50 can act as an isolation belt for the photosensitive region 40, reducing the cross-influence of stray light between different photosensitive regions 40, ensuring that the electrical signals output by each photosensitive region 40 correspond only to the target measurement light signal, and reducing the interference of stray light on the difference value calculation of the differential signal.

[0064] In addition, the photosensitive regions 40 are arranged in a concentrated manner according to measurement requirements to adapt to multi-spot detection, and the non-photosensitive region 50 is reasonably planned to have electrode and lead wire layouts to avoid component crowding or overlapping. This orderly layout can efficiently integrate more photoelectric detection units 30 in a limited chip area, while reserving reasonable space for the bonding of the photoelectric detection chip 20 and the detector substrate 10 and the connection of the pads 60, thereby reducing the integration difficulty.

[0065] In an optional embodiment, the grating microstructure 303 in the photosensitive region 40 is arranged periodically.

[0066] The periodic arrangement of the grating microstructure 303 is a key to achieving light splitting and light coupling, and a uniform period size can ensure uniform absorption and modulation of light signals of a specific wavelength, thereby avoiding signal fluctuations caused by disordered structures.

[0067] For example, a semiconductor lithography process can be used to achieve the periodic arrangement of the grating microstructure 303. First, photoresist is coated on the surface of a semiconductor substrate layer, a periodic pattern is formed through a mask exposure, and then an etching process is used to manufacture grating grooves with a depth of 100-200 nm. The period deviation is controlled to be less than ±1 nm through the lithography process to ensure the uniformity of light signal absorption in the photosensitive region 40.

[0068] The embodiments of the present application achieve uniform grating structure parameters at different positions in the photosensitive region 40 through periodic arrangement, so that the incident light is uniformly absorbed and modulated in the region, ensuring that the light signals received by different sub-units only have a phase difference and no intensity deviation, thereby improving the consistency and accuracy of the differential measurement results. In addition, the periodic grating can convert more incident light into photo-generated carriers, thereby improving the signal response sensitivity of the photoelectric detection chip 20 and enabling weak light signals to be effectively detected.

[0069] Here, the periodically arranged grating microstructure 303 is highly compatible with the lithography process, and the lithography process can use a unified mask to copy a periodic grating pattern in the photosensitive region 40 at one time, without the need for separate processing of each grating. This adaptability greatly simplifies the processing flow, reduces process errors, and facilitates large-area and batch production, thereby reducing the production cost of the detector array.

[0070] In an optional embodiment, the probe array structure adopts a vertical coupling light coupling mode. The incident light is incident on the photoelectric detection chip 20 through the upper surface of the grating microstructure 303.

[0071] The vertical coupling mode refers to that the incident light is incident in a direction perpendicular to the surface of the probe chip. The grating microstructure 303 guides the incident light into the semiconductor substrate layer through vertical light coupling, so as to realize efficient absorption of the optical signal. After the incident light is vertically incident on the grating microstructure 303, the grating microstructure 303 divides the incident light into two optical signals with a phase difference, which respectively enter the two sub-photoelectric detection units arranged in cross, thereby providing a basis for subsequent differential measurement without additional optical system adjustment of the light path direction. This mode does not need a complex optical collimation system, thereby simplifying the overall optical structure.

[0072] Specifically, the incident light is focused by an external lens and is incident in a direction perpendicular to the upper surface of the grating microstructure 303. The diameter of the focused light spot matches the photosensitive area 40, so as to ensure that the optical signal enters the photosensitive area 40. For example, a convex lens with a focal length of 50 mm is used to focus the incident light into a light spot with a diameter of 1 mm, which is vertically incident on the upper surface of the grating microstructure 303. The light coupling efficiency can reach more than 80%, thereby greatly reducing the loss of the optical signal.

[0073] Here, the vertical coupling mode is adopted, so that the incident light can be directly vertically incident on the grating microstructure 303 without the need of additional optical elements to change the light path. Meanwhile, the grating microstructure 303 has both coupling and beam splitting functions, thereby eliminating the need of an independent beam splitting system. This greatly simplifies the optical system structure, reduces the number of elements, and reduces the difficulty of light path alignment and the debugging workload during system integration.

[0074] Moreover, the vertical coupling mode can make the incident light accurately cover the photosensitive area 40 of the grating microstructure 303, thereby reducing the reflection and loss of the optical signal. Meanwhile, the periodic design of the grating microstructure 303 can further enhance the coupling effect of the vertically incident light, so that more optical signals are converted into photo-generated carriers. This can reduce the loss of the optical signal in the coupling link, improve the strength of the electrical signal, provide a clearer signal source for differential measurement, and ensure the measurement accuracy.

[0075] In addition, the vertical coupling mode does not need additional light path adjustment space. The grating microstructure 303 is directly integrated on the chip surface, so that the overall volume of the probe is more compact. Meanwhile, the eliminated optical elements can reduce the occupied space of the system, thereby facilitating the integration of the probe array and other electronic components. Moreover, no complex light path space needs to be reserved during the integration process, thereby further improving the integration efficiency.

[0076] In an optional embodiment, a plurality of pads 60 are arranged on the probe substrate 10 outside the photoelectric detection chip 20, and the plurality of pads 60 are used for signal transmission of the probe.

[0077] The pad 60 is an interface component for connecting the detector with an external circuit, and is connected with the conductive electrode 301 or lead wire of the photoelectric detection chip 20 through a wire to transmit the electrical signal generated by the chip to an external processing circuit, and can also realize the power supply function of the detector.

[0078] Specifically, the pad 60 is made of a highly conductive material to reduce signal transmission loss, and is usually made of metal such as copper or gold, and the surface conductivity is improved by electroplating process. For example, a gold plating process is used to make 8 circular pads 60 with a diameter of 0.5 mm in the reserved area of the detector substrate 10, which correspond to the signal output terminals and common electrode terminals of the two sub-photoelectric detection units respectively to ensure independent signal transmission without crosstalk.

[0079] In the embodiment of the present application, the pad 60 is arranged in the area of the detector substrate 10 outside the photoelectric detection chip 20, which can connect the conductive electrode 301 of the photoelectric detection chip 20 through a short wire to shorten the signal transmission path and reduce the loss, and can also avoid the interference between the pad 60 and the functional components of the photoelectric detection chip 20 to ensure that the electrical signal is transmitted to the external circuit in a pure and efficient manner, and provides a stable signal source for subsequent differential signal processing.

[0080] Here, the pad 60 as an external interface is arranged in an area outside the photoelectric detection chip 20, which can facilitate the wire welding of operators or automatic equipment, and does not need to avoid the functional area of the chip, thereby reducing the difficulty of welding operation; meanwhile, multiple pads 60 can correspond to the signal output terminals and power supply terminals of different sub-photoelectric detection units respectively, which facilitates the precise connection of external circuits according to functions and reduces the probability of wiring errors. In this way, the integration and assembly process of the detector and the external system can be simplified, the system debugging workload can be reduced, and the integration efficiency can be improved.

[0081] Specifically, multiple pads 60 are arranged on one side of the detector substrate 10 close to the conductive electrode 301 in the photoelectric detection chip 20, and multiple pads 60 are arranged on the other side of the detector substrate 10 away from the conductive electrode 301 in the photoelectric detection chip 20, and the number of pads 60 arranged on the side close to the conductive electrode 301 in the photoelectric detection chip 20 is greater than the number of pads 60 arranged on the side away from the conductive electrode 301 in the photoelectric detection chip 20.

[0082] Among them, the pads 60 on the side close to the conductive electrode 301 are used to directly connect the signal output terminals of the chip, and need to match the number of sub-photoelectric detection units and signal channels; the pads 60 on the side away from the conductive electrode 301 are mostly common interfaces (such as ground and power supply), and the number is relatively small. This layout can shorten the signal transmission path and reduce the loss.

[0083] For example, if the photoelectric detection chip 20 includes 2 photoelectric detection units 30 (4 sub-photoelectric detection units in total), 6 pads 60 (4 signal output pads and 2 common electrode pads) are arranged on the side close to the conductive electrode 301, and 2 pads 60 (1 ground pad and 1 power supply pad) are arranged on the side away from the conductive electrode 301, which can meet the multi-channel signal transmission requirement and simplify the wiring structure on the other side of the substrate.

[0084] Here, more pads 60 are arranged on the side close to the conductive electrode 301, so that the conductive electrode 301 of each sub-photoelectric detection unit can be connected to the corresponding pad 60 through the shortest wire, avoiding the problems of increased resistance and signal attenuation caused by excessively long wires. For example, if the chip has 4 sub-photoelectric detection units (4 signal pads are required), 4 signal pads 60 are arranged on the close side, and the wire length can be controlled within 0.5-1mm, which is much shorter than the wire length connected to the pad 60 on the side away from the side, greatly reducing the loss in the signal transmission process and ensuring the strength and stability of the electrical signal required for differential measurement.

[0085] Here, the number of pads 60 on the side away from the conductive electrode 301 is small, which can form a functional partition with the signal pads 60 on the close side. The close side focuses on signal transmission, and the side away from the side focuses on energy supply and ground protection, avoiding the cross-over of lines with different functions on the substrate. This partition layout makes the substrate wiring clearer, which can not only reduce the probability of wiring errors during welding operation, but also facilitate quick positioning of signal or power supply lines during subsequent system debugging, reducing the difficulty of troubleshooting caused by messy lines and improving the efficiency of detector integration.

[0086] In the embodiments of the present application, more signal pads 60 are required for multi-channel differential measurement, and increasing the number of pads 60 on the close side can meet the multi-channel signal output requirement. Only a small number of common functional pads 60 are required on the side away from the side, and the number does not need to be increased, avoiding unnecessary pad 60 processing costs. This on-demand allocation of the number of pads 60 can meet the multi-channel measurement requirement while controlling the substrate manufacturing and processing costs.

[0087] For example, the detector array structure provided by the embodiment of the present application is applied as follows: a ceramic material is selected to manufacture the detector substrate 10, the photoelectric detection chip 20 is glued on the detector substrate 10 by an adhesive method, the semiconductor substrate layer of the photoelectric detection chip 20 adopts an N-type silicon material; nine independent photoelectric detection units 30 are manufactured on the semiconductor substrate layer, each photoelectric detection unit 30 is divided into two sub photoelectric detection units through cross intersection, the grating microstructure 303 is arranged in the photosensitive area 40 of the sub photoelectric detection unit, and there is no grating microstructure in the non-photosensitive area 50; each photoelectric detection sub unit is configured with an aluminum conductive electrode 301 and a conductive lead 302, the conductive lead 302 connects the grating microstructure 303 and the conductive electrode 301, and the solder pad 60 is further arranged on the detector substrate 10 for signal transmission.

[0088] In use, the incident light is focused into a light spot with a diameter of 1 mm through the convex lens, is incident on the upper surface of the grating microstructure 303 in the vertical direction, and is coupled into the semiconductor substrate layer through vertical coupling; the photosensitive area 40 generates photo-generated carriers, the electrons move to the N-type substrate layer (common cathode), and the holes are transmitted to the gold electrode (anode) through the conductive lead 302; the electrical signals output by the two electrodes are transmitted to the external differential processing circuit through the solder pad 60 on the substrate, the difference between the two signals is calculated, the differential measurement of the optical signal is realized, the error caused by the change of the light spot intensity is effectively offset, the measurement accuracy is improved, and the response time is shorter.

[0089] The embodiment of the present application directly realizes the differential measurement of the optical signal without an additional optical beam splitting system by arranging the cross sub photoelectric detection units and the corresponding grating microstructures in the photoelectric detection unit, effectively reduces the design difficulty of the optical system and the integration and debugging complexity, not only reduces the optical signal transmission loss, improves the measurement efficiency, but also simplifies the overall structure, and improves the reliability and integration of the differential measurement.

[0090] Finally, it should be noted that: the above-described embodiments are merely specific embodiments of the present application, used to illustrate the technical solutions of the present application, rather than limit them, the protection scope of the present application is not limited thereto, although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art within the technical range disclosed by the present application can modify or easily think of changes to the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and all should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A detector array structure, characterized by, The application relates to a detector array structure, which comprises a detector substrate, a photoelectric detection chip arranged on the detector substrate, the photoelectric detection chip comprising a semiconductor substrate layer and at least one photoelectric detection unit arranged on the semiconductor substrate layer, the photoelectric detection unit comprising two cross-arranged sub-photoelectric detection units, each of the sub-photoelectric detection units comprising a conductive electrode, a plurality of conductive leads connected with the conductive electrode, and a grating microstructure connected with each of the conductive leads, wherein the grating microstructures in the two sub-photoelectric detection units are cross-arranged. The photoelectric detection chip is provided with a non-photosensitive region and a photosensitive region, the photosensitive region refers to the region of the grating microstructure on the photoelectric detection chip, and the photo-generated carriers generated by the photosensitive region are conducted through the conductive leads and the conductive electrode; the non-photosensitive region refers to the region of the photoelectric detection chip except the photosensitive region.

2. The detector array structure of claim 1, wherein, The grating microstructures in the photosensitive region are periodically arranged.

3. The detector array structure of claim 2, wherein, A plurality of pads are arranged on the detector substrate outside the photoelectric detection chip, and the pads are used for signal transmission of the detector.

4. The detector array structure of claim 1, wherein, A plurality of pads are arranged on one side of the detector substrate close to the conductive electrodes in the photoelectric detection chip, and a plurality of pads are arranged on the other side of the detector substrate away from the conductive electrodes in the photoelectric detection chip, the number of the pads arranged on the one side of the detector substrate close to the conductive electrodes in the photoelectric detection chip is greater than the number of the pads arranged on the other side of the detector substrate away from the conductive electrodes in the photoelectric detection chip.

5. The detector array structure of claim 4, wherein, The detector array structure adopts a vertical coupling light coupling mode, and incident light is incident to the photoelectric detection chip through the upper surface of the grating microstructure.

6. The detector array structure of claim 1, wherein, Each of the photoelectric detection units is isolated from each other.

7. The detector array structure of claim 1, wherein, The semiconductor substrate layer adopts a semiconductor material and serves as a common anode or a common cathode of the photoelectric detection chip.

8. The detector array structure of claim 1, wherein, The detector substrate is made of ceramic and is used for providing a stable supporting basis for the photoelectric detection chip.

9. The structure of an array of detectors according to claim 1, characterized in that, The photoelectric detection chip is glued to the detector substrate by an adhesive.

10. The structure of an array of detectors according to claim 1, characterized in that, ​

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