CN107677380B - Color digital silicon photomultiplier - Google Patents
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 92
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- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
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Abstract
The invention discloses a color digital silicon photomultiplier, which comprises a pixel array formed by a plurality of rows and columns of color digital silicon photomultiplier pixel units, and a reading module for reading data and address information in each color digital silicon photomultiplier pixel unit. Each color digital silicon photomultiplier pixel unit sequentially comprises three layers of detectors sensitive to blue light, green light and red light from top to bottom and a signal processing circuit layer positioned below the detector layers. The invention has the advantages that three primary colors of red, green and blue can be detected in a single pixel unit, and all color information can be sensed by using one pixel, thereby avoiding the color distortion of an image; the sensitivity of single photon level is provided, which can be conveniently applied in the field of lower luminous flux detection; the signal digitization can be realized at a single pixel level, so that a complex reading circuit is not needed, and the power consumption of the device can be greatly reduced.
Description
Technical Field
The invention relates to the technical field of semiconductors, in particular to a color digital silicon photomultiplier for photon detection.
Background
The research of applying silicon-based technology to low-photon flux sensors is first started in the later 70 s of the 20 th century, and a researcher spatially arranged uniformly distributed Metal-Resistor-Semiconductor (MRS) microsensor array has separate quenching and common output, so that the detection of low-flux photons is realized. Such sensors are known as silicon photomultipliers (Silicon Photomultiplier, siPM) in the future. Since then, sipms have been developed that occupy the half-wall mountain of the low-photon flux detector research field, and many researchers' synergy has made a unique contribution to the development of sipms. Modern sipms are array structures consisting of PN junctions (also known as microelements) operating in geiger mode, each of which is connected in series with an independent passive quenching resistor. Sipms can exhibit clear single photon responses at room temperature with significant photon number resolution. In the same period, single photon avalanche diodes (Single Photon Avalanche Diode, SPAD) have also emerged in the single photon detection field. SPADs are also single photon detectors operating in geiger mode, with a photodetection portion equivalent to one microcell of SiPM. The layout of SPADs is different from that of sipms because SPADs also include integrated active quenching electronic circuit portions. In other words, siPM is equivalent to an array of SPADs in a passive quenching form. Sipms and SPADs have been used as low photon flux sensors in place of photomultiplier tubes (Photomultiplier Tube, PMTs), for example, from high energy physics based scintillation crystals to nuclear medicine devices, radiation detectors, laser radar systems to wearable devices, and the like, as a trail of their applications.
The latest research direction of SiPM and SPAD is to explore whether photon detection can be achieved under standard CMOS process conditions. This means that CMOS processes may allow integration of the readout circuitry and the photodetector on a single chip, thereby greatly reducing power consumption and simplifying the operating conditions of the detector. Furthermore, the use of CMOS processes reduces the cost of sensor fabrication, allowing for efficient and stable commercial mass production. The production of modern sipms under standard CMOS process conditions has a significant impact on the development of advanced low-flux photon and ion radiation integrated detectors. Furthermore, CMOS 3D interconnect technology may be applied to SiPM development in the future, which may significantly improve the detection efficiency, as demonstrated by Globalfoundries/Tezzaron nm process node. With 3D interconnect technology, new digital avalanche pixel structures can be further developed that can enable individual readout of each pixel. Avalanche pixel imagers and avalanche pixel trackers have been reported using 3D interconnect technology for low flux photon detection and ion radiation detection, respectively. Solutions to apply CMOS avalanche photodiode schemes to digital silicon photomultipliers have been demonstrated at 800nm and 350nm process nodes.
The sensor performance developed by CMOS process technology is limited to a certain extent by the process rules of CMOS. SiPM and SPAD can exhibit localized breakdown phenomena at junction edges due to high electric field concentrations. The guard ring structure is arranged along the periphery of the photosensitive region of each microcell, so that a uniform electric field can be obtained in the whole photosensitive region, and the problem of local breakdown is relieved. The CMOS process provides several schemes for realizing the guard ring structure, and the guard ring structure is realized by the SPAD or SPAD array or SiPM detection structure on the CMOS process nodes of 800nm to 90nm by using the layout design technology and is used for detecting single photon signals under the avalanche breakdown bias condition. There are still two main limitations to the use of CMOS technology: i.e., sipms fabricated using CMOS processes have higher dark count rates and lower detection efficiencies than commercial sipms fabricated based on custom-made processes. One possible solution is to adjust the well concentration profile of a standard CMOS process and adjust the mask to allow the highly doped and lowly doped regions to overlap each other.
One major limitation of SPAD arrays or digital sipms development is that they are not sensitive to the photons to be measured for a particular wavelength (e.g., red or blue). A detected photon will produce a signal pulse, but the signal pulse is independent of the incident photon energy. One possible solution is to use CMOS image sensor technology to address this problem. The basic structure of a CMOS image sensor is a PN junction diode, but it does not operate in geiger mode. A digital image can be formed by reading out data from a two-dimensional matrix of such PN junction diodes. For a CMOS image sensor, 70% of the area in each pixel is occupied by the readout circuitry including amplifiers, shapers, comparators, and digitizing units, with only 30% of the area belonging to the sensitive detection unit. The color information of the image is obtained by disposing bayer color filters on the detection array. Bayer color filters consist of tiny meniscus lenses that focus the detected photons onto a photosensitive area. The image sensor surface formed by bayer color filters is like a mosaic array, each pixel is covered with three filters of red, green and blue, wherein the number of green filters is twice the number of red and blue filters. The reason for this is that the human eye has a higher resolution of the green image details than the red and blue images. The bayer color filter may simulate the visual response of the retina of the human eye with a peak sensitivity of 550 nm.
CMOS image sensors are currently in use and development in a wide variety of fields, ranging from digital cameras to astronomical telescopes. CMOS image sensors still suffer from a number of drawbacks: first, since it is a detection unit made of a simple PN structure, it is not sensitive to single photons; second, since the readout circuitry occupies a large area, its sensitivity is not high; furthermore, metal interconnects on image sensors can produce halation, cross-talk between pixels, and light scattering effects, which can seriously affect the overall quality of the image.
Disclosure of Invention
The invention aims to solve the technical problems, and provides a color digital silicon photomultiplier which is used for realizing color imaging of the silicon photomultiplier and solving the problems that a CMOS image sensor is insensitive to single photon, has low sensitivity and has poor imaging effect. In order to achieve the above purpose, the present invention provides the following technical solutions:
the color digital silicon photomultiplier is characterized by comprising a pixel array formed by a plurality of rows and columns of color digital silicon photomultiplier pixel units and a reading module for reading data and address information in each color digital silicon photomultiplier pixel unit; each color digital silicon photomultiplier pixel unit sequentially comprises a first detector layer, a second detector layer, a third detector layer and a signal processing circuit layer positioned on a fourth layer from top to bottom; the reading module is positioned in the signal processing circuit layer; and the first detector layer, the second detector layer and the third detector layer are all electrically connected with the signal processing circuit layer.
Preferably, the detectors in the first, second and third detector layers in each of the color digital silicon photomultiplier pixel units are each comprised of single photon avalanche diodes operating in geiger mode; the first detector layer is sensitive to blue light; the second detector layer is sensitive to green light; the third detector layer is sensitive to red light.
Preferably, the signal processing circuit layer further comprises a quenching unit for quenching the avalanche state of each single photon avalanche diode, a discrimination unit for converting the analog signal output by each single photon avalanche diode into a digital signal, a storage unit for storing the digital signal output by the discrimination unit, and an input/output interface for controlling the operation of the detector, the reading module and the signal processing circuit.
Preferably, the quenching unit in the processing circuit layer is electrically connected with the single photon avalanche photodiodes in the first, second and third detector layers; the signal output end of the single photon avalanche photodiode is electrically connected with the discrimination unit; and the signal output end of the screening unit is electrically connected with the storage unit.
Preferably, the quenching unit is arranged in one-to-one correspondence with the first, second and third detector layers in each color digital silicon photomultiplier pixel unit; the screening unit is respectively arranged in one-to-one correspondence with the first detector layer, the second detector layer and the third detector layer in each color digital silicon photomultiplier pixel unit; the storage unit is respectively arranged in one-to-one correspondence with the first detector layer, the second detector layer and the third detector layer in each color digital silicon photomultiplier pixel unit.
Preferably, all single photon avalanche diodes in the first, second and third detector layers share the same voltage input.
Preferably, the reading module comprises an address unit, a control unit and an output unit; the address unit is used for determining the position of each color digital silicon photomultiplier pixel unit; the control unit controls the data of each color digital silicon photomultiplier pixel unit and the sending of an address output instruction; the output unit is used for transmitting the data sent by each color digital silicon photomultiplier pixel unit and the corresponding address information.
Preferably, the first, second and third detector layers and the signal processing circuit layer are manufactured on different wafers respectively, and then the detector layers and the signal processing circuit layer are stacked together through wafer thinning and bonding technology; the electrical connection is realized by adopting a silicon through hole mode.
Preferably, the first, second and third detector layers and the signal processing circuit layer are all manufactured and implemented by using a CMOS (complementary metal oxide semiconductor) process.
The beneficial effects of the invention are as follows: firstly, the color digital silicon photomultiplier can detect three primary colors of red, green and blue in a single pixel unit, and can sense all color information by using one pixel, so that complex micro-lens (Bayer filter) process steps are omitted, and color distortion of an image is avoided; secondly, as the detector is positioned on the surface and the reading module and the data processing circuit are positioned below the detection layer, the area of the light-sensitive area is not occupied by the reading module and the data processing circuit, and the three-dimensional detector structure layout ensures that the color digital silicon photomultiplier has higher filling factor, thus having higher sensitivity and being conveniently applied to the field of lower luminous flux detection; again, thanks to the high internal gain of the single photon avalanche photodiode, the pixel data readout does not require complex readout circuitry; finally, since the output signal is digitized at the pixel level, not only the complexity of the subsequent signal processing circuit is greatly simplified, but also the power consumption of the color digital silicon photomultiplier is reduced.
Drawings
The invention is described in detail below with reference to examples and figures, wherein:
FIG. 1 is a schematic view of a longitudinal structure of a color digital silicon photomultiplier;
FIG. 2 is a schematic diagram of an equivalent circuit of a color digital silicon photomultiplier pixel cell;
FIG. 3 is a schematic top view of a color digital silicon photomultiplier device;
In the drawings, the meanings of the reference numerals are as follows: 10-a first detector layer; 11-photodetectors in the first detector layer; 20-a second detector layer; 21-photodetectors in the second detector layer; 30-a third detector layer; 31-photodetectors in the third detector layer; 40-a signal processing circuit layer; 41-a quenching unit; 42-screening unit; a 43-memory cell; 50-color digital silicon photomultiplier pixel cells.
Detailed Description
As shown in fig. 1, a color digital silicon photomultiplier is characterized by comprising a pixel array formed by a plurality of rows and columns of color digital silicon photomultiplier pixel units 50, and a reading module for reading data and address information in each color digital silicon photomultiplier pixel unit 50; each color digital silicon photomultiplier pixel unit 50 sequentially comprises a first detector layer 10, a second detector layer 20, a third detector layer 30 and a signal processing circuit layer 40 positioned on a fourth layer from top to bottom; the reading module is located in the signal processing circuit layer 40; the first detector layer 10, the second detector layer 20, and the third detector layer 30 are electrically connected to the signal processing circuit layer 40.
As a preferred option, the detectors in the first detector layer 10, the second detector layer 20 and the third detector layer 30 in each of the color digital silicon photomultiplier pixel units 50 are each comprised of single photon avalanche diodes operating in geiger mode; the first detector layer 10 is sensitive to blue light; the second detector layer 20 is sensitive to green light; the third detector layer 30 is sensitive to red light. Each color digital silicon photomultiplier pixel unit 50 in the present invention includes a first detector layer 10 that is sensitive to blue light, a second detector layer 20 that is sensitive to green light, and a third detector layer 30 that is sensitive to red light. For example, taking a device formed by M rows and N columns (where M and N are positive integers) of the color digital silicon photomultiplier pixel unit 50 as an example, the number of detectors is calculated by (m×n) detectors in the first, second, and third detector layers, respectively, and a total of 3 (m×n) single photon avalanche photodiode detectors are formed. It should be noted that the photodetectors 11 in all the first detector layers 10 are located on the same horizontal plane, as is the case for all the photodetectors 21 of the second detector layers 20 and all the photodetectors 31 in the third detector layers 30, i.e. the three detector layers (10, 20, 30) are separated into three different horizontal planes. For a single color digital silicon photomultiplier pixel unit 50, the photodetectors (11, 21, 31) in the first, second, and third detector layers 10, 20, 30 are all located on the same vertical line, i.e., the photosurface locations of the three-layer detectors in a single pixel are coincident. In order to further improve the detection performance of the detector, the detectors in the same layer are isolated from each other in the implementation; it is possible to adopt a scheme in which a trench is provided between adjacent detectors, and then a light blocking material is filled in the trench to suppress mutual interference between adjacent pixel units.
As a preferred solution, the signal processing circuit layer 40 further includes a quenching unit 41 for quenching the avalanche state of each single photon avalanche diode, a discrimination unit 42 for converting the analog signal output by each single photon avalanche diode into a digital signal, a storage unit 43 for storing the digital signal output by the discrimination unit, and an input/output interface for controlling the operation of the detector, the reading module, and the signal processing circuit. In particular, a quenching unit 41 of the processing circuit layer 40 is electrically connected with the single photon avalanche photodiodes in the first, second, third detector layers (10, 20, 30); the signal output end of the single photon avalanche photodiode is electrically connected with the discrimination unit 42; the signal output of the discrimination unit 42 is electrically connected to a memory unit 43.
As a preferred solution, the quenching unit 41 is disposed in one-to-one correspondence with the first, second, and third detector layers in each color digital silicon photomultiplier pixel unit; the discriminating unit 42 is arranged in one-to-one correspondence with the first, second and third detector layers in each color digital silicon photomultiplier pixel unit; the storage unit 43 is arranged in one-to-one correspondence with the first, second and third detector layers in each color digital silicon photomultiplier pixel unit. An equivalent circuit schematic of a color digital silicon photomultiplier pixel unit 50 in accordance with the present invention is shown in FIG. 2. Each detector in the pixel unit 50 corresponds to one quenching unit 41, one screening unit 42 and one storage unit 43. After the light incident on the detector layer is detected by the single photon avalanche photodiode, an electric pulse signal is generated by the quenching action of the quenching unit 41; the electrical pulse signal is an analog signal, which is processed by the discrimination unit 42, and is converted into a digital logic signal, which is finally stored in the storage unit 43. Also taking the device made up of M rows and N columns of color digital silicon photomultiplier pixel cells 50 as an example, each pixel cell 50 has three quenching cells 41, three screening cells 42 and three storage cells 43, and the entire device has a total of 3 (mxn) quenching cells 41, 3 (mxn) screening cells 42 and 3 (mxn) storage cells 43. The same discrimination unit 42 and the same storage unit 43 may be shared by a single pixel unit in a multiplexing manner. Thus, although the complexity of the device circuit can be reduced, the signal reading time is prolonged, and the real-time reading cannot be performed, so that the performance of the device is reduced.
As a preferred solution, all single photon avalanche diodes in the first, second and third detector layers (10, 20, 30) share the same voltage input. A schematic top view of the color digital silicon photomultiplier of the present invention is shown in FIG. 3.
As a preferred scheme, the reading module comprises an address unit, a control unit and an output unit; the address unit is used for determining the position of each color digital silicon photomultiplier pixel unit; the control unit controls the transmission of color information and address output instructions of each color digital silicon photomultiplier pixel unit; the output unit is used for transmitting the color information and the corresponding address information sent by each color digital silicon photomultiplier pixel unit.
As a preferred embodiment, the address unit includes a row decoder and a column decoder; the input end of each row decoder comprises a row strobe signal input end and X row address information input ends; each row decoder further comprises 2 X output ends, and each output end of the row decoder is respectively connected with the storage unit of each color digital silicon photomultiplier pixel unit in a communication manner so as to determine row address information of each color digital silicon photomultiplier pixel unit in the device; each column decoder comprises a column selection communication input end, X column address information input ends and 2 X output ends, and each output end of the column decoder is respectively in communication connection with a storage unit of each color digital silicon photomultiplier pixel unit in the device so as to determine the column address information of each color digital silicon photomultiplier pixel unit in the device; and the row address information input end and the row strobe signal input end of the row decoder are both in communication connection with the control unit to receive the drive of the control unit, and control the strobe of the pixel unit of the color digital silicon photomultiplier of the designated address and the transmission of color information and address information. For 3 memory cells in each color digital silicon photomultiplier pixel cell, their inputs are connected in parallel with each other, i.e., the memory address information in the same pixel cell is the same.
As a preferable scheme, the control unit is in communication connection with the address unit and is used for controlling the gating of the pixel units of the color digital silicon photomultipliers of the designated address and the transmission of corresponding color information and address output instructions; the control unit pre-stores address information of a color digital silicon photomultiplier pixel unit color information output logic sequence, and comprises a row strobe signal output end, a column strobe signal output end, at least X row address information output ends and at least X column address information output ends. The X row address information output ends of the control unit are correspondingly and communicatively connected with the X row address information input ends respectively through address lines; the column selection communication output end of the control unit is in communication connection with the column selection communication input end of the column decoder, and the X column address information output ends of the control unit are in corresponding communication connection with the X column address information input ends through address lines respectively. The control unit controls whether the address unit works or not through the row address gating signal and the column address gating signal, namely, the row decoder and the column decoder are both in a working state by sending the row address gating signal and the column address gating signal, and then the control unit sends pre-stored address information to the row decoder and the column decoder in the working state through the row address information output end and the column address information output end through address wires, and the gating of the pixel unit of the designated color digital silicon photomultiplier is realized through the joint cooperation of the row decoder and the column decoder. And outputting the color information and the corresponding address information stored in the corresponding storage unit through the output unit immediately after the designated color digital silicon photomultiplier pixel unit is gated. The logic sequence of the signals sent by the row and column address signal output ends follows the control of the pre-stored address information in the control unit, so that the pixel unit of the color digital silicon photomultiplier sends color information and address information according to the logic sequence in the address information.
The logic sequence of outputting the address information pre-stored in the control unit only needs to enable the color information and the address information in each storage unit in the device to be output, and in order to facilitate the effective determination of the output state of each storage unit, the logic sequence of outputting the data in the address information can be one by one to gate each storage unit so as to realize the reading of the color information and the sending of the address in each storage unit in sequence; or, the memory cells in the same row are controlled to be sequentially gated so as to read the color information and send the address in the memory cells row by row; or, the memory cells in the same column are controlled to be sequentially gated so as to read the color information and send the address in the memory cells column by column. The row decoder can identify any row of memory units in the color digital silicon photomultiplier after receiving the row address strobe signal, and the column decoder can identify any column of memory units in the color digital silicon photomultiplier after receiving the column address strobe signal, so that the control unit can sequentially control the transmission of the row address strobe signal and the column address strobe signal according to the logic sequence of pre-stored address information, and further control the memory units in the device to output color information and address information according to the determined logic sequence. The output unit is in communication connection with each color digital silicon photomultiplier pixel unit to transmit color information and corresponding address information sent by the color digital silicon photomultiplier pixel units after the color digital silicon photomultiplier pixel units with the designated addresses are gated. Specifically, the output end of each memory cell is respectively connected with the output cell in a communication way through a data bus so as to transmit the color information and the address information in the corresponding memory cell after the pixel cell of the designated color digital silicon photomultiplier is gated.
The invention provides a color digital silicon photomultiplier which adopts the working principle that the absorption effect of silicon materials on light rays with different wavelengths is utilized, and the first, second and third detector layers (10, 20 and 30) are like a vertically distributed color filter. Since silicon material has a high absorption coefficient for blue light, the first detector layer 40 at the very top of the pixel cell is most sensitive to blue light and thus is mainly used to detect blue light; when light is incident on the middle second detector layer 30, only red light and green light remain in the light, and in this detector layer, the silicon material has a higher absorption coefficient for green light, and is mainly used to detect green light; when the light is incident on the lower third detector layer 20, only red light is in the light, and the third detector layer 20 can well detect the red light. Thus, the color information (i.e., R < red >, G < green >, B < blue > color components) in the light can be extracted by the first-third layer detectors and stored in the memory cells in the pixel unit. The first, second and third detector layers are a vertical color filter, which can separate the three primary colors of red, green and blue, and omit complex and complicated micro-lens (Bayer filter) process steps. The three primary colors of red, green and blue can be extracted in one pixel at the same time, so that the color distortion of an image is avoided. Meanwhile, as the detectors in the first detector, the second detector and the third detector are all single photon avalanche diodes working in a Geiger mode, the single photon avalanche diodes have higher internal gain, and therefore a signal amplifying circuit is not needed, and the complexity of a pixel unit signal processing circuit can be greatly simplified. Since each pixel unit of the color digital silicon photomultiplier can output undistorted color information, that is, each pixel point can obtain color information, after the color information in each pixel unit of the color digital silicon photomultiplier is read, the color image can be restored by processing by the digital circuit in the signal processing circuit layer 40.
As shown in figure 2, each pixel unit in the color digital silicon photomultiplier provided by the invention belongs to a single detection unit, and can be controlled and operated conveniently independently of each other. The signal processing circuit layer is arranged at the bottom of the detector layer, and the three-dimensional pixel structure layout ensures that the detector pixels have larger photosensitive areas, so that the pixel units have higher filling factors, have higher sensitivity and can be widely applied to the field of lower luminous flux detection.
As a preferred solution, the first, second, third detector layers (10, 20, 30) and the signal processing circuit layer 40 are manufactured on different wafers, respectively, and then the detector layers and the signal processing circuit layer are stacked together by wafer thinning and bonding techniques; the electrical connection is realized by adopting a silicon through hole mode. The thickness of the first detector layer 10 should be controlled between 0.2 μm and 1 μm in consideration of the absorption effect of the silicon material on light of different wavelengths; the total thickness of the first detector layer 10 and the second detector layer 20 should be less than 2 μm and the thickness of the second detector layer 20 should be controlled between 0.2 μm and 1 μm.
As a preferred embodiment, the first, second, and third detector layers (10, 20, 30) and the signal processing circuit layer 40 are manufactured by CMOS processes, so as to be as simple and efficient as possible, while realizing the present invention at low cost.
The invention has the beneficial effects that: 1. three primary colors of red, green and blue can be detected in a single pixel unit, and all color information can be sensed by using one pixel, so that not only is the complex micro-lens (Bayer filter) process step omitted, but also the color distortion of an image is avoided; 2. the detector is positioned on the surface, the reading module and the data processing circuit are positioned below the detection layer, the reading module and the data processing circuit do not occupy the area of the light-sensitive area, and the three-dimensional detector structure layout ensures that the color digital silicon photomultiplier has higher filling factor, so that the color digital silicon photomultiplier has higher sensitivity and can be conveniently applied to the field of lower luminous flux detection; 3. thanks to the high internal gain of the single photon avalanche photodiode, the pixel data readout does not require complex readout circuitry; 4. the output signal is digitized at the pixel level, so that the complexity of a subsequent signal processing circuit can be greatly simplified, and the power consumption of the color digital silicon photomultiplier can be reduced.
The embodiments described above are described in order to facilitate the understanding and use of the present invention by those of ordinary skill in the art. It will be apparent to those skilled in the art that various modifications can be readily made to these embodiments and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above-described embodiments, and those skilled in the art, based on the present disclosure, should make improvements and modifications without departing from the scope of the present invention.
Claims (8)
1. The color digital silicon photomultiplier is characterized by comprising a pixel array formed by a plurality of rows and columns of color digital silicon photomultiplier pixel units and a reading module for reading data and address information in each color digital silicon photomultiplier pixel unit; each color digital silicon photomultiplier pixel unit sequentially comprises a first detector layer, a second detector layer, a third detector layer and a signal processing circuit layer positioned on a fourth layer from top to bottom; the reading module is positioned in the signal processing circuit layer; the first detector layer, the second detector layer and the third detector layer are electrically connected with the signal processing circuit layer; the first, second and third detector layers and the signal processing circuit layer are manufactured on different wafers respectively, and then the detector layers and the signal processing circuit layer are stacked together through wafer thinning and bonding technology; the electrical connection is realized by adopting a silicon through hole mode.
2. The color digital silicon photomultiplier of claim 1, wherein the detectors in the first, second, and third detector layers in each color digital silicon photomultiplier pixel unit are each comprised of a single photon avalanche diode operating in geiger mode; the first detector layer is sensitive to blue light; the second detector layer is sensitive to green light; the third detector layer is sensitive to red light.
3. The color digital silicon photomultiplier of claim 2, wherein the signal processing circuit layer further comprises a quenching unit for quenching the avalanche state of each single photon avalanche diode, a discrimination unit for converting the analog signal output by each single photon avalanche diode into a digital signal, a storage unit for storing the digital signal output by the discrimination unit, and an input/output interface for controlling the operation of the detector, the reading module, and the signal processing circuit.
4. A color digital silicon photomultiplier according to claim 3, wherein the quenching unit in the processing circuitry layer is electrically connected to single photon avalanche photodiodes in the first, second, and third detector layers; the signal output end of the single photon avalanche photodiode is electrically connected with the discrimination unit; and the signal output end of the screening unit is electrically connected with the storage unit.
5. The color digital silicon photomultiplier of claim 4, wherein the quenching unit is disposed in one-to-one correspondence with the first, second, and third detector layers in each of the color digital silicon photomultiplier pixel units; the screening unit is respectively arranged in one-to-one correspondence with the first detector layer, the second detector layer and the third detector layer in each color digital silicon photomultiplier pixel unit; the storage unit is respectively arranged in one-to-one correspondence with the first detector layer, the second detector layer and the third detector layer in each color digital silicon photomultiplier pixel unit.
6. A color digital silicon photomultiplier according to claim 2, wherein all single photon avalanche diodes in the first, second and third detector layers share the same voltage input.
7. The color digital silicon photomultiplier of claim 1, wherein the read module comprises an address unit, a control unit, and an output unit; the address unit is used for determining the position of each color digital silicon photomultiplier pixel unit; the control unit controls the data of each color digital silicon photomultiplier pixel unit and the sending of an address output instruction; the output unit is used for transmitting the data sent by each color digital silicon photomultiplier pixel unit and the corresponding address information.
8. The color digital silicon photomultiplier of claim 1, wherein the first, second, and third detector layers and the signal processing circuit layer are each implemented using CMOS fabrication.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1298483A (en) * | 1998-04-24 | 2001-06-06 | 福维昂公司 | Color separation in an active pixel cell imaging array using a triple-well structure |
| CN104272460A (en) * | 2012-04-30 | 2015-01-07 | 皇家飞利浦有限公司 | Imaging detector with per pixel analog channel well isolation with decoupling |
| CN207423375U (en) * | 2017-10-30 | 2018-05-29 | 湖北京邦科技有限公司 | A kind of colorful digital silicon photo multiplier device |
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| CN102763005B (en) * | 2007-08-08 | 2016-10-19 | 皇家飞利浦电子股份有限公司 | Silicon photomultiplier readout circuitry |
| EP2490441A1 (en) * | 2011-02-16 | 2012-08-22 | Paul Scherrer Institut | Single photon counting detector system having improved counter architecture |
| JP5604703B1 (en) * | 2013-09-10 | 2014-10-15 | 弘一 関根 | Solid-state imaging device |
| US9693035B2 (en) * | 2014-08-22 | 2017-06-27 | Voxtel, Inc. | Reconfigurable asynchronous readout array |
| WO2016171733A1 (en) * | 2015-04-24 | 2016-10-27 | Hewlett-Packard Development Company, L.P. | Stacked photodetectors |
| CN106657826B (en) * | 2016-12-08 | 2019-08-13 | 中国科学院上海高等研究院 | A kind of single-photon avalanche diode type pixel circuit |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1298483A (en) * | 1998-04-24 | 2001-06-06 | 福维昂公司 | Color separation in an active pixel cell imaging array using a triple-well structure |
| CN104272460A (en) * | 2012-04-30 | 2015-01-07 | 皇家飞利浦有限公司 | Imaging detector with per pixel analog channel well isolation with decoupling |
| CN207423375U (en) * | 2017-10-30 | 2018-05-29 | 湖北京邦科技有限公司 | A kind of colorful digital silicon photo multiplier device |
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