Vertical charge transfer type three-dimensional photoelectric device with multilayer structure

Abstract

The invention discloses a vertical charge transfer type three-dimensional photoelectric device with a multilayer structure, and belongs to the field of photoelectric detectors and memories. The vertical charge transfer type three-dimensional photoelectric device with the multilayer structure comprises a charge reading layer, a charge transfer layer and a charge storage layer which are formed in a semiconductor substrate and are sequentially arranged in the vertical direction. Wherein the charge reading layer is a semiconductor device which has a reading function of converting a charge signal into a voltage or current signal and a reset function of resetting the charge signal to an initial state, the charge transfer layer has a function of transferring the charge signal along a vertical direction, and the charge storage layer has a function of storing one or more charge packets. By applying proper voltage to different layers, the detection unit can realize light sensing, transferring, reading and resetting. According to the device, the photoelectric detection function is converted from a plane to a three-dimensional mode, and multispectral detection, photomultiplication, data storage and other applications can be carried out.

Description

Technical Field

[0001] The present invention relates to the field of photoelectric detectors and memories, and in particular to a photosensitive detector or memory in which a signal reading unit and a photoelectric conversion unit or a storage unit are arranged in a vertical direction and which works by vertically transferring signal charges in a multi-layer structure. Background Art

[0002] A photodetector is a device that can convert light signals into electrical signals. Its working principle is based on the photoelectric effect; that is, when photons interact with electrons in matter, electrons absorb the energy of photons and are released from atoms or molecules to form free electrons, thereby generating current. By measuring the magnitude of this current, the intensity of the measured light can be indirectly obtained. It has a wide range of applications in military and civilian fields due to its advantages such as fast response speed, high sensitivity, wide wavelength range, and good stability.

[0003] The main photodetectors currently used are CCD (Charge-Coupled Device) and CMOS (Complementary Metal-Oxide-Semiconductor). CCD is composed of several MOS capacitors connected in series. These capacitors can store and transfer charges. By applying voltage timing pulses on the MOS capacitors, the signal charge can be collected, stored, transferred, and read out. However, due to its complex transfer voltage timing, the charge transfer speed is limited, resulting in a slow device operation speed. In addition, since CCD is a series connection of capacitors, a problem with a pixel will affect the performance of other pixels, so CCD has extremely high process requirements.

[0004] CMOS photodetectors integrate the photosensitivity and readout functions in a single pixel. The pixels are independent of each other and do not require charge transfer, so they work faster and do not affect each other. However, each CMOS pixel contains multiple transistors, and the actual photosensitive area accounts for a small proportion, which also leads to relatively poor performance indicators such as CMOS sensitivity and dynamic range.

[0005] Traditional image sensors usually use color filter arrays, covering the pixels of CCD or CMOS image sensors with color filters, usually red, green, and blue (RGB) filters arranged in a certain pattern, so that each pixel is only sensitive to light of a specific color. In this way, the sensor can capture the basic information of the color image and restore the full-color image through post-processing. Although color filter arrays are more common, they will cause the light passing through to lose some of its energy and only allow light of a specific wavelength to pass through. As the number of array channels increases, the photosensitivity of the sensor will continue to decline.

[0006] In order to solve the problems existing in the above-mentioned optoelectronic devices, there is an urgent need for an optoelectronic device that can provide higher photoelectric conversion efficiency. Summary of the invention

[0007] In order to address various problems existing in the optoelectronic devices in the prior art, the present invention proposes a three-dimensional optoelectronic device with a vertical charge transfer structure with a multi-layer structure, which realizes the integration of the photoelectric detection function in the vertical direction, transforms the photoelectric detection function from a plane to a three-dimensional structure, and utilizes the light absorption characteristics of semiconductor materials to realize the multi-spectral imaging technology of a single detector. Another purpose of the present invention is to propose other applications based on the three-dimensional optoelectronic device with a vertical charge transfer structure with a multi-layer structure.

[0008] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0009] A three-dimensional photoelectric device with a multi-layer structure and vertical charge transfer, comprising a charge reading layer, a charge transfer layer and a charge storage layer arranged in sequence along the vertical direction, wherein the charge reading layer is a semiconductor device having a readout function of converting a charge signal into a voltage or current signal and a reset function of resetting the charge signal to an initial state, including: a complementary metal oxide semiconductor image sensor, a composite dielectric gate dual transistor photosensitive detector, a flash memory device, and a dynamic random access memory; the charge transfer layer has a function of transferring the charge signal along the vertical direction, including a single-layer or multi-layer vertical transfer gate; the charge storage layer has a function of storing a single or multiple charge packets, including a PN junction with one pole capable of floating, and a single-layer or multi-layer charge coupled device distributed along the vertical direction.

[0010] Furthermore, the semiconductor device involved in the vertical charge transfer three-dimensional optoelectronic device of the multilayer structure includes a surface channel semiconductor device or a buried channel semiconductor device.

[0011] Furthermore, the charge transfer layer and charge storage layer of the vertical charge transfer three-dimensional optoelectronic device of the multi-layer structure are located in the vertical direction and are recorded as charge storage and transfer layers, the charge reading layer is adjacent to the charge storage and transfer layer in the vertical direction, and an isolation structure composed of insulating material is arranged between adjacent multi-layer vertical charge transfer three-dimensional optoelectronic devices.

[0012] The present invention also provides a multi-layer vertical charge transfer three-dimensional optoelectronic device array, in which the multi-layer vertical charge transfer three-dimensional optoelectronic devices are arranged on a semiconductor plane, and the multi-layer vertical charge transfer three-dimensional optoelectronic devices are arranged to work together, and the charge reading layer and the charge transfer layer in the multi-layer vertical charge transfer three-dimensional optoelectronic device array have a site selection function.

[0013] Furthermore, the charge reading layer has row addressing and column addressing functions in the reading phase, and has row addressing or column addressing functions in the resetting phase, and the setting of the addressing function depends on the semiconductor device used in the charge reading layer.

[0014] Furthermore, the site selection function of the charge transfer layer is divided into two cases:

[0015] (1) The charge transfer layer has a row addressing function or a column addressing function: at least one layer of the charge transfer layer is connected to the vertical transfer gates in the same row, and the vertical transfer gates in different rows are separated; or at least one layer of the charge transfer layer is connected to the vertical transfer gates in the same column, and the vertical transfer gates in different columns are separated.

[0016] (2) The charge transfer layer has row and column addressing functions: the charge transfer layer includes at least two layers of the vertical transfer gates, at least one layer of which has the vertical transfer gates in the same row connected and the vertical transfer gates in different rows separated, and at least one layer of which has the vertical transfer gates in the same column connected and the vertical transfer gates in different columns separated.

[0017] The present invention also provides a photoelectric detection method of a three-dimensional photoelectric device of a multi-layer structure with vertical charge transfer, wherein the three-dimensional photoelectric device of a multi-layer structure with vertical charge transfer or a three-dimensional photoelectric device array of a multi-layer structure with vertical charge transfer is used as a photoelectric detector, and the photoelectric detection method includes four basic operations: resetting, photosensing, transferring, and reading:

[0018] Reset: The charge reading layer is set to an initial state using different reset methods according to different semiconductor devices;

[0019] Photosensitive: In the vertical direction, the charge storage layer acts as a photosensitive surface. When a light signal is incident from the photosensitive surface, photogenerated carriers are generated in the charge storage layer by the photoelectric effect, and the photogenerated carriers are stored in the charge storage layer;

[0020] Transfer: controlling the vertical transfer gate in the charge transfer layer to be in an on state, and transferring the photogenerated carriers in the charge storage layer to the charge reading layer along a vertical direction through the charge transfer layer;

[0021] Reading: After the charge reading layer obtains the photogenerated carriers from the charge storage layer, it uses different reading methods to convert the charge signal into a voltage or current signal according to different semiconductor devices used.

[0022] The present invention also provides a three-dimensional optoelectronic device with a buried channel multilayer structure and a vertical charge transfer type. The charge storage layer of the three-dimensional optoelectronic device with a vertical charge transfer type and a multilayer structure adopts a single-layer buried channel semiconductor device to form a low-concentration impurity layer with a conductivity type opposite to that of the substrate on the semiconductor substrate, so that the charge collection area is away from the semiconductor surface.

[0023] The present invention also provides a spectrum detection method for a three-dimensional optoelectronic device of a multi-layer structure with vertical charge transfer, wherein the above-mentioned three-dimensional optoelectronic device of a multi-layer structure with vertical charge transfer or a three-dimensional optoelectronic device array of a multi-layer structure with vertical charge transfer is used as a photodetector, and according to the number of multi-spectral channels required for imaging, a number of multi-layer charge-coupled devices equal to the number of channels are arranged in the vertical direction of the charge storage layer. Each charge-coupled device can store photogenerated carriers in its own charge collection well to form a charge storage node. According to the absorption characteristics of the light incident on the semiconductor material, the charge-coupled devices of different layers can sense the light intensity of different spectral bands, and the spectral information can be inverted through subsequent processing to achieve multi-spectral detection.

[0024] The present invention also provides a photomultiplication imaging method for a three-dimensional optoelectronic device with a multi-layer structure and a vertical charge transfer type. In the photoelectric detection method for a three-dimensional optoelectronic device with a multi-layer structure and a vertical charge transfer type, the charge storage transfer layer includes a plurality of groups of multi-phase charge coupled devices distributed along the vertical direction, and each charge coupled device can store carriers in its respective charge collection well.

[0025] The photomultiplication process includes: applying periodic voltage signals to the gates of the multiple groups of multi-phase charge coupled devices so that the photogenerated carriers move in the vertical direction in the charge storage transfer layer, and applying high voltage to the gate of a specific layer during the movement of the photogenerated carriers so that the photogenerated carriers are accelerated and collided to ionize and generate new electron-hole pairs.

[0026] After the photomultiplication process is completed, the multiplied photogenerated carriers are transferred to the charge reading layer to complete the charge signal reading.

[0027] The present invention also provides a storage method for a three-dimensional optoelectronic device with a multi-layer structure and a vertical charge transfer type, wherein the three-dimensional optoelectronic device with a multi-layer structure and a vertical charge transfer type or a three-dimensional optoelectronic device array with a multi-layer structure is used as a memory, and the charge reading layer is a semiconductor device with a charge writing function, including: a complementary metal oxide semiconductor image sensor, a composite dielectric gate dual transistor photosensitive detector, and a dynamic random access memory. The charge storage and transfer layer is a single-layer or multi-layer charge coupled device, which has the ability to store signal charges. The storage method includes four basic operations: writing, transferring, reading, and resetting:

[0028] Writing: The charge reading layer uses different writing methods to write the charge signal into the charge reading layer according to different semiconductor devices used.

[0029] Transfer: The charge storage and transfer layer can realize bidirectional transfer of charge signals, that is, the charge in the charge reading layer can be transferred to the charge storage and transfer layer, and the charge in the charge storage and transfer layer can be transferred to the charge reading layer;

[0030] Reading: transferring the signal charge of the storage node to the charge reading layer through the charge storage and transfer layer, the charge reading layer obtains the signal charge from the charge storage layer, and uses different reading methods to convert the charge signal into a voltage or current signal according to different semiconductor devices;

[0031] Reset: The charge reading layer uses different reset methods to set the charge signal to an initial state according to different semiconductor devices used.

[0032] The present invention also provides a method for storing multiple data in a three-dimensional optoelectronic device of a vertical charge transfer type with a multi-layer structure. In the storage method of the three-dimensional optoelectronic device of a vertical charge transfer type with a multi-layer structure, the charge storage and transfer layer includes a multi-layer charge coupling device distributed in a vertical direction, which can store signal charges in respective charge collection wells to form charge storage nodes. The method for storing multiple data can store multiple data in the same three-dimensional optoelectronic device of a vertical charge transfer type with a multi-layer structure, and includes multi-layer signal charge writing and multi-layer signal charge reading operations.

[0033] Multi-layer signal charge writing: The charge storage and transfer layer has multiple charge storage nodes. When writing, the signal stored in the storage node is transferred to the next level charge storage node in sequence according to the method of charge coupled device, and the data to be written this time is transferred to the vacant charge storage node;

[0034] Multi-layer signal charge readout: the signal charge of the first-level charge storage node adjacent to the charge reading layer in the charge storage and transfer layer is transferred to the charge reading layer for the readout and reset operations, and at the same time, the signals stored in the multiple charge storage nodes of the charge storage and transfer layer are transferred to the previous-level charge storage node according to the charge coupled device method and read out in sequence.

[0035] The beneficial effects of the present invention are:

[0036] By integrating the photoelectric detection function in the vertical direction, the photoelectric detection function is transformed from a plane to a three-dimensional one. Its characteristics and advantages include:

[0037] 1. The three-dimensional photoelectric device of vertical charge transfer type of the multi-layer structure has a buried channel structure in the charge storage layer, and forms a depletion layer by making the PN junction formed by the N-type impurity layer and the substrate reverse biased, and at the same time generates a depletion layer of a certain depth on the surface of the N-type impurity layer; the two depletion layers are connected, resulting in the lowest point of the electron potential energy not on the surface but in the body, so that the collection and transfer of photoelectrons occur in the body, avoiding the influence of the interface state on the free electrons, reducing dark current and noise. Since the carrier mobility in the body is higher than the surface mobility, and there is a larger drift electric field in the channel, the charge transfer speed is faster than the surface, which can achieve higher transfer efficiency and operating frequency;

[0038] 2. The vertical charge transfer type three-dimensional optoelectronic device of the multi-layer structure has a multi-layer stacking structure in the vertical direction. By setting a multi-layer charge-coupled device with the same number of multi-spectral channels as the required imaging and at different distances from the photosensitive surface, the semiconductor material's absorption characteristics of light are used to enable the semiconductor devices set at different depths from the photosensitive surface to sense the light intensity of different spectral bands. The spectral information can be restored through subsequent inversion processing to achieve single-pixel multi-spectral detection;

[0039] 3. The vertical charge transfer type three-dimensional optoelectronic device of the multi-layer structure has a multi-layer stacking structure in the vertical direction. The multiple groups of multi-phase charge-coupled devices in the charge storage transfer layer can store carriers in their respective charge collection wells. By applying a periodic voltage signal to the gate of the charge-coupled device, the photogenerated carriers move in the charge storage transfer layer in the vertical direction. In the process of movement, a high voltage is applied to the gate of the high-voltage multiplication phase in each group of charge-coupled devices to accelerate the photogenerated carriers and generate new electron-hole pairs by collision ionization, thereby realizing charge multiplication in the vertical direction. By applying a periodic voltage signal to multiple groups of gates, electron multiplication with different magnifications can be realized; thereby, weak signal detection can be realized while ensuring pixel density;

[0040] 4. The three-dimensional optoelectronic device of the vertical charge transfer type with the multi-layer structure has a multi-layer stacking structure in the vertical direction. By applying voltage timing to the gate of the multi-layer charge-coupled device of the charge storage and transfer layer, the signal charge is transferred to the corresponding storage node in the vertical direction, so that data storage in the vertical direction can be realized. Compared with the traditional storage method, the device of the present invention can achieve high storage density and multi-value storage while maintaining the same storage unit size. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 It is a schematic diagram of the structure of a three-dimensional optoelectronic device with a multi-layer vertical charge transfer type;

[0043] Figure 2 It is a schematic structural diagram of a vertical charge transfer three-dimensional optoelectronic device provided by an example of the present invention;

[0044] Figure 3 It is a schematic diagram of the structural layout of the charge reading layer based on the composite dielectric gate dual transistor photosensitive detector;

[0045] Figure 4 It is a schematic diagram of the structure of the charge reading layer in the gate width direction (X-X') based on the composite dielectric gate dual transistor photosensitive detector;

[0046] Figure 5 It is a schematic diagram of the structure of the charge reading layer in the gate length direction (Y-Y') based on the composite dielectric gate dual transistor photosensitive detector;

[0047] Figure 6 It is an equivalent circuit diagram of a three-dimensional optoelectronic device with a multi-layer structure and vertical charge transfer;

[0048] Figure 7 It is a simplified circuit symbol diagram of a three-dimensional optoelectronic device with a multi-layer structure and vertical charge transfer;

[0049] Figure 8 It is a diagram of a three-dimensional optoelectronic device array of a multi-layer structure and vertical charge transfer;

[0050] Fig. 9 It is a schematic diagram of the energy band of a three-dimensional photoelectric device of a multi-layer structure with vertical charge transfer when performing reset and photosensitivity operations;

[0051] Fig.10 It is a schematic diagram of the energy band of a three-dimensional photoelectric device with a multi-layer structure and vertical charge transfer when performing a transfer operation;

[0052] Fig.11 It is a schematic diagram of the energy band and the change diagram of the charge reading layer threshold value when a three-dimensional optoelectronic device with a multi-layer structure and a vertical charge transfer type performs a reading operation;

[0053] Fig.12 It is a schematic diagram of the structure of a three-dimensional optoelectronic device of a vertical charge transfer type with a buried channel multilayer structure;

[0054] Fig.13 It is the spectral response curve of red, green and blue light;

[0055] Fig.14 It is a schematic diagram of the structure of a multi-layer vertical charge transfer three-dimensional optoelectronic device applied to multi-spectral detection;

[0056] Fig.15 It is a schematic diagram of the structure of a multi-layer vertical charge transfer three-dimensional optoelectronic device applied to photomultiplier imaging;

[0057] Fig.16 It is a schematic diagram of the multiplication process when a three-dimensional photoelectric device of a multilayer structure and vertical charge transfer is applied to photomultiplication imaging;

[0058] Fig.17 It is a schematic diagram of the structure of a three-dimensional photoelectric device of a multi-layer structure and vertical charge transfer type when it is applied to storage;

[0059] Fig.18 It is a schematic diagram of a multi-layer vertical charge transfer three-dimensional optoelectronic device for multi-data writing and multi-data transfer. DETAILED DESCRIPTION

[0060] The present invention provides a three-dimensional photoelectric device of a multi-layer structure of vertical charge transfer, including a stacking structure formed in a semiconductor substrate, wherein the stacking structure divides the semiconductor substrate into a charge reading layer, a charge transfer layer and a charge storage layer, such as Figure 1 As shown. The charge reading layer is a semiconductor device with a readout function of converting a charge signal into a voltage or current signal and a reset function of resetting the charge signal to an initial state; the charge transfer layer has a function of transferring the charge signal in a vertical direction; and the charge storage layer has a function of storing a single or multiple charge packets.

[0061] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] Embodiment 1:

[0063] The three-dimensional photoelectric device of the multilayer structure vertical charge transfer type of the embodiment of the present invention is as follows Figure 2 As shown, it includes a charge reading layer, a charge transfer layer and a charge storage layer formed on the same P-type semiconductor substrate.

[0064] The charge reading layer uses a composite dielectric gate dual transistor photosensitive detector, and its structure is as follows Figure 3-Figure 5As shown, it includes a composite dielectric gate MOS capacitor and a composite dielectric gate transistor. The structures of the composite dielectric gate MOS capacitor and the composite dielectric gate transistor are: a bottom dielectric layer, a floating gate layer, a top dielectric layer and a control gate are sequentially arranged above a P-type semiconductor substrate, wherein the floating gate layer and the control gate are shared by the composite dielectric gate MOS capacitor and the composite dielectric gate transistor. The composite dielectric gate MOS capacitor and the composite dielectric gate transistor are separated by shallow trench isolation in the P-type semiconductor substrate. The composite dielectric gate transistor is also provided with a source and a drain in the P-type semiconductor substrate.

[0065] The charge transfer layer is composed of two MOS capacitors arranged in series along a vertical direction, including a first transfer gate and a second transfer gate.

[0066] The charge storage layer is composed of a three-phase charge coupled device, including a first storage gate, a second storage gate and a third storage gate.

[0067] The equivalent circuit of the vertical charge transfer type three-dimensional optoelectronic device of the multilayer structure in this embodiment is as follows: Figure 6 As shown, the control gate of the composite dielectric gate dual transistor photosensitive detector of the charge reading layer is denoted as RWL, the source is denoted as RSL, and the drain is denoted as RBL; the first transfer gate of the charge transfer layer is denoted as TWL1, and the second transfer gate is denoted as TWL2; the first storage gate of the charge storage layer is denoted as SWL1, the second storage gate is denoted as SWL2, and the third storage gate is denoted as SWL3. The external equivalent circuit model of the vertical charge transfer type three-dimensional optoelectronic device with a multi-layer structure can be further simplified, as shown in FIG. Figure 7 shown.

[0068] like Figure 8 As shown, the multi-layer structure of the vertical charge transfer type three-dimensional optoelectronic device proposed in this embodiment can be used to form an N×M array. In the detection array, the drain terminals of the composite dielectric gate dual transistors of each column of the charge reading layer are connected to form a read bit line, the gate terminals of the composite dielectric gate dual transistors of each row of the charge reading layer are connected to form a read word line, and the source terminals of the composite dielectric gate dual transistors of all the charge reading layers are grounded; in the detection array, the charge transfer layer has two layers of transfer gates, one of which is connected to other transfer gates in the same row to form a transfer word line, and the other is connected to other transfer gates in the same column to form a transfer bit line; the substrates of all detection units are connected to form a common source CSL.

[0069] The multi-layer vertical charge transfer type three-dimensional optoelectronic device array composed of the multi-layer vertical charge transfer type three-dimensional optoelectronic devices can realize XY addressing of the reading process by controlling the read word line and the read bit line during use. By controlling the transfer word line and the transfer bit line, conventional imaging of the detection unit or correlated double sampling imaging can be realized.

[0070] The operation of the multi-layer vertical charge transfer three-dimensional optoelectronic device is mainly divided into four processes: reset, photosensitization, transfer, and reading:

[0071] like Fig. 9 As shown, the multi-layer structure of the vertical charge transfer type three-dimensional photoelectric device is reset before operation to make all layers in the initial state. During the reset, negative voltage is applied to the gates of all layers, and zero voltage is applied to the substrate. During photosensitivity, zero voltage is applied to the P-type semiconductor substrate, and a positive voltage is applied to the selected charge storage layer gate SWL1, which generates a depletion region under the gate. Zero voltage is applied to the gates of the remaining charge storage layers, and no depletion region is generated. The photogenerated electrons generated by the incident light entering the semiconductor material are collected under the selected charge storage layer gate SWL1 to complete photosensitivity.

[0072] like Fig.10 As shown, after the photosensitization of the three-dimensional photoelectric device with a multi-layer structure and vertical charge transfer is completed, the signal charge packet is stored under the selected charge storage layer gate SWL1, and a voltage is applied to the adjacent charge storage layer gate SWL2, and the signal charge is evenly distributed under SWL1 and SWL2. Then the voltage of the charge storage layer gate SWL1 is changed to zero voltage, and the signal charge is completely transferred to the charge storage layer gate SWL2, completing a transfer. Repeat the above operation until the signal charge is completely transferred to the charge reading layer.

[0073] like Fig.11 As shown, when the charge of the three-dimensional optoelectronic device with a multi-layer structure and vertical charge transfer is read, according to the position of the pixel to be read in the array, a suitable ramp voltage is applied to the read word line of the row to scan the device threshold, and a suitable voltage is applied to the read bit line of the column to read out the voltage or current related to the signal charge.

[0074] When resetting the three-dimensional optoelectronic device of the vertical charge transfer type with a multi-layer structure, a negative voltage is applied to all read word lines to complete the resetting.

[0075] Embodiment 2:

[0076] The present invention also discloses a buried-channel multilayer vertical charge transfer type three-dimensional optoelectronic device, wherein the charge storage layer of the multilayer vertical charge transfer type three-dimensional optoelectronic device adopts a buried-channel type semiconductor device. On a P-type semiconductor substrate, a low-concentration N-type impurity layer with a conductivity opposite to that of the semiconductor substrate is formed by ion implantation or diffusion, and a high-concentration N-type impurity layer is formed on one side of the low-concentration N-type impurity layer. +The device structure is shown in Figure 12. When the device is working, the N+ region is connected to the highest potential, so that the PN junction formed by the N-type impurity layer and the substrate is reverse biased to form a depletion layer. At the same time, the N-type impurity layer is at a positive potential. If the storage gate is at a low potential, it is equivalent to applying a negative voltage to the gate for the N-type impurity layer, and a depletion layer of a certain depth is generated on the surface of the N-type impurity layer. By controlling the external potential of the N+ region, the two depletion layers are connected. At this time, the lowest point of the electron potential energy is not on the surface but in the body, so that the collection and transfer of photoelectrons occur in the body, avoiding the influence of the interface state on the free electrons, and reducing dark current and noise. Since the carrier mobility in the body is higher than the surface mobility, and there is a larger drift electric field in the channel, the charge transfer speed is faster than the surface, which can achieve higher transfer efficiency and operating frequency.

[0077] Embodiment three:

[0078] The present invention also discloses a spectrum detection method of a three-dimensional photoelectric device of a vertical charge transfer type with a multi-layer structure, wherein the three-dimensional photoelectric device of a vertical charge transfer type with a multi-layer structure or a three-dimensional photoelectric device array of a vertical charge transfer type with a multi-layer structure is used as a photodetector, and according to the number of multi-spectral channels required for imaging, a number of multi-layer charge-coupled devices equal to the number of channels are arranged in the vertical direction of the charge storage layer. Each charge-coupled device can store photogenerated carriers in its respective charge collection well to form a charge storage node. According to the absorption characteristics of semiconductor materials, charge-coupled devices of different layers can sense the light intensity of different spectral bands, and the spectral information can be inverted through subsequent processing to achieve multi-spectral detection.

[0079] In this embodiment, three sets of two-phase charge-coupled devices are set in the charge storage layer to collect red, green and blue light. One phase of the two-phase charge-coupled device is used to collect photogenerated carriers, and the other phase is used to isolate other phases during collection. The spectral response curve of the red, green and blue light is shown in FIG. Fig.13 As shown, the penetration depth of light of different wavelengths can be calculated using the following formula:

[0080]

[0081] Where α is the absorption coefficient, which is related to the wavelength of light.

[0082] Different wavelengths of light are converted into photoelectrons at different depths. The charge-coupled devices at different layers of the charge reading layer can be used to collect photogenerated carriers of different wavelengths. The collection process is shown in Figure 14. A positive voltage is applied to SWL0-1 to generate a depletion region to collect photogenerated carriers generated by red light. SWL0-2 does not generate a depletion region and plays an isolation role. Similarly, a positive voltage is applied to SWL1-1 and SWL2-1 to collect photogenerated carriers generated by green and blue light. After the collection is completed, the signal charge packets are transferred to the charge reading layer for reading in turn.

[0083] The embodiment of the present invention also relates to restoring the collected multi-spectral data, and obtaining the equation of the light response curve of a single pixel to different wavelengths by calibrating monochromatic lights of different wavelengths one by one.

[0084] According to the raw data output value of a single pixel and the calibrated light response equation, the multi-spectral channel signal intensity detected by a single pixel can be obtained:

[0085]

[0086] Where δ is the single pixel multispectral output grayscale value, θλ n is a single pixel in the spectral band λ n The light response equation under n is a single pixel in the spectral band λ n The output grayscale value.

[0087] Embodiment 4:

[0088] The present invention also discloses a photoelectric multiplication imaging method for a three-dimensional optoelectronic device with a multi-layer structure and a vertical charge transfer type. The charge storage transfer layer of the three-dimensional optoelectronic device with a multi-layer structure and a vertical charge transfer type is provided with a plurality of groups of multi-phase charge coupled devices distributed along the vertical direction, and each charge coupled device can store carriers in its respective charge collection well.

[0089] In this example, the charge storage transfer layer is composed of multiple groups of three-phase charge coupled devices, and one phase in the ordinary structure is replaced with a high-voltage multiplication phase and a low-voltage DC phase. The multiplication structure is shown in Figure 15. The low-voltage DC phase ensures that the photogenerated carriers have a stable high-voltage avalanche multiplication electric field during transfer. Under the action of the high-voltage avalanche multiplication electric field, the photogenerated carriers are accelerated and collision-ionized to produce new electron-hole pairs. After collision ionization, the holes are absorbed by the substrate, and the electrons obtain a multiplication factor greater than 1 to form a new charge packet. The multiplication process is shown in Figure 16.

[0090] The impact ionization of electrons is a random process, and the gain multiples that can be provided by a single multiplication are limited. Apply periodic voltage signals to multiple sets of gates so that the photogenerated carriers are continuously impact-ionized in the vertical direction under the clock drive. Assuming that the gain of a single multiplication is g, after N multiplications, the total gain G is:

[0091] G=(1+g)N

[0092] The single multiplication gain g is related to the gate voltage of the high-voltage multiplication phase, and the typical value is between 0.01 and 0.02. By adjusting the gate voltage of the high-voltage multiplication phase, electron multiplication with different magnifications can be achieved without breaking down the oxide layer of the charge-coupled device.

[0093] After the photomultiplication process is completed, the multiplied photogenerated carriers are transferred to the charge reading layer to complete the charge signal reading.

[0094] Embodiment five:

[0095] The present invention also discloses a storage method for a three-dimensional photoelectric device with a vertical charge transfer structure of a multi-layer structure, and the storage method can be applied to the storage of single data or multiple data. The charge reading layer of the three-dimensional photoelectric device with a vertical charge transfer structure of the multi-layer structure is a semiconductor device with a charge writing function, including: a complementary metal oxide semiconductor image sensor, a composite dielectric gate dual transistor photosensitive detector, and a dynamic random access memory. The charge storage and transfer layer is a semiconductor device with the function of storing a single or multiple charge packets.

[0096] The storage method includes four basic operations: writing, transferring, reading and resetting.

[0097] In this example, the charge reading layer is a dynamic random access memory structure, and the charge storage and transfer layer is a multi-layer charge coupled device distributed in the vertical direction, which can realize the storage of single data or multiple data. The equivalent circuit diagram of the vertical charge transfer type three-dimensional optoelectronic device of the multi-layer structure used for storage in this example is as follows Fig.17 The storage method of the vertical charge transfer type three-dimensional optoelectronic device with a multilayer structure is divided into the following four basic operations.

[0098] Writing of a three-dimensional photoelectric device with a multi-layer structure and vertical charge transfer: the substrate is grounded, and an appropriate voltage is applied to the gate of the charge reading layer of the selected storage device, and the first gate of the charge storage and transfer layer is opened at the same time. After the charge reading layer writes the signal charge according to the digital signal or analog signal, the gate of the charge reading layer is closed, and the voltage of the first gate of the charge storage and transfer layer is kept unchanged, so that the signal charge is stored under the first gate of the charge storage and transfer layer, and the writing is completed;

[0099] Transfer of a three-dimensional optoelectronic device with a multi-layer structure and vertical charge transfer: voltage is applied to the gate of the multi-layer charge-coupled device in the charge storage and transfer layer to transfer the signal charge in the vertical direction to the corresponding storage node;

[0100] Multi-data writing and multi-data transfer of a three-dimensional optoelectronic device with a vertical charge transfer type of multi-layer structure: After one charge writing and charge transfer, the signal charge has been stored in the corresponding storage node. According to the writing method and charge transfer method of the three-dimensional optoelectronic device with a vertical charge transfer type of multi-layer structure, writing and transfer are performed again, and at the same time, the stored signal charge is transferred to the next level storage node, and the data to be written this time is transferred to the vacant storage node. The multi-data writing and multi-data transfer process of the three-dimensional optoelectronic device with a vertical charge transfer type of multi-layer structure is as follows Fig.18shown.

[0101] Reading and resetting of a three-dimensional photoelectric device with a multi-layer structure and vertical charge transfer: transfer the signal charge of the primary charge storage node adjacent to the charge transfer layer in the charge storage layer to the charge reading layer, open the reading gate RWL and the reading drain RBL, and read out the relevant voltage signal or current signal. After the reading is completed, a negative voltage is applied to the gate to complete the reset.

[0102] Some steps in the embodiments of the present invention may be implemented using software, and the corresponding software program may be stored in a readable storage medium, such as a CD or a hard disk.

[0103] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-dimensional photoelectric device of a multi-layer structure with vertical charge transfer, characterized in that: The device comprises: a charge reading layer, a charge transfer layer and a charge storage layer which are formed in a semiconductor substrate and arranged in sequence along a vertical direction; The charge reading layer is a semiconductor device having a readout function of converting a charge signal into a voltage or current signal and a reset function of resetting the charge signal to an initial state, including: a complementary metal oxide semiconductor image sensor, a composite dielectric gate dual transistor photosensitive detector, a flash memory device and a dynamic random access memory; The charge transfer layer has the ability to transfer the charge signal in the vertical direction, and includes a single-layer or multi-layer vertical transfer gate; The charge storage layer has the function of storing a single or multiple charge packets, and includes a single-layer or multi-layer charge coupling device with one pole capable of floating PN junction and distributed in a vertical direction.

2. The three-dimensional optoelectronic device of the multi-layer structure vertical charge transfer type according to claim 1, characterized in that: The semiconductor device involved in the vertical charge transfer three-dimensional optoelectronic device of the multi-layer structure includes a surface channel semiconductor device or a buried channel semiconductor device.

3. The three-dimensional optoelectronic device of the multi-layer structure vertical charge transfer type according to claim 2, characterized in that: An isolation structure made of insulating material is arranged between adjacent multi-layer vertical charge transfer three-dimensional optoelectronic devices.

4. A three-dimensional photoelectric device array of a multi-layer structure with vertical charge transfer, characterized in that: The array is implemented by a device according to any one of claims 1 to 3 being arranged on a semiconductor plane, the devices being arranged to work in coordination, and the charge reading layer and the charge transfer layer in the array having a site selection function; The charge reading layer has row addressing and column addressing functions in the reading stage, and has row addressing or column addressing functions in the resetting stage, and the setting of the addressing function depends on the semiconductor device used in the charge reading layer; The site selection function of the charge transfer layer is divided into two cases: (1) The charge transfer layer has a row addressing function or a column addressing function: at least one layer of the charge transfer layer has vertical transfer gates in the same row connected and vertical transfer gates in different rows separated; or at least one layer of the charge transfer layer has vertical transfer gates in the same column connected and vertical transfer gates in different columns separated; (2) The charge transfer layer has row and column addressing functions: the charge transfer layer includes at least two layers of vertical transfer gates, at least one layer of vertical transfer gates in the same row are connected, and vertical transfer gates in different rows are separated, and at least one layer of vertical transfer gates in the same column are connected, and vertical transfer gates in different columns are separated.

5. A photoelectric detection method, characterized in that: The photoelectric detection method is implemented based on the device according to any one of claims 1 to 4, and the photoelectric detection method includes four basic operations: resetting, photosensing, transferring, and reading: Reset: The charge reading layer uses different reset methods to set the charge reading layer to an initial state according to different semiconductor devices used; Photosensitive: In the vertical direction, the charge storage layer acts as a photosensitive surface. The light signal is incident from the photosensitive surface, and photoelectric effect is used to generate photogenerated carriers in the charge storage layer, and the photogenerated carriers are stored in the charge storage layer. Transfer: Control the vertical transfer gate in the charge transfer layer to be in an on state, and transfer the photogenerated carriers in the charge storage layer to the charge reading layer in a vertical direction through the charge transfer layer; Reading: After the charge reading layer obtains the photogenerated carriers from the charge storage layer, it uses different reading methods to convert the charge signal into a voltage or current signal depending on the different semiconductor devices used.

6. A buried-channel multilayer vertical charge transfer three-dimensional optoelectronic device, characterized in that: The charge storage layer in the vertical charge transfer three-dimensional optoelectronic device of the buried channel multilayer structure adopts a single-layer buried channel semiconductor device, and forms a low-concentration impurity layer with a conductivity type opposite to that of the substrate on the semiconductor substrate, so that the charge collection area is far away from the semiconductor surface.

7. A spectrum detection method, characterized in that: The spectral detection method is implemented based on the device described in claims 1-4. The method is implemented by setting charge-coupled devices with the same number of multi-spectral channels as the required imaging and different distances from the photosensitive surface. Each charge-coupled device can store photogenerated carriers in its own charge collection well to form a charge storage node. According to the absorption characteristics of the semiconductor material to the incident light, the charge-coupled devices in different layers can sense the light intensity of different spectral bands, and the spectral information is inverted through subsequent processing to achieve multi-spectral detection.

8. A photomultiplier imaging method, characterized in that: The photomultiplication imaging method is implemented based on any one of claims 1 to 4, wherein the charge storage transfer layer comprises a plurality of groups of multiphase charge coupled devices distributed in a vertical direction, each charge coupled device being capable of storing carriers in a respective charge collection well; The photomultiplication process includes: applying periodic voltage signals to the gates of the plurality of groups of multi-phase charge coupled devices so that the photogenerated carriers move in the vertical direction in the charge storage transfer layer, and applying high voltage to the gates of a specific layer during the movement of the photogenerated carriers so that the photogenerated carriers are accelerated and collided to generate new electron-hole pairs; After the photomultiplication process is completed, the multiplied photogenerated carriers are transferred to the charge reading layer to complete the charge signal reading.

9. A storage method, characterized in that: The storage method is implemented based on the device described in claims 1-4; The charge reading layer is a semiconductor device with charge writing function, including: a complementary metal oxide semiconductor image sensor, a composite dielectric gate dual transistor photosensitive detector, and a dynamic random access memory; The charge storage and transfer layer is a single-layer or multi-layer charge coupled device, which has the ability to store signal charges; The storage method includes four basic operations: writing, transferring, reading and resetting: Writing: the charge reading layer uses different writing methods to write the charge signal into the charge reading layer according to different semiconductor devices; Transfer: The charge storage and transfer layer can realize bidirectional transfer of charge signals between the charge reading layer and the charge storage and transfer layer; Reading: transferring the signal charge of the storage node to the charge reading layer through the charge storage and transfer layer, the charge reading layer obtains the signal charge from the charge storage layer, and uses different reading methods to convert the charge signal into a voltage or current signal according to different semiconductor devices; Reset: The charge reading layer uses different reset methods to set the charge signal to an initial state according to different semiconductor devices used.

10. A method for storing multiple data, characterized in that: The multi-data storage method is implemented based on the storage method of claim 9, wherein the charge storage and transfer layer includes a plurality of charge-coupled devices distributed in a vertical direction, capable of storing signal charges in respective charge collection wells to form charge storage nodes; The multi-data storage method can store multiple data in the same vertical charge transfer type three-dimensional optoelectronic device of the multi-layer structure, and includes multi-layer signal charge writing and multi-layer signal charge reading operations; Multi-layer signal charge writing: The charge storage and transfer layer has multiple charge storage nodes. When writing this time, the signal stored in the storage node is transferred to the next level charge storage node in sequence according to the method of charge coupled device, and the data to be written this time is transferred to the vacant charge storage node at the same time; Multi-layer signal charge readout: the signal charge of the first-level charge storage node adjacent to the charge reading layer in the charge storage and transfer layer is transferred to the charge reading layer for the readout and reset operations, and at the same time, the signals stored in the multiple charge storage nodes of the charge storage and transfer layer are transferred to the previous-level charge storage node according to the charge coupled device method and read out in sequence.

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