A three-band image sensor and a manufacturing method thereof

Abstract

The application belongs to the technical field of semiconductor process, and discloses a three-waveband image sensor and a manufacturing method thereof. The image sensor comprises a substrate layer, a silicon oxide layer, an aluminum oxide layer, a first electrode layer, an ultraviolet light sensing layer, a visible light sensing layer, an infrared light sensing layer, a second electrode layer and a passivation layer which are sequentially stacked. A plurality of rectangular grooves with the same shape and distributed at a preset interval penetrate the second electrode layer, the infrared light sensing layer, the visible light sensing layer and the ultraviolet light sensing layer in sequence. The ultraviolet light sensing layer adopts intrinsic aluminum arsenide material. The visible light sensing layer adopts intrinsic gallium arsenide material. The infrared light sensing layer adopts intrinsic germanium material with a 6-degree bevel. The passivation layer uniformly covers the inner walls of the second electrode layer and each rectangular groove. The application can solve the problems of lattice mismatch and polarity mismatch between the three sensing layers in the prior art, reduce manufacturing cost and be suitable for mass production.

Description

Technical Field

[0001] This application relates to the field of semiconductor process technology, and in particular to a three-band image sensor and its manufacturing method. Background Technology

[0002] The ultraviolet-visible-shortwave infrared image sensor features wide spectral sensitivity, with a spectral response range covering the ultraviolet band (100-400nm), the visible band (380-750nm), and the shortwave infrared band (1000-2500nm). It has multi-functional imaging capabilities, providing strong support for the widespread application and development of wide-spectrum imaging technology.

[0003] The mainstream ultraviolet light sensing layer, visible light sensing layer, and short-wave infrared light sensing layer use wide bandgap semiconductor materials (such as GaN, SiC, Ga2O3, ZnO, etc.), Si semiconductor materials, and narrow bandgap semiconductor materials (such as InGaAs, PbS, SnS, etc.), respectively. However, there is a large lattice mismatch among the three, and the InGaAs / InP structure technology also has the problems of fragile InP wafers, small wafer size, and high raw material costs. Summary of the Invention

[0004] This application provides a three-band image sensor and its manufacturing method, which can solve the problems of lattice mismatch and polarity mismatch between the three sensing layers in the prior art, reduce manufacturing costs, and is suitable for mass production.

[0005] In a first aspect, embodiments of this application provide a three-band image sensor, including:

[0006] The N-type electrode, P-type electrode and readout circuit, and the substrate layer, silicon oxide layer, aluminum oxide layer, first electrode layer, ultraviolet light sensing layer, visible light sensing layer, infrared light sensing layer, second electrode layer and passivation layer are stacked in sequence.

[0007] Multiple rectangular grooves of the same shape, distributed at preset intervals, sequentially penetrate the second electrode layer, the infrared light sensing layer, the visible light sensing layer, and the ultraviolet light sensing layer; the ultraviolet light sensing layer is made of intrinsic aluminum arsenide material; the visible light sensing layer is made of intrinsic gallium arsenide material; and the infrared light sensing layer is made of intrinsic germanium-based material with a 6-degree bevel.

[0008] The passivation layer is uniformly covered on the second electrode layer and the inner walls of each rectangular groove;

[0009] The N-type electrode is located in a rectangular groove and passes through the passivation layer to connect to the first electrode layer; the P-type electrode passes through the passivation layer to connect to the second electrode layer; the readout circuit is connected to the N-type electrode and the P-type electrode respectively.

[0010] Furthermore, the substrate is a glass substrate or a sapphire substrate; the thickness of the silicon oxide layer is between 10 nanometers and 100 nanometers.

[0011] Furthermore, the first electrode layer is a P-type aluminum arsenide electrode layer with a 6-degree bevel; the second electrode layer is an N-type germanium electrode layer with a 6-degree bevel; or the first electrode layer is an N-type aluminum arsenide electrode layer with a 6-degree bevel; and the second electrode layer is a P-type germanium electrode layer with a 6-degree bevel.

[0012] Furthermore, the thickness of the alumina layer is 10 nanometers;

[0013] The thickness of both the first and second electrode layers is between 100 nanometers and 500 nanometers.

[0014] Furthermore, the thickness of the ultraviolet light sensing layer is between 100 nanometers and 500 nanometers; the thickness of the visible light sensing layer is between 100 nanometers and 1000 nanometers; and the thickness of the infrared light sensing layer is between 500 nanometers and 3000 nanometers.

[0015] Furthermore, the germanium-based materials used in the infrared light sensing layer include germanium-tin alloy, germanium quantum well, germanium-silicon quantum well, germanium-tin quantum well, or silicon-germanium-tin quantum well.

[0016] Secondly, embodiments of this application provide a method for manufacturing a three-band image sensor, comprising:

[0017] A silicon substrate with a 6-degree bevel is provided; a germanium buffer layer, a second electrode layer, an infrared light sensing layer, a visible light sensing layer, an ultraviolet light sensing layer, a first electrode layer, and an aluminum oxide layer with a 6-degree bevel are sequentially stacked on the silicon substrate to obtain a donor substrate;

[0018] The ultraviolet light sensing layer uses intrinsic aluminum arsenide material; the visible light sensing layer uses intrinsic gallium arsenide material; and the infrared light sensing layer uses intrinsic germanium-based material with a 6-degree bevel.

[0019] Provide a substrate layer; stack a silicon oxide layer on the substrate layer to obtain the acceptor substrate;

[0020] Wafer bonding is performed between the donor substrate and the acceptor substrate;

[0021] The silicon substrate and germanium buffer layer are removed to obtain the sensor wafer;

[0022] Multiple rectangular grooves of the same shape and distributed at preset intervals are provided on the sensor wafer; the rectangular grooves pass through the second electrode layer, the infrared light sensing layer, the visible light sensing layer and the ultraviolet light sensing layer in sequence;

[0023] A passivation layer, an N-type electrode, and a P-type electrode are configured, and the N-type electrode and the P-type electrode are connected to the readout circuit.

[0024] Furthermore, the removal of the silicon substrate and germanium buffer layer yields a sensor wafer, comprising:

[0025] The silicon substrate and germanium buffer layer are removed by back thinning, wet etching, dry etching, or chemical mechanical polishing.

[0026] Thirdly, embodiments of this application provide a three-band image sensor, including:

[0027] The N-type electrode, P-type electrode and readout circuit, and the substrate layer, silicon oxide layer, aluminum oxide layer, first electrode layer, ultraviolet light sensing layer, visible light sensing layer, infrared light sensing layer, second electrode layer and passivation layer are stacked in sequence.

[0028] Multiple rectangular grooves of the same shape, distributed at a preset interval, sequentially penetrate the infrared light sensing layer, the visible light sensing layer, and the ultraviolet light sensing layer; the second electrode layer is located between two adjacent rectangular grooves, embedded in the infrared light sensing layer, and its length is less than the preset interval.

[0029] The ultraviolet light sensing layer is made of intrinsic aluminum arsenide; the visible light sensing layer is made of intrinsic gallium arsenide; the infrared light sensing layer is made of intrinsic germanium-based material with a 6-degree bevel; and the passivation layer is uniformly covered on the second electrode layer and the inner walls of each rectangular groove.

[0030] The N-type electrode is located in a rectangular groove and passes through the passivation layer to connect to the first electrode layer; the P-type electrode passes through the passivation layer to connect to the second electrode layer; the readout circuit is connected to the N-type electrode and the P-type electrode respectively.

[0031] Fourthly, embodiments of this application provide a method for manufacturing a three-band image sensor, comprising:

[0032] A silicon substrate with a 6-degree bevel is provided; a germanium buffer layer, an infrared light sensing layer, a visible light sensing layer, an ultraviolet light sensing layer, a first electrode layer, and an aluminum oxide layer with a 6-degree bevel are sequentially stacked on the silicon substrate to obtain a donor substrate;

[0033] The ultraviolet light sensing layer uses intrinsic aluminum arsenide material; the visible light sensing layer uses intrinsic gallium arsenide material; and the infrared light sensing layer uses intrinsic germanium-based material with a 6-degree bevel.

[0034] Provide a substrate layer; stack a silicon oxide layer on the substrate layer to obtain the acceptor substrate;

[0035] Wafer bonding is performed between the donor substrate and the acceptor substrate;

[0036] The silicon substrate and germanium buffer layer are removed to obtain the sensor wafer;

[0037] Multiple second electrode layers are formed on the infrared light sensing layer by ion implantation;

[0038] Multiple rectangular grooves of the same shape and distributed at a preset interval are set on the sensor wafer; the rectangular grooves pass through the infrared light sensing layer, the visible light sensing layer and the ultraviolet light sensing layer in sequence; the second electrode layer is located between two adjacent rectangular grooves, embedded in the infrared light sensing layer and with a length less than the preset interval.

[0039] A passivation layer, an N-type electrode, and a P-type electrode are configured, and the N-type electrode and the P-type electrode are connected to the readout circuit.

[0040] In summary, compared with the prior art, the beneficial effects of the technical solution provided in this application include at least the following:

[0041] This application provides a three-band image sensor, wherein the ultraviolet light sensing layer is made of intrinsic aluminum arsenide, the visible light sensing layer is made of intrinsic gallium arsenide, and the infrared light sensing layer is made of intrinsically obliquely cut germanium-based material at 6 degrees. The lattice constants of these three semiconductor materials are respectively... and The crystal lattice is perfectly matched, which solves the problems of crystal lattice mismatch and polarity mismatch between the three sensing layers in the prior art. In addition, compared with InGaAs, PbS and SnS short-wave infrared optoelectronic materials, the epitaxial process of aluminum arsenide, gallium arsenide and germanium materials in this application is stable and simple, with high product yield and lower manufacturing cost, which is suitable for mass production of image sensors. Attached Figure Description

[0042] Figure 1 This is a structural diagram of a platform-type three-band image sensor provided as an exemplary embodiment of this application.

[0043] Figure 2 This is a schematic diagram of wafer bonding operation steps provided for an exemplary embodiment of this application.

[0044] Figure 3 A rendering of the rectangular groove forming steps provided in an exemplary embodiment of this application.

[0045] Figure 4 A schematic diagram of a tabletop image sensor connected to a readout circuit, provided as an exemplary embodiment of this application.

[0046] Figure 5 This is a structural diagram of a planar three-band image sensor provided as an exemplary embodiment of this application.

[0047] Figure 6 An illustration showing the effect of ion implantation forming a second electrode layer, provided as an exemplary embodiment of this application.

[0048] Figure 7 This is a schematic diagram of a planar image sensor connected to a readout circuit, provided as an exemplary embodiment of this application.

[0049] Explanation of reference numerals in the attached figures:

[0050] 001, Silicon substrate; 002, Germanium buffer layer; 101, Substrate layer; 102, Silicon oxide layer; 103, Aluminum oxide layer; 104, First electrode layer; 105, Ultraviolet light sensing layer; 106, Visible light sensing layer; 107, Infrared light sensing layer; 108, Second electrode layer; 109, Passivation layer; 201, N-type electrode; 202, P-type electrode; 203, Readout circuit. Detailed Implementation

[0051] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0052] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] Please see Figure 1 This application provides a three-band image sensor, including:

[0054] The system comprises an N-type electrode 201, a P-type electrode 202, and a readout circuit 203, as well as a substrate layer 101, a silicon oxide layer 102, an aluminum oxide layer 103, a first electrode layer 104, an ultraviolet light sensing layer 105, a visible light sensing layer 106, an infrared light sensing layer 107, a second electrode layer 108, and a passivation layer 109, which are stacked sequentially.

[0055] Multiple rectangular grooves of the same shape, distributed at preset intervals, sequentially penetrate the second electrode layer 108, the infrared light sensing layer 107, the visible light sensing layer 106, and the ultraviolet light sensing layer 105; the ultraviolet light sensing layer 105 is made of intrinsic aluminum arsenide material; the visible light sensing layer 106 is made of intrinsic gallium arsenide material; and the infrared light sensing layer 107 is made of intrinsic germanium-based material with a 6-degree bevel.

[0056] The passivation layer 109 is uniformly covered on the second electrode layer and the inner walls of each rectangular groove.

[0057] The N-type electrode 201 is disposed in a rectangular groove and passes through the passivation layer 109 to connect to the first electrode layer 104; the P-type electrode 202 passes through the passivation layer 109 to connect to the second electrode layer 108; the readout circuit 203 is connected to the N-type electrode 201 and the P-type electrode 202 respectively.

[0058] The sensing layers of this application collect light waves in the three bands: 100-400nm (ultraviolet band), 380-750nm (visible band), and 1000-2500nm (shortwave infrared band), respectively, to achieve a wide spectral response from ultraviolet to visible light and then to shortwave infrared. This wide spectral coverage capability enables the image sensor to work under various lighting conditions.

[0059] Specifically, this application uses epitaxially stable AlAs, GaAs, and Ge as the ultraviolet light sensing layer 105, the visible light sensing layer 106, and the infrared light sensing layer 107, respectively. The three vertically stacked sensing layer materials have good crystal quality and excellent interface quality, and low defect density, which is beneficial to improving the resolution and yield of the ultraviolet-visible-shortwave infrared three-band image sensor. It is suitable for the mass production and large-scale application of ultraviolet-visible-shortwave infrared image sensors.

[0060] The AlAs ultraviolet light sensing layer 105, GaAs visible light sensing layer 106, and Ge infrared light sensing layer 107 of this application, in addition to having a very good lattice polarity match, all have a certain resonant cavity effect, which can significantly improve the performance indicators of the three-band image sensor, such as dark current, peak responsivity, peak quantum efficiency, and operating speed.

[0061] In the specific production process, the thickness of the silicon oxide layer 102 is between 10 nanometers and 100 nanometers; the thickness of the aluminum oxide layer 103 is 10 nanometers; and the thickness of the first electrode layer 104 and the second electrode layer 108 are both between 100 nanometers and 500 nanometers.

[0062] The thickness of the ultraviolet light sensing layer 105 is between 100 nanometers and 500 nanometers; the thickness of the visible light sensing layer 106 is between 100 nanometers and 1000 nanometers; and the thickness of the infrared light sensing layer 107 is between 500 nanometers and 3000 nanometers. The first electrode layer 104 is a P-type aluminum arsenide electrode layer with a 6-degree bevel; the second electrode layer 108 is an N-type germanium electrode layer with a 6-degree bevel; or the first electrode layer 104 is an N-type aluminum arsenide electrode layer with a 6-degree bevel; and the second electrode layer 108 is a P-type germanium electrode layer with a 6-degree bevel.

[0063] Furthermore, in addition to germanium, the germanium-based materials used in the infrared light sensing layer 107 can also include group IV semiconductor material structures such as germanium-tin alloy, germanium quantum well, germanium-silicon quantum well, germanium-tin quantum well, or silicon-germanium-tin quantum well.

[0064] The above embodiment provides a three-band image sensor, wherein the ultraviolet light sensing layer 105 is made of intrinsic aluminum arsenide, the visible light sensing layer 106 is made of intrinsic gallium arsenide, and the infrared light sensing layer 107 is made of intrinsic germanium-based material with a 6-degree oblique cut. The lattice constants of these three semiconductor materials are respectively... and The crystal lattice is perfectly matched, which solves the problems of crystal lattice mismatch and polarity mismatch between the three sensing layers in the prior art. In addition, compared with InGaAs, PbS and SnS short-wave infrared optoelectronic materials, the epitaxial process of aluminum arsenide, gallium arsenide and germanium materials in this application is stable and simple, with high product yield and lower manufacturing cost, which is suitable for mass production of image sensors.

[0065] In some embodiments, the substrate 101 may be a glass substrate or a sapphire substrate.

[0066] Glass or sapphire substrates are highly transparent in the ultraviolet-visible-shortwave infrared bands and have low absorption and low scattering characteristics in the ultraviolet, visible, and shortwave infrared bands. This allows light signals in the ultraviolet-visible-shortwave infrared bands to pass through effectively, reducing light loss, achieving extremely high light collection efficiency, and improving the sensitivity and accuracy of the sensor.

[0067] Secondly, glass and sapphire substrates offer advantages in terms of large size and excellent uniformity, ensuring the large-area uniformity of the ultraviolet-visible-shortwave infrared imaging chip and facilitating the realization of large-area focal plane arrays. Furthermore, glass and sapphire substrates exhibit good environmental stability, maintaining stable performance under various environmental conditions. This allows the resulting ultraviolet-visible-shortwave infrared image sensors to be used in harsh environments such as high temperature, high humidity, and strong radiation.

[0068] This application provides a method for manufacturing a three-band image sensor, including:

[0069] Step S11: Provide a silicon substrate 001 with a 6-degree bevel; sequentially stack a germanium buffer layer 002 with a 6-degree bevel, a second electrode layer 108, an infrared light sensing layer 107, a visible light sensing layer 106, an ultraviolet light sensing layer 105, a first electrode layer 104, and an aluminum oxide layer 103 on the silicon substrate 001 to obtain a donor substrate.

[0070] In this application, the ultraviolet light sensing layer 105 is made of intrinsic aluminum arsenide; the visible light sensing layer 106 is made of intrinsic gallium arsenide; and the infrared light sensing layer 107 is made of intrinsic germanium-based material with a 6-degree bevel. Only the silicon substrate 001, germanium buffer layer 002, second electrode layer 108, infrared light sensing layer 107, and first electrode layer 104 are beveled at a 6-degree angle. The use of a 6-degree beveled silicon substrate 001 in this application can solve the polarity mismatch problem between group IV Ge materials and group III-V GaAs and AlAs materials.

[0071] Step S12: Provide a substrate layer 101; stack a silicon oxide layer 102 on the substrate layer 101 to obtain the host substrate.

[0072] The substrate layer 101 is a glass substrate or a sapphire substrate; the thickness of the germanium buffer layer 002 is between 100 nanometers and 500 nanometers. The thickness ranges of the second electrode layer 108, infrared light sensing layer 107, visible light sensing layer 106, ultraviolet light sensing layer 105, first electrode layer 104, and alumina layer 103 have been given in the above embodiments and will not be repeated here.

[0073] Step S13: Perform wafer bonding between the donor substrate and the acceptor substrate.

[0074] Specifically, such as Figure 2 As shown, wafer bonding involves flipping the donor substrate 180 degrees and then stacking it on the recipient substrate.

[0075] By using wafer bonding to stack semiconductor layers, the vertically stacked sensing layer materials can have good crystal quality and excellent interface quality, low defect density, and improved product yield and resolution.

[0076] Step S14: Remove the silicon substrate 001 and the germanium buffer layer 002 to obtain the sensor wafer; specifically, back thinning, wet etching, dry etching or chemical mechanical polishing can be used to remove the silicon substrate 001 and the germanium buffer layer 002.

[0077] Step S15: Multiple rectangular grooves of the same shape and distributed at preset intervals are formed on the sensor wafer; the rectangular grooves pass through the second electrode layer 108, the infrared light sensing layer 107, the visible light sensing layer 106 and the ultraviolet light sensing layer 105 in sequence.

[0078] Specifically, please see Figure 3 After the rectangular groove penetrates the ultraviolet light sensing layer 105, a portion of the first electrode layer 104 needs to be removed to ensure that the first electrode layer 104 can be exposed and connected to the N-type electrode 201 that passes through the passivation layer 109.

[0079] It is worth noting that the manufacturing method of this embodiment is a manufacturing method of a mesa-type ultraviolet-visible-shortwave infrared image sensor. It can be considered that after the rectangular groove is punched out, the second electrode layer 108, infrared light sensing layer 107, visible light sensing layer 106 and ultraviolet light sensing layer 105 between the two grooves form a "mesa", and ultraviolet-visible-shortwave infrared pixels are obtained.

[0080] Step S16: Set the passivation layer 109, N-type electrode 201 and P-type electrode 202, and connect the N-type electrode 201 and P-type electrode 202 to the readout circuit 203.

[0081] Please see Figure 4This application can use flip-chip technology to perform In bump bonding or Cu bump bonding between the readout circuit 203 and the ultraviolet-visible-shortwave infrared focal plane array chip.

[0082] Please see Figure 5 Another embodiment of this application also provides a three-band image sensor, including:

[0083] The system comprises an N-type electrode 201, a P-type electrode 202, and a readout circuit 203, along with a substrate layer 101, a silicon oxide layer 102, an aluminum oxide layer 103, a first electrode layer 104, an ultraviolet light sensing layer 105, a visible light sensing layer 106, an infrared light sensing layer 107, a second electrode layer 108, and a passivation layer 109, stacked sequentially. Multiple rectangular grooves of identical shape, spaced at predetermined intervals, sequentially penetrate the infrared light sensing layer 107, the visible light sensing layer 106, and the ultraviolet light sensing layer 105. The second electrode layer 108 is located between two adjacent rectangular grooves, embedded in the infrared light sensing layer 107, and its length is less than the predetermined interval. The ultraviolet light sensing layer 105 is made of intrinsic aluminum arsenide; the visible light sensing layer 106 is made of intrinsic gallium arsenide; the infrared light sensing layer 107 is made of intrinsic germanium-based material with a 6-degree bevel; and the passivation layer 109 uniformly covers the second electrode layer 108 and the inner walls of each rectangular groove.

[0084] The N-type electrode 201 is disposed in a rectangular groove and passes through the passivation layer 109 to connect to the first electrode layer 104; the P-type electrode 202 passes through the passivation layer 109 to connect to the second electrode layer 108; the readout circuit 203 is connected to the N-type electrode 201 and the P-type electrode 202 respectively.

[0085] The thickness of the silicon oxide layer 102 is between 10 nanometers and 100 nanometers; the thickness of the aluminum oxide layer 103 is 10 nanometers; and the thickness of the first electrode layer 104 and the second electrode layer 108 are both between 100 nanometers and 500 nanometers.

[0086] The thickness of the ultraviolet light sensing layer 105 is between 100 nanometers and 500 nanometers; the thickness of the visible light sensing layer 106 is between 100 nanometers and 1000 nanometers; and the thickness of the infrared light sensing layer 107 is between 500 nanometers and 3000 nanometers. The first electrode layer 104 is a P-type aluminum arsenide electrode layer with a 6-degree bevel; the second electrode layer 108 is an N-type germanium electrode layer with a 6-degree bevel; or the first electrode layer 104 is an N-type aluminum arsenide electrode layer with a 6-degree bevel; and the second electrode layer 108 is a P-type germanium electrode layer with a 6-degree bevel.

[0087] In addition to germanium, the germanium-based materials used in the infrared light sensing layer 107 can also include group IV semiconductor material structures such as germanium-tin alloy, germanium quantum well, germanium-silicon quantum well, germanium-tin quantum well, or silicon-germanium-tin quantum well.

[0088] It can be considered that, except for the provision of the second electrode layer 108, the thickness and material type of other semiconductor layers in the image sensor of this embodiment are consistent with those of the mesa-type image sensor in the aforementioned embodiment. Since the second electrode layer 108 is injected into the infrared light sensing layer 107, the thickness of the infrared light sensing layer 107 must be greater than that of the second electrode layer 108.

[0089] Specifically, almost all ultraviolet-visible-shortwave infrared image sensors currently in the field employ the mesa structure defined in the aforementioned embodiments. This structure is suitable for focal plane arrays with large pixel sizes and can meet the practical needs of some application scenarios. However, for pixels with small pixel pitch, since the second electrode layer 108 is only covered by the passivation layer 109 on both sides, there is a prominent leakage current problem on the sidewalls of the mesa structure, and the electrical crosstalk between adjacent small pixels increases, leading to an increase in dark current, which is detrimental to the improvement of the performance of the focal plane array. Although surface treatment and passivation processes can minimize sidewall leakage current, suppressing the sidewall leakage current of small pixel pitch pixels in the mesa structure remains very challenging.

[0090] Therefore, this application further proposes a planar three-band image sensor, in which the sensing layers for ultraviolet, visible, and infrared light still employ AlAs, GaAs, and Ge structures to address the lattice adaptation issue. Furthermore, compared to mesa-structured sensors, the second electrode layer 108 of the planar sensor is not exposed. Figure 5 As shown, the length of the second electrode layer 108 is less than the length of the mesa formed by the adjacent rectangular grooves. The entire layer is embedded in the infrared light sensing layer 107 below it, so that the junction interface is buried, eliminating electrical crosstalk between adjacent small pixels as much as possible, and completely avoiding the problems of leakage current on the sensor surface and sidewall leakage current. This makes it more suitable for manufacturing germanium-based sensors with small pixel pitch and low dark current.

[0091] Preferably, the length of the second electrode layer 108 is half the length of the entire platform, that is, the length of the second electrode layer 108 is 1 / 2 the length of the sensing layer, so as to balance the working performance and leakage of the second electrode layer 108.

[0092] This application also provides a method for manufacturing a three-band image sensor, including:

[0093] Step S21: Provide a silicon substrate 001 with a 6-degree bevel; sequentially stack a germanium buffer layer 002 with a 6-degree bevel, an infrared light sensing layer 107, a visible light sensing layer 106, an ultraviolet light sensing layer 105, a first electrode layer 104, and an aluminum oxide layer 103 on the silicon substrate 001 to obtain a donor substrate; wherein, the ultraviolet light sensing layer 105 is made of intrinsic aluminum arsenide material; the visible light sensing layer 106 is made of intrinsic gallium arsenide material; and the infrared light sensing layer 107 is made of intrinsic germanium material with a 6-degree bevel.

[0094] The substrate 101 is a glass substrate or a sapphire substrate; the thickness of the germanium buffer layer 002 is between 100 nanometers and 500 nanometers.

[0095] The thickness range and material limitations of the second electrode layer 108, infrared light sensing layer 107, visible light sensing layer 106, ultraviolet light sensing layer 105, first electrode layer 104, and alumina layer 103 have been given in the above embodiments and will not be repeated here.

[0096] Step S22: Provide a substrate layer 101; stack a silicon oxide layer 102 on the substrate layer 101 to obtain the host substrate.

[0097] Step S23: Perform wafer bonding between the donor substrate and the acceptor substrate.

[0098] Step S24: Remove the silicon substrate 001 and the germanium buffer layer 002 to obtain the sensor wafer; specifically, back thinning, wet etching, dry etching or chemical mechanical polishing can be used to remove the silicon substrate 001 and the germanium buffer layer 002.

[0099] The steps for manufacturing planar sensor wafers are basically the same as those for mesa-type image sensors. The only difference is that the donor substrate of the planar sensor does not have a second electrode layer 108, which needs to be generated by ion implantation in the next step.

[0100] In step S25, multiple second electrode layers 108 are formed on the infrared light sensing layer 107 by ion implantation.

[0101] like Figure 6 As shown, in addition to ion implantation, ion diffusion can also be used to form the second electrode layer 108.

[0102] When generating the second electrode layer 108, it is important to ensure that the distance between two adjacent second electrode layers 108 is greater than the preset interval to facilitate the subsequent setting of various rectangular grooves.

[0103] Step S26: Multiple rectangular grooves of the same shape and distributed at a preset interval are set on the sensor wafer; the rectangular grooves pass through the infrared light sensing layer 107, the visible light sensing layer 106 and the ultraviolet light sensing layer 105 in sequence; the second electrode layer 108 is located between two adjacent rectangular grooves, embedded in the infrared light sensing layer 107 and with a length less than the preset interval.

[0104] Specifically, when setting the rectangular grooves, the second electrode layer 108 is positioned in the middle of the two rectangular grooves to avoid the sides of the second electrode layer 108 being exposed and causing current leakage. This results in a planar ultraviolet-visible-shortwave infrared pixel.

[0105] Step S27: Set the passivation layer 109, N-type electrode 201 and P-type electrode 202, and connect the N-type electrode 201 and P-type electrode 202 to the readout circuit 203.

[0106] Please see Figure 7 This application can use flip-chip technology to perform In bump bonding or Cu bump bonding between the readout circuit 203 and the ultraviolet-visible-shortwave infrared focal plane array chip.

[0107] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A three-band image sensor, characterized in that, include: The N-type electrode, P-type electrode and readout circuit, and the substrate layer, silicon oxide layer, aluminum oxide layer, first electrode layer, ultraviolet light sensing layer, visible light sensing layer, infrared light sensing layer, second electrode layer and passivation layer are stacked in sequence. Multiple rectangular grooves of the same shape, distributed at predetermined intervals, sequentially penetrate the second electrode layer, the infrared light sensing layer, the visible light sensing layer, and the ultraviolet light sensing layer; the ultraviolet light sensing layer is made of intrinsic aluminum arsenide material; the visible light sensing layer is made of intrinsic gallium arsenide material; the infrared light sensing layer is made of intrinsic germanium-based material with a 6-degree bevel; the germanium-based material used in the infrared light sensing layer includes germanium-tin alloy, germanium quantum well, germanium-silicon quantum well, germanium-tin quantum well, or silicon-germanium-tin quantum well; The passivation layer is uniformly covered on the second electrode layer and the inner walls of each rectangular groove; The N-type electrode is disposed in a rectangular groove and passes through the passivation layer to connect to the first electrode layer; the P-type electrode passes through the passivation layer to connect to the second electrode layer; the readout circuit is connected to the N-type electrode and the P-type electrode respectively.

2. The three-band image sensor according to claim 1, characterized in that, The substrate is a glass substrate or a sapphire substrate; the thickness of the silicon oxide layer is between 10 nanometers and 100 nanometers.

3. The three-band image sensor according to claim 1, characterized in that, The first electrode layer is a P-type aluminum arsenide electrode layer with a 6-degree bevel; the second electrode layer is an N-type germanium electrode layer with a 6-degree bevel; or the first electrode layer is an N-type aluminum arsenide electrode layer with a 6-degree bevel; the second electrode layer is a P-type germanium electrode layer with a 6-degree bevel.

4. The three-band image sensor according to claim 1, characterized in that, The thickness of the alumina layer is 10 nanometers; the thickness of both the first electrode layer and the second electrode layer is between 100 nanometers and 500 nanometers.

5. The three-band image sensor according to claim 1, characterized in that, The thickness of the ultraviolet light sensing layer is between 100 nanometers and 500 nanometers; the thickness of the visible light sensing layer is between 100 nanometers and 1000 nanometers; and the thickness of the infrared light sensing layer is between 500 nanometers and 3000 nanometers.

6. A method for manufacturing a three-band image sensor, characterized in that, include: A silicon substrate with a 6-degree bevel is provided; a germanium buffer layer, a second electrode layer, an infrared light sensing layer, a visible light sensing layer, an ultraviolet light sensing layer, a first electrode layer, and an aluminum oxide layer with a 6-degree bevel are sequentially stacked on the silicon substrate to obtain a donor substrate; The ultraviolet light sensing layer is made of intrinsic aluminum arsenide; the visible light sensing layer is made of intrinsic gallium arsenide; the infrared light sensing layer is made of intrinsic germanium-based material with a 6-degree bevel; the germanium-based material used in the infrared light sensing layer includes germanium-tin alloy, germanium quantum well, germanium-silicon quantum well, germanium-tin quantum well, or silicon-germanium-tin quantum well. A substrate layer is provided; a silicon oxide layer is stacked on the substrate layer to obtain a host substrate; The donor substrate and the acceptor substrate are wafer-bonded; Remove the silicon substrate and the germanium buffer layer to obtain the sensor wafer; Multiple rectangular grooves of the same shape and distributed at preset intervals are provided on the sensor wafer; the rectangular grooves sequentially penetrate the second electrode layer, the infrared light sensing layer, the visible light sensing layer and the ultraviolet light sensing layer; A passivation layer, an N-type electrode, and a P-type electrode are provided, with the passivation layer uniformly covering the second electrode layer and the inner walls of each rectangular groove; the N-type electrode is located in the rectangular groove, passes through the passivation layer, and connects to the first electrode layer; the P-type electrode passes through the passivation layer and connects to the second electrode layer; and the N-type electrode and the P-type electrode are connected to the readout circuit.

7. The method for manufacturing a three-band image sensor according to claim 6, characterized in that, The process of removing the silicon substrate and the germanium buffer layer to obtain the sensor wafer includes: The silicon substrate and the germanium buffer layer are removed by back thinning, wet etching, dry etching, or chemical mechanical polishing.

8. A three-band image sensor, characterized in that, include: The N-type electrode, P-type electrode and readout circuit, and the substrate layer, silicon oxide layer, aluminum oxide layer, first electrode layer, ultraviolet light sensing layer, visible light sensing layer, infrared light sensing layer, second electrode layer and passivation layer are stacked in sequence. Multiple rectangular grooves of the same shape, distributed at preset intervals, sequentially penetrate the infrared light sensing layer, the visible light sensing layer, and the ultraviolet light sensing layer; the second electrode layer is located between two adjacent rectangular grooves, embedded in the infrared light sensing layer, and its length is less than the preset interval; the ultraviolet light sensing layer is made of intrinsic aluminum arsenide material; the visible light sensing layer is made of intrinsic gallium arsenide material; the infrared light sensing layer is made of intrinsic germanium-based material with a 6-degree bevel; the germanium-based material used in the infrared light sensing layer includes germanium-tin alloy, germanium quantum well, germanium-silicon quantum well, germanium-tin quantum well, or silicon-germanium-tin quantum well; The passivation layer is uniformly covered on the second electrode layer and the inner walls of each rectangular groove; The N-type electrode is disposed in a rectangular groove and passes through the passivation layer to connect to the first electrode layer; the P-type electrode passes through the passivation layer to connect to the second electrode layer; the readout circuit is connected to the N-type electrode and the P-type electrode respectively.

9. A method for manufacturing a three-band image sensor, characterized in that, include: A silicon substrate with a 6-degree bevel is provided; a germanium buffer layer, an infrared light sensing layer, a visible light sensing layer, an ultraviolet light sensing layer, a first electrode layer, and an aluminum oxide layer with a 6-degree bevel are sequentially stacked on the silicon substrate to obtain a donor substrate; The ultraviolet light sensing layer is made of intrinsic aluminum arsenide; the visible light sensing layer is made of intrinsic gallium arsenide; the infrared light sensing layer is made of intrinsic germanium-based material with a 6-degree bevel; the germanium-based material used in the infrared light sensing layer includes germanium-tin alloy, germanium quantum well, germanium-silicon quantum well, germanium-tin quantum well, or silicon-germanium-tin quantum well. A substrate layer is provided; a silicon oxide layer is stacked on the substrate layer to obtain a host substrate; The donor substrate and the acceptor substrate are wafer-bonded; Remove the silicon substrate and the germanium buffer layer to obtain the sensor wafer; Multiple second electrode layers are formed on the infrared light sensing layer by ion implantation; Multiple rectangular grooves of the same shape and distributed at a preset interval are provided on the sensor wafer; the rectangular grooves pass through the infrared light sensing layer, the visible light sensing layer and the ultraviolet light sensing layer in sequence; the second electrode layer is located between two adjacent rectangular grooves, embedded in the infrared light sensing layer and with a length less than the preset interval; A passivation layer, an N-type electrode, and a P-type electrode are provided, with the passivation layer uniformly covering the second electrode layer and the inner walls of each rectangular groove; the N-type electrode is located in the rectangular groove, passes through the passivation layer, and connects to the first electrode layer; the P-type electrode passes through the passivation layer and connects to the second electrode layer; and the N-type electrode and the P-type electrode are connected to the readout circuit.

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