Germanium-based multi-junction double-color long-wave infrared detector and preparation method thereof

Abstract

The invention relates to the technical field of semiconductor devices, in particular to a germanium-based multi-junction double-color long-wave infrared detector and a preparation method thereof. The electrode injection region, the blocking regions, the first monochromatic absorption regions and the second monochromatic absorption regions are arranged on the surface of the germanium substrate; the common electrode, the first absorption region electrodes and the second absorption region electrodes are arranged on the electrode injection region; the passivation layer is arranged on the plurality of blocking regions, the plurality of first monochromatic absorption regions and the plurality of second monochromatic absorption regions; the plurality of first monochromatic absorption regions and the plurality of blocking regions are positioned between the common electrode and the plurality of first absorption region electrodes and are periodically distributed; the plurality of second monochromatic absorption regions and the plurality of blocking regions are located between the common electrode and the plurality of second absorption region electrodes and are distributed periodically. According to the invention, the detection rate can be improved and double-color detection can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a germanium-based multi-junction two-color long-wave infrared detector and a preparation method thereof. Background Art

[0002] Infrared astronomy is a key branch of astronomy, and its development relies on advances in infrared detectors. Currently, common infrared detectors are primarily made of materials such as mercury cadmium telluride, indium antimonide, and indium gallium arsenide. These materials utilize the intrinsic absorption properties of semiconductors to detect infrared light. However, their maximum detectable wavelength is limited by the bandgap of the materials themselves, making them unable to meet the longer wavelength requirements of infrared astronomy. Furthermore, a single detector only corresponds to a fixed wavelength band. Multicolor detection requires combining multiple monochromatic detectors and employing complex optical systems, resulting in high costs.

[0003] Unlike the aforementioned detectors, impurity-band blocking detectors (BBDs) detect infrared light by introducing energy levels through the introduction of impurities into semiconductor materials. The response wavelength of these detectors depends on the ionization activation energy of the impurities, and the detectable wavelength range can be expanded by selecting different doping impurities. For example, silicon-based detectors have a response range of 2-50μm, while germanium-based and gallium arsenide-based detectors extend this range to 200μm and 300μm, respectively. BBDs have a significant advantage in long-wavelength detection in mid- and far-infrared astronomy and have become the mainstream detector.

[0004] However, conventional barrier impurity band detectors also have limitations in their detection performance. Theoretical analysis shows that the electric field within the device's absorption region is concentrated only in a very narrow depletion region, while the electric field in the remaining neutral region is very weak. As a result, only photogenerated carriers generated in the depletion region can contribute to the effective signal. However, further widening the depletion region is difficult under existing processes. In addition, conventional structures are only capable of single-color detection. As the requirements for detection performance continue to increase, such as improving the detection rate and achieving multi-color detection, it is necessary to optimize and improve the existing detector structure to meet these new demands.

[0005] It can be seen from this that the traditional BIB detector (Blocked Impurity Band detector) has the technical problem of low device quantum efficiency and cannot achieve dual-color detection. Furthermore, it is difficult to further reduce the preparation cost. Summary of the Invention

[0006] In order to solve the technical problem of low device quantum efficiency caused by the narrow depletion layer of traditional BIB detectors, the present invention provides a germanium-based multi-junction two-color long-wave infrared detector and a preparation method thereof.

[0007] The present invention provides a germanium-based multi-junction two-color long-wave infrared detector, which adopts the following technical solutions: A germanium-based multi-junction two-color long-wave infrared detector, comprising a germanium substrate; An electrode injection region, a plurality of blocking regions, a plurality of first monochromatic absorption regions and a plurality of second monochromatic absorption regions are arranged on the surface of the germanium substrate; A common electrode, a plurality of first absorption region electrodes, and a plurality of second absorption region electrodes are provided on the electrode injection region; a passivation layer disposed on the plurality of blocking regions, the plurality of first monochromatic absorption regions, and the plurality of second monochromatic absorption regions; The plurality of first monochromatic absorption regions and the plurality of blocking regions are located between the common electrode and the plurality of first absorption region electrodes and are distributed periodically; The plurality of second monochromatic absorption regions and the plurality of blocking regions are located between the common electrode and the plurality of second absorption region electrodes and are distributed periodically; The first monochromatic absorption region (4) and the second monochromatic absorption region (5) are both made of degenerately doped germanium materials, and the first monochromatic absorption region (4) and the second monochromatic absorption region (5) have different types of doping impurities.

[0008] In a specific embodiment, the electrode injection region, the blocking region, the first monochromatic absorption region and the second monochromatic absorption region are all located near the surface of the germanium substrate, and the depth of the germanium substrate surface is 0.1 μm-3 μm.

[0009] In a specific embodiment, the ratio of the first monochromatic absorption region, the second monochromatic absorption region, and the blocking region is 1:1:2.

[0010] In a specific embodiment, the number of the first monochromatic absorption regions+the number of the second monochromatic absorption regions=the number of the blocking regions; The result of (the number of first monochromatic absorption regions×the width of the first monochromatic absorption region)+(the number of second monochromatic absorption regions×the width of the second monochromatic absorption region) is a constant value.

[0011] In a specific embodiment, the germanium substrate is a high-resistance germanium substrate with an impurity concentration range of 1×10 12 to 1×10 14 cm -3 .

[0012] In a specific embodiment, the doping element of the first monochromatic absorption region is one or more of boron, gallium, beryllium, phosphorus or sulfur, and the impurity concentration range is 1×10 16 to 1×10 17 cm -3, doping depth ranges from 0.1μm to 3μm, width ranges from 5μm to 50μm, The doping element of the second monochromatic absorption region is one or more of boron, gallium, beryllium, phosphorus or sulfur, and the impurity concentration range is 1×10 16 to 1×10 17 cm -3 , the doping depth ranges from 0.1μm to 3μm, and the width ranges from 5μm to 50μm.

[0013] In a specific embodiment, the electrode injection region is a degenerate doped germanium material doped with one or more impurities selected from boron, gallium, beryllium or phosphorus, and the concentration of the impurities is 1×10 18 to 1×10 19 cm -3 , the doping depth is 0.1μm to 3μm, and the width is 5μm to 50μm.

[0014] The present invention also provides a germanium-based multi-junction two-color long-wave infrared detector, which adopts the following technical solution: A method for preparing a germanium-based multi-junction dual-color long-wave infrared detector, for preparing the above-mentioned germanium-based multi-junction dual-color long-wave infrared detector, comprises the following steps: forming a pattern of a plurality of first monochromatic absorption regions on the surface of the germanium substrate, and then implanting impurities thereinto by an ion implantation process to form the plurality of first monochromatic absorption regions; forming a pattern of a plurality of second monochromatic absorption regions on the surface of the germanium substrate, and then implanting impurities thereinto by an ion implantation process to form the plurality of second monochromatic absorption regions; forming a pattern of the electrode injection region on the surface of the germanium substrate, and then injecting impurities thereinto by an ion implantation process to form the electrode injection region; Depositing the passivation layer on the surface of the germanium substrate using a plasma enhanced chemical vapor deposition process, and then performing a heat treatment to activate the implanted impurities; Electrode holes are made on the passivation layer by using a wet etching process, and then the common electrode, a plurality of first absorption region electrodes, and a plurality of second absorption region electrodes are formed by using a metal deposition process.

[0015] In a specific embodiment, the doping concentration of the germanium substrate is 1×10 12 cm -3 The number of the first monochromatic absorption regions is 2, the width is 50 μm, and the spacing between adjacent first monochromatic absorption regions is 10 μm; gallium is injected into the first monochromatic absorption region with a doping depth of 3 μm and a doping concentration of 1×10 17 cm -3The number of the second monochromatic absorption regions is 2, the width is 50 μm, and the spacing between adjacent second monochromatic absorption regions is 10 μm; gallium is injected into the second monochromatic absorption region with a doping depth of 3 μm and a doping concentration of 1×10 cm -3 The width of the electrode injection region is 50 μm, and boron is doped into it, the doping depth is 3 μm, and the doping concentration is 1×10 19 cm -3 .

[0016] In a specific embodiment, the doping concentration of the germanium substrate is 1×10 13 cm -3 The number of the first monochromatic absorption regions is 4, the width is 20 μm, and the spacing between adjacent first monochromatic absorption regions is 5 μm; gallium is injected into the first monochromatic absorption region with a doping depth of 0.5 μm and a doping concentration of 5×10 16 cm -3 The number of the second monochromatic absorption regions is 4, the width is 20 μm, and the spacing between adjacent second monochromatic absorption regions is 5 μm; boron is injected into the second monochromatic absorption region with a doping depth of 1 μm and a doping concentration of 5×10 16 cm -3 The width of the electrode injection region is 25 μm, and boron is doped into it, the doping depth is 1 μm, and the doping concentration is 3×10 18 cm -3 .

[0017] In a specific embodiment, the doping concentration of the germanium substrate is 1×10 14 cm -3 The number of the first monochromatic absorption regions is 5, the width is 5 μm, and the spacing between adjacent first monochromatic absorption regions is 3 μm; boron is injected into the first monochromatic absorption region with a doping depth of 0.1 μm and a doping concentration of 1×10 16 cm -3 The number of the second monochromatic absorption regions is 5, the width is 5 μm, and the spacing between adjacent second monochromatic absorption regions is 3 μm; gallium is injected into the second monochromatic absorption region with a doping depth of 0.1 μm and a doping concentration of 1×10 16 cm -3 The width of the electrode injection region is 5 μm, and boron is doped into it, the doping depth is 0.1 μm, and the doping concentration is 1×10 18 cm -3 .

[0018] In summary, the present invention has the following beneficial effects: This invention significantly improves quantum efficiency and enhances detection capabilities. It achieves dual-band detection, expanding its application range. It simplifies the structure, reducing manufacturing complexity and cost. It is compatible with mainstream semiconductor processes, making it easy to popularize and apply. It inherits the advantages of BIB in detecting long-wave infrared light while effectively addressing its low quantum efficiency and narrow detection range. It is suitable for both silicon- and gallium arsenide-based devices and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of a germanium-based impurity-barrier dual-color long-wave infrared light detector. Figure 2 The present invention is a flow chart of a method for preparing a germanium-based impurity-barrier dual-color long-wave infrared light detector. Figure 3 Schematic diagram of the specific structure of the dual-color long-wave infrared light detector in Example 1. Figure 4 Schematic diagram of the specific structure of the dual-color long-wave infrared light detector in Example 2. Figure 5 3 is a schematic diagram of the specific structure of the dual-color long-wave infrared light detector in Example 3. Figure 6 A schematic diagram of the ion implantation process for forming the first monochromatic absorption region is shown.

[0020] Figure 7 A schematic diagram of the ion implantation process for forming the second monochromatic absorption region is shown.

[0021] Figure 8 A schematic diagram of the ion implantation process for forming the electrode implantation region is shown.

[0022] Figure 9 A schematic diagram of the process for opening electrode holes is shown.

[0023] Explanation of the accompanying drawings: 1. Germanium substrate; 2. Electrode injection region; 3. Blocking region; 4. First monochromatic absorption region; 5. Second monochromatic absorption region; 6. Common electrode; 7. Passivation layer; 8. First absorption region electrode; 9. Second absorption region electrode. DETAILED DESCRIPTION

[0024] The following combination Figures 1-9 The present invention is described in further detail.

[0025] Reference Figure 1 The germanium-based multi-junction dual-color long-wave infrared detector includes a germanium substrate 1, which is specifically a high-resistance germanium substrate with an impurity concentration range of 1×10 12 -1×10 14 cm -3Compared with the response wavelength of traditional silicon substrates less than or equal to 30μm, the response wavelength of germanium substrate 1 can reach more than 50μm, which improves the performance of infrared detectors, makes them suitable for high-impedance scenarios, and realizes a wider band detection function.

[0026] A plurality of first monochromatic absorption regions 4, second monochromatic absorption regions 5, electrode injection regions 2, and blocking regions 3 are fabricated on a germanium substrate 1 by ultraviolet lithography. Both the first monochromatic absorption regions 4 and the second monochromatic absorption regions 5 are made of degenerately doped germanium materials and are located near the surface of the germanium substrate 1.

[0027] The doping elements of the first monochromatic absorption region 4 are one or more of boron, gallium, beryllium, phosphorus or sulfur, and the impurity concentration range is 1×10 16 to 1×10 17 cm -3 , the doping depth ranges from 0.1μm to 3μm, and the width ranges from 5μm to 50μm.

[0028] The doping elements of the second monochromatic absorption region 5 are one or more of boron, gallium, beryllium, phosphorus or sulfur, and the impurity concentration range is 1×10 16 to 1×10 17 cm -3 , the doping depth ranges from 0.1 μm to 3 μm, and the width ranges from 5 μm to 50 μm. It should be noted that the doping impurity types of the multiple first monochromatic absorption regions 4 are the same, and the doping impurity types of the multiple second monochromatic absorption regions 5 are the same, but the doping impurity types of the first monochromatic absorption regions 4 and the second monochromatic absorption regions 5 are different.

[0029] The electrode injection region 2 and the barrier region 3 are both located near the surface of the germanium substrate 1 , and are located at a depth of 0.1 μm to 3 μm from the surface of the germanium substrate 1 .

[0030] The electrode injection region 2 is a degenerate doped germanium material doped with one or more impurities selected from boron, gallium, beryllium or phosphorus, with an impurity concentration of 1×10 18 to 1×10 19 cm -3 , the doping depth is 0.1μm to 3μm, and the width is 5μm to 50μm.

[0031] The barrier region 3 is made of high-resistance germanium material, and has a width ranging from 3 μm to 10 μm.

[0032] A passivation layer 7 is deposited on the barrier region 3 , the first monochromatic absorption region 4 and the second monochromatic absorption region 5 .

[0033] A common electrode 6, a first absorption area electrode 8 and a second absorption area electrode 9 are deposited on the electrode injection area 2. The first absorption area electrode 8 and the second absorption area electrode 9 are distributed at opposite ends of the common electrode 6, and a passivation layer 7 is between the first absorption area electrode 8 and the second absorption area electrode 9 and the common electrode 6.

[0034] Furthermore, the first monochromatic absorption region 4 and the barrier region 3 are periodically distributed below the common electrode 6 and the first absorption region electrode 8, i.e., the first monochromatic absorption region 4 and the barrier region 3 are staggered. The second monochromatic absorption region 5 and the plurality of barrier regions 3 are periodically distributed below the common electrode 6 and the second absorption region electrode 9, i.e., the second monochromatic absorption region 5 and the barrier region 3 are staggered.

[0035] In addition, the ratio of the number of first monochromatic absorption regions 4, second monochromatic absorption regions 5, and barrier regions 3 is 1:1:2; that is, the two-color long-wave infrared detector has n first monochromatic absorption regions 4, n second monochromatic absorption regions 5, and 2n barrier regions 3, where 2≤n≤5, n∈R. For each first monochromatic absorption region 4 or second monochromatic absorption region 5, there are n depletion regions.

[0036] The widths of the first monochromatic absorption region 4, the second monochromatic absorption region 5 and the blocking region 3 are related to each other. This is mainly because in the design of infrared detectors, it is hoped to achieve as large an absorption area as possible within a limited area. Therefore, the design mainly considers splitting the wide blocking region into multiple narrow blocking regions to adjust the performance, that is, the number of first monochromatic absorption regions 4 + the number of second monochromatic absorption regions 5 = the number of blocking regions 3, and it is hoped that the absorption region area remains unchanged as much as possible, that is, the result of (number of first monochromatic absorption regions 4 × width of first monochromatic absorption region 4) + (number of second monochromatic absorption regions 5 × width of second monochromatic absorption region 5) is basically a constant.

[0037] In the infrared detector, the first monochromatic absorption region 4 and the second monochromatic absorption region 5 absorb light and generate corresponding light response current (photocurrent) through doped impurities, but the first monochromatic absorption region 4 and the second monochromatic absorption region 5 will also generate current (dark current) when not exposed to light; by introducing an undoped high-purity blocking region 3, part of the dark current can be suppressed by the blocking region 3. The suppression effect depends on the width of the blocking region 3, but an excessively large width will affect the photocurrent while blocking the dark current. By splitting the blocking region 3, the influence of the blocking layer on the photocurrent can be reduced while retaining a good dark current suppression effect, thereby optimizing the detection efficiency.

[0038] In traditional production processes, the blocking region 3, the first monochromatic absorption region 4, and the second monochromatic absorption region 5 are all formed by homoepitaxially growing a new semiconductor thin film on a substrate. Vertical epitaxy is difficult and risky, and presents significant production process difficulties. In the present invention, the blocking region 3, the first monochromatic absorption region 4, and the second monochromatic absorption region 5 are formed by ion implantation and doping on a high-purity germanium substrate 1. This process step does not encounter the difficulties encountered by homoepitaxial growth, and thus the first monochromatic absorption region 4, the second monochromatic absorption region 5, and multiple blocking regions 3 can be achieved. Because the first monochromatic absorption region 4 and the second monochromatic absorption region 5 are located at different positions on the device plane, the mutual interference of light between the first monochromatic absorption region 4 and the second monochromatic absorption region 5 is reduced, and the electrical interference caused by the incident light is difficult to cross the common electrode 6 to reach the electrode on the other side, thereby ensuring low electrical interference.

[0039] By precisely arranging the electrode injection region 2, the blocking region 3, the first monochromatic absorption region 4 and the second monochromatic absorption region 5, as well as the corresponding first absorption region electrode 8, the second absorption region electrode 9 and the passivation layer 7 on the germanium substrate 1, efficient two-color detection is achieved.

[0040] Example 1: like Figure 3 As shown, the method for preparing the germanium-based multi-junction dual-color long-wave infrared detector of this example includes the following steps: Step 110: Select a high-resistance germanium substrate 1 as the substrate. The doping concentration of the germanium substrate 1 is 1×10 12 Two first monochromatic absorption regions 4 were patterned on the surface of the germanium substrate 1 using ultraviolet photolithography. The width of each first monochromatic absorption region 4 was set to 50 μm, and the width of the barrier region 3 between the two first monochromatic absorption regions 4 was set to 10 μm. When patterning the first monochromatic absorption regions 4, a photoresist with a thickness of approximately 3 μm was used as a masking layer, which served as a mask during the subsequent ion implantation process.

[0041] Step 120: Boron (B) impurities are implanted into the first monochromatic absorption region 4 through multiple ion implantation processes. The implantation depth of boron is about 3 μm, and the doping concentration is about 1×10 17 cm -3 .

[0042] Step 130: Using UV lithography again, pattern two second monochromatic absorption regions 5 on the surface of the germanium substrate 1. The width of each second monochromatic absorption region 5 is set to 50 μm, and the width of the barrier region 3 between the two second monochromatic absorption regions 5 is set to 10 μm.

[0043] Step 140: Gallium (Ga) impurities are injected into the second monochromatic absorption region 5 again through multiple ion injection processes. The injection depth of Ga is about 3 μm, and the doping concentration is about 1×10 17 cm -3 .

[0044] Step 150: Using UV lithography technology again, pattern the electrode injection region 2 on the surface of the germanium substrate 1. The width of the electrode injection region 2 is set to 50 μm.

[0045] Step 160: Boron (B) impurities are implanted into the electrode implantation region 2 again through multiple ion implantation processes. The implantation depth of boron is about 3 μm, and the doping concentration is about 1×10 19 cm -3 .

[0046] Step 170: Using plasma enhanced chemical vapor deposition (PECVD) technology, a 200 nm thick Si 3 N 4 layer is deposited on the surface of the germanium substrate 1 as the passivation layer 7 of the device.

[0047] Step 180: Using UV lithography technology again to make an electrode pattern on the surface of the passivation layer, and then using wet etching technology to open an electrode window on the passivation layer.

[0048] Step 190: Using electron beam evaporation, a 20 nm thick layer of palladium (Pd) and a 200 nm thick layer of gold (Au) are sequentially deposited at the electrode windows to form the common electrode 6, the first absorption region electrode 8, and the second absorption region electrode 9. Finally, the device is annealed at 300°C for 300 seconds using a rapid annealing technique.

[0049] Example 2: like Figure 4 As shown, the method for preparing the germanium-based multi-junction dual-color long-wave infrared detector of this example includes the following steps: Step 210: Select a high-resistance germanium substrate 1, and set its doping concentration to 1×10 13 cm -3 Using ultraviolet lithography, four first monochromatic absorption regions 4 are designed on the surface of the germanium substrate 1. Each absorption region is set to a width of 20 μm, and the blocking region 3 between two adjacent absorption regions is 5 μm wide. The photoresist used at this stage is approximately 3 μm thick, sufficient to serve as an effective masking layer for the subsequent ion implantation step.

[0050] Step 220: Boron (B) impurities are implanted into the first monochromatic absorption region 4 through multiple ion implantation processes. The implantation depth of boron is about 1 μm, and the target doping concentration is about 5×10 16 cm -3 .

[0051] Step 230: Using UV lithography technology again, four second monochromatic absorption regions 5 are designed on the surface of the germanium substrate 1. The width of each absorption region is still set to 20 μm, and the width of the blocking region 3 between adjacent absorption regions remains unchanged at 5 μm.

[0052] Step 240: Gallium (Ga) impurities are injected into the second monochromatic absorption region 5 again through multiple ion implantations. The implantation depth is about 1 μm and the target doping concentration is about 5×10 16 cm -3 .

[0053] Step 250: Using UV lithography technology again, design an electrode injection region 2 on the surface of the germanium substrate 1. The width of the electrode injection region 2 is set to 25 μm.

[0054] Step 260: Boron (B) impurities are implanted into the electrode implantation region 2 again through multiple ion implantation processes. The implantation depth of boron is about 1 μm, and the target doping concentration is about 3×10 18 cm -3 .

[0055] Step 270: Using plasma enhanced chemical vapor deposition (PECVD) technology, a 200 nm thick Si 3 N 4 layer is deposited on the surface of the germanium substrate 1 as the passivation layer 7 of the device.

[0056] Step 280: Design an electrode pattern on the passivation layer using UV lithography technology again, and then open an electrode window on the passivation layer using a wet etching process.

[0057] Step 290: Electron beam evaporation is used to deposit 20 nm thick palladium (Pd) and 200 nm thick gold (Au) at the electrode windows to form the common electrode 6, the first absorption region electrode 8, and the second absorption region electrode 9. Subsequently, the device is annealed at 300°C for 300 seconds using a rapid annealing technique.

[0058] Example 3: like Figure 5 As shown, the method for preparing the germanium-based multi-junction dual-color long-wave infrared detector of this example includes the following steps: Step 310: First, select a doping concentration of 1×10 14 A high-resistance germanium substrate 1 (cm⁻³) is constructed. Ultraviolet lithography is then used to construct five first monochromatic absorption regions 4 on the surface of the germanium substrate 1. Each absorption region is 5μm wide, and the barrier regions 3 separating adjacent absorption regions are 3μm wide. The photoresist used in this process is approximately 3μm thick and will serve as a masking layer for the subsequent ion implantation step.

[0059] Step 320: Boron (B) impurities are implanted into the first monochromatic absorption region 4 through multiple ion implantation processes. The implantation depth of boron is about 0.1 μm, and the target doping concentration is about 1×10 16 cm -3 .

[0060] Step 330: Using the UV lithography technology again, five second monochromatic absorption regions 5 are constructed on the surface of the germanium substrate 1 . The width of each absorption region is 5 μm, and the width of the blocking regions 3 between adjacent absorption regions remains unchanged at 3 μm.

[0061] Step 340: Gallium (Ga) impurities are injected into the second monochromatic absorption region 5 again through multiple ion implantation processes. The implantation depth of Ga is about 0.1 μm and the target doping concentration is about 1×10 16 cm -3 .

[0062] Step 350: Using the ultraviolet lithography technology again, an electrode injection region 2 with a width of 5 μm is constructed on the surface of the germanium substrate 1 .

[0063] Step 360: Boron (B) impurities are implanted into the electrode implantation region 2 again through multiple ion implantation processes. The implantation depth of boron is about 0.1 μm, and the target doping concentration is about 1×10 18 cm⁻³.

[0064] Step 370: Using PECVD technology, deposit 200 nm thick Si 3 N 4 on the surface of the germanium substrate 1 as the passivation layer 7 of the device.

[0065] Step 380: Apply UV lithography technology again to construct an electrode pattern on the surface of the passivation layer, and then use a wet etching process to open an electrode window on the passivation layer.

[0066] Step 390: Deposit 20 nm thick Pd and 200 nm thick Au at the electrode window using electron beam evaporation to form the common electrode 6, the first absorption region electrode 8, and the second absorption region electrode 9. Finally, perform rapid annealing at 300°C for 300 seconds.

[0067] The above are all preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A germanium-based multi-junction two-color long-wave infrared detector, characterized in that: comprising a germanium substrate (1); An electrode injection region (2), a plurality of blocking regions (3), a plurality of first monochromatic absorption regions (4), and a plurality of second monochromatic absorption regions (5) are arranged on the surface of the germanium substrate (1); A common electrode (6), a plurality of first absorption region electrodes (8), and a plurality of second absorption region electrodes (9) arranged on the electrode injection region (2); a passivation layer (7) provided on the plurality of blocking regions (3), the plurality of the first monochromatic absorption regions (4), and the plurality of the second monochromatic absorption regions (5); The plurality of first monochromatic absorption regions (4) and the plurality of blocking regions (3) are located between the common electrode (6) and the plurality of first absorption region electrodes (8), and are distributed periodically; The plurality of second monochromatic absorption regions (5) and the plurality of blocking regions (3) are located between the common electrode (6) and the plurality of second absorption region electrodes (9), and are distributed periodically; The first monochromatic absorption region (4) and the second monochromatic absorption region (5) are both made of degenerately doped germanium materials, and the first monochromatic absorption region (4) and the second monochromatic absorption region (5) have different types of doping impurities.

2. The germanium-based multi-junction two-color long-wave infrared detector according to claim 1, characterized in that: The electrode injection region (2), the blocking region (3), the first monochromatic absorption region (4) and the second monochromatic absorption region (5) are all located near the surface of the germanium substrate (1), and are located at a depth of 0.1 μm to 3 μm from the surface of the germanium substrate (1).

3. The germanium-based multi-junction two-color long-wave infrared detector according to claim 1, characterized in that: The ratio of the number of the first monochromatic absorption area (4), the second monochromatic absorption area (5), and the blocking area (3) is 1:1:

2.

4. The germanium-based multi-junction two-color long-wave infrared detector according to claim 1, characterized in that: The number of the first monochromatic absorption areas (4) + the number of the second monochromatic absorption areas (5) = the number of the blocking areas (3); The result of (the number of first monochromatic absorption regions (4)×the width of the first monochromatic absorption region (4))+(the number of second monochromatic absorption regions (5)×the width of the second monochromatic absorption region (5)) is a constant value.

5. The germanium-based multi-junction two-color long-wave infrared detector according to claim 1, characterized in that: The germanium substrate (1) is a high-resistance germanium substrate with an impurity concentration range of 1×10 12 to 1×10 14 cm -3 .

6. The germanium-based multi-junction two-color long-wave infrared detector according to claim 1, characterized in that: The doping element of the first monochromatic absorption region (4) is one or more of boron, gallium, beryllium, phosphorus or sulfur, and the impurity concentration range is 1×10 16 to 1×10 17 cm -3 , doping depth ranges from 0.1μm to 3μm, width ranges from 5μm to 50μm, The doping element of the second monochromatic absorption region (5) is one or more of boron, gallium, beryllium, phosphorus or sulfur, and the impurity concentration range is 1×10 16 to 1×10 17 cm -3 , the doping depth ranges from 0.1μm to 3μm, and the width ranges from 5μm to 50μm.

7. The germanium-based multi-junction two-color long-wave infrared detector according to claim 1, characterized in that: The electrode injection region (2) is a degenerate doped germanium material doped with one or more impurities selected from boron, gallium, beryllium or phosphorus, and the concentration of the impurities is 1×10 18 to 1×10 19 cm -3 , the doping depth is 0.1μm to 3μm, and the width is 5μm to 50μm.

8. A method for preparing a germanium-based multi-junction dual-color long-wave infrared detector, characterized in that: The method for preparing the germanium-based multi-junction dual-color long-wave infrared detector according to any one of claims 1 to 7 comprises the following steps: forming a pattern of a plurality of the first monochromatic absorption regions (4) on the surface of the germanium substrate (1), and then injecting impurities thereinto using an ion implantation process to form the plurality of the first monochromatic absorption regions (4); forming a pattern of a plurality of the second monochromatic absorption regions (5) on the surface of the germanium substrate (1), and then injecting impurities thereinto using an ion implantation process to form the plurality of the second monochromatic absorption regions (5); forming a pattern of the electrode injection region (2) on the surface of the germanium substrate (1), and then injecting impurities thereinto using an ion implantation process to form the electrode injection region (2); Depositing the passivation layer (7) on the surface of the germanium substrate (1) using a plasma enhanced chemical vapor deposition process, and then performing a heat treatment to activate the injected impurities; Electrode holes are made on the passivation layer (7) using a wet etching process, and then the common electrode (6), a plurality of the first absorption region electrodes (8), and a plurality of the second absorption region electrodes (9) are formed using a metal deposition process.

9. The method for preparing the germanium-based multi-junction dual-color long-wave infrared detector according to claim 8, characterized in that: The doping concentration of the germanium substrate is 1×10 12 cm -3 The number of the first monochromatic absorption regions is 2, the width is 50 μm, and the spacing between adjacent first monochromatic absorption regions is 10 μm; gallium is injected into the first monochromatic absorption region with a doping depth of 3 μm and a doping concentration of 1×10 17 cm -3 The number of the second monochromatic absorption regions is 2, the width is 50 μm, and the spacing between adjacent second monochromatic absorption regions is 10 μm; gallium is injected into the second monochromatic absorption region with a doping depth of 3 μm and a doping concentration of 1×10 cm -3 The width of the electrode injection region is 50 μm, and boron is doped into it, the doping depth is 3 μm, and the doping concentration is 1×10 19 cm -3 .

10. The method for preparing the germanium-based multi-junction dual-color long-wave infrared detector according to claim 8, wherein: The doping concentration of the germanium substrate is 1×10 13 cm -3 The number of the first monochromatic absorption regions is 4, the width is 20 μm, and the spacing between adjacent first monochromatic absorption regions is 5 μm; gallium is injected into the first monochromatic absorption region with a doping depth of 0.5 μm and a doping concentration of 5×10 16 cm -3 The number of the second monochromatic absorption regions is 4, the width is 20 μm, and the spacing between adjacent second monochromatic absorption regions is 5 μm; boron is injected into the second monochromatic absorption region with a doping depth of 1 μm and a doping concentration of 5×10 16 cm -3 The width of the electrode injection region is 25 μm, and boron is doped into it, the doping depth is 1 μm, and the doping concentration is 3×10 18 cm -3 .

11. The method for preparing the germanium-based multi-junction dual-color long-wave infrared detector according to claim 8, wherein: The doping concentration of the germanium substrate is 1×10 14 cm -3 The number of the first monochromatic absorption regions is 5, the width is 5 μm, and the spacing between adjacent first monochromatic absorption regions is 3 μm; boron is injected into the first monochromatic absorption region with a doping depth of 0.1 μm and a doping concentration of 1×10 16 cm -3 The number of the second monochromatic absorption regions is 5, the width is 5 μm, and the spacing between adjacent second monochromatic absorption regions is 3 μm; gallium is injected into the second monochromatic absorption region with a doping depth of 0.1 μm and a doping concentration of 1×10 16 cm -3 The width of the electrode injection region is 5 μm, and boron is doped into it, the doping depth is 0.1 μm, and the doping concentration is 1×10 18 cm -3 .

Images