Ring hole infrared detector and ring hole infrared detector preparation method

Abstract

The invention discloses a ring hole infrared detector and a ring hole infrared detector preparation method, which are applied to the field of infrared detectors, and comprise a reading circuit, an absorption layer and a ring hole channel, the annular hole channel penetrates through the absorption layer and the passivation layer prepared on the surface of the absorption layer, and the reading circuit is exposed; a tunneling passivation layer, a carrier selection transmission layer and a conducting layer are arranged on the surface of the annular hole channel in a stacked mode, the part, exposed out of the annular hole channel, of the absorption layer is conductively connected with the reading circuit through the conducting layer, and the part, not exposed out of the annular hole channel, of the absorption layer is conductively connected with a common electrode. Based on the structure of the tunneling passivation layer, the carrier selection transmission layer and the conductive layer which are arranged in a stacked mode, the part, exposed out of the ring hole channel, of the absorption layer is conductively connected with the reading circuit, the tunneling passivation layer promotes electron tunneling, the carrier selection transmission layer improves the electron migration capacity, normal operation of the detector is guaranteed, and meanwhile the performance of the detector is improved. Passivation of the surface of the annular hole channel and electrode contact without opening holes are achieved, and leakage current of the device is reduced.

Description

Technical Field

[0001] The invention relates to the field of infrared detectors, and in particular to a ring-hole infrared detector and a method for preparing the ring-hole infrared detector. Background Art

[0002] In the existing ring hole infrared detector, the pn junction is perpendicular to the surface of the epitaxial layer and parallel to the incident light, which has the advantages of reducing the cross dislocation density of the epitaxial layer, reducing the leakage current of the device, and improving the quantum efficiency. A ring hole channel is formed in the existing epitaxial layer. The epitaxial layer material around the ring hole channel is inverted and forms a pn junction with the epitaxial layer material far away from the ring hole channel. Then, by directly depositing a conductive layer, the epitaxial layer around the ring hole channel is inverted and conductively connected to the readout circuit; or by growing a passivation layer, partially opening the grown passivation layer, and then depositing a conductive layer, the epitaxial layer around the ring hole channel is inverted and conductively connected to the readout circuit. Regardless of which of the above methods is used, the damage caused by etching in the ring hole channel cannot be effectively repaired, and the direct contact between the conductive layer and the inverted epitaxial layer will increase the interface resistance, affect the transmission of interface carriers, and cause the leakage current of the device to increase, thereby affecting the performance of the infrared detector.

[0003] Therefore, how to provide a device that can repair the damage caused by etching in the annular ring channel and at the same time effectively passivate the sidewalls of the annular ring channel to reduce the leakage current of the device is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a ring-hole infrared detector and a method for preparing a ring-hole infrared detector, which solves the problem in the prior art that the damage caused by etching in the ring-hole channel cannot be effectively repaired, and the direct contact between the conductive layer and the inverted epitaxial layer will increase the interface resistance, affect the transmission of interface carriers, lead to an increase in device leakage current, and further affect the performance of the infrared detector.

[0005] In order to solve the above technical problems, the present invention provides a ring aperture infrared detector, comprising:

[0006] readout circuit, absorption layer and annular hole channel;

[0007] The absorption layer comprises a first surface and a second surface opposite to each other, a first passivation layer is disposed on the first surface of the absorption layer, a second passivation layer is disposed on the second surface of the absorption layer, and the first passivation layer is connected to the readout circuit;

[0008] The annular hole channel penetrates the second passivation layer, the absorption layer and the first passivation layer, and exposes the readout circuit;

[0009] The absorption layer comprises a first type epitaxial absorption region close to the annular hole channel and a second type epitaxial absorption region far from the annular hole channel, and the first type epitaxial absorption region and the second type epitaxial absorption region form a pn junction;

[0010] A tunnel passivation layer, a carrier selection and transport layer and a conductive layer are sequentially stacked on the surface of the annular channel, and the first type epitaxial absorption region is conductively connected to the readout circuit through the conductive layer;

[0011] A common electrode conductively connected to the second type epitaxial absorption region is disposed at a position of the second passivation layer corresponding to the second type epitaxial absorption region.

[0012] Optionally, the absorption layer is a mercury cadmium telluride absorption layer;

[0013] The first type epitaxial absorption region is an N-type mercury cadmium telluride absorption region, and the second type epitaxial absorption region is a P-type mercury cadmium telluride absorption region.

[0014] Optionally, the thickness of the tunnel passivation layer is less than 10 nanometers;

[0015] The thickness of the carrier selective transport layer is 100 nanometers to 200 nanometers.

[0016] Optionally, the first passivation layer is connected to the readout circuit via an adhesive.

[0017] The present invention also provides a method for preparing a ring-shaped aperture infrared detector, which is used to prepare the ring-shaped aperture infrared detector as described above, comprising:

[0018] A detector preform is provided; the detector preform comprises a readout circuit, an absorption layer and an annular hole channel, the absorption layer comprises a first surface and a second surface opposite to each other, a first passivation layer is arranged at the first surface of the absorption layer, a second passivation layer is arranged at the second surface of the absorption layer, the first passivation layer is connected to the readout circuit, the annular hole channel penetrates the second passivation layer, the absorption layer and the first passivation layer, and exposes the readout circuit, the absorption layer comprises a first type epitaxial absorption region close to the annular hole channel and a second type epitaxial absorption region away from the annular hole channel, and the first type epitaxial absorption region and the second type epitaxial absorption region form a pn junction;

[0019] A tunnel passivation layer, a carrier selection and transport layer, and a conductive layer are sequentially stacked on the surface of the annular channel;

[0020] A common electrode conductively connected to the second type epitaxial absorption region is prepared at a position of the second passivation layer corresponding to the second type epitaxial absorption region.

[0021] Optionally, a tunnel passivation layer, a carrier selection and transport layer and a conductive layer are sequentially stacked on the surface of the annular channel, including:

[0022] The tunnel passivation layer is prepared on the surface of the annular channel by an anodic oxidation method through an electrochemical process;

[0023] Prepare the carrier selection and transport layer on the surface of the prepared tunnel passivation layer;

[0024] The conductive layer is prepared on the surface of the prepared carrier selective transport layer.

[0025] Optionally, preparing the carrier selection transport layer on the surface of the prepared tunnel passivation layer includes:

[0026] The carrier selection and transport layer is prepared on the surface of the prepared tunnel passivation layer by using a plasma enhanced chemical vapor deposition process.

[0027] Optionally, providing a detector prefabricated part includes:

[0028] Providing a substrate, and epitaxially growing an absorption layer on a surface of the substrate;

[0029] A passivation layer is prepared on the surface of the absorption layer facing away from the substrate, the substrate is removed, and a passivation layer is prepared on the surface of the absorption layer after the substrate is removed; the passivation layer prepared on one surface of the absorption layer is used as the first passivation layer, and the passivation layer prepared on the other surface of the absorption layer is used as the second passivation layer;

[0030] Connecting the first passivation layer to the readout circuit to obtain a preform to be processed;

[0031] A hole is formed by etching on the surface of the preform to be processed which faces away from the readout circuit until the readout circuit is exposed, so as to prepare the annular channel and obtain the detector preform.

[0032] Optionally, after providing a substrate and epitaxially growing an absorption layer on the surface of the substrate, the method further includes:

[0033] Calculating the thickness of the absorbing layer according to Fourier test;

[0034] Etching and opening a hole on the surface of the preform to be processed facing away from the readout circuit until the readout circuit is exposed to prepare the annular hole channel to obtain the detector preform, comprising:

[0035] Calculating the etching opening processing time according to the thickness of the absorption layer, the thickness of the first passivation layer and the thickness of the second passivation layer;

[0036] Based on the etching and opening processing time, etching and opening are performed on the surface of the preform to be processed facing away from the readout circuit to expose the readout circuit, thereby obtaining the detector preform prepared with the annular hole channel.

[0037] Optionally, connecting the first passivation layer to the readout circuit to obtain a preform to be processed includes:

[0038] The first passivation layer is connected to the readout circuit by adhesive using a vacuum tablet press to obtain the preform to be processed.

[0039] It can be seen that the annular hole infrared detector provided by the present invention includes a readout circuit, an absorption layer and an annular hole channel; the absorption layer includes a first surface and a second surface relative to each other, a first passivation layer is arranged at the first surface of the absorption layer, a second passivation layer is arranged at the second surface of the absorption layer, and the first passivation layer is connected to the readout circuit; the annular hole channel runs through the second passivation layer, the absorption layer and the first passivation layer, and exposes the readout circuit; the absorption layer includes a first type epitaxial absorption region close to the annular hole channel and a second type epitaxial absorption region away from the annular hole channel, and the first type epitaxial absorption region forms a pn junction with the second type epitaxial absorption region; a tunneling passivation layer, a carrier selection and transmission layer and a conductive layer are sequentially stacked on the surface of the annular hole channel, and the first type epitaxial absorption region is conductively connected to the readout circuit through the conductive layer; a common electrode conductively connected to the second type epitaxial absorption region is arranged at the position of the second passivation layer corresponding to the second type epitaxial absorption region. The present invention is based on the structure of a tunneling passivation layer, a carrier selection transport layer and a conductive layer stacked in sequence on the surface of an annular hole channel. The tunneling passivation layer is used to promote the tunneling of electron carriers in the first type epitaxial absorption region to the carrier selection transport layer, and the carrier selection transport layer is used to increase the migration probability of the electron carriers migrating to the conductive layer. After being transferred through the conductive layer and passing through the carrier selection transport layer and the tunneling passivation layer on the surface of the readout circuit again, the electron carriers are collected by the readout circuit. While realizing the normal operation of the detector, the surface of the annular hole channel can be effectively passivated, and electrode contact can be realized without opening holes in the carrier selection transport layer and the tunneling passivation layer, thereby reducing the leakage current of the device and improving the device performance.

[0040] In addition, the present invention also provides a method for preparing a ring-hole infrared detector, which also has the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0042] Figure 1 It is a structural schematic diagram of an existing ring hole infrared detector;

[0043] Figure 2 A schematic diagram of the structure of a ring-shaped infrared detector provided by an embodiment of the present invention;

[0044] Figure 3 A flowchart of a method for preparing a ring-shaped infrared detector provided by an embodiment of the present invention;

[0045] Figure 4 A flowchart of a method for preparing a ring-shaped infrared detector provided by an embodiment of the present invention;

[0046] Figure 1 , Figure 2 and Figure 4 In the figure, the reference numerals are described as follows:

[0047] 1-substrate, 2-passivation layer, 3-N-type region, 4-P-type region, 5-metal layer, 10-readout circuit, 20-absorption layer, 21-N-type mercury cadmium telluride absorption region, 22-P-type mercury cadmium telluride absorption region, 23-mercury cadmium telluride absorption layer, 30-ring hole channel, 40-first passivation layer, 50-second passivation layer, 61-tunneling passivation layer, 62-carrier selection and transport layer, 63-conductive layer, 70-common electrode, 80-adhesive. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, 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.

[0049] Taking the mercury cadmium telluride ring-aperture infrared detector as an example, initially, the mercury cadmium telluride ring-aperture infrared detector used ion implantation or diffusion to prepare a pn junction array on the epitaxial absorption layer of the P-type material, and then etched a ring-aperture channel perpendicular to the junction surface in the n-type region. By metallizing the ring-aperture channel, the electrical connection between the HgCdTe FPA (mercury cadmium telluride focal plane array) and the readout circuit was achieved. Later, after improvements, when the ion beam bombarded the P-type HgCdTe (mercury cadmium telluride) absorption layer, part of the material was etched away to produce excess mercury atoms. These mercury atoms diffused into the mercury cadmium telluride absorption layer and were captured by the mercury vacancies in the mercury cadmium telluride absorption layer, causing the P-type mercury cadmium telluride material to invert and form a pn junction.

[0050] The existing HgCdTe ring hole infrared detector has the following advantages: the formed pn junction is perpendicular to the surface of the formed HgCdTe epitaxial material, that is, perpendicular to the light incident surface, and the cross dislocation density formed in the epitaxial layer is greatly reduced, which helps to reduce the leakage current of the device; the incident light is parallel to the pn junction, which is conducive to the improvement of quantum efficiency; the n-type region and the readout circuit are interconnected by metallization of the ring hole channel, and there is no need to use the In (indium) column interconnection method, which improves the reliability of the device against high temperature shock and is not affected by the size and scale of the device; the substrate of the epitaxial layer is completely removed, and the thermal mismatch problem between the substrate and the readout circuit is solved. However, further, the etched ring hole channel in the existing HgCdTe ring hole infrared detector is either directly in contact with the prepared metal layer, or the electrode is led out by local opening after the passivation layer is grown, which makes it impossible to effectively passivate and repair the damage caused by etching in the ring hole channel, and the direct contact between the metal electrode and the N-type HgCdTe absorption layer will increase the interface resistance, affect the transmission of interface carriers, and then increase the leakage current of the device, affecting the device performance. The structure of the existing ring hole infrared detector can refer to Figure 1 , Figure 1 The schematic diagram of the structure of an existing ring hole infrared detector is shown in FIG. The absorption layer includes an N-type region 3 and a P-type region 4, and a passivation layer 2 is provided on both opposite sides of the absorption layer. A metal layer 5 is provided in the ring hole channel prepared in the absorption layer to electrically connect the N-type region 3 with the readout circuit 10, and the metal layer 5 is in direct contact with the N-type region 3.

[0051] Therefore, how to provide a device that can repair the damage caused by etching in the annular ring channel and at the same time effectively passivate the sidewalls of the annular ring channel to reduce the leakage current of the device is a technical problem that technical personnel in this field urgently need to solve.

[0052] The present invention adopts a novel passivation contact method, grows a tunnel passivation layer on the surface of the annular hole channel after etching, and then uses the carrier selection transmission layer to realize the transmission of electrons, and then continues to grow a conductive layer, which not only realizes effective passivation repair of the annular hole channel, but also realizes electrode contact without opening holes, which can reduce the leakage current of the device and improve the device performance. Specifically, based on the structure of the tunnel passivation layer, the carrier selection transmission layer and the conductive layer stacked in sequence on the surface of the annular hole channel, the present invention uses the tunnel passivation layer to promote the electron carriers in the first type epitaxial absorption region to tunnel to the carrier selection transmission layer, uses the carrier selection transmission layer to improve the migration ability of the electron carriers to the conductive layer, and transfers through the conductive layer, and passes through the carrier selection transmission layer and the tunnel passivation layer on the surface of the readout circuit again, so that the electron carriers are collected by the readout circuit, and while realizing the normal operation of the detector, the surface of the annular hole channel can be effectively passivated, and the electrode contact without opening holes in the carrier selection transmission layer and the tunnel passivation layer can be realized, which can reduce the leakage current of the device and improve the device performance. For details, please refer to the following embodiments:

[0053] Please refer to Figure 2 , Figure 2 A schematic diagram of the structure of a ring-shaped infrared detector provided by an embodiment of the present invention. The ring-shaped infrared detector may include:

[0054] Readout circuit 10, absorption layer 20 and annular hole channel 30;

[0055] The absorption layer 20 includes a first surface and a second surface opposite to each other. A first passivation layer 40 is disposed on the first surface of the absorption layer 20 , and a second passivation layer 50 is disposed on the second surface of the absorption layer 20 . The first passivation layer 40 is connected to the readout circuit 10 .

[0056] The annular hole channel 30 penetrates the second passivation layer 50, the absorption layer 20 and the first passivation layer 40, and exposes the readout circuit 10;

[0057] The absorption layer 20 includes a first type epitaxial absorption region close to the annular hole channel 30 and a second type epitaxial absorption region away from the annular hole channel 30, and the first type epitaxial absorption region and the second type epitaxial absorption region form a pn junction;

[0058] A tunnel passivation layer 61, a carrier selection and transport layer 62 and a conductive layer 63 are sequentially stacked on the surface of the ring hole channel 30, and the first type epitaxial absorption region is conductively connected to the readout circuit 10 through the conductive layer 63;

[0059] A common electrode 70 conductively connected to the second type epitaxial absorption region is disposed at a position of the second passivation layer 50 corresponding to the second type epitaxial absorption region.

[0060] It should be noted that the key points in this embodiment are: using the tunneling passivation layer 61 and the carrier selective transport layer 62 to jointly realize the passivation repair of the annular ring channel 30 after etching, and the selective transport of the carrier selective transport layer 62; directly growing the conductive layer 63 to realize electrode contact without opening. The present invention is based on the structure of the tunneling passivation layer 61, the carrier selective transport layer 62 and the conductive layer 63 stacked in sequence on the surface of the annular ring channel 30. On the one hand, the tunneling passivation layer 61 and the carrier selective transport layer 62 are used to passivate and repair the damage on the surface of the annular ring channel 30 after etching. On the other hand, the tunneling passivation layer 61 can promote the electron carriers in the first type epitaxial absorption region to tunnel to the carrier selective transport layer 62, and the carrier selective transport layer 62 can improve the migration ability of the electron carriers to the conductive layer 63. Specifically, the stacked structure composed of the tunneling passivation layer 61 and the carrier selective transport layer 62 causes the surface of the absorption layer 20 to produce band bending, thereby This promotes the electrons to tunnel to the carrier selection transport layer 62 and blocks the recombination of holes, and then the electrons are collected by the conductive layer 63 through the carrier selection transport layer 62. After the electrons are collected by the conductive layer 63, they are transferred to a position close to the readout circuit 10 through the conductive layer 63. At this time, the electrons pass through the carrier selection transport layer 62 and the tunneling passivation layer 61 on the surface of the readout circuit 10 again and are collected by the readout circuit 10, so that there is no need to open holes in the carrier selection transport layer 62 and the tunneling passivation layer 61 prepared on the side of the readout circuit 10 close to the absorption layer 20, so as to achieve conductive connection between the conductive layer 63 and the readout circuit 10, thereby reducing the leakage current of the device and improving the device performance. The surface of the annular hole channel 30 in this embodiment is the contour surface of the annular hole channel 30 after the annular hole channel 30 is formed by etching and opening. The readout circuit 10, the first passivation layer 40, the absorption layer 20 and the second passivation layer 50 are stacked from bottom to top in sequence. At this time, the annular hole channel 30 is prepared by etching the opening downward along the second passivation layer 50 until the readout circuit 10 is exposed. Therefore, the upper side of the annular hole channel 30 is open. At this time, the surface of the annular hole channel 30 only includes the side wall and the bottom of the annular hole channel 30, and the annular hole channel The sidewall of the channel 30 is mainly composed of the absorption layer 20, and the bottom of the annular channel 30 is mainly formed by the exposed readout circuit 10. In the present application, a tunneling passivation layer 61, a carrier selection and transmission layer 62 and a conductive layer 63 are sequentially stacked on the surface of the annular channel 30. At this time, the tunneling passivation layer 61 covers the surface of the above-mentioned annular channel 30, and the carrier selection and transmission layer 62 covers the surface of the tunneling passivation layer 61 at this time. Correspondingly, the conductive layer 63 is formed on the surface of the carrier selection and transmission layer 62 at this time, forming a structure stacked in sequence.

[0061] In addition, the ring hole infrared detector in this embodiment can refer to the existing ring hole infrared detector, including a readout circuit 10, an absorption layer 20 and a ring hole channel 30, and the first surface and the second surface of the absorption layer 20 are respectively provided with a first passivation layer 40 and a second passivation layer 50, and the first passivation layer 40 and the second passivation layer 50 are generally provided with the same material. The first passivation layer 40 and the second passivation layer 50 are divided here to distinguish the passivation layers located at different surfaces of the absorption layer 20. Generally, during preparation, the first surface and the second surface of the absorption layer 20 are respectively provided with a first passivation layer 40 and a second passivation layer 50. The surface is divided into upper and lower surfaces, the first surface is generally arranged downward, and the corresponding second surface is arranged upward. If the surface of the absorption layer 20 arranged upward is defined as the front surface of the absorption layer 20, then the corresponding surface of the absorption layer 20 arranged downward is the back surface of the absorption layer 20, and at this time the back surface of the absorption layer 20 faces the readout circuit 10, and the annular hole channel 30 is etched along the direction from the front surface of the absorption layer 20 to the back surface of the absorption layer 20, and the annular hole channel 30 penetrates the absorption layer 20 and the passivation layer on the front and back surfaces of the absorption layer 20, and exposes the readout circuit 10. In this embodiment, the absorption layer 20 includes a first type epitaxial absorption region close to the annular hole channel 30 and a second type epitaxial absorption region away from the annular hole channel 30, and the first type epitaxial absorption region forms a pn junction with the second type epitaxial absorption region, that is, when the first type epitaxial absorption region is an N-type region, the second type epitaxial absorption region is a P-type region, or when the first type epitaxial absorption region is a P-type region, the second type epitaxial absorption region is correspondingly an N-type region. It should be further explained that, in this embodiment, the second type epitaxial absorption region is conductively connected to the readout circuit 10 via the common electrode 70 .

[0062] This embodiment does not limit the specific material of the absorption layer 20, that is, this embodiment does not limit the specific type of the ring hole infrared detector, as long as it is a ring hole type infrared detector. For example, it can be set as a gallium arsenide indium (InGaAs) ring hole type infrared detector, an indium antimonide (InSb) ring hole type infrared detector, a quantum dot ring hole type infrared photon detector (QDIP), and a silicon-based ring hole type infrared detector (Si-based IR Detectors). This embodiment does not limit the specific location of the common electrode 70. For ease of extraction, the common electrode 70 can be set at the edge of one end of the second type epitaxial absorption region away from the ring hole channel 30.

[0063] Furthermore, in order to ensure the functionality and adaptability of the ring-aperture infrared detector, the absorption layer 20 may be set as a mercury cadmium telluride absorption layer;

[0064] The first type epitaxial absorption region is an N-type HgCdTe absorption region 21 , and the second type epitaxial absorption region is a P-type HgCdTe absorption region 22 .

[0065] It should be noted that in this embodiment, the absorption layer 20 is set as a mercury cadmium telluride absorption layer, that is, the ring-shaped aperture infrared detector is set as a mercury cadmium telluride ring-shaped aperture infrared detector, which has significant advantages in improving infrared detection performance, reducing space charge effect, and increasing saturation threshold. Correspondingly, in this embodiment, when the absorption layer 20 is set as a mercury cadmium telluride absorption layer, the second type of epitaxial absorption region can be set as a P-type mercury cadmium telluride absorption region 22, and the above-mentioned N-type mercury cadmium telluride absorption region 21 can be set to be obtained by inversion of the material after the P-type mercury cadmium telluride absorption region 22 is treated by doping, etc. In a feasible embodiment, when the ion beam bombards the P-type mercury cadmium telluride absorption layer to prepare the ring-shaped aperture channel 30, part of the P-type mercury cadmium telluride absorption layer is etched to generate excess mercury atoms, which are similar to donor impurities, diffuse into the P-type mercury cadmium telluride absorption layer, and are captured by mercury vacancies in the P-type mercury cadmium telluride absorption layer, so that the material of the P-type mercury cadmium telluride absorption layer is inverted to form a pn junction. In this embodiment, the tunneling passivation layer 61 and the carrier selective transport layer 62 form a passivation contact layer, and at this time, the passivation contact layer can cause the surface of the mercury cadmium telluride absorption layer to generate energy band bending, so as to promote the majority carriers (electron carriers) in the mercury cadmium telluride absorption layer to tunnel to the carrier selective transport layer 62, block the minority carriers (hole carriers) from recombination, and then realize the electrons to be collected by the conductive layer 63 through the carrier selective transport layer 62. In this embodiment, the conductive layer 63 can be specifically set as a metal layer.

[0066] Furthermore, in order to ensure electron tunneling and reduce the loss caused by resistance to avoid affecting the current density, the thickness of the tunnel passivation layer 61 can be set to be less than 10 nanometers;

[0067] The thickness of the carrier selective transport layer 62 is 100 nanometers to 200 nanometers.

[0068] It should be noted that in this embodiment, the thickness of the tunneling passivation layer 61 is less than 10 nanometers, and the thickness of the carrier selection and transport layer 62 is 100 nanometers to 200 nanometers. This can block the hole carriers in the mercury cadmium telluride absorption layer while promoting the tunneling and migration of electron carriers in the mercury cadmium telluride absorption layer, thereby reducing the resistance of the conductive path and ensuring the performance of the device.

[0069] Furthermore, in order to reduce the complexity of the fixed connection while ensuring that the HgCdTe absorption layer is fixed to the readout circuit 10 , the first passivation layer 40 may be connected to the readout circuit 10 via an adhesive 80 .

[0070] In the present embodiment, a first passivation layer 40 prepared on one side of the mercury cadmium telluride absorption layer is provided, and is connected to the readout circuit 10 via an adhesive 80. The adhesive 80 can, on the one hand, play an insulating and isolating role, and on the other hand, can realize a fixed connection between the first passivation layer 40 and the readout circuit 10. At this time, the mercury cadmium telluride absorption layer is also firmly connected to the readout circuit 10, and while ensuring the simplicity of preparation, a firm connection between the readout circuit 10 and the mercury cadmium telluride absorption layer is realized.

[0071] The ring hole infrared detector provided by the embodiment of the present invention includes a readout circuit 10, an absorption layer 20 and a ring hole channel 30, the absorption layer 20 includes a first surface and a second surface opposite to each other, a first passivation layer 40 is arranged on the first surface of the absorption layer 20, a second passivation layer 50 is arranged on the second surface of the absorption layer 20, the first passivation layer 40 is connected to the readout circuit 10, the ring hole channel 30 passes through the second passivation layer 50, the absorption layer 20 and the first passivation layer 40, and exposes the readout circuit 10, and the absorption layer 20 includes a first surface near the ring hole channel The first type epitaxial absorption region 30 and the second type epitaxial absorption region away from the annular channel 30, and the first type epitaxial absorption region and the second type epitaxial absorption region form a pn junction, a tunnel passivation layer 61, a carrier selection and transmission layer 62 and a conductive layer 63 are sequentially stacked on the surface of the annular channel 30, the first type epitaxial absorption region is conductively connected to the readout circuit 10 through the conductive layer 63, and a common electrode 70 conductively connected to the second type epitaxial absorption region is arranged at the position of the second passivation layer 50 corresponding to the second type epitaxial absorption region. The present invention is based on the structure of a tunneling passivation layer 61, a carrier selective transport layer 62 and a conductive layer 63 which are sequentially stacked on the surface of the annular hole channel 30. The tunneling passivation layer 61 is used to promote the electron carriers in the first type epitaxial absorption region to tunnel to the carrier selective transport layer 62. The carrier selective transport layer 62 is used to improve the migration ability of the electron carriers to the conductive layer 63. After being transferred through the conductive layer 63, the electron carriers are again passed through the carrier selective transport layer 62 and the tunneling passivation layer 61 on the surface of the readout circuit 10, so that the electron carriers are collected by the readout circuit 10. While realizing the normal operation of the detector, the surface of the annular hole channel 30 can be effectively passivated, and electrode contact can be realized without opening holes in the carrier selective transport layer 62 and the tunneling passivation layer 61, thereby reducing the leakage current of the device and improving the device performance.

[0072] In addition, the embodiment of the present invention sets the absorption layer 20 as a mercury cadmium telluride absorption layer, which can improve the infrared detection performance, reduce the space charge effect, and increase the saturation threshold of the device, thereby ensuring the functionality and adaptability of the above-mentioned ring-aperture infrared detector. At this time, the passivation contact layer formed by the tunneling passivation layer 61 and the carrier selection transmission layer 62 can cause the surface of the mercury cadmium telluride absorption layer to generate band bending, promote the majority carriers in the mercury cadmium telluride absorption layer to tunnel to the carrier selection transmission layer 62, block the minority carriers from recombination, and then realize the collection of electrons by the conductive layer 63 through the carrier selection transmission layer 62; By setting the thickness of the tunneling passivation layer 61 to be less than 10 nanometers and setting the thickness of the carrier selection transport layer 62 to be 100 nanometers to 200 nanometers, it is possible to block the hole carriers in the mercury cadmium telluride absorption layer while promoting the tunneling and migration of the electron carriers in the mercury cadmium telluride absorption layer, thereby reducing the resistance of the conductive path and ensuring the performance of the device; by providing a first passivation layer 40 prepared on one side of the mercury cadmium telluride absorption layer and connecting it to the readout circuit 10 through an adhesive 80, it is possible to reduce the complexity of the fixed connection while ensuring that the mercury cadmium telluride absorption layer and the readout circuit 10 are fixed.

[0073] A method for preparing a ring-shaped aperture infrared detector provided in an embodiment of the present invention is introduced below. The method for preparing a ring-shaped aperture infrared detector described below is used to prepare the ring-shaped aperture infrared detector as described above, and can be referred to in correspondence with the ring-shaped aperture infrared detector described above.

[0074] Please refer to Figure 3 , Figure 3 A flowchart of a method for preparing a ring-shaped infrared detector provided by an embodiment of the present invention, the method may include:

[0075] S101: Provide a detector preform; the detector preform includes a readout circuit, an absorption layer and an annular hole channel, the absorption layer includes a first surface and a second surface opposite to each other, a first passivation layer is arranged at the first surface of the absorption layer, a second passivation layer is arranged at the second surface of the absorption layer, the first passivation layer is connected to the readout circuit, the annular hole channel penetrates the second passivation layer, the absorption layer and the first passivation layer, and exposes the readout circuit, the absorption layer includes a first type epitaxial absorption region close to the annular hole channel and a second type epitaxial absorption region away from the annular hole channel, and the first type epitaxial absorption region forms a pn junction with the second type epitaxial absorption region.

[0076] The execution subject of this embodiment may be a ring-hole infrared detector manufacturing device. Regarding the definitions of the readout circuit, the absorption layer, the ring-hole channel, the first passivation layer, the second passivation layer, the first type epitaxial absorption region and the second type epitaxial absorption region in this embodiment, reference may be made to the above-mentioned embodiment of the ring-hole infrared detector.

[0077] Furthermore, in a feasible embodiment, providing the detector prefabricated part may include:

[0078] Step S11: providing a substrate, and epitaxially growing an absorption layer on the surface of the substrate;

[0079] Step S12: preparing a passivation layer on the surface of the absorption layer facing away from the substrate, removing the substrate, and preparing a passivation layer on the surface of the absorption layer after the substrate is removed; the passivation layer prepared on one surface of the absorption layer is used as the first passivation layer, and the passivation layer prepared on the other surface of the absorption layer is used as the second passivation layer;

[0080] Step S13: connecting the first passivation layer to the readout circuit to obtain a preform to be processed;

[0081] Step S14: etching and opening holes on the surface of the preform to be processed that faces away from the readout circuit until the readout circuit is exposed, so as to prepare an annular hole channel and obtain a detector preform.

[0082] In this embodiment, the detector preform is prepared through the above steps to ensure that the detector preform is successfully prepared. In this embodiment, the thermal mismatch problem between the substrate and the readout circuit is solved by completely removing the substrate.

[0083] Furthermore, in order to ensure the accuracy of the preparation of the annular channel, after providing the substrate and epitaxially growing the absorption layer on the surface of the substrate, the following steps may be further included:

[0084] Calculate the thickness of the absorbing layer based on Fourier testing;

[0085] The above-mentioned etching and opening of holes on the surface of the preform to be processed facing away from the readout circuit until the readout circuit is exposed to prepare an annular hole channel to obtain the detector preform may include:

[0086] Calculating the etching opening processing time according to the thickness of the absorption layer, the thickness of the first passivation layer and the thickness of the second passivation layer;

[0087] Based on the etching and opening processing time, an etching and opening is performed on the surface of the preform to be processed which faces away from the readout circuit to expose the readout circuit, thereby obtaining a detector preform prepared with an annular hole channel.

[0088] In this embodiment, the thickness of the prepared absorption layer is calculated based on the Fourier test, and the thickness of other passivation layers or functional layers in this embodiment is a fixed known value, so only the thickness of the prepared absorption layer needs to be calculated to obtain the thickness that needs to be etched and removed when the ring hole channel is finally prepared. At this time, the processing time of etching the hole when preparing the ring hole channel can be determined. In order to further improve the accuracy of the preparation, the thickness of other functional layers that need to be processed during the etching and opening process can also be measured and calculated.

[0089] Furthermore, in order to reduce the complexity of preparation, the above-mentioned connecting the first passivation layer with the readout circuit to obtain the preform to be processed may include:

[0090] The first passivation layer is connected to the readout circuit by adhesive using a vacuum tablet press to obtain a preform to be processed.

[0091] It should be noted that in this embodiment, a vacuum tablet press is used to fix the first passivation layer and the readout circuit structure with adhesive, so that the preparation efficiency can be guaranteed.

[0092] S102: preparing a tunnel passivation layer, a carrier selection and transport layer and a conductive layer by stacking them in sequence on the surface of the ring hole channel.

[0093] In this embodiment, the readout circuit, the first passivation layer, the absorption layer, and the second passivation layer can be stacked from bottom to top in sequence, and at this time, the annular hole channel is etched downward from the second passivation layer to open a hole. At this time, the surface of the annular hole channel only includes the side wall and the bottom surface, so the tunneling passivation layer is prepared on the side wall and the bottom surface of the annular hole channel, and the carrier selection transmission layer is prepared on the side wall and the bottom surface of the tunneling passivation layer on the side surface facing away from the annular hole channel surface. Correspondingly, the conductive layer is prepared on the side wall and the bottom surface of the carrier selection transmission layer on the side surface facing away from the tunneling passivation layer. The conductive layer can be specifically set as a metal conductive layer. In this embodiment, the specific method of preparing the above-mentioned tunneling passivation layer and the carrier selection transmission layer is not limited. For example, a thin layer of tunneling passivation layer can be grown by oxidation method or PECVD (plasma enhanced chemical vapor deposition) and other methods. It should be noted that the thinner the thickness of the tunneling passivation layer, the greater the probability of electron carrier tunneling. Correspondingly, the preparation method of the carrier selection transmission layer is also not limited in this embodiment.

[0094] Furthermore, in order to ensure that the tunneling passivation layer, the carrier selection transport layer and the conductive layer are successfully prepared, and the prepared tunneling passivation layer is uniform, the above-mentioned sequentially stacking of the tunneling passivation layer, the carrier selection transport layer and the conductive layer on the surface of the annular channel may include:

[0095] Step S21: preparing a tunnel passivation layer on the surface of the annular channel by an electrochemical process using an anodic oxidation method;

[0096] Step S22: preparing a carrier selection transport layer on the surface of the prepared tunnel passivation layer;

[0097] Step S23: preparing a conductive layer on the surface of the prepared carrier selective transport layer.

[0098] It should be noted that in this embodiment, the above-mentioned tunneling passivation layer is prepared by an anodic oxidation method. The anodized film contains a large amount of fixed positive charges, which helps to build an electric field on the contact surface, driving the minority carriers (hole carriers) generated by the incident photons on the surface of the N-type mercury cadmium telluride absorption region away from the interface, separating them from the majority carriers (electron carriers), reducing the recombination rate of carriers at the interface, and increasing the carrier lifetime, which is beneficial to improving the device response rate and detection rate.

[0099] Furthermore, in order to ensure that the carrier selection transport layer is successfully prepared, the above-mentioned preparation of the carrier selection transport layer on the surface of the prepared tunnel passivation layer may include:

[0100] A carrier selection transport layer is prepared on the surface of the prepared tunnel passivation layer by utilizing a plasma enhanced chemical vapor deposition process.

[0101] It should be noted that the growth method of the carrier selection transport layer in this embodiment is not limited to the PECVD (plasma enhanced chemical vapor deposition) process, and the LPCVD (low pressure chemical vapor deposition) process can also be used, but the influence of the plating growth needs to be considered, or it can also be prepared by sputtering. In this embodiment, the tunnel passivation layer and the carrier selection transport layer are combined to realize the passivation contact at the opening interface, which not only realizes the passivation of the hole sidewall, but also the passivation contact layer composed of the tunnel passivation layer and the carrier selection transport layer, and the contact with the N-type mercury cadmium telluride absorption area forms a band bending, which can promote majority carrier transmission, block minority carrier recombination, reduce the probability of electron-hole recombination, and facilitate more carriers to be collected by the conductive layer.

[0102] S103: preparing a common electrode conductively connected to the second type epitaxial absorption region at a position of the second passivation layer corresponding to the second type epitaxial absorption region.

[0103] In this embodiment, a common electrode is prepared in the second passivation layer, and the common electrode is conductively connected to the second type epitaxial absorption region to realize electrode extraction of the second type epitaxial absorption region.

[0104] The method for preparing an annular hole infrared detector provided by the embodiment of the present invention includes S101: providing a detector preform, the detector preform includes a readout circuit, an absorption layer and an annular hole channel, the absorption layer includes a first surface and a second surface relative to each other, a first passivation layer is arranged at the first surface of the absorption layer, a second passivation layer is arranged at the second surface of the absorption layer, the first passivation layer is connected to the readout circuit, the annular hole channel runs through the second passivation layer, the absorption layer and the first passivation layer, and exposes the readout circuit, the absorption layer includes a first type epitaxial absorption region close to the annular hole channel and a second type epitaxial absorption region away from the annular hole channel, and the first type epitaxial absorption region forms a pn junction with the second type epitaxial absorption region; S102: sequentially stacking a tunneling passivation layer, a carrier selection and transport layer and a conductive layer on the surface of the annular hole channel; S103: preparing a common electrode conductively connected to the second type epitaxial absorption region at a position of the second passivation layer corresponding to the second type epitaxial absorption region. The present invention is based on the structure of a tunneling passivation layer, a carrier selection transport layer and a conductive layer stacked in sequence on the surface of an annular hole channel. The tunneling passivation layer is used to promote the tunneling of electron carriers in the first type epitaxial absorption region to the carrier selection transport layer. The carrier selection transport layer is used to improve the migration ability of the electron carriers to the conductive layer. After being transferred through the conductive layer and passing through the carrier selection transport layer and the tunneling passivation layer on the surface of the readout circuit again, the electron carriers are collected by the readout circuit. While realizing the normal operation of the detector, the surface of the annular hole channel can be effectively passivated, and electrode contact can be realized without opening holes in the carrier selection transport layer and the tunneling passivation layer, thereby reducing the leakage current of the device and improving the device performance.

[0105] In addition, the embodiment of the present invention ensures that the detector preform is successfully prepared through the above-mentioned specific steps of preparing the detector preform, and solves the thermal mismatch problem between the substrate and the readout circuit by completely removing the substrate; the thickness of the prepared absorption layer is calculated according to the Fourier test, and the thickness that needs to be etched and removed when the annular hole channel is finally prepared can be obtained. At this time, the processing time of etching and opening the hole when preparing the annular hole channel can be determined, which ensures the accuracy of the preparation of the annular hole channel; using a vacuum sheet press, the first passivation layer and the readout circuit structure are fixedly connected by adhesive, which can improve the preparation efficiency; the above-mentioned tunneling passivation layer is prepared by anodizing. Since the anodized film contains a large amount of fixed positive charges, it is helpful to construct an electric field on the contact surface, drive the hole carriers generated by the incident photons on the surface of the N-type mercury cadmium telluride absorption area away from the interface, separate them from the electron carriers, reduce the recombination rate of carriers at the interface, increase the life of carriers, and help improve the device response rate and detection rate; the carrier selection transport layer is prepared by plasma enhanced chemical vapor deposition process, which ensures that the carrier selection transport layer is successfully prepared.

[0106] In a feasible embodiment, the above-mentioned ring hole infrared detector preparation method can refer to Figure 4 , Figure 4 A flowchart of a method for preparing a ring-shaped infrared detector provided in an embodiment of the present invention may specifically include the following steps:

[0107] Step S1: preparing a mercury cadmium telluride absorption layer 23 on the upper surface of the substrate 1, calculating the thickness of the prepared mercury cadmium telluride absorption layer 23 by Fourier test, and calculating the etching time of the ring hole channel according to the thickness of the mercury cadmium telluride absorption layer 23.

[0108] This step S1 is as follows Figure 4 As shown in (a) in .

[0109] Step S2: passivating the front surface of the mercury cadmium telluride absorption layer 23 to obtain a second passivation layer 50 , removing the substrate 1 , and preparing a first passivation layer 40 on the surface of the mercury cadmium telluride absorption layer 23 after removing the substrate 1 .

[0110] The structure prepared in step S2 is as follows Figure 4 As shown in (b) to (d) in FIG.

[0111] Step S3: using a vacuum sheet press, the first passivation layer 40 prepared on the back side of the mercury cadmium telluride absorption layer 23 is bonded to the readout circuit 10 by means of an adhesive 80 to obtain a preform to be processed.

[0112] The preform to be processed prepared in step S3 is as follows Figure 4 As shown in (e) in .

[0113] Step S4: According to the etching time of the annular channel, the second passivation layer 50 prepared along the front side of the mercury cadmium telluride absorption layer 23 is photolithographically opened in the direction of the back side of the mercury cadmium telluride absorption layer 23, and the preform to be processed is placed in a plasma etcher to etch the annular channel 30 until the readout circuit 10 is exposed, thereby obtaining a detector preform.

[0114] The detector preform prepared in step S4 is as follows Figure 4 As shown in (f) in .

[0115] Step S5: a patterned photoresist is prepared on the front side of the detector preform, and a tunnel passivation layer 61, a carrier selection and transport layer 62 and a conductive layer 63 are sequentially stacked on the surface of the annular channel 30. The specific preparation method is as follows:

[0116] Step S51: preparing a tunnel passivation layer 61 on the surface of the annular channel by an electrochemical process using an anodic oxidation method;

[0117] In the present embodiment, the electrolyte is 0.1 mol / L potassium hydroxide, the solvent is a mixture of 90% ethylene glycol and 10% deionized water, the mercury cadmium telluride absorption layer 23 is used as the anode, and the graphite or platinum electrode is used as the cathode. Oxidation is performed under a constant current condition of 0.1-0.5 mA / cm2 to grow a thin tunnel passivation layer with a thickness of less than 10 nm.

[0118] Step S52: using a plasma enhanced chemical vapor deposition process to prepare a carrier selective transport layer 62 with a thickness of 100 nanometers to 200 nanometers on the surface of the prepared tunnel passivation layer 61 .

[0119] The structure prepared in step S5 is as follows Figure 4 As shown in (g) in .

[0120] Step S6: preparing a conductive layer 63 on the surface of the prepared carrier selective transport layer 62;

[0121] In this embodiment, the conductive layer 63 can be set as a conductive metal layer. During preparation, the structure prepared in step S5 can be placed in a metal deposition device. The deposited metal layer can be made of Cr (chromium) or Au (gold), but is not limited to the above metal materials. The structure prepared in step S6 is as follows Figure 4 As shown in (h) in .

[0122] Step S7: removing the patterned photoresist, and then patterning the position of the second passivation layer 50 corresponding to the P-type HgCdTe absorption region 22 to expose the P-type HgCdTe absorption region 22 , and depositing a common electrode 70 at the exposed P-type HgCdTe absorption region 22 .

[0123] In this embodiment, the common electrode 70 prepared by deposition can be made of Cr (chromium) or Au (gold), but is not limited to the above metal materials. The structure prepared in step S7 is as follows: Figure 4 As shown in (i) in .

[0124] Compared with traditional device processes, the present invention avoids direct contact between metal and absorption layer semiconductor, realizes carrier collection without local opening through the carrier selection transmission layer 62, reduces contact resistance, and reduces metal contact recombination current, thereby improving device efficiency. It also reduces the number of photolithography steps before electrode growth and avoids the problem of inaccurate overlay caused by multiple photolithography.

[0125] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0126] In addition, it should be noted that, in this article, relationships such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0127] The above is a detailed introduction to a ring-hole infrared detector and a method for preparing a ring-hole infrared detector provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A ring hole infrared detector, characterized in that: include: readout circuit, absorption layer and annular hole channel; The absorption layer comprises a first surface and a second surface opposite to each other, a first passivation layer is disposed on the first surface of the absorption layer, a second passivation layer is disposed on the second surface of the absorption layer, and the first passivation layer is connected to the readout circuit; The annular hole channel penetrates the second passivation layer, the absorption layer and the first passivation layer, and exposes the readout circuit; The absorption layer comprises a first type epitaxial absorption region close to the annular hole channel and a second type epitaxial absorption region far from the annular hole channel, and the first type epitaxial absorption region and the second type epitaxial absorption region form a pn junction; A tunnel passivation layer, a carrier selection and transport layer and a conductive layer are sequentially stacked on the surface of the annular channel, and the first type epitaxial absorption region is conductively connected to the readout circuit through the conductive layer; A common electrode conductively connected to the second type epitaxial absorption region is disposed at a position of the second passivation layer corresponding to the second type epitaxial absorption region.

2. The ring-shaped infrared detector according to claim 1, characterized in that: The absorption layer is a mercury cadmium telluride absorption layer; The first type epitaxial absorption region is an N-type mercury cadmium telluride absorption region, and the second type epitaxial absorption region is a P-type mercury cadmium telluride absorption region.

3. The ring-shaped infrared detector according to claim 1, characterized in that: The thickness of the tunnel passivation layer is less than 10 nanometers; The thickness of the carrier selective transport layer is 100 nanometers to 200 nanometers.

4. The ring-shaped infrared detector according to claim 1, characterized in that: The first passivation layer is connected to the readout circuit via adhesive.

5. A method for preparing a ring-shaped infrared detector, characterized in that: Used to prepare the ring-shaped infrared detector according to any one of claims 1 to 4, comprising: A detector preform is provided; the detector preform comprises a readout circuit, an absorption layer and an annular hole channel, the absorption layer comprises a first surface and a second surface opposite to each other, a first passivation layer is arranged at the first surface of the absorption layer, a second passivation layer is arranged at the second surface of the absorption layer, the first passivation layer is connected to the readout circuit, the annular hole channel penetrates the second passivation layer, the absorption layer and the first passivation layer, and exposes the readout circuit, the absorption layer comprises a first type epitaxial absorption region close to the annular hole channel and a second type epitaxial absorption region away from the annular hole channel, and the first type epitaxial absorption region and the second type epitaxial absorption region form a pn junction; A tunnel passivation layer, a carrier selection and transport layer, and a conductive layer are sequentially stacked on the surface of the annular channel; A common electrode conductively connected to the second type epitaxial absorption region is prepared at a position of the second passivation layer corresponding to the second type epitaxial absorption region.

6. The method for preparing the ring-shaped infrared detector according to claim 5, characterized in that: A tunnel passivation layer, a carrier selection and transport layer, and a conductive layer are sequentially stacked on the surface of the annular hole channel, including: The tunnel passivation layer is prepared on the surface of the annular channel by an anodic oxidation method through an electrochemical process; Prepare the carrier selection and transport layer on the surface of the prepared tunnel passivation layer; The conductive layer is prepared on the surface of the prepared carrier selective transport layer.

7. The method for preparing the ring-shaped infrared detector according to claim 6, characterized in that: The carrier selection and transport layer is prepared on the surface of the prepared tunnel passivation layer, comprising: The carrier selection and transport layer is prepared on the surface of the prepared tunnel passivation layer by using a plasma enhanced chemical vapor deposition process.

8. The method for preparing the ring-shaped infrared detector according to claim 5, characterized in that: The provision of a detector prefabricated component comprises: Providing a substrate, and epitaxially growing an absorption layer on a surface of the substrate; A passivation layer is prepared on the surface of the absorption layer facing away from the substrate, the substrate is removed, and a passivation layer is prepared on the surface of the absorption layer after the substrate is removed; the passivation layer prepared on one surface of the absorption layer is used as the first passivation layer, and the passivation layer prepared on the other surface of the absorption layer is used as the second passivation layer; Connecting the first passivation layer to the readout circuit to obtain a preform to be processed; A hole is formed by etching on the surface of the preform to be processed which faces away from the readout circuit until the readout circuit is exposed, so as to prepare the annular channel and obtain the detector preform.

9. The method for preparing the ring-shaped infrared detector according to claim 8, characterized in that: After providing a substrate and epitaxially growing an absorption layer on the surface of the substrate, the method further includes: Calculating the thickness of the absorbing layer according to Fourier test; Etching and opening a hole on the surface of the preform to be processed facing away from the readout circuit until the readout circuit is exposed to prepare the annular hole channel to obtain the detector preform, comprising: Calculating the etching opening processing time according to the thickness of the absorption layer, the thickness of the first passivation layer and the thickness of the second passivation layer; Based on the etching and opening processing time, etching and opening are performed on the surface of the preform to be processed facing away from the readout circuit to expose the readout circuit, thereby obtaining the detector preform prepared with the annular hole channel.

10. The method for preparing the ring-shaped infrared detector according to claim 8, characterized in that: Connecting the first passivation layer to the readout circuit to obtain a preform to be processed, comprising: The first passivation layer is connected to the readout circuit by adhesive using a vacuum tablet press to obtain the preform to be processed.

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