A multi-electrode high-purity germanium detector

Abstract

The present disclosure provides a multi-electrode high-purity germanium detector, comprising: a planar high-purity germanium crystal having an exposed intrinsic layer surface; a lithium diffusion electrode layer formed by diffusing lithium ions on one end face of the planar high-purity germanium crystal and a portion of the side surface connected to the end face, for achieving a stable connection between the planar high-purity germanium crystal and a crystal mechanical fixture; an amorphous barrier layer located on the other end face of the planar high-purity germanium crystal; a guard ring located on the amorphous barrier layer; and a plurality of independent electrodes spaced apart and located within the guard rings. The multi-electrode high-purity germanium detector provided by the present disclosure, by using both amorphous coating and lithium diffusion layer processes, simplifies electrode fabrication, improves yield, reduces dead zone range, reduces assembly and maintenance difficulty, and improves detector reliability.

Description

Technical Field

[0001] The present disclosure relates to the technical field of semiconductor radiation detectors, and in particular to a multi-electrode high-purity germanium detector. Background Art

[0002] Multi-electrode high-purity germanium detectors utilize multiple electrodes to obtain the position information of incident particle impact points while maintaining high energy resolution. These multiple electrodes can operate independently, playing an important role in radiation measurement, nuclear safety, and fundamental physics experiments. However, existing multi-electrode detectors are complex to manufacture and require expensive equipment. This leads to low yields, large dead zones, and significant assembly and maintenance difficulties, significantly limiting their application. Summary of the Invention

[0003] In view of the above problems, the present disclosure provides a multi-electrode high-purity germanium detector, which aims to solve the technical problems in the prior art such as the complex manufacturing process of the multi-electrode detector, expensive equipment required, low yield, and large dead zone.

[0004] The present disclosure provides a multi-electrode high-purity germanium detector, comprising: a planar high-purity germanium crystal having an exposed intrinsic layer surface; a lithium diffusion electrode layer formed by diffusing lithium ions on one end face and a portion of the connected side faces of the planar high-purity germanium crystal, for achieving a stable connection between the planar high-purity germanium crystal and a crystal mechanical fixture; an amorphous barrier layer located on the other end face of the planar high-purity germanium crystal; a guard ring located on the amorphous barrier layer; and a plurality of independent electrodes, each spaced apart and located within the guard ring.

[0005] Furthermore, the planar high-purity germanium crystal is cylindrical, and its germanium doping concentration is 0.1×10 10 ~2×10 10 / cm 3 .

[0006] Furthermore, the multi-electrode high-purity germanium detector further includes: a preamplifier circuit; wherein, some or all of the multiple independent electrodes are respectively led out to be connected to a channel of the preamplifier circuit.

[0007] Furthermore, the potential of the guard ring and the independent electrodes that are not drawn out among the plurality of independent electrodes is substantially the same as the potential of some of the independent electrodes that are drawn out.

[0008] Furthermore, the plurality of independent electrodes are one-dimensional parallel strip electrodes or two-dimensional densely packed array electrodes; wherein the center distance between two adjacent independent electrodes is 0.02 mm to 10 mm, and the spacing range is 0.01 mm to 2 mm.

[0009] Furthermore, the planar high-purity germanium crystal is an N-type high-purity germanium crystal or a P-type high-purity germanium crystal.

[0010] Furthermore, the exposed surface of the intrinsic layer is the portion of the planar high-purity germanium crystal side excluding the side of the lithium diffusion electrode layer, which is used to isolate the lithium diffusion electrode layer and the amorphous barrier layer.

[0011] Furthermore, the outer diameter of the planar high-purity germanium crystal ranges from 10 mm to 150 mm, and the thickness ranges from 5 mm to 90 mm. The outer diameter of the guard ring is smaller than the outer diameter of the planar high-purity germanium crystal.

[0012] Furthermore, the multiple independent electrodes and the guard ring are aluminum layers, and the thickness of each layer is 10 nm to 5000 nm.

[0013] Furthermore, the amorphous barrier layer is an amorphous germanium layer or an amorphous silicon layer, and its thickness is 10 nm to 5000 nm.

[0014] The embodiments of the present disclosure provide a multi-electrode high-purity germanium detector, which utilizes the end face of a planar high-purity germanium crystal and a lithium diffusion electrode layer that continuously extends to the side of the planar high-purity germanium crystal to achieve stable fixation of the planar high-purity germanium crystal, facilitate assembly operations and maintenance, and do not require the production of additional structures on the crystal, thereby reducing the dead zone of the device. The exposed surface of the intrinsic layer in the planar high-purity germanium crystal and the guard ring on the amorphous barrier layer can effectively control leakage current and ensure the energy resolution of each central electrode of the multi-electrode high-purity germanium detector. In addition, multiple central electrodes can be read independently to obtain the position information of the point of action of the incident particle. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] For a more complete understanding of the present disclosure and its advantages, reference will now be made to the following description taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 Schematically shows a three-dimensional diagram of a multi-electrode high-purity germanium detector according to an embodiment of the present disclosure;

[0017] Figure 2 The schematic diagram shows a multi-electrode high purity germanium detector according to an embodiment of the present disclosure. Figure 1 Cross-sectional view in the AA direction;

[0018] Figure 3 Schematically shows a top view of a multi-electrode high-purity germanium detector according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the detailed description below, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0020] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element or intervening elements may be present. Moreover, in the specification and claims, when it is described that an element is "connected to" another element, the element may be "directly connected to" the other element or "connected to" the other element through a third element.

[0021] When describing the embodiments of the present disclosure, for ease of explanation, cross-sectional views of device structures may be partially enlarged and not to scale. Furthermore, these schematic views are merely illustrative and should not limit the scope of protection of the present disclosure. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0022] Based on the technical problems existing in the prior art, the embodiments of the present disclosure provide a multi-electrode high-purity germanium detector. The provision of guard rings on the intrinsic surface and amorphous barrier layer in the multi-electrode high-purity germanium detector effectively controls leakage current, ensuring the energy resolution of each electrode within the detector guard ring. Multiple electrodes can independently read out information, enabling the location information of the point of impact of incident particles to be obtained. Furthermore, by utilizing the end face of a planar high-purity germanium crystal and a lithium diffusion layer that continuously extends to the side of the planar high-purity germanium crystal, the planar high-purity germanium crystal can be stably fixed, facilitating assembly operations and maintenance. No additional structures are required on the crystal, thereby reducing the dead zone of the device.

[0023] Figure 1 A perspective view of a multi-electrode high-purity germanium detector according to an embodiment of the present disclosure is schematically shown.

[0024] like Figure 1 As shown, the multi-electrode high-purity germanium detector 100 includes: a crystal mechanical fixture 10 , a lithium diffusion electrode layer 20 , a planar high-purity germanium crystal 30 , an amorphous barrier layer 40 , a plurality of independent electrodes 50 and a guard ring 60 .

[0025] In the disclosed embodiments, the planar high-purity germanium crystal 30 can be cylindrical, with one end surface continuously extending to a portion of the side surface of the planar high-purity germanium crystal 30 to form a lithium diffusion electrode layer 20 by diffusing lithium ions. This lithium diffusion electrode layer 20 is used to achieve a stable connection between the planar high-purity germanium crystal 30 and the crystal mechanical fixture 10 and also serves as an electrode. The other end surface of the planar high-purity germanium crystal 30 is formed by an amorphous barrier layer 40, which covers the entire end surface of the planar high-purity germanium crystal 30 and acts as an electron blocking layer.

[0026] like Figure 2 As shown, the outermost ring of the amorphous barrier layer 40 is a guard ring 60. The guard ring 60 divides the upper surface of the amorphous barrier layer 40 into a first region 41 and a second region 42. The first region 41 is located outside the guard ring 60, and the second region 42 is located inside the guard ring 60. A plurality of independent electrodes 50 are disposed in the second region 42. The plurality of independent electrodes 50 are spaced apart and located inside the guard ring 60 and are non-contactably connected to the guard ring 60. The guard ring 60 surrounds the plurality of independent electrodes 50 within the ring, and each independent electrode within the ring serves as a central electrode.

[0027] In the embodiment of the present disclosure, the planar high-purity germanium crystal 30 can be an N-type high-purity germanium crystal or a P-type high-purity germanium crystal, and the portion of its side excluding the side of the amorphous barrier layer 40 is the exposed surface 31 of the intrinsic layer. The exposed surface 31 of the intrinsic layer is used to isolate the lithium diffusion electrode layer 20 and the amorphous barrier layer 40.

[0028] According to the embodiments of the present disclosure, the multi-electrode high-purity germanium detector 100 utilizes the end face of the planar high-purity germanium crystal 30 and the lithium diffusion electrode layer 20 (i.e., the lithium diffusion electrode) that continuously extends to the side of the planar high-purity germanium crystal 30 to achieve stable fixation of the planar high-purity germanium crystal, facilitating assembly, operation, and maintenance of the multi-electrode high-purity germanium detector 100. No additional structures need to be fabricated on the crystal, thereby reducing dead zones. The guard ring 60 on the exposed surface 31 of the intrinsic layer and the amorphous barrier layer 40 effectively controls leakage current, ensuring the energy resolution of each central electrode of the multi-electrode high-purity germanium detector 100. Multiple central electrodes can be read independently, enabling the acquisition of positional information about the point of impact of incident particles.

[0029] Specifically, the multi-electrode high-purity germanium detector 100 also includes a preamplifier circuit. Some or all of the multiple independent electrodes are individually led out, with each led-out independent electrode connected to a channel of the preamplifier circuit. In the disclosed embodiment, the guard ring 60 and readout electrode region can be led out as needed. The potential of the guard ring 60 and the unleaded independent electrodes 50 is maintained at approximately the same level as that of the led-out independent electrodes.

[0030] In the embodiment of the present disclosure, the guard ring 60 may be directly connected to a fixed potential, or may be connected to a channel of the preamplifier circuit to achieve a potential substantially the same as that of the derived independent electrode.

[0031] As a radiation detector made using the principle of ionizing radiation, a high-purity germanium detector can detect microscopic particles that cause ionizing radiation. Microscopic particles that cause ionizing radiation (generally with energy greater than 10eV) can interact within the sensitive volume of the high-purity germanium detector to generate carriers. These carriers can be collected by applying a bias voltage to electrodes made on a planar high-purity germanium crystal, generating a recordable electrical signal that provides information about the energy deposited by the particles. The multi-electrode high-purity germanium detector 100 provided in the embodiment of the present disclosure can obtain information about the particle's action position and the number of action points by making multiple independent electrodes, thereby enabling the acquisition of more information and improving the counting rate.

[0032] According to an embodiment of the present disclosure, the planar high-purity germanium crystal 30 is cylindrical with an outer diameter ranging from 10 mm to 150 mm and a thickness of 5 mm to 90 mm, preferably with a diameter of 30 mm and a thickness of 10 mm. In other exemplary embodiments, the planar high-purity germanium crystal 30 may also have other shapes, such as a rectangular parallelepiped. Its specific dimensions may be set according to actual needs. The embodiment of the present disclosure does not limit the shape and size of the planar high-purity germanium crystal 30.

[0033] According to an embodiment of the present disclosure, the height of the lithium diffusion electrode layer 20 continuously extending to the side of the planar high-purity germanium crystal 30 can be 2 mm to 5 mm, preferably 3 mm. In other exemplary embodiments, the height of the lithium diffusion electrode layer 20 continuously extending to the side of the planar high-purity germanium crystal 30 can also be other values, which can be adjusted according to actual application requirements.

[0034] According to an embodiment of the present disclosure, the amorphous barrier layer 40 can be prepared by magnetron sputtering. The amorphous barrier layer 40 is an amorphous germanium layer or an amorphous silicon layer, and its thickness is 10 nm to 5000 nm, preferably 100 nm. In other exemplary embodiments, the amorphous barrier layer 40 can also be an amorphous electron blocking layer of reasonable thickness prepared by other methods. The embodiments of the present disclosure do not limit the preparation method of the amorphous barrier layer 40, and its layer thickness range includes but is not limited to that shown in the above embodiments.

[0035] According to the embodiment of the present disclosure, multiple independent electrodes 50 and protective rings 60 can be formed by evaporating an aluminum layer, and the layer thickness is 10nm to 5000nm, for example, it can be 100nm, 200nm, etc. The layer thickness can be adjusted according to actual application requirements. The embodiment of the present disclosure does not limit the preparation method of the metal layer.

[0036] Specifically, the outer diameter of the guard ring 60 is smaller than the outer diameter of the planar high-purity germanium crystal 30, or the outer diameter of the guard ring 60 can be close to the outer diameter of the planar high-purity germanium crystal 30. The outer diameter can range from 5 mm to 149 mm, and the ring width ranges from 0.01 to 5 mm. Preferably, the outer diameter of the guard ring 60 is slightly smaller than the outer diameter of the planar high-purity germanium crystal 30, and the ring width is preferably 2 mm. In other exemplary embodiments, the guard ring 60 can also have other shapes and sizes, such as a rectangular body or a square body.

[0037] Specifically, the multiple independent electrodes 50 inside the guard ring 60 can be one-dimensional parallel strip electrodes (such as Figure 1 as shown) or two-dimensional dense array electrodes (as Figure 3 As shown in FIG, the center distance between two adjacent independent electrodes is 0.02 mm to 10 mm, wherein the two adjacent independent electrodes are independent of each other and the spacing range is 0.01 mm to 2 mm. It should be noted that the center distance in the embodiment of the present disclosure refers to the distance between the center positions of two adjacent independent electrodes.

[0038] like Figure 1 The figure shows a schematic diagram of a plurality of parallel strip electrodes 50 , each of which is independent of each other and spaced apart. By independently reading out part or all of the plurality of parallel strip electrodes 50 , the position information of the impact point of the incident particle can be obtained.

[0039] like Figure 3 The illustrated two-dimensional damascene array of electrodes can be shaped in one or more geometric shapes, such as square, rectangular, triangular, hexagonal, trapezoidal, or parallelogram, to form a two-dimensional damascene array. This allows for a denser distribution of independent electrodes within a guard ring 60 of the same size. By independently reading multiple central electrodes within the two-dimensional damascene array, the positional information of the incident particle's impact point is acquired with an additional dimension, broadening the applicability of the multi-electrode high-purity germanium detector.

[0040] In the embodiment of the present disclosure, the number N of multiple independent electrodes 50 is determined by the center distance D and the size of the guard ring 60. Taking a one-dimensional parallel strip electrode as an example, the electrode width is the center distance minus d, d is the distance between adjacent electrodes, and the inner diameter of the guard ring is L. The reference value of the number of electrodes N is L / D. Generally, L / D is rounded down (when L / D is not an integer) or subtracted by 1 (when L / D is an integer) to obtain the number of electrodes N. The guard ring 60 should cover the area within the ring except the center electrode as much as possible, and can expand inward. For example, if Figure 2The schematic diagram shows the structure of seven parallel strip electrodes 50 within a guard ring 60. When the outer diameter of the guard ring 60 is 28 mm, the inner diameter is 24 mm, and the center-to-center distance is 3 mm, N is 7, the spacing between the electrodes is 0.5 mm, and the electrode width is 2.5 mm. The guard ring 60 is expanded inward to cover as much of the area within the ring as possible, excluding the center electrode.

[0041] It should be noted that, in the embodiment of the present disclosure, the number of the plurality of independent electrodes 50 is not less than 2, and may be 3, 4, 7 or other greater numbers, which is not limited in the embodiment of the present disclosure.

[0042] The multi-electrode high-purity germanium detector provided by the embodiment of the present disclosure uses a combination of amorphous coating and lithium diffusion layer processes. While ensuring low leakage current and high energy resolution, it also simplifies electrode production, improves the yield rate, reduces the dead zone range, reduces the difficulty of assembly and maintenance, and improves the reliability of the detector.

[0043] While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive.

[0044] Those skilled in the art will appreciate that the features described in the various embodiments and / or claims of this disclosure may be combined and / or coupled in a variety of ways, even if such combinations or couplings are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure may be combined and / or coupled in a variety of ways without departing from the spirit and teachings of this disclosure. All such combinations and / or couplings are intended to fall within the scope of this disclosure.

[0045] Although the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made to the present disclosure without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. Therefore, the scope of the present disclosure should not be limited to the above-described embodiments, but should be determined not only by the appended claims but also by the equivalents of the appended claims.

Claims

1. A multi-electrode high-purity germanium detector, characterized in that: include: A planar high-purity germanium crystal having an exposed intrinsic layer surface, wherein the exposed intrinsic layer surface is a portion of the side surface of the planar high-purity germanium crystal excluding the side surface of the lithium diffusion electrode layer, and is used to isolate the lithium diffusion electrode layer and the amorphous barrier layer; A lithium diffusion electrode layer, formed by diffusing lithium ions on one end face of the planar high-purity germanium crystal and a portion of the side face connected to the end face, for achieving a stable connection between the planar high-purity germanium crystal and a crystal mechanical fixture, and also serving as an electrode; an amorphous barrier layer, which is located on the other end surface of the planar high-purity germanium crystal; a guard ring located on the amorphous barrier layer; A plurality of independent electrodes are respectively arranged at intervals and located within the guard ring.

2. The multi-electrode high-purity germanium detector according to claim 1, characterized in that: The multi-electrode high-purity germanium detector further includes: a preamplifier circuit; wherein, part or all of the multiple independent electrodes are respectively led out to connect to a channel of the preamplifier circuit.

3. The multi-electrode high-purity germanium detector according to claim 2, characterized in that: The potential of the guard ring and the independent electrodes that are not drawn out among the plurality of independent electrodes is substantially the same as the potential of some of the independent electrodes that are drawn out.

4. The multi-electrode high-purity germanium detector according to claim 1, characterized in that: The multiple independent electrodes are one-dimensional parallel strip electrodes or two-dimensional dense array electrodes; wherein the center distance between two adjacent independent electrodes is 0.02mm~10mm, and the spacing range is 0.01mm~2mm.

5. The multi-electrode high-purity germanium detector according to claim 1, characterized in that: The planar high-purity germanium crystal is an N-type high-purity germanium crystal or a P-type high-purity germanium crystal.

6. The multi-electrode high-purity germanium detector according to claim 1, characterized in that: The outer diameter of the planar high-purity germanium crystal ranges from 10 mm to 150 mm, and the thickness ranges from 5 mm to 90 mm. The outer diameter of the guard ring is smaller than the outer diameter of the planar high-purity germanium crystal.

7. The multi-electrode high-purity germanium detector according to claim 1, characterized in that: The plurality of independent electrodes and the guard ring are aluminum layers, and the thickness of the aluminum layers is 10 nm to 5000 nm.

8. The multi-electrode high-purity germanium detector according to claim 1, characterized in that: The amorphous barrier layer is an amorphous germanium layer or an amorphous silicon layer, and its thickness is 10nm-5000nm.

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