Semiconductor X-ray detector and preparation method thereof
By adopting PNN-type dual built-in electric field configuration and multi-layer semiconductor structure in semiconductor X-ray detectors, the problems of low sensitivity and high energy consumption in high-energy X-ray detection are solved, and self-energy supply is achieved. Sensitive and stable X-ray detection effect.
Patent Information
- Application Number
- CN202411474520.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-02-07
AI Technical Summary
Existing semiconductor X-ray detectors have problems such as low sensitivity, high spectral noise and high energy consumption in high energy X-ray detection, especially in deep space detection and wearable devices, which are difficult to achieve continuous energy supply and efficient detection.
Using PNN-type dual built-in electric field configuration, multi-layer semiconductor structure is deposited through radio frequency magnetron sputtering technology, including P-type NiO, N-type Ga2O3 and Si-doped Ga2O3, forming self-energized detection The device avoids the need for applied bias voltage.
It realizes the self-energy supply through the Compton effect and photovoltaic effect of X-ray without external power supply, improves the sensitivity and stability of the detector, reduces energy consumption, and is small in size and light in weight, making it easy to carry.
Smart Images
Figure CN119403249A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of semiconductor devices and discloses a semiconductor X-ray detector and a preparation method, a recording medium and a system thereof. Background Art
[0002] X-rays are electromagnetic waves with extremely high frequency (30PHz~300EHz), extremely short wavelength (0.01nm~10nm), and high energy (100eV~10MeV). When they interact with matter, the main processes are photoelectric effect and Compton effect. They are widely used in deep space exploration, nuclear industry, materials science, medical imaging, radiotherapy, security monitoring and other fields. These application scenarios have given rise to a huge demand for X-ray detectors.
[0003] The most widely used semiconductor X-ray detector is the Si-based narrow-bandgap semiconductor X-ray detector, which has a mature preparation process and high material quality, and its performance can meet certain application requirements. However, due to the small atomic number of Si (Z = 14), the absorption efficiency of X-rays (especially hard X-rays with energy higher than 10 keV) is not ideal. Other commercialized semiconductor X-ray detectors such as Se, Ge, CdTe, CdZnTe (CZT) have problems such as large spectral noise and low sensitivity. In order to improve the sensitivity of X-ray detection, the most effective way is to increase the bias voltage of the semiconductor X-ray detector. If an external bias voltage is required in wearable X-ray detection equipment, it will bring safety and endurance problems and inconvenience in wearing and taking off; and for deep space X-ray detection application scenarios, applying a higher working voltage will bring greater energy consumption problems. Therefore, how to solve the continuous power supply of the detector, effectively shield the spectral noise, and enable the detector to perform X-ray detection sensitively and stably is a technical problem that the industry urgently needs to solve. Summary of the invention
[0004] In view of the above problems, the present invention provides a semiconductor X-ray detector, comprising a first electrode, a second electrode, a galvanometer, and a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer stacked in sequence; the first electrode and the second electrode are both made of metal, one end of the first electrode is in ohmic contact with the first semiconductor layer, and the other end is electrically connected to one end of the galvanometer; the other end of the galvanometer is electrically connected to one end of the second electrode, and the other end of the second electrode is in ohmic contact with the third semiconductor layer; the first semiconductor layer is a P-type semiconductor, the second semiconductor layer and the third semiconductor layer are both N-type semiconductors, the free electron concentration of the third semiconductor layer is higher than the free electron concentration of the second semiconductor layer, and the bandgap widths of the first semiconductor layer, the second semiconductor layer, and the third semiconductor layer are all ≥3.26eV.
[0005] Preferably, the material of the first electrode is Pt, and the material of the second electrode is Ag.
[0006] Preferably, the first semiconductor layer is NiO, the second semiconductor layer is Ga2O3, and the third semiconductor layer is Si-doped Ga2O3.
[0007] Preferably, the first semiconductor layer is GaN, the second semiconductor layer is ZnO, and the third semiconductor layer is SnO2.
[0008] Preferably, the device further comprises a processor for converting the current signal obtained by the galvanometer into an X-ray dose rate.
[0009] In order to complete the preparation of the above-mentioned semiconductor X-ray detector, the present invention also provides a method for preparing a semiconductor X-ray detector, and the specific scheme includes the following steps:
[0010] S1. Depositing a second semiconductor layer and a third semiconductor layer in sequence from bottom to top on the first semiconductor layer by radio frequency magnetron sputtering technology; the first semiconductor layer is a P-type semiconductor, the second semiconductor layer and the third semiconductor layer are both N-type semiconductors, the free electron concentration of the third semiconductor layer is higher than the free electron concentration of the second semiconductor layer, and the bandgap widths of the first semiconductor layer, the second semiconductor layer and the third semiconductor layer are all ≥3.26eV;
[0011] S2. Depositing a second electrode made of metal on the surface of the third semiconductor so that the second electrode forms an ohmic contact with the surface of the third semiconductor; flipping the three-layer semiconductor as a whole, and depositing a first electrode on the surface of the first semiconductor so that the first electrode forms an ohmic contact with the surface of the first semiconductor;
[0012] S3. Connect the two poles of the galvanometer to the first electrode and the second electrode respectively through wires to complete the preparation of the semiconductor X-ray detector.
[0013] Another embodiment of the present invention is to provide a non-transitory readable recording medium for storing one or more programs including a plurality of instructions. When the instructions are executed, the processing circuit will execute the above-mentioned method for manufacturing a semiconductor X-ray detector.
[0014] Another embodiment of the present invention is to provide a system for preparing a semiconductor X-ray detector, comprising a processing circuit and a memory electrically coupled thereto, wherein the memory is configured to store at least one program, wherein the program includes a plurality of instructions, and the processing circuit runs the program to execute the above-mentioned method for preparing a semiconductor X-ray detector.
[0015] Compared with the prior art, the present invention produces the following beneficial effects:
[0016] By controlling the bandgap width of each semiconductor layer to be ≥3.26eV, electromagnetic waves with lower frequencies such as visible light and infrared light will not cause the valence electrons in the semiconductor to transition to form free electrons, thereby preventing these stray lights from being absorbed by the detector and causing the galvanometer to capture noise signals, resulting in misjudgment.
[0017] The semiconductor external bias voltage configuration of the traditional X-ray detector is changed to a PN junction type without bias voltage. Since the PN junction will form a built-in electric field in the junction area under the irradiation of X-rays, the electric field force completes the electron transport, allowing the galvanometer to detect the current. This change removes the bias power supply; however, when high-energy hard X-rays interact with the semiconductor, in addition to the classical photoelectric effect, the Compton effect will also occur, which will produce a higher concentration of high-energy recoil electrons and may destroy the built-in electric field; in response to this situation, the present application adopts a PNN type dual built-in electric field configuration with a step-by-step increase in free electron density, which enhances the strength of the built-in electric field and especially enhances the built-in electric field's ability to transport free electrons from valence band transitions and recoil electrons generated by the Compton effect, so that in the absence of an external power supply, self-energy supply is achieved through the Compton effect and photovoltaic effect of X-rays to complete efficient detection of X-rays.
[0018] The built-in electric field of the detector is strong enough, and its absorption of X-ray energy and transport of carriers are better than traditional X-ray detectors, and its detection is sensitive. Since it has no power supply, the detector has the technical effects of no power consumption, low failure rate, light weight, small size, and easy to carry. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a schematic diagram of the structure of a semiconductor X-ray detector in an embodiment of the present invention;
[0020] Figure 2 It is the It curve of the semiconductor X-ray detector of the first embodiment of the present invention under the working voltage of 6MV and X-ray irradiation of different dose rates.
[0021] Figure 3 It is the It curve of the semiconductor X-ray detector of the second embodiment of the present invention under the working voltage of 6MV and X-ray irradiation of different dose rates.
[0022] In the figure, 01. first semiconductor layer; 02. second semiconductor layer; 03. third semiconductor layer; 4. first metal electrode; 05. second metal electrode; 06. galvanometer. DETAILED DESCRIPTION
[0023] 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 described below in conjunction with the drawings in the embodiments of the present invention. The described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making innovative efforts are within the scope of protection of the present invention.
[0024] The implementation method provided by the present invention illustrates the structure of each layer and the connection relationship of the detector through the preparation process of the semiconductor X-ray detector, and is an embodiment including a "method" and a "device".
[0025] like Figure 1 As shown, the X-ray detector includes a first semiconductor layer 01, a second semiconductor layer 02, a third semiconductor layer 03, a first metal electrode 04 forming an ohmic contact with the first semiconductor layer, and a second metal electrode 05 forming an ohmic contact with the third semiconductor layer, and also includes: a galvanometer 06 connecting the first metal electrode 04 and the second metal electrode 05 through a wire, which is used to collect current data generated by the detector and convert it into an X-ray dose rate.
[0026] Embodiment 1
[0027] This embodiment provides a method for preparing a semiconductor X-ray detector based on N-type Ga2O3 and N-type Ga2O3:Si by radio frequency magnetron sputtering technology and a way of detecting X-rays. The first semiconductor layer 01 is P-type NiO; the second semiconductor layer 02, located on the first semiconductor layer 01, is N-type Ga2O3 prepared by radio frequency magnetron sputtering technology using Ga2O3 target material; the third semiconductor layer 03, located on the second semiconductor layer 02, is N-type Ga2O3:Si prepared by radio frequency magnetron sputtering technology using Ga2O3:Si target material, Si doping makes the electron concentration of N-type Ga2O3:Si higher than that of N-type Ga2O3; the first metal electrode 04, located below the first semiconductor layer 01, is a Pt electrode, and forms an ohmic contact with the first semiconductor layer 01; the second metal electrode 05, located on the first semiconductor layer 03, is an Ag electrode, and forms an ohmic contact with the third semiconductor layer 03.
[0028] The prepared X-ray detector is connected to the wires through the two metal electrodes on it, and the other ends of the two wires are connected to the galvanometer 06, forming a complete semiconductor PNN structure self-powered X-ray detector. X-rays irradiate the semiconductor X-ray detector chip, and the chip transmits the current data to the galvanometer 06 through the wire, and finally the processor calculates and converts it into the X-ray dose rate.
[0029] Figure 2The It curves of the detector in this specific embodiment under different dose rate X-rays are shown to evaluate its dose rate resolution and minimum detection limit for hard X-rays. The experimental conditions are set to 6MV X-ray acceleration voltage and the dose rate range is 12.5 to 100.0mGy air / s, and the device has no external bias. It can be seen from the figure that the detector has a significant response to X-rays of different dose rates under 0V bias, and the degree of response varies with the dose rate.
[0030] Embodiment 2
[0031] This embodiment provides a method for preparing a semiconductor X-ray detector based on N-type ZnO and N-type SnO2 by radio frequency magnetron sputtering technology and a way of detecting X-rays. The first semiconductor layer 01 is P-type GaN; the second semiconductor layer 02, located on the first semiconductor layer 01, is N-type ZnO prepared by radio frequency magnetron sputtering technology using a ZnO target; the third semiconductor layer 03, located on the second semiconductor layer 02, is N-type SnO2 prepared by radio frequency magnetron sputtering technology using a SnO2 target, and the preparation process is controlled to make its electron concentration higher than that of the second semiconductor layer 02; the first metal electrode 04, located below the first semiconductor layer 01, is a Pt electrode, forming an ohmic contact with the first semiconductor layer 01; the second metal electrode 05, located on the first semiconductor layer 03, is an Ag electrode, forming an ohmic contact with the third semiconductor layer 03.
[0032] The prepared X-ray detector is connected to the wires through the two metal electrodes on it, and the other ends of the two wires are connected to the galvanometer 06 to form a complete semiconductor PNN self-powered X-ray detector. X-rays irradiate the semiconductor X-ray detector chip, and the chip transmits the current data to the galvanometer 06 through the wire, and finally converts it into the X-ray dose rate through calculation.
[0033] Figure 3 The It curves of the detector in this specific embodiment under different dose rate X-rays are shown to evaluate its dose rate resolution and minimum detection limit for hard X-rays. The experimental conditions are set to 6MV X-ray acceleration voltage and the dose rate range is 12.5 to 100.0mGy air / s, and the device has no external bias. It can be seen from the figure that the detector has a significant response to X-rays of different dose rates under 0V bias, and the degree of response varies with the dose rate.
[0034] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computers, available storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.
[0035] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.
[0036] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.
[0037] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.
[0038] Compiling the above method steps into a program and then storing it on a hard disk or other non-transitory storage medium constitutes the technical solution of "a non-transitory readable recording medium" of the present invention; and electrically connecting the storage medium to a computer processor to complete the preparation of a semiconductor X-ray detector through data processing constitutes the technical solution of "a semiconductor X-ray detector preparation system" of the present invention.
[0039] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A semiconductor X-ray detector, characterized in that include: A first electrode, a second electrode, a galvanometer, and a first semiconductor layer, a second semiconductor layer, and a third semiconductor layer stacked in sequence; the first electrode and the second electrode are both made of metal, one end of the first electrode is in ohmic contact with the first semiconductor layer, and the other end is electrically connected to one end of the galvanometer; the other end of the galvanometer is electrically connected to one end of the second electrode, and the other end of the second electrode is in ohmic contact with the third semiconductor layer; The first semiconductor layer is a P-type semiconductor, the second semiconductor layer and the third semiconductor layer are both N-type semiconductors, the free electron concentration of the third semiconductor layer is higher than the free electron concentration of the second semiconductor layer, and the bandgap widths of the first semiconductor layer, the second semiconductor layer and the third semiconductor layer are all ≥3.26eV.
2. A semiconductor X-ray detector according to claim 1, characterized in that: The material of the first electrode is Pt, and the material of the second electrode is Ag.
3. A semiconductor X-ray detector according to claim 2, characterized in that: The first semiconductor layer is NiO, the second semiconductor layer is Ga2O3, and the third semiconductor layer is Si-doped Ga2O3.
4. The semiconductor X-ray detector according to claim 2, characterized in that: The first semiconductor layer is GaN, the second semiconductor layer is ZnO, and the third semiconductor layer is SnO2.
5. A semiconductor X-ray detector according to any one of claims 3 to 4, characterized in that: The device also includes a processor for converting the current signal obtained by the galvanometer into a dose rate of X-rays.
6. A method for preparing a semiconductor X-ray detector, characterized in that The following steps are involved: S1. Depositing a second semiconductor layer and a third semiconductor layer in sequence from bottom to top on the first semiconductor layer by radio frequency magnetron sputtering technology; the first semiconductor layer is a P-type semiconductor, the second semiconductor layer and the third semiconductor layer are both N-type semiconductors, the free electron concentration of the third semiconductor layer is higher than the free electron concentration of the second semiconductor layer, and the bandgap widths of the first semiconductor layer, the second semiconductor layer and the third semiconductor layer are all ≥3.26eV; S2. Depositing a second electrode made of metal on the surface of the third semiconductor so that the second electrode forms an ohmic contact with the surface of the third semiconductor; The three-layer semiconductor is turned over as a whole, and a first electrode is deposited on the surface of the first semiconductor so that the first electrode forms an ohmic contact with the surface of the first semiconductor; S3. Connect the two poles of the galvanometer to the first electrode and the second electrode respectively through wires to complete the preparation of the semiconductor X-ray detector.
7. A non-transitory readable recording medium for storing one or more programs including a plurality of instructions, characterized in that: When the instruction is executed, the processing circuit will be caused to execute the method for manufacturing a semiconductor X-ray detector as claimed in claim 6.
8. A system for preparing a semiconductor X-ray detector, comprising a processing circuit and a memory electrically coupled thereto, characterized in that: The memory configuration stores at least one program, wherein the program includes a plurality of instructions, and the processing circuit runs the program to execute the method for preparing a semiconductor X-ray detector according to claim 6.