Silicon carbide / semiconductor type graphene detection-amplification integrated radiation detector
By epitaxially growing semiconductor graphene on a silicon carbide substrate and preparing a channel structure and top gate control layer, the problem of difficulty in signal amplification of semiconductor radiation detectors in the prior art is solved, and efficient signal amplification and detection integration is achieved Function.
Patent Information
- Application Number
- CN202411639911.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-18
- Publication Date
- 2025-02-14
AI Technical Summary
Existing semiconductor radiation detectors have difficulties in amplifying high-energy particle signals, especially in the case of high environmental noise, which makes it difficult to effectively distinguish weak signals.
Using silicon carbide/semiconductor type graphene detection-amplification integrated radiation detector, the channel structure is prepared on the graphene epitaxial layer by epitaxial growth of intrinsic silicon carbide and semiconductor type graphene epitaxial layer on the silicon carbide substrate, and the channel structure is prepared on the graphene epitaxial layer. The source and drain electrode and top gate control layer realize signal amplification.
The signal generated by radiation is amplified by the graphene FET structure as gate voltage, realizing the detection-amplification integrated function, improving the signal response capability, and effectively distinguishing signals in a noisy environment.
Smart Images
Figure CN119451250A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of radiation detectors, and in particular to a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector. Background Art
[0002] Semiconductor radiation detectors have the advantages of small size, high integration capability, high energy resolution, and strong radiation resistance. They are an optimal high-energy particle detection technology. The signals generated by high-energy particles in semiconductors are all weak signals. If the environmental noise is relatively large, it is difficult to distinguish them. How to amplify the generated signals is an important direction for the future optimization of radiation detectors. Summary of the invention
[0003] In order to solve the above problems, the present invention provides a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector.
[0004] The first object of the present invention is to provide a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector, comprising: a bottom electrode, a silicon carbide substrate, an intrinsic silicon carbide epitaxial layer and a semiconductor graphene epitaxial layer tightly stacked from bottom to top, and a source-drain electrode and a top gate regulating layer located on the surface of the semiconductor graphene epitaxial layer facing away from the silicon carbide substrate; The semiconductor graphene epitaxial layer is a channel structure; The source-drain electrodes and the top gate regulating layer are respectively located at the two ends and the middle area of the channel surface of the semiconductor-type graphene epitaxial layer.
[0005] Preferably, the top gate regulating layer includes a top gate dielectric layer and a top gate electrode disposed on the top gate dielectric layer; the top gate dielectric layer is located in a middle region of the channel surface of the semiconductor-type graphene epitaxial layer.
[0006] Preferably, the top gate dielectric layer and the top gate electrode are prepared on the semiconductor graphene epitaxial layer by a photolithography overlay process; the material of the top gate dielectric layer is silicon dioxide, silicon nitride, hafnium oxide, polyvinylidene fluoride or hafnium zirconium oxide.
[0007] Preferably, the source-drain electrodes and the top gate electrode are made of gold, titanium or aluminum.
[0008] Preferably, the semiconductor graphene epitaxial layer is prepared into a long strip-shaped channel structure by a semiconductor etching process.
[0009] Preferably, the surface of the intrinsic silicon carbide epitaxial layer is a silicon surface suitable for the growth of the semiconductor-type graphene epitaxial layer.
[0010] Preferably, the bottom electrode is a Ti / Au or Ti / Al / Ti / Au composite metal electrode.
[0011] The second object of the present invention is to provide a method for preparing a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector, which specifically comprises the following steps: S1. Selecting a conductive silicon carbide substrate, placing the silicon carbide substrate in a growth chamber; preparing an intrinsic silicon carbide epitaxial layer on the silicon carbide substrate by epitaxial growth technology; S2. Preparing a semiconductor graphene epitaxial layer on the intrinsic silicon carbide epitaxial layer by ultra-slow thermal decomposition method; S3. Preparing a bottom electrode on the lower surface of the silicon carbide substrate; S4. preparing a strip channel structure in the semiconductor graphene epitaxial layer by photolithography combined with plasma etching; S5. Preparing source and drain electrodes on the surface of the semiconductor graphene epitaxial layer by photolithography; S6. Prepare a top gate dielectric layer and a top gate electrode on the surface of the semiconductor graphene epitaxial layer by a photolithography process.
[0012] Preferably, in step S3, the bottom electrode is prepared by vacuum evaporation, magnetron sputtering or electron beam deposition.
[0013] Compared with the prior art, the present invention can achieve the following beneficial effects: The present invention selects semiconductor graphene material as the channel layer; the intrinsic silicon carbide epitaxial layer absorbs high-energy rays to generate carriers, which plays the role of gate voltage. The carriers generated by radiation will move to the graphene channel to achieve the regulation of graphene carrier concentration; the top gate regulation layer formed by the graphene top gate dielectric layer and the top gate electrode can regulate the initial Fermi level of graphene to near the Dirac point, thereby increasing the regulation amplitude of the carriers generated by silicon carbide radiation on the carrier concentration of the graphene channel, and the source and drain electrodes at both ends of the graphene channel collect signals; at the same time, the bottom electrode bias can be used to increase the charge generated by radiation to move to the graphene channel to improve the signal response. The silicon carbide / semiconductor graphene radiation detection device proposed by the present invention can use the signal generated by radiation as the gate voltage to amplify the signal through the graphene FET structure, realizing the detection-amplification integrated function. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 1 is an overall schematic diagram of the structure of a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector provided according to an embodiment of the present invention.
[0015] Figure 2 1 is a side view of a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector provided according to an embodiment of the present invention.
[0016] Figure 31 is a microscopic diagram of the growth of a semiconductor graphene epitaxial layer provided according to an embodiment of the present invention; in the diagram, (a) is the microstructure in an ultra-fast graphene growth mode; (b) is the microstructure in a medium-speed graphene growth mode; (c) is the microstructure in an ultra-slow growth mode; and (d) is the Raman spectra in the three growth modes.
[0017] Figure 4 : It is a characterization diagram of the graphene carrier concentration regulation principle provided by an embodiment of the present invention; (a) is a characterization diagram of the graphene potential before and after UV irradiation under different bias voltages; (b) is when the bias voltage is less than 1.5V, the graphene is p-type; (c) is when the bias voltage is about 1.5V, the graphene Fermi level is close to the Dirac point; (d) is when the bias voltage is greater than 1.5V, the graphene is n-type.
[0018] Reference numerals: 1. Bottom electrode; 2. Silicon carbide substrate; 3. Intrinsic silicon carbide epitaxial layer; 4. Semiconductor graphene epitaxial layer; 5. Source and drain electrodes; 6. Top gate dielectric layer; 7. Top gate electrode. DETAILED DESCRIPTION
[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same modules are represented by the same reference numerals. In the case of the same reference numerals, their names and functions are also the same. Therefore, the detailed description thereof will not be repeated.
[0020] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.
[0021] The present invention provides a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector, comprising: a bottom electrode, a silicon carbide substrate, an intrinsic silicon carbide epitaxial layer and a semiconductor graphene epitaxial layer tightly stacked from bottom to top, and a source-drain electrode and a top gate regulating layer located on the surface of the semiconductor graphene epitaxial layer facing away from the silicon carbide substrate; The top gate regulating layer includes a top gate dielectric layer and a top gate electrode disposed on the top gate dielectric layer; The intrinsic silicon carbide epitaxial layer is prepared by epitaxial growth technology on a conductive silicon carbide substrate; The semiconductor type graphene epitaxial layer is epitaxially grown on the surface of the intrinsic silicon carbide epitaxial layer; specifically, the semiconductor type graphene epitaxial layer is prepared on the intrinsic silicon carbide epitaxial layer by thermal decomposition; The semiconductor graphene epitaxial layer is prepared into a channel structure by a semiconductor etching process; specifically, the channel is a long strip channel; the semiconductor etching process is a method of combining photolithography with plasma etching; The source and drain electrodes are located at two ends of the channel surface of the semiconductor graphene epitaxial layer; The top gate dielectric layer is located in the middle area of the channel surface of the semiconductor graphene epitaxial layer (except the area covered by the source and drain electrodes); specifically, the material of the top gate dielectric layer is selected from dielectric or ferroelectric materials such as silicon dioxide, silicon nitride, hafnium oxide, polyvinylidene fluoride (PVDF), and hafnium zirconium oxide (HZO); The top gate dielectric layer and the top gate electrode are prepared on the semiconductor type graphene epitaxial layer by a photolithography overlay process; The source and drain electrodes are fabricated by photolithography on the semiconductor graphene epitaxial layer; The materials of the source-drain electrode and the top gate electrode are selected from metal materials such as gold, titanium, and aluminum; The surface of the intrinsic silicon carbide epitaxial layer is a silicon surface suitable for the growth of a semiconductor-type graphene epitaxial layer; Specifically, the bottom electrode is a composite metal electrode such as Ti / Au, Ti / Al / Ti / Au, etc.
[0022] The method for preparing a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector specifically comprises the following steps: S1. Selecting a conductive silicon carbide substrate, placing the silicon carbide substrate in a growth chamber; preparing an intrinsic silicon carbide epitaxial layer on the silicon carbide substrate by epitaxial growth technology; S2. Preparing a semiconductor graphene epitaxial layer on the intrinsic silicon carbide epitaxial layer by ultra-slow thermal decomposition method; S3. Preparing a bottom electrode on the lower surface of the silicon carbide substrate; S4. preparing a graphene strip channel in the semiconductor graphene epitaxial layer by photolithography combined with plasma etching; S5. Preparing source and drain electrodes on the surface of the semiconductor graphene epitaxial layer by photolithography; S6. Prepare a top gate dielectric layer and a top gate electrode on the surface of the semiconductor graphene epitaxial layer by a photolithography process.
[0023] Specifically, in the present application, the bottom electrode and the top gate electrode can be prepared by vacuum evaporation, magnetron sputtering, electron beam deposition and the like; the silicon carbide epitaxial layer can be prepared by chemical vapor deposition, molecular beam epitaxy, magnetron sputtering and the like.
[0024] Example 1 like Figure 1-Figure 2As shown, this embodiment provides a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector, including: a bottom electrode 1, a silicon carbide substrate 2, an intrinsic silicon carbide epitaxial layer 3 and a semiconductor graphene epitaxial layer 4 tightly stacked from bottom to top, and a source-drain electrode 5 and a top gate dielectric layer 6 located on the surface of the semiconductor graphene epitaxial layer 4 facing away from the silicon carbide substrate 2, and a top gate electrode 7 is provided on the top gate dielectric layer 6.
[0025] The preparation method is as follows: S1. Select a conductive silicon carbide substrate 2, place the silicon carbide substrate 2 in a growth chamber; prepare an intrinsic silicon carbide epitaxial layer 3 on the silicon carbide substrate 2 by epitaxial growth technology; S2. Preparing a semiconductor-type graphene epitaxial layer 4 on the intrinsic silicon carbide epitaxial layer 3 by an ultra-slow thermal decomposition method, wherein the ultra-slow thermal decomposition method requires placing silicon carbide in a small space growth chamber and placing a homogeneous silicon carbide cover sheet on the silicon carbide sample; S3. A bottom electrode 1 is prepared by vacuum evaporation on the lower surface of the silicon carbide substrate 2; S4. Preparing a graphene strip channel in the semiconductor graphene epitaxial layer 4 by photolithography combined with plasma etching; S5. Preparing source and drain electrodes 5 on the surface of the semiconductor graphene epitaxial layer 4 by photolithography; S6. Prepare a top gate dielectric layer 6 and a top gate electrode 7 on the surface of the semiconductor graphene epitaxial layer 4 by photolithography.
[0026] The silicon carbide surface of the intrinsic silicon carbide epitaxial layer 3 is selected as the upper surface, and a semiconductor-type graphene material is prepared as a semiconductor-type graphene epitaxial layer (channel layer) by an ultra-slow growth mode. The ultra-slow growth mode is as follows: Figure 3 As shown in c, this is achieved by reducing the growth space above the silicon carbide surface and increasing the saturated vapor pressure of silicon near the silicon carbide surface. We have successfully implemented this method in the epitaxial growth of high-quality graphene on the carbon surface of silicon carbide.
[0027] The carriers generated by the intrinsic silicon carbide epitaxial layer 3 absorbing high-energy rays will be transported to the graphene, playing the role of gate voltage and regulating the carrier concentration of the graphene channel. The top gate control layer formed by the top gate dielectric layer 6 and the top gate electrode 7 of the graphene can regulate the initial Fermi level of the graphene to the vicinity of the Dirac point, thereby increasing the regulation range of the silicon carbide radiation-generated carriers on the graphene channel carrier concentration. The feasibility of the adjustable carrier concentration of graphene, which enables its Fermi level to be regulated to the vicinity of the Dirac point, has been proven by the detection method of KPFM. The Fermi level of graphene will move up or down with different gate voltages. When a suitable gate voltage is given, the graphene Fermi level may reach the vicinity of the Dirac point.
[0028] The source and drain electrodes of graphene are used as source and drain electrodes 5 to collect signals; at the same time, the bottom electrode 1 bias can be used to increase the charge generated by radiation to move to the graphene channel to improve the signal response. The silicon carbide / semiconductor type graphene radiation detection device (heterojunction high-energy particle detector) proposed in the present invention can use the signal generated by radiation as the gate voltage to amplify the signal through the graphene FET structure, thereby realizing the detection-amplification integrated function ( Figure 4 ).
[0029] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.
[0030] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims
1. A silicon carbide / semiconductor graphene detection-amplification integrated radiation detector, characterized in that: include: A bottom electrode, a silicon carbide substrate, an intrinsic silicon carbide epitaxial layer and a semiconductor-type graphene epitaxial layer are tightly stacked from bottom to top, and a source-drain electrode and a top gate regulating layer are located on the surface of the semiconductor-type graphene epitaxial layer facing away from the silicon carbide substrate; The semiconductor graphene epitaxial layer is a channel structure; The source-drain electrodes and the top gate regulating layer are respectively located at the two ends and the middle area of the channel surface of the semiconductor-type graphene epitaxial layer.
2. The silicon carbide / semiconductor graphene detection-amplification integrated radiation detector according to claim 1, characterized in that: The top gate regulating layer comprises a top gate dielectric layer and a top gate electrode arranged on the top gate dielectric layer; the top gate dielectric layer is located in the middle area of the channel surface of the semiconductor-type graphene epitaxial layer.
3. The silicon carbide / semiconductor graphene detection-amplification integrated radiation detector according to claim 2, characterized in that: The top gate dielectric layer and the top gate electrode are prepared on the semiconductor graphene epitaxial layer by a photolithography overlay process; the material of the top gate dielectric layer is silicon dioxide, silicon nitride, hafnium oxide, polyvinylidene fluoride or zirconium hafnium oxide.
4. The silicon carbide / semiconductor graphene detection-amplification integrated radiation detector according to claim 3, characterized in that: The source-drain electrodes and the top gate electrode are made of gold, titanium or aluminum.
5. The silicon carbide / semiconductor graphene detection-amplification integrated radiation detector according to claim 1, characterized in that: The semiconductor graphene epitaxial layer is prepared into a long strip channel structure through a semiconductor etching process.
6. The silicon carbide / semiconductor graphene detection-amplification integrated radiation detector according to claim 5, characterized in that: The surface of the intrinsic silicon carbide epitaxial layer is a silicon surface suitable for the growth of the semiconductor-type graphene epitaxial layer.
7. The silicon carbide / semiconductor graphene detection-amplification integrated radiation detector according to claim 1, characterized in that: The bottom electrode is a Ti / Au or Ti / Al / Ti / Au composite metal electrode.
8. A method for preparing a silicon carbide / semiconductor graphene detection-amplification integrated radiation detector according to any one of claims 1 to 7, characterized in that: The specific steps include: S1. Selecting a conductive silicon carbide substrate, placing the silicon carbide substrate in a growth chamber; preparing an intrinsic silicon carbide epitaxial layer on the silicon carbide substrate by epitaxial growth technology; S2. Preparing a semiconductor graphene epitaxial layer on the intrinsic silicon carbide epitaxial layer by ultra-slow thermal decomposition method; S3. Preparing a bottom electrode on the lower surface of the silicon carbide substrate; S4. preparing a strip channel structure in the semiconductor graphene epitaxial layer by photolithography combined with plasma etching; S5. Preparing source and drain electrodes on the surface of the semiconductor graphene epitaxial layer by photolithography; S6. Prepare a top gate dielectric layer and a top gate electrode on the surface of the semiconductor graphene epitaxial layer by a photolithography process.
9. The method for preparing the silicon carbide / semiconductor graphene detection-amplification integrated radiation detector according to claim 8, characterized in that: In the step S3, the bottom electrode is prepared by vacuum evaporation, magnetron sputtering or electron beam deposition.