Polarization amplification system, method of manufacture and method of polarization analysis

Abstract

The application provides a polarization amplification system, a preparation method and a polarization analysis method, and relates to the technical field of semiconductor photodetectors and preparation thereof. The polarization amplification system comprises a polarization detector, a reference resistor and a transistor, wherein: the polarization detector comprises a first silicon wafer substrate, a first active layer, a first source electrode and a first drain electrode which are sequentially arranged on the first silicon wafer substrate from left to right, and the first source electrode and the first drain electrode are both metal materials; the transistor comprises a second silicon wafer substrate, a second active layer, a second source electrode, a second drain electrode, a dielectric layer and a gate electrode which are sequentially arranged on the second silicon wafer substrate from left to right, and the second source electrode, the second drain electrode and the gate electrode are all metal materials; the first drain electrode of the polarization detector is electrically connected with the reference resistor and is commonly connected to the gate electrode of the transistor; wherein the first active layer and the second active layer are both two-dimensional semiconductor materials, and the detection wave band of the polarization detector is visible light to near-infrared wave band.

Description

Technical Field

[0001] This invention relates to the field of semiconductor photodetectors and their fabrication technology, and particularly to a polarization amplification system, fabrication method, and polarization analysis method. Background Technology

[0002] Traditional photodetectors detect the intensity and wavelength of incident light and convert them into electrical signals, achieving photoelectric conversion. Polarization detectors, compared to traditional photodetectors, add another dimension to the measurement of light intensity and wavelength—the polarization state of the light. Since the polarization state of light carries a wealth of information, polarization detection can enhance the information of the detected object. The optical image obtained by a polarization detector can better reflect the information of the measured object, thus leading to its wider application.

[0003] Existing polarization detectors lack intrinsic polarization sensitivity and require a pre-polarization array to acquire polarization information. These detectors often suffer from large size and limitations in miniaturization and integration. However, low-dimensional materials possess inherent in-plane anisotropy, enabling direct polarization detection without a polarizer, thus facilitating device miniaturization and integration. However, common two-dimensional materials often have insufficient anisotropy ratios, requiring amplification through design. Therefore, finding an amplification method that offers significant amplification, facilitates device integration, and is easy to build is a highly valuable research question.

[0004] In terms of data analysis, directly comparing the photocurrent before and after device amplification only provides numerical information about the amplification effect of the detection system and cannot intuitively demonstrate the advantages of the device in various applications. Furthermore, traditional imaging methods place high demands on device stability and are slow in acquiring images, making them unsuitable for neural network analysis methods that require large amounts of data. Summary of the Invention

[0005] In view of this, the present invention provides a polarization amplification system, a preparation method, and a polarization analysis method to solve the technical problems of existing polarization detectors being bulky, commonly used amplification methods not being universally applicable to various materials, and traditional analysis results not being intuitive enough.

[0006] The first aspect of the present invention provides a polarization amplification system, comprising a polarization detector, a reference resistor, and a transistor, wherein:

[0007] The polarization detector includes a first silicon wafer substrate, and a first active layer, a first source electrode, and a first drain electrode located sequentially from left to right on the first silicon wafer substrate. The first source electrode and the first drain electrode are both made of metallic materials.

[0008] The transistor includes a second silicon substrate, and a second active layer, a second source electrode, a second drain electrode, a dielectric layer and a gate electrode arranged sequentially from left to right on the second silicon substrate. The second source electrode, the second drain electrode and the gate electrode are all made of metal.

[0009] The first drain electrode of the polarization detector is electrically connected to the reference resistor, and together they are connected to the gate electrode of the transistor.

[0010] The first active layer and the second active layer are both two-dimensional semiconductor materials, and the polarization detector has a detection band from visible light to near-infrared.

[0011] A second aspect of the present invention provides a method for preparing the above-described polarization amplification system, comprising the following steps:

[0012] A first active layer, a first source electrode, and a first drain electrode are sequentially formed on a first silicon wafer substrate to obtain a polarization detector, wherein the first active layer is peeled off using adhesive tape.

[0013] A second active layer, a second source electrode, a second drain electrode, a dielectric layer, and a gate electrode are sequentially formed on a second silicon wafer substrate to obtain a transistor, wherein the second active layer is peeled off using adhesive tape.

[0014] The first drain electrode of the polarization detector is electrically connected to a reference resistor, and together they are connected to the gate electrode of the transistor to obtain the polarization amplification system.

[0015] A third aspect of the present invention provides a polarization analysis method, comprising:

[0016] Obtain the target under test before and after amplification, and measure the polarization photocurrent of the target under test using the above-mentioned polarization amplification system;

[0017] The polarized photocurrent is fitted to obtain a fitting formula;

[0018] The MATLAB program is used to perform imaging according to the fitting formula. By taking different angle values ​​and the magnitude of the polarization current, the target body, background and noise parts are divided to obtain a polarization simulation image.

[0019] The MATLAB program was applied to the devices before and after amplification to obtain image datasets of the devices before and after amplification, respectively.

[0020] Compared with the prior art, the polarization amplification system, preparation method, and polarization analysis method provided by the present invention have at least the following beneficial effects:

[0021] (1) Compared with traditional polarization detectors, polarization detectors based on two-dimensional semiconductor materials have in-plane anisotropy, which eliminates the need for a pre-polarizer to detect polarized light, thus facilitating system miniaturization and solving the problem of the large size of traditional polarization detectors.

[0022] (2) By designing the circuit, the amplification effect of the polarization detector is achieved by using the MoS2 transistor, which can greatly improve the ratio of anisotropic photocurrent. Moreover, this method is not based on material design, but on circuit design, and can be used in various materials.

[0023] (3) The MATLAB program is used to perform polarization imaging on the system before and after amplification, which can generate a large number of images and is not affected by the stability of the device.

[0024] (4) By using neural network image classification and recognition analysis, a more intuitive comparison of polarization performance can be obtained, thus obtaining the analysis results of the amplification effect. Attached Figure Description

[0025] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0026] Figure 1 A schematic diagram of a polarization amplification system according to a first embodiment of the present invention is shown.

[0027] Figure 2 A flowchart illustrating a method for fabricating a polarization amplification system according to a second embodiment of the present invention is shown schematically.

[0028] Figure 3 A flowchart illustrating a polarization analysis method according to a third embodiment of the present invention is shown schematically. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0031] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0032] Figure 1 A schematic diagram of a polarization amplification system according to a first embodiment of the present invention is shown.

[0033] like Figure 1 As shown, the polarization amplification system according to this embodiment includes a polarization detector (PD), a reference resistor, and a transistor.

[0034] The polarization detector includes a first silicon substrate and, from left to right, a first active layer, a first source electrode, and a first drain electrode, all located on the first silicon substrate. Both the first source electrode and the first drain electrode are made of metallic materials. The transistor includes a second silicon substrate and, from left to right, a second active layer, a second source electrode, a second drain electrode, a dielectric layer, and a gate electrode, all located on the second silicon substrate. The second source electrode, the second drain electrode, and the gate electrode are all made of metallic materials. The first drain electrode of the polarization detector is electrically connected to a reference resistor and together they are connected to the gate electrode of the transistor. Both the first and second active layers are two-dimensional semiconductor materials, and the polarization detector's detection band is the visible to near-infrared range.

[0035] In this embodiment of the invention, the first active layer is a GeSe two-dimensional semiconductor material, and the second active layer is a MoS2 two-dimensional semiconductor material.

[0036] In this embodiment of the invention, the first source electrode and the first drain electrode are both made of Au, a metallic material with a thickness of 60 nm. The second source electrode, the second drain electrode, and the gate electrode are all made of Ti / Au, wherein the thickness of Ti is 10 nm and the thickness of Au is 50 nm.

[0037] In this embodiment of the invention, the dielectric layer is made of HfO2 and has a thickness of 20 nm.

[0038] In this embodiment of the invention, the polarization detector and the reference resistor have the same resistance value.

[0039] Through the above embodiments, the polarization detector based on two-dimensional semiconductor materials of the present invention, compared with the traditional polarization detector, has the advantage of in-plane anisotropy, which eliminates the need for a pre-polarizer to detect polarized light, thus facilitating system miniaturization and solving the problem of the large size of traditional polarization detectors.

[0040] Furthermore, this invention utilizes MoS2 transistors through circuit design to achieve the amplification effect of the polarization detector, which can significantly improve the ratio of anisotropic photocurrent. Moreover, this method is not based on material design, but on circuit design, and can be used across various materials.

[0041] Figure 2 A flowchart illustrating a method for preparing a polarization amplification system according to a second embodiment of the present invention is shown.

[0042] like Figure 2 As shown, the preparation method of the polarization amplification system according to this embodiment includes the following steps S210-S230.

[0043] Step S210: A first active layer, a first source electrode, and a first drain electrode are sequentially formed on a first silicon substrate to obtain a polarization detector, wherein the first active layer is peeled off using adhesive tape.

[0044] Specifically, the polarization detector is fabricated according to the following steps:

[0045] GeSe two-dimensional semiconductor material is peeled off using adhesive tape and transferred to a first silicon substrate using PDMS to form a first active layer on the first silicon substrate;

[0046] Transfer of the gold mask using a probe station;

[0047] The first source electrode and the first drain electrode are deposited by thermal evaporation.

[0048] By peeling off the gold mask using a probe station, the overall structure formed by the first silicon substrate, the first active layer, the first source electrode, and the first drain electrode is encapsulated to obtain a polarization detector.

[0049] In step S220, a second active layer, a second source electrode, a second drain electrode, a dielectric layer, and a gate electrode are sequentially formed on the second silicon wafer substrate to obtain a transistor, wherein the second active layer is peeled off using adhesive tape.

[0050] Specifically, transistors are fabricated according to the following steps:

[0051] MoS2 two-dimensional semiconductor material is peeled off using adhesive tape and transferred to a second silicon substrate using PDMS to form a second active layer on the second silicon substrate;

[0052] Design the layout of the source and drain electrodes, and form the second source and second drain electrodes through spin coating, photolithography and development;

[0053] Design source and drain electrode layout, perform photolithography on source and drain electrodes and develop, deposit second source and drain electrodes by electron beam evaporation, and remove excess material.

[0054] Design the dielectric layer layout, perform photoresist coating, photolithography of the dielectric layer and development, deposit the dielectric layer by ion beam sputtering, and remove excess material;

[0055] Design the gate layout, perform photoresist coating, photolithography of the gate and development, deposit the gate electrode by electron beam evaporation, and remove excess material;

[0056] A transistor is obtained by encapsulating the overall structure formed by the second silicon substrate, the second active layer, the second source electrode, the second drain electrode, the dielectric layer, and the gate electrode.

[0057] In this embodiment of the invention, the photolithography process in step S220 above uses photoresist, and the photoresist is cleaned sequentially with acetone, ethanol and deionized water.

[0058] In step S230, the first drain electrode of the polarization detector is electrically connected to the reference resistor, and together they are connected to the gate electrode of the transistor to obtain the polarization amplification system.

[0059] Through the above embodiments, the present invention can prepare a polarization amplification system.

[0060] Figure 3 A flowchart illustrating a polarization analysis method according to a third embodiment of the present invention is shown schematically.

[0061] like Figure 3 As shown, the polarization analysis method according to this embodiment includes the following steps S310-S340.

[0062] Step S310: Obtain the target under test before and after amplification, and use the above-mentioned polarization amplification system to measure the polarization photocurrent of the target under test.

[0063] Step S320: Fit the polarized photocurrent to obtain the fitting formula.

[0064] Step S330: Using MATLAB program to perform imaging according to the fitting formula, the target body, background and noise parts are divided by different angle ranges and the magnitude of polarization current to obtain a polarization simulation image.

[0065] Step S340: Apply the MATLAB program to the devices before and after amplification to obtain image datasets of the devices before and after amplification.

[0066] Therefore, by using MATLAB imaging to obtain a large number of images in a short time for classification and recognition by convolutional neural networks, sufficient image training and test sets can be obtained, which is suitable for neural network analysis methods that require a large amount of data.

[0067] Furthermore, after step S340 above, the polarization analysis method of this embodiment may further include the following steps:

[0068] Obtain an image dataset for training and testing, and import the image dataset into a preset neural network model for image recognition and classification. The neural network model uses a convolutional neural network with the SoftMax activation function. The output data is the probability of different categories, and the sum of the output results of all categories is 1.

[0069] The image dataset is split into two parts: 80% is used as the training set and 20% is used as the test set. The trained neural network model is applied to the test set, and the recognition and classification results of the test set are finally output and compared with the actual results to observe its accuracy, so as to reflect the comparison of the polarization performance of the device.

[0070] Early stopping during training is used to prevent overfitting, and training efficiency is improved by dynamically adjusting the learning rate.

[0071] Through the above embodiments, this invention uses MATLAB to perform polarization imaging on the system before and after amplification, generating a large number of images unaffected by device stability. Furthermore, this invention employs neural network image classification and recognition analysis to obtain a more intuitive comparison of polarization performance, thereby yielding analytical results on the amplification effect.

[0072] In summary, the polarization amplification system, fabrication method, and polarization analysis method provided by this invention comprise a polarization detection amplification system consisting of a GeSe polarization detector and a MoS2 transistor. Polarization imaging is performed using MATLAB, and device imaging analysis is conducted using a Python convolutional neural network. This invention amplifies the electrical signal from the polarization detector by fabricating a transistor with a small subthreshold swing. Imaging the amplification system using MATLAB and employing neural network image classification and recognition provides a more intuitive analysis of the amplification effect.

[0073] The accompanying drawings show some block diagrams and / or flowcharts. It should be understood that some blocks or combinations thereof in the block diagrams and / or flowcharts 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, or other programmable data processing device, so that when executed by the processor, these instructions can create means for implementing the functions / operations described in these block diagrams and / or flowcharts.

[0074] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. Furthermore, the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

[0075] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polarization amplification system, characterized in that, Includes a polarization detector, a reference resistor, and a transistor, wherein: The polarization detector includes a first silicon wafer substrate, and a first source electrode, a first active layer and a first drain electrode located on the first silicon wafer substrate from left to right, wherein the first source electrode and the first drain electrode are both made of metallic materials; The transistor includes a second silicon substrate, and a second active layer, a second source electrode, a second drain electrode, a dielectric layer and a gate electrode located on the second silicon substrate, wherein the second source electrode, the second drain electrode and the gate electrode are all made of metal materials; The first drain electrode of the polarization detector is electrically connected to the reference resistor, and together they are connected to the gate electrode of the transistor. The first active layer is a GeSe two-dimensional semiconductor material, the second active layer is a MoS2 two-dimensional semiconductor material, and the polarization detector has a detection band from visible light to near-infrared.

2. The polarization amplification system according to claim 1, characterized in that, Both the first source electrode and the first drain electrode are made of metallic material Au, with a thickness of 60 nm. The second source electrode, the second drain electrode, and the gate electrode are all made of metallic material Ti / Au, wherein the thickness of Ti is 10 nm and the thickness of Au is 50 nm.

3. The polarization amplification system according to claim 1, characterized in that, The dielectric layer is made of HfO2 and has a thickness of 20 nm.

4. The polarization amplification system according to claim 1, characterized in that, The polarization detector and the reference resistor have the same resistance value.

5. A method for preparing a polarization amplification system according to any one of claims 1-4, characterized in that, Includes the following steps: A first active layer is formed on a first silicon wafer substrate, and a first source electrode and a first drain electrode are formed on the first active layer to obtain a polarization detector, wherein the first active layer is peeled off using adhesive tape. A second active layer is formed on a second silicon substrate, and a second source electrode, a second drain electrode, a dielectric layer and a gate electrode are formed on the second active layer to obtain a transistor, wherein the second active layer is peeled off using adhesive tape. The first drain electrode of the polarization detector is electrically connected to a reference resistor, and together they are connected to the gate electrode of the transistor to obtain the polarization amplification system.

6. The preparation method according to claim 5, characterized in that, The polarization detector is specifically prepared according to the following steps: GeSe two-dimensional semiconductor material is peeled off using adhesive tape and transferred to a first silicon substrate using PDMS to form a first active layer on the first silicon substrate; Transfer of the gold mask using a probe station; The first source electrode and the first drain electrode are deposited by thermal evaporation. The gold mask is peeled off using a probe station, and the overall structure formed by the first silicon substrate, the first active layer, the first source electrode, and the first drain electrode is encapsulated to obtain a polarization detector.

7. The preparation method according to claim 5, characterized in that, The transistor is fabricated according to the following steps: MoS2 two-dimensional semiconductor material is peeled off using adhesive tape and transferred to a second silicon substrate using PDMS to form a second active layer on the second silicon substrate; Design the layout of the source and drain electrodes, and form the second source and second drain electrodes through spin coating, photolithography and development; Design source and drain electrode layout, perform photolithography on source and drain electrodes and develop, deposit second source and drain electrodes by electron beam evaporation, and remove excess material. Design the dielectric layer layout, perform photoresist coating, photolithography of the dielectric layer and development, deposit the dielectric layer by ion beam sputtering, and remove excess material; Design the gate layout, perform photoresist coating, photolithography of the gate and development, deposit the gate electrode by electron beam evaporation, and remove excess material; A transistor is obtained by encapsulating the overall structure formed by the second silicon substrate, the second active layer, the second source electrode, the second drain electrode, the dielectric layer, and the gate electrode.

8. The preparation method according to claim 7, characterized in that, The photolithography process uses photoresist, and the photoresist is cleaned sequentially with acetone, ethanol, and deionized water.

9. A polarization analysis method, characterized in that, include: Obtain the target under test before and after amplification, and measure the polarization photocurrent of the target under test using the polarization amplification system described in any one of claims 1-4; The polarized photocurrent is fitted to obtain a fitting formula; The MATLAB program is used to perform imaging according to the fitting formula. By taking different angle values ​​and the magnitude of the polarization current, the target body, background and noise parts are divided to obtain a polarization simulation image. The MATLAB program was applied to the devices before and after amplification to obtain image datasets of the devices before and after amplification, respectively.

10. The polarization analysis method according to claim 9, characterized in that, The method further includes: Obtain an image dataset for training and testing, and import the image dataset into a preset neural network model for image recognition and classification. The neural network model is a convolutional neural network with a SoftMax activation function. The output data is the probability of different categories, and the sum of the output results of all categories is 1. The image dataset is split into two parts: 80% is used as the training set and 20% is used as the test set. The trained neural network model is applied to the test set, and the recognition and classification results of the test set are finally output. The results are compared with the actual results to observe the accuracy and reflect the polarization performance of the device. Early stopping during training is used to prevent overfitting, and training efficiency is improved by dynamically adjusting the learning rate.

Images