Method and device for preparing nanopore based on two-beam microscope

Abstract

The invention provides a method for preparing a nanopore based on a two-beam microscope. The method comprises the following steps: providing a silicon wafer substrate base body; wherein a layer of silicon nitride film is deposited on the surface of each of the two sides of the silicon wafer substrate base body; imaging the silicon nitride thin film through a semiconductor process to obtain an imaged silicon nitride thin film; the imaging silicon nitride thin film is punched through the two-beam microscope, and nanopores are obtained; and carrying out electrochemical characterization detection on the nanopores. The two-beam microscope is utilized, the resolution ratio is good, and pulse signals of a plurality of particle via holes can be simultaneously detected in an optical or electrical mode by adopting a silicon nitride material. The invention further provides a device which has corresponding advantages.

Description

Technical Field

[0001] The invention belongs to the technical field of micro-nano structure processing, and in particular relates to a method and a device for preparing nanopores based on a double-beam microscope. Background Art

[0002] Solid-state nanopores are small holes ranging in size from a few nanometers to several hundred nanometers, which can be used to detect substances and perform single particle analysis at the nanoscale through electrical signals. In recent years, solid-state nanopores of various sizes with strong materials, stable chemical properties and thermal stability have been prepared on solid-state thin film materials (such as silicon dioxide, silicon nitride, etc.) by focused ion beams and focused electron microscopes. These nanopores are expected to be used in reading data stored in molecules, energy collection and power generation, DNA and protein sequencing and other fields.

[0003] Dual beam microscope refers to a system that has both focused ion beam (FIB) and scanning electron microscope (SEM) functions, which can realize the real-time observation of FIB micro-machining process by SEM, and integrates the advantages of high spatial resolution of electron beam and fine processing of ion beam. Among them, FIB accelerates the ion beam output by liquid metal ion source and focuses it on the surface of the sample to generate secondary electron signal to form an electron image, or uses a strong current ion beam to etch and process micro-nano morphology on the surface of the sample.

[0004] In the prior art, a method combining physical sputtering and chemical gas reaction is mainly used to selectively etch or deposit metal and insulating layers. With the rapid development of electrical signal analysis and testing technology at the nanoscale, the structure of nanopores has become increasingly complex, which has put forward higher requirements for process diagnosis, failure analysis and micro-nano processing. However, the nanopores prepared by the prior art are roughly processed, cannot achieve a high electrical signal resolution, and cannot detect the pulse signal of the via in real time. Summary of the invention

[0005] The present invention aims to solve all or part of the problems of the above-mentioned prior art and provides a method and device for preparing solid-state nanopores based on a double-beam microscope, which has more precise processing, good resolution, and can achieve real-time monitoring of multi-pore pulse signals.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A first aspect of an embodiment of the present invention provides a method for preparing a nanopore based on a double-beam microscope, comprising:

[0008] A silicon wafer substrate base is provided; wherein a layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base; the silicon nitride film is imaged by the semiconductor process to obtain an imaged silicon nitride film; the imaged silicon nitride film is punched by the double-beam microscope to obtain nanopores; and the nanopores are electrochemically characterized and detected.

[0009] A layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base, and also includes: a layer of silicon nitride film deposited on one side of the silicon wafer substrate base is called a front silicon nitride film; a layer of silicon nitride film deposited on the other side of the silicon wafer substrate base is called a back silicon nitride film.

[0010] The silicon nitride film is imaged by the semiconductor process to obtain an imaged silicon nitride film, and further includes: imaging the front silicon nitride film by the semiconductor process to form a marking pattern on the front silicon nitride film; wherein the marking pattern includes at least a scribe marking pattern and a nanopore marking pattern; imaging the back silicon nitride film by the semiconductor process to form an alignment mark on the back silicon nitride film.

[0011] The imaged silicon nitride film is punched by the double beam microscope to obtain a nanopore, and the method further includes: punching a silicon wafer substrate base by the double beam microscope according to the marking pattern formed on the front silicon nitride and the alignment mark formed on the back silicon nitride to obtain a nanopore. The nanopore prepared by the double beam microscope has good resolution and can detect pulse signals of multiple particles passing through the hole.

[0012] A second aspect of the disclosed embodiment provides a device for preparing nanopores based on a double-beam microscope, characterized in that it includes:

[0013] An acquisition module is used to provide a silicon wafer substrate base; wherein a layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base; a first processing module is used to image the silicon nitride film through the semiconductor process to obtain an imaged silicon nitride film; a second processing module is used to perform a hole processing on the imaged silicon nitride film through the double-beam microscope to obtain nanopores; and a detection module is used to perform electrochemical characterization detection on the nanopores.

[0014] A third aspect of an embodiment of the present disclosure provides an electronic device, comprising: a memory; and a processor, connected to the memory, for executing computer executable instructions stored on the memory, and capable of implementing the method for preparing nanopores based on a double-beam microscope provided by any technical solution of any of the first aspect or the second aspect mentioned above.

[0015] The fourth aspect of the embodiments of the present disclosure provides a computer storage medium, including: the computer storage medium stores computer executable instructions; after the computer executable instructions are executed, the method for preparing nanopores using a dual-beam microscope provided by any technical solution of the first aspect or the second aspect can be implemented.

[0016] Compared with the prior art, the main beneficial effects of the present invention are as follows: through the technology of double-beam microscopy, the obtained nanopores are fine and have good resolution, and the pulse signals of multiple particles passing through the pores can be detected simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of a process for preparing nanopores based on a double-beam microscope provided by the present invention;

[0018] Figure 2 A side view of a double-sided thin film on a silicon substrate in a method for preparing nanopores based on a double-beam microscope provided in an embodiment of the present invention;

[0019] Figure 3 A side view of back side silicon nitride film patterning in a method for preparing nanopores based on a double beam microscope provided in an embodiment of the present invention;

[0020] Figure 4 A side view of a front silicon nitride film patterning method for preparing nanopores based on a double-beam microscope provided in an embodiment of the present invention;

[0021] Figure 5 A top view of a back side silicon nitride film of a method for preparing nanopores based on a double beam microscope provided in an embodiment of the present invention;

[0022] Figure 6 A top view of a method for preparing nanopores based on a double-beam microscope after drilling provided by an embodiment of the present invention;

[0023] Figure 7 A schematic diagram of the structure of a nanopore preparation device based on a double-beam microscope provided in an embodiment of the present invention;

[0024] Figure 8 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention; DETAILED DESCRIPTION

[0025] In order to enable a more detailed understanding of the features and technical contents of the present application, the implementation of the present application is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the present application.

[0026] like Figure 1 As shown, the embodiment of the present disclosure provides a method for preparing nanopores based on a double-beam microscope, the method comprising:

[0027] S110: providing a silicon wafer substrate base; wherein a layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base;

[0028] S120: patterning the silicon nitride film through the semiconductor process to obtain a patterned silicon nitride film;

[0029] S130: punching the imaged silicon nitride film by using the double-beam microscope to obtain nanopores;

[0030] S140: Perform electrochemical characterization detection on the nanopore.

[0031] Semiconductor is an electronic device that can convert electrical signals into optical signals or optical signals into electrical signals. It is mainly used in applications such as radio, computer, information transmission, automotive electronics, etc. The development of semiconductors and their manufacturing process are an interrelated process, and the development of semiconductor technology also has a great impact on semiconductor processes.

[0032] The semiconductor process can be divided into two categories: one is semiconductor packaging technology, which can package various circuit chips and components into a container, thereby improving the reliability and stability of semiconductor components. The other is semiconductor microstructure technology, which can form fine semiconductor structures at the micron scale, including high-impedance films, loaded inductors, ferroelectric memory, ceramic packaging, etc. In the semiconductor manufacturing process, in addition to the semiconductor microstructure process, some special technologies are also used, such as evaporation technology, passive high-speed process, electron beam etching technology, electron beam evaporation technology, etc. Evaporation technology is a technology that covers metal materials on the surface of semiconductor devices, generally used to manufacture components such as resistors and capacitors. Passive high-speed technology can use special technologies such as lasers and sound waves to replace traditional circuit manufacturing technology to improve manufacturing speed and quality. Electron beam etching technology can use high-energy electron beams to etch out precise packaged chip shapes, while electron beam evaporation technology can evaporate ultrafine metals onto tiny packaged chips, greatly improving the density of chips. In the present invention, the photolithography, KOH etching and corrosion technologies in the semiconductor process are mainly used.

[0033] The dual-beam microscope refers to a system that has both the functions of a focused ion beam (FIB) and a scanning electron microscope (SEM), also known as a focused ion beam scanning electron microscope (FIB-SEM). The dual-beam microscope can be combined with a corresponding gas deposition device and a nanomanipulator as well as various detectors and a controllable sample stage and other accessories to become an analytical instrument that integrates micro-area imaging, processing and analysis, and manipulation. ， It has a wide range of applications in many fields such as physics, chemistry, biology, new materials, agriculture, environment and energy. The double-beam microscope is a device that simultaneously mounts the FIB system and the traditional scanning electron microscope system at a certain angle, and adjusts the sample to a concentric height position. This allows the sample surface to be perpendicular to the electron beam or ion beam by rotating the sample table during the test, thereby ultimately achieving the effects of real-time observation of the electron beam and cutting or micro-machining of the ion beam. In the present invention, the double-beam microscope is used to prepare nanopores, and the nanopores obtained in this way are more refined, thereby achieving the effect of improving resolution.

[0034] The silicon nitride film is a new type of material with many excellent properties and application prospects. It is a film made of silicon nitride material, which contains many nanopores, the size of which is usually between a few nanometers and tens of nanometers. This material has a very high surface area and porosity. Nanoporous silicon nitride film has many excellent properties, such as high specific surface area, high porosity, high chemical stability and good biocompatibility. These properties make it widely used in many fields. For example, in the field of catalysis, nanoporous silicon nitride film can be used as a catalyst carrier to improve the activity and selectivity of the catalyst. In the field of sensing, it can be used to prepare highly sensitive gas sensors and biosensors. In the field of separation, it can be used to prepare efficient separation membranes and nanofilters. In the field of energy storage, it can be used to prepare high-performance supercapacitors and lithium-ion batteries. In addition, silicon nitride film is used because silicon nitride materials can be tested in two different ways: optically and electrically.

[0035] In some embodiments, S110 may include: providing a silicon wafer substrate base; wherein a layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base;

[0036] The thickness of the silicon wafer substrate base body may be a predetermined empirical value or experimental value such as 100, 200, 300, etc.; and in the present invention, the thickness of the silicon wafer substrate base body is 420 μm.

[0037] The surface of the silicon wafer substrate is subjected to low pressure chemical vapor deposition (LPCVD) to deposit a thin film, wherein the low pressure chemical vapor deposition refers to a process in which a solid film is deposited on the surface of the wafer through a chemical reaction of a gas mixture under a relatively low pressure. In this way, the solid film is formed uniformly, the film performance is better, the production capacity is higher, and the cost is lower.

[0038] In addition, the film is a SiNx film, and the thickness can be a predetermined empirical value or experimental value such as 100, 200, 300, etc.; and in the present invention, the film thickness is 200nm.

[0039] In some embodiments, the S120 may include:

[0040] A layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base, and also includes: a layer of silicon nitride film deposited on one side of the silicon wafer substrate base is called a front silicon nitride film; a layer of silicon nitride film deposited on the other side of the silicon wafer substrate base is called a back silicon nitride film.

[0041] The method of imaging the silicon nitride film by the semiconductor process to obtain an imaged silicon nitride film also includes: imaging the front silicon nitride film by the semiconductor process to form a marking pattern on the front silicon nitride film; wherein the marking pattern includes at least a scribe marking pattern and a nanopore marking pattern; imaging the back silicon nitride film by the semiconductor process to form an alignment mark on the back silicon nitride film. In this way, the double-beam microscope can be better used to find the drilling position accurately.

[0042] In some embodiments, the S130 may include:

[0043] The ion beam in the double beam microscope is formed by the liquid ion source pulling out positively charged ions under the action of a strong electric field, and then finally focusing through an electrostatic lens and a multi-stage deflection device, thereby completing the micro-nano level surface morphology processing. The nanopores prepared in this way are more precise and have higher resolution.

[0044] In some embodiments, the S140 may include:

[0045] The nanopore was electrochemically characterized. The translocation signal of spherical nanoparticles is different from that of long-chain DNA molecules. The movement distance corresponding to the translocation signal is only a few hundred nanometers, which is the sum of the diameter and the thickness of the nanopore. Since the carboxyl polystyrene nanoparticles have a negative charge on the surface in the electrolyte solution, when an external voltage is applied, they pass through the nanopore due to the electrophoretic force. Most of the spike pulses are within a few hundred microseconds. It can be seen that the SiNx nanopore prepared by the double-beam microscope has good resolution and can detect pulse signals of multiple particles passing through the hole.

[0046] In other embodiments,

[0047] On the SiNx film, SiN optical waveguides can also be used to make nanoholes for optical detection of via-hole materials. SiN is a good optical waveguide material in the visible light band with low light loss. A beam of blue light propagates in the optical waveguide. When the blue light encounters the fluorescent molecules on the via-hole material, the fluorescent molecules are excited to emit red light. By detecting the light signal at the end of the optical waveguide, it can be determined whether there are corresponding biological molecules.

[0048] like Figure 2 As shown, this embodiment provides a method for preparing nanopores based on a double-beam microscope, a side view of a double-sided thin film on a silicon substrate;

[0049] In some embodiments,

[0050] A 200nm thick SiNx film is deposited on both sides of a 420μm thick silicon substrate using low-pressure chemical vapor deposition; low-pressure chemical vapor deposition refers to a process in which a solid film is deposited on the surface of the wafer through a chemical reaction of gas mixture under a relatively low pressure. In this way, the solid film is formed evenly, the film performance is better, the production capacity is higher, and the cost is lower.

[0051] like Figure 3 As shown, a side view of back side silicon nitride film patterning of a method for preparing nanopores based on a double beam microscope provided by an embodiment of the present invention;

[0052] In some embodiments,

[0053] The silicon nitride film on the back side is patterned by photolithography and KOH etching to form a square window with a side length of 600 μm and an alignment mark.

[0054] like Figure 4 As shown, a front side view of a silicon nitride film patterning method for preparing nanopores based on a double-beam microscope provided by an embodiment of the present invention;

[0055] In some embodiments,

[0056] The silicon nitride film on the front side was patterned by photolithography and KOH etching (the silicon nitride was not completely etched, and a thickness of 100 nm was retained) to form a scribe mark pattern and a nanohole mark pattern, and the side length of the square window was 10 μm.

[0057] like Figure 5 As shown, a top view of a back side silicon nitride film of a method for preparing nanopores based on a double beam microscope provided by an embodiment of the present invention;

[0058] In some embodiments,

[0059] KOH etches through the back silicon layer, and the thickness of the silicon nitride film at the square window with a side length of 10μm on the front side is reduced to 20nm.

[0060] like Figure 6 As shown, a top view of a method for preparing nanopores based on a double-beam microscope after drilling provided by an embodiment of the present invention;

[0061] In some embodiments,

[0062] The double-beam microscope is used to process nanopores of specified diameter on SiNx film. The beam current is 1.3-1.6pA, the dose is 6000mc / cm2, and the diameter of the nanopore is 40-50nm. The nanopores after drilling are electrochemically characterized. The translocation signal of spherical nanoparticles is different from that of long-chain DNA molecules. The movement distance corresponding to their translocation signals is only a few hundred nanometers, which is the sum of the diameter and the thickness of the nanopore. Since carboxyl polystyrene nanoparticles have a negative charge on their surface in the electrolyte solution, when an external voltage is applied, they pass through the nanopore due to the electrophoretic force. Most of the spike pulses are within a few hundred microseconds. The experimental results show that the SiNx nanopores prepared by the double-beam microscope have good resolution and can detect pulse signals of multiple particles passing through the hole.

[0063] like Figure 7 As shown, a schematic structural diagram of a nanopore preparation device based on a double-beam microscope provided in this embodiment.

[0064] The acquisition module 110 is used to provide a silicon wafer substrate base; wherein a layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base;

[0065] A first processing module 120, configured to pattern the silicon nitride film by the semiconductor process to obtain a patterned silicon nitride film;

[0066] A second processing module 130 is used to perform a hole punching process on the imaged silicon nitride film through the dual-beam microscope to obtain nanopores;

[0067] The detection module 140 is used to perform electrochemical characterization detection on the nanopore.

[0068] In some embodiments, the acquisition module 110, the first processing module 120, the second processing module 130 and the detection module 140 may be program modules; after the program modules are executed by the processor, the operations of the above modules may be implemented.

[0069] In other embodiments, the acquisition module 110, the first processing module 120, the second processing module 130 and the detection module 140 may be a combination of soft and hard modules; the combination of soft and hard modules include but are not limited to: various programmable arrays; the programmable arrays include but are not limited to: field programmable arrays and / or complex programmable arrays.

[0070] In some other embodiments, the acquisition module 110, the first processing module 120, the second processing module 130 and the detection module 140 may be pure hardware modules; the pure hardware modules include but are not limited to: application specific integrated circuits.

[0071] like Figure 8 As shown, an embodiment of the present disclosure provides an electronic device, characterized in that the electronic device includes:

[0072] Memory;

[0073] A processor is connected to the memory and is used to implement the method provided by any of the above embodiments by executing computer executable instructions stored in the memory, such as executing Figures 1 to 6 Any of the methods shown.

[0074] The electronic device may be a terminal device and / or a server in a service platform.

[0075] like Figure 8 As shown, the electronic device may also include a network interface, which can be used to interact with a peer device through a network.

[0076] The present disclosure provides a computer storage medium storing computer executable instructions. After the computer executable instructions are executed by a processor, the method provided in any of the above embodiments can be implemented. For example, Figures 1 to 6 Any of the methods shown.

[0077] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing nanopores based on double-beam microscopy, characterized in that: include: A silicon wafer substrate base is provided; wherein a layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base; Patterning the silicon nitride film through the semiconductor process to obtain a patterned silicon nitride film; Punching the imaged silicon nitride film by using the double beam microscope to obtain nanopores; The nanopore is subjected to electrochemical characterization detection.

2. The method for preparing nanopores based on double-beam microscopy according to claim 1, characterized in that: A layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base, and also includes: a layer of silicon nitride film deposited on one side of the silicon wafer substrate base is called a front silicon nitride film; a layer of silicon nitride film deposited on the other side of the silicon wafer substrate base is called a back silicon nitride film.

3. The method for preparing nanopores using a double beam microscope according to claim 2, characterized in that: The silicon nitride film is patterned by the semiconductor process to obtain a patterned silicon nitride film, and further comprises: The front silicon nitride film is imaged by a semiconductor process to form a marking pattern on the front silicon nitride film; wherein the marking pattern includes at least a scribe marking pattern and a nanohole marking pattern; The back side silicon nitride film is patterned by a semiconductor process to form an alignment mark on the back side silicon nitride film.

4. The method for preparing nanopores using a double beam microscope according to claim 3, characterized in that: The imaged silicon nitride film is punched with the double beam microscope to obtain nanopores, and further comprising: According to the marking pattern formed on the front silicon nitride and the alignment mark formed on the back silicon nitride, the silicon wafer substrate is punched with the double-beam microscope to obtain nanopores.

5. A device for preparing nanopores based on a double-beam microscope, characterized in that: include: The acquisition module is used to provide a silicon wafer substrate base; wherein a layer of silicon nitride film is deposited on both sides of the silicon wafer substrate base; A first processing module, used for patterning the silicon nitride film through the semiconductor process to obtain a patterned silicon nitride film; A second processing module is used to perform a hole punching process on the imaged silicon nitride film through the double-beam microscope to obtain nanopores; A detection module is used to perform electrochemical characterization detection on the nanopore.

6. An electronic device, characterized in that: include: Memory; A processor is connected to the memory and is used to execute computer executable instructions stored in the memory and implement the method for preparing nanopores based on a double-beam microscope provided in any one of claims 1 to 4.

7. A computer storage medium, characterized in that: The computer storage medium stores computer executable instructions; after the computer executable instructions are executed, the method for preparing nanopores based on a double-beam microscope provided in any one of claims 1 to 4 can be implemented.

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