CN109946340B - Preparation method of two-dimensional layered material sample electrical testing microelectrode - Google Patents
Preparation method of two-dimensional layered material sample electrical testing microelectrode Download PDFInfo
- Publication number
- CN109946340B CN109946340B CN201910298039.9A CN201910298039A CN109946340B CN 109946340 B CN109946340 B CN 109946340B CN 201910298039 A CN201910298039 A CN 201910298039A CN 109946340 B CN109946340 B CN 109946340B
- Authority
- CN
- China
- Prior art keywords
- sample
- ion beam
- microelectrode
- dimensional layered
- electron beam
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The invention discloses a preparation method of a two-dimensional layered material sample electrical test microelectrode, which comprises the following steps: providing a silicon chip, distributing a single-layer or few-layer two-dimensional material on the silicon chip, positioning a single-layer or few-layer two-dimensional layered sample to be detected through an Atomic Force Microscope (AFM), and marking near the two-dimensional layered sample through a Laser mark. Depositing silicon oxide with the thickness of about 5-10nm on the surface of the sample by using an FIB-assisted electron beam deposition method to protect the central area of the sample to a certain degree; in the method, the centering of the electron beam and the ion beam is carried out at the laser mark position, then the sample is moved to the screen area under the weak electron beam, and the ion beam is switched to carry out the deposition of the ion beam auxiliary metal microelectrode on four corners of the sample. And finally, a large electrode is led out from the micro electrode by a method of depositing a metal electrode by evaporation, and the method can be popularized and applied to the electrical performance test of small samples.
Description
Technical Field
The invention belongs to the field of two-dimensional layered material characterization, and relates to a preparation method of a microelectrode suitable for electrical test of a two-dimensional layered material sample.
Background
In recent years, two-dimensional semiconductor materials have attracted wide scientific attention due to their unique material structures and electron transport properties, and are used in the fields of optoelectronic devices, catalysis, biosensors, and the like. Ultrathin two-dimensional layered nanomaterials are an emerging class of nanomaterials that have a platelet structure with horizontal dimensions of only a few microns in size and a thickness of only a single or a few atoms thick (typical thicknesses are less than 5 nm). Due to the restriction of the photoetching technology, the size of a mask for manufacturing an electrode of a general manufactured bulk material is in the micron level, the size of a deposited electrode can also be in the micron level, and a more complex device cannot be manufactured. In addition, when the photolithography technique is used, the used photoresist and the subsequent photoresist removing process may affect the properties of the two-dimensional material, which has great limitations. Alternatively, the electrodes are prepared and then the two-dimensional material is transferred onto the electrodes. The method has the advantages of wide applicability, but the contact between the two-dimensional material and the electrode is not good, so that the test of the electrical performance is influenced. The thickness of the two-dimensional material is very thin, and the two-dimensional material is sensitive to electron beams and the like, so that the electrical test by using a nano probe station is difficult.
Disclosure of Invention
The invention aims to provide a preparation method of a microelectrode for electrical property characterization of a two-dimensional layered material, which solves the problem that the electrical property of a small-size two-dimensional layered material cannot be directly demonstrated by a conventional electrical testing method. The microelectrode is led out from the two-dimensional material by an FIB (focused ion beam) assisted deposition method, can be used for being connected with an electrode prepared by a conventional method, realizes direct characterization aiming at the electrical property of the two-dimensional material, and provides great convenience for the research of the electrical property of the material.
The specific technical scheme for realizing the purpose of the invention is as follows:
a preparation method of a microelectrode for electrical test of a two-dimensional layered material sample is used for leading out the microelectrode from the two-dimensional layered material in a focused ion beam assisted deposition mode, and comprises the following specific steps:
step 1: providing a silicon wafer, and distributing a single layer or a few layers of two-dimensional layered materials on the silicon wafer;
step 2: positioning a single-layer or few-layer two-dimensional layered sample to be detected by an Atomic Force Microscope (AFM), confirming the thickness of the two-dimensional layered material, and selecting a proper sample;
and step 3: laser marking is made near the two-dimensional layered sample, and the laser marking has a safe distance from the sample;
and 4, step 4: transferring the sample into a focused ion beam microscope, finding the sample through a laser mark under weak electron beams, and depositing 5-10nm of silicon oxide through the electron beams to protect the central area of the sample;
and 5: selecting a characteristic point near the sample to perform centering of an electron beam and an ion beam, and avoiding the ion beam from scanning a sample area;
step 6: moving the sample by weak electron beams, and carrying out deposition of microelectrodes on four corners of the sample by switching to the ion beams;
and 7: the metal electrode is connected with the microelectrode by conventional evaporation electrode deposition.
The preparation method, step 3, the laser marking specifically includes:
a1: confirming the position of the sample under an optical microscope;
a2: a mark is formed by laser at a distance of 1-2cm from any edge of the sample, and the mark is unlimited in shape and has a depth of about 1-5 μm.
The preparation method, step 5 of the electron beam and ion beam centering, specifically comprises:
b1: selecting laser marking debris near a sample as a characteristic point under an electron beam;
b2: the electron beam and ion beam centering under the focused ion beam is performed for the selected feature point of B1.
The preparation method, step 6, the microelectrode deposition, specifically comprises the following steps:
b3: moving the two-dimensional material sample to the center of a screen under the condition of low voltage and low beam current electron beams; the voltage of the electron beam is lower than 2kv, and the beam current is lower than 50 PA;
b4: switching to ion beams, and performing ion beam assisted microelectrode deposition at four corners of the sample, wherein the width direction of the electrode is 50nm-500nm, and the length direction is 2-10 μm; the ion beam voltage is lower than 5kv, and the beam current is lower than 80 PA.
According to the preparation method, the electron beam and the ion beam are centered in the step 5, a characteristic point is found under the condition of 0-degree electron beam, the sample stage is tilted to 52 degrees, and the characteristic point is always located at the center of the screen by adjusting the height Z.
In the preparation method, the deposited electrode metal selected in the step 6 can be C, W, Pt.
In the preparation method, in the step 7, the electrode material is Au, Ag, Pt, W, Al or Cu.
The invention has the beneficial effects that:
the microelectrode is led out from the two-dimensional layered material by an FIB (focused ion beam) assisted deposition method, can be used for being connected with an electrode prepared by a conventional method to establish a conductive channel, realizes direct characterization of the electrical property of the two-dimensional material, and provides great convenience for the research of the electrical property of the material. The method can be used for testing the electrical properties of two-dimensional layered materials such as single-layer or few-layer graphene, molybdenum disulfide, vanadium diselenide and the like.
Drawings
FIG. 1 shows VSe on a silicon wafer2Optical electron microscopeAnd atomic force microscopy pictures;
FIG. 2 is a schematic surface view of a sample after a silicon oxide protective film is deposited in step 4, wherein 1 is a two-dimensional sheet sample, 2 is a laser marking point, and 3 is a deposited silicon oxide protective film;
FIG. 3 is a schematic view of the present invention after deposition of the microelectrodes and connection of external electrodes in step 6, wherein 4 is the deposited microelectrodes and 5 is the external electrodes;
Detailed Description
The present invention will be described in detail with reference to specific examples.
A preparation method of a two-dimensional layered material sample microelectrode for testing electrical properties comprises the following specific steps:
firstly, step 1) is implemented, a silicon wafer with the side length of 1cm is provided, and the silicon wafer substrate is cleaned. Forming VSe in single or few layers by CVD or direct solution transfer2Transferring to the surface of the cleaned silicon wafer;
next, step 2) of selecting VSe with a relatively large diameter of the monolayer by atomic force microscopy was performed2A sample; the optical microscope picture (a) and AFM picture (B) of the sample are shown in fig. 1;
step 3) is then carried out, in the present embodiment, the sample selected in step 2) is found by an optical microscope in a laser marking machine, and a mark is laser-marked at a position 1cm away from the sample, as shown in 2 in fig. 2, the mark is not limited in shape and has a depth of about 1-5 μm; facilitating positioning to a sample under a focused ion beam microscope (FIB) electron beam;
and then, implementing the step 4) to find the sample under the electron beam voltage of 2kv and 50Pa and the beam current of 50PA by laser marking under the electron beam voltage of 2kv, and performing SiO2 film deposition on the surface of the sample to protect the central area of the sample. The deposition was carried out under electron beam, and the deposited film had a shape of orientation, a side length of 3 μm and a thickness of 15 nm. Fig. 2 is a schematic view of the surface of the sample after the silicon oxide protective film is deposited through step 4.
Then, step 5) is carried out, centering of the electron beam and the ion beam is carried out on the specific debris generated by the laser marking, specifically, a characteristic point is found under the condition of 0-degree electron beam, the sample stage is tilted to 52 degrees, and the characteristic point is always located at the center of the screen by adjusting the height Z;
step 6) is then implemented, in this embodiment, step 6) comprises:
6-1): moving the two-dimensional material sample to the center of a screen under the voltage of an electron beam of 2kv and the beam current of 50 PA;
6-2): switching to ion beams (the ion beam voltage is lower than 5kv, the beam current is lower than 80PA), carrying out ion beam auxiliary microelectrode deposition at four corners of the sample, wherein the size of a single electrode is 200nm in width and 10 μm in length, and deposited metal is Pt; in order to minimize the effect of microelectrode deposition on the sample, the thickness of the deposited metal is relatively thin, about 200nm, near the sample; the thickness and width of the metal deposit far away from the sample can be increased properly, in the embodiment, the width is increased to 500nm, and the thickness is increased to 1 μm;
and 7) performing step 7), in this embodiment, selecting a suitable mask plate to deposit a Pt electrode by using a magnetron sputtering method, and connecting the Pt electrode with the deposited microelectrode of step 6), where fig. 3 is a schematic surface diagram of the sample after Pt electrode deposition.
It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.
Claims (7)
1. A preparation method of a microelectrode for electrical test of a two-dimensional layered material sample is characterized in that the microelectrode is led out of a two-dimensional layered material in a focused ion beam assisted deposition mode, and the method comprises the following specific steps:
step 1: providing a silicon wafer, and distributing a single layer or a few layers of two-dimensional layered materials on the silicon wafer;
step 2: positioning a single-layer or few-layer two-dimensional layered sample to be detected by an Atomic Force Microscope (AFM), confirming the thickness of the two-dimensional layered material, and selecting a proper sample;
and step 3: laser marking is made near the two-dimensional layered sample, and the laser marking has a safe distance from the sample;
and 4, step 4: transferring the sample into a focused ion beam microscope, finding the sample through a laser mark under weak electron beams, and depositing 5-10nm of silicon oxide through the electron beams to protect the central area of the sample;
and 5: selecting a characteristic point near the sample to perform centering of an electron beam and an ion beam, and avoiding the ion beam from scanning a sample area;
step 6: moving the sample by weak electron beams, and carrying out deposition of microelectrodes on four corners of the sample by switching to the ion beams;
and 7: the metal electrode is connected with the microelectrode by conventional evaporation electrode deposition.
2. The method according to claim 1, wherein the laser marking in step 3 specifically comprises:
a1: confirming the position of the sample under an optical microscope;
a2: and (3) marking a mark with a laser at a position 1-2cm away from any edge of the sample, wherein the mark is unlimited in shape and 1-5 mu m in depth.
3. The method according to claim 1, wherein the step 5 of centering the electron beam and the ion beam specifically comprises:
b1: selecting laser marking debris near a sample as a characteristic point under an electron beam;
b2: the electron beam and ion beam centering under the focused ion beam is performed for the selected feature point of B1.
4. The preparation method according to claim 3, wherein the microelectrode deposition of step 6 specifically comprises:
b3: moving the two-dimensional material sample to the center of a screen under the condition of low voltage and low beam current electron beams; the voltage of the electron beam is lower than 2kv, and the beam current is lower than 50 PA;
b4: switching to ion beams, and performing ion beam assisted microelectrode deposition at four corners of the sample, wherein the width direction of the electrode is 50nm-500nm, and the length direction is 2-10 μm; the ion beam voltage is lower than 5kv, and the beam current is lower than 80 PA.
5. The method of claim 3, wherein in the step 5, the electron beam and the ion beam are centered, a characteristic point is found under the condition of 0 degree electron beam, the sample stage is tilted to 52 degrees, and the characteristic point is always located at the center of the screen by adjusting the height Z.
6. The method according to claim 4, wherein the deposited electrode metal selected in step 6 is W or Pt.
7. The production method according to claim 1, wherein the electrode material in step 7 is Au, Ag, Pt, W, Al or Cu.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910298039.9A CN109946340B (en) | 2019-04-15 | 2019-04-15 | Preparation method of two-dimensional layered material sample electrical testing microelectrode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910298039.9A CN109946340B (en) | 2019-04-15 | 2019-04-15 | Preparation method of two-dimensional layered material sample electrical testing microelectrode |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109946340A CN109946340A (en) | 2019-06-28 |
| CN109946340B true CN109946340B (en) | 2020-02-18 |
Family
ID=67015155
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910298039.9A Active CN109946340B (en) | 2019-04-15 | 2019-04-15 | Preparation method of two-dimensional layered material sample electrical testing microelectrode |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109946340B (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100437120C (en) * | 2004-11-17 | 2008-11-26 | 中国科学院物理研究所 | Testing electrode of single nanometer materials and production thereof |
| JP2008185931A (en) * | 2007-01-31 | 2008-08-14 | Sii Nanotechnology Inc | Method for correcting defect in photomask using focused ion beam microfabrication device |
| CN101174673A (en) * | 2007-08-31 | 2008-05-07 | 南京大学 | Double-layer compound film non-volatile memory device and method for producing the same |
| CN101354416B (en) * | 2008-09-05 | 2011-05-11 | 北京工业大学 | Method for preparing small separation distance electrode on transmission electric mirror sample |
| CN108470777B (en) * | 2018-03-13 | 2020-01-07 | 华东师范大学 | Preparation method of material testing unit with nano-scale interval small electrodes for in-situ power-on chip of transmission electron microscope |
-
2019
- 2019-04-15 CN CN201910298039.9A patent/CN109946340B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109946340A (en) | 2019-06-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5249196B2 (en) | Method for forming a pattern of metal, metal oxide and / or semiconductor material on a substrate | |
| Meitl et al. | Transfer printing by kinetic control of adhesion to an elastomeric stamp | |
| US7736979B2 (en) | Method of forming nanotube vertical field effect transistor | |
| US8257566B2 (en) | Nanotube device and method of fabrication | |
| JP5297581B2 (en) | Pattern transfer printing with dynamic control of adhesion to elastomeric stamps | |
| Li et al. | Precise alignment of single nanowires and fabrication of nanoelectromechanical switch and other test structures | |
| TW200914367A (en) | Method and system for printing aligned nanowires and other electrical devices | |
| KR101039630B1 (en) | Method to assemble nano-structure on a substrate and nano-molecule device comprising nano-structure formed thereby | |
| KR20110081683A (en) | Ambi-polar memory device based on reduced graphene oxide using metal nanoparticle and the method for preparation of ambi-polar memory device | |
| Guillorn et al. | Fabrication of dissimilar metal electrodes with nanometer interelectrode distance for molecular electronic device characterization | |
| US8420530B2 (en) | Nano-interconnects for atomic and molecular scale circuits | |
| US20110167526A1 (en) | Microsprings Having Nanowire Tip Structures | |
| Luber et al. | Nanometre spaced electrodes on a cleaved AlGaAs surface | |
| Langford et al. | Comparison of different methods to contact to nanowires | |
| KR101182522B1 (en) | fabrication method of nano pattern and fabrication method for TFT and LCD using the same | |
| CN109946340B (en) | Preparation method of two-dimensional layered material sample electrical testing microelectrode | |
| CN102891083B (en) | A kind of method preparing single electron transistor at room temperature | |
| CN112599419B (en) | Printing type construction method of micro-nano semiconductor device | |
| Strobel et al. | A silicon-on-insulator vertical nanogap device for electrical transport measurements in aqueous electrolyte solution | |
| Ong et al. | Suspended graphene devices with local gate control on an insulating substrate | |
| KR101029995B1 (en) | High Integrating Method of 1 Dimensional or 2 Dimensional Conductive Nanowires Using Charged Materials, and High Integrated Conductive Nanowires by the Same | |
| Wang et al. | Development of a thermoelectric nanowire characterization platform (TNCP) for structural and thermoelectric investigation of single nanowires | |
| Dalla Francesca et al. | Large-area in plane molecular junctions by electrografting in 10 nm metallic nanotrenches | |
| Sapkov et al. | Method of creation of monomolecular transistor with overhanging electrodes | |
| CN109075189B (en) | Method for producing a flat free contact surface of a semiconductor nanostructure |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |