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Preparation method of STEM sample of two-dimensional nano material

A two-dimensional nanomaterial and sample technology, which is applied in the field of STEM sample preparation, can solve the problems of destroying the structure of STEM samples and contamination of STEM samples, so as to reduce damage, isolate the atmosphere and pollutants well, and have strong resistance to ion beam bombardment. Effect

Pending Publication Date: 2022-05-03
INST OF PHYSICS - CHINESE ACAD OF SCI +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Using the method of in-situ evaporating protective layer in high vacuum, it solves the problem of STEM sample contamination caused by the exposure of STEM samples to the atmosphere when preparing two-dimensional nanomaterials prepared in a vacuum environment, and the destruction of two-dimensional nanomaterials by cutting and sampling by focused ion beam (FIB) STEM Sample Structure Questions

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  • Preparation method of STEM sample of two-dimensional nano material
  • Preparation method of STEM sample of two-dimensional nano material
  • Preparation method of STEM sample of two-dimensional nano material

Examples

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preparation example Construction

[0035](3) Preparation of STEM samples: Take out the two-dimensional nanomaterials with two protective layers evaporated from the vacuum environment, and deposit platinum on the two-dimensional nanomaterials with two protective layers evaporated by electron beam and ion beam induced deposition thin film, and then use the focused ion beam to sample the two-dimensional nanomaterials of the deposited platinum film and the evaporated two-layer protective layer to obtain a sample sheet, and use the focused ion beam to thin the sample sheet until the sample sheet is scanned The contrast in the electron microscope (SEM) is whitened, resulting in a STEM sample of the 2D nanomaterial.

[0036] Further, in a method for preparing a STEM sample of a two-dimensional nanomaterial, the two-dimensional nanomaterial is a two-dimensional nanomaterial prepared in a vacuum environment.

[0037] Further, in a method for preparing a STEM sample of a two-dimensional nanomaterial, the vacuum degree of...

Embodiment 1

[0044] In this embodiment, the two-dimensional nanomaterial is double-layer vanadium ditelluride.

[0045] Step one, first as figure 1 and figure 2 As shown, there is no need to transfer or expose to the atmosphere in vacuum, and the C 60 Evaporation of thin films, C 60 The evaporation method is resistive thermal evaporation, the evaporation temperature is 370°C, and the evaporation rate is about 1nm / mins. After the evaporation is completed, the C 60 The film thickness was 10 nm.

[0046] Step 2, then as image 3 As shown, in the vacuum environment for the evaporated C 60 The double-layer vanadium ditelluride thin film is vapor-deposited in situ. The evaporation method of the antimony source is resistive thermal evaporation. The evaporation temperature is 390°C and the evaporation rate is about 1nm / mins. After the evaporation is completed, the obtained The metal antimony film thickness is 50nm.

[0047] Step 3, then using the above-mentioned double-layer vanadium ditel...

Embodiment 2

[0052] In this embodiment, the two-dimensional nanomaterial is double-layer vanadium ditelluride. The technical features in this embodiment that are the same as those in Embodiment 1 will not be described in detail.

[0053] Step one, such as figure 1 and figure 2 As shown, in ultra-high vacuum, there is no need to transfer or expose to the atmosphere, and the C 60 Evaporation of thin films, C 60 The evaporation method is resistive thermal evaporation, the evaporation temperature is 360°C, and the evaporation rate is about 0.6nm / mins. After the evaporation is completed, the C 60 The film thickness is 7 nm.

[0054] Step 2, in a vacuum environment, evaporated C 60 The non-metallic selenium film is evaporated in situ on the double-layer vanadium ditelluride of the film. The evaporation method of the selenium source is resistive thermal evaporation. The evaporation temperature is 130°C, and the evaporation rate is about 2.5nm / mins. After the evaporation is completed The th...

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Abstract

The invention discloses a preparation method of a STEM sample of a two-dimensional nano material. The preparation method comprises the following steps: performing in-situ evaporation of a first protective layer on the prepared two-dimensional nano material in a vacuum environment; evaporating a second protective layer in situ on the two-dimensional nano material evaporated with the first protective layer in a vacuum environment; taking out the two-dimensional nano material evaporated with the two protective layers from a vacuum environment, depositing a platinum film in an electron beam and ion beam induced deposition mode, then sampling by adopting a focused ion beam to obtain a sample sheet, thinning the sample sheet by adopting the focused ion beam until the contrast of the sample sheet becomes white in a scanning electron microscope (SEM), and finally obtaining the two-dimensional nano material evaporated with the two protective layers. The STEM sample of the two-dimensional nano material is obtained. According to the method, a fullerene (C60) thin film and a metal thin film or a non-metal thin film are evaporated in situ in vacuum, so that the problems that a sample is polluted and a characterization structure is damaged in subsequent sampling due to the fact that the STEM sample prepared from a two-dimensional nano material needs to be exposed to the atmosphere are solved.

Description

technical field [0001] The invention relates to the technical field of scanning electron microscope sample preparation, in particular to a method for preparing a STEM sample of a two-dimensional nanomaterial. Background technique [0002] In recent years, two-dimensional nanomaterials have received extensive attention. Because they have only one or a few atomic layers in a certain dimension, the confinement effect makes them have strange properties different from three-dimensional materials. These novel properties are often determined by its own structure, so the high-precision characterization of its structure is of great significance to the research of related fields. Among the atomic-scale structural characterization techniques, transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) techniques can perform atomic-scale characterization and measurement of the sample structure from different directions, so it has become the current two-di...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01Q30/20
CPCG01Q30/20
Inventor 朱知力王业亮时金安刘中流武旭周武高鸿钧
Owner INST OF PHYSICS - CHINESE ACAD OF SCI