阅读说明：本技术 一种基于x射线多层膜波带片的修正方法及系统 (X-ray-based multilayer film zone plate correction method and system ) 是由 陈溢祺 朱忆雪 张秀霞 金宇 朱东风 朱运平 于 2020-08-13 设计创作，主要内容包括：本发明涉及一种基于X射线多层膜波带片的修正方法及系统,方法包括：在多层膜波带片的上端和下端各镀制N层周期膜；对镀制的N层周期膜进行掠入射X射线反射测试,确定两端镀制的N层周期膜的周期厚度；利用电子显微镜对多层膜波带片以及两端镀制的N层周期膜进行拍摄,获得拍摄图像；读取拍摄图像中每层膜波带片的厚度以及两端镀制的N层周期膜的厚度；根据周期厚度和拍摄图像中的周期膜厚度对拍摄图像中每层膜波带片的厚度进行修正。本发明在多层膜波带片上下两端增加了周期膜,修正了电子显微镜图像拍摄时引入的误差,提高了电子显微镜定位与厚度表征的精确度。(The invention relates to a correction method and a system based on an X-ray multilayer film zone plate, wherein the method comprises the following steps: plating N layers of periodic films on the upper end and the lower end of the multilayer film zone plate respectively; grazing incidence X-ray reflection test is carried out on the N layers of plated periodic films, and the periodic thickness of the N layers of plated periodic films at two ends is determined; shooting the multilayer film zone plate and the N layers of periodic films plated at two ends by using an electron microscope to obtain a shot image; reading the thickness of each layer of the zone plate in the shot image and the thickness of the N layers of the periodic films plated at two ends; and correcting the thickness of each layer of the zone plate in the shot image according to the period thickness and the period film thickness in the shot image. According to the invention, the periodic films are added at the upper end and the lower end of the multi-layer film zone plate, so that errors introduced during image shooting of an electron microscope are corrected, and the accuracy of positioning and thickness characterization of the electron microscope is improved.)

1. A correction method based on an X-ray multilayer film zone plate is characterized by comprising the following steps:

plating N layers of periodic films on the upper end and the lower end of the multilayer film zone plate respectively; n is a positive integer greater than 2;

grazing incidence X-ray reflection test is carried out on the N layers of plated periodic films, and the periodic thickness of the N layers of plated periodic films at two ends is determined to be the first upper end thickness and the first lower end thickness;

shooting the multilayer film zone plate and the N layers of periodic films plated at two ends by using an electron microscope to obtain a shot image;

reading the thickness of each layer of the zone plate in the shot image and the thickness of the N layers of the periodic films plated at two ends; the read thickness of the N layers of periodic films plated at the two ends comprises a second upper end thickness and a second lower end thickness;

and correcting the thickness of each layer of the zone plate in the shot image according to the first upper end thickness, the first lower end thickness, the second upper end thickness and the second lower end thickness.

2. The correction method according to claim 1, wherein the X-ray source in the X-ray reflection test is a Cu-ka line, the wavelength is 0.154nm, and the test mode is a θ -2 θ linked scan mode.

3. The correction method according to claim 1, wherein the periodic thickness of the N layers of periodic films plated at both ends is determined by: and determining the periodic thickness of the N layers of periodic films plated at two ends according to a Bragg formula.

4. The correction method according to claim 3, wherein the Bragg formula is as follows:

wherein D is the period thickness of N layers of periodic films at the end to be measured, theta_rThe grazing incidence angle corresponding to the r-th Bragg peak, q is the diffraction order, and lambda is the wavelength of X-ray and is the average refraction small quantity of the multilayer film.

5. The correction method according to claim 1, wherein the correcting the thickness of each layer of the zone plate in the captured image according to the first upper end thickness, the first lower end thickness, the second upper end thickness, and the second lower end thickness includes:

determining a proportional function according to the first upper end thickness, the first lower end thickness, the second upper end thickness and the second lower end thickness;

and correcting the thickness of each layer of the film zone plate in the shot image according to the proportional function.

6. The correction method according to claim 5, wherein the specific formula for correcting the thickness of each layer of the film zone plate in the captured image according to the proportional function is as follows:

wherein y is the thickness of each layer of the film zone plate after correction, and delta D₁＝D₁-D′₁，ΔD₂＝D₂-D′₂，D₁Is a first upper end thickness, D₂Is a first lower end thickness, D'₁Is a second upper end thickness, D'₂And the thickness of the second lower end is n, the total number of film layers of the multilayer film zone plate is n, and the thickness of each film zone plate in the shot image is x.

7. An X-ray multilayer film zone plate-based correction system is characterized by comprising:

the plating module is used for plating N layers of periodic films on the upper end and the lower end of the multilayer film zone plate respectively; n is a positive integer greater than 2;

the X-ray reflection testing module is used for carrying out grazing incidence X-ray reflection testing on the plated N layers of periodic films and determining the periodic thicknesses of the N layers of periodic films plated at two ends, namely the thickness of the first upper end and the thickness of the first lower end;

the shooting module is used for shooting the multilayer film zone plate and the N layers of periodic films plated at two ends by using an electron microscope to obtain a shot image;

the thickness reading module is used for reading the thickness of each layer of the zone plate in the shot image and the thickness of the N layers of the periodic films plated at two ends; the read thickness of the N layers of periodic films plated at the two ends comprises a second upper end thickness and a second lower end thickness;

and the correcting module is used for correcting the thickness of each layer of the zone plate in the shot image according to the first upper end thickness, the first lower end thickness, the second upper end thickness and the second lower end thickness.

Technical Field

The invention relates to the technical field of multilayer film zone plates, in particular to a correction method and system based on an X-ray multilayer film zone plate.

Background

The X-ray wave band covers the resonance lines of most elements, the wavelength is short, the penetrability is strong, and nondestructive measurement can be realized. Therefore, X-ray microscopy is an important research tool in the research fields of biology, medicine, materials, physics, chemistry and the like. The resolution of the X-ray microscopic imaging system is determined by the size of the focal spot available from the focusing element, and therefore, the development of high-quality nano focusing optical elements is a prerequisite for realizing high-resolution X-ray microscopy. The X-ray multilayer film zone plate is an ideal novel optical element for converging X-rays at present. This method was proposed in 2004 and is based on the physical idea of an X-ray laue lens. Depositing thousands of nano film layers by adopting a sputtering technology, and then slicing and thinning the cross section of the film layers to prepare the wave zone plate with the depth of microns. The preparation process of the X-ray multilayer film zone plate is extremely precise, and is the ultimate challenge of the current micro-nano processing technology.

For the research of the multilayer film zone plate, the current international main face is the stress problem, the accurate positioning problem of the nanometer film layer and the bottleneck problem of the resolution improvement. To solve the problem of the multilayer film zone plate, a high-resolution electron microscope (SEM) is required to observe and mark the nano film layer. At present, the main research groups of all countries in the world adopt electron microscope assistance to obtain very good research results. However, when SEM imaging is used, errors may be caused by the angle change between the incident electrons and the sample surface and mechanical vibration, and for a multi-layer zone plate with thousands of layers, the accumulation of errors may cause distortion of the layer positioning and thickness characterization.

Disclosure of Invention

The invention aims to provide a correction method and a correction system based on an X-ray multilayer film zone plate, which are used for correcting errors introduced during image shooting of an electron microscope and improving the accuracy of positioning and thickness characterization of the electron microscope.

In order to achieve the purpose, the invention provides the following scheme:

a correction method based on an X-ray multilayer film zone plate comprises the following steps:

plating N layers of periodic films on the upper end and the lower end of the multilayer film zone plate respectively; n is a positive integer greater than 2;

grazing incidence X-ray reflection test is carried out on the N layers of plated periodic films, and the periodic thickness of the N layers of plated periodic films at two ends is determined to be the first upper end thickness and the first lower end thickness;

shooting the multilayer film zone plate and the N layers of periodic films plated at two ends by using an electron microscope to obtain a shot image;

reading the thickness of each layer of the zone plate in the shot image and the thickness of the N layers of the periodic films plated at two ends; the read thickness of the N layers of periodic films plated at the two ends comprises a second upper end thickness and a second lower end thickness;

and correcting the thickness of each layer of the zone plate in the shot image according to the first upper end thickness, the first lower end thickness, the second upper end thickness and the second lower end thickness.

Preferably, the X-ray source in the X-ray reflection test is a Cu-Ka line, the wavelength is 0.154nm, and the test mode is a theta-2 theta linkage scanning mode.

Preferably, the determining the periodic thickness of the N-layer periodic film plated at the two ends specifically comprises: and determining the periodic thickness of the N layers of periodic films plated at two ends according to a Bragg formula.

Preferably, the bragg formula is as follows:

wherein D is the period thickness of N layers of periodic films at the end to be measured, theta_rThe grazing incidence angle corresponding to the r-th Bragg peak, q is the diffraction order, and lambda is the wavelength of X-ray and is the average refraction small quantity of the multilayer film.

Preferably, the correcting the thickness of each layer of the zone plate in the captured image according to the first upper end thickness, the first lower end thickness, the second upper end thickness, and the second lower end thickness includes:

determining a proportional function according to the first upper end thickness, the first lower end thickness, the second upper end thickness and the second lower end thickness;

and correcting the thickness of each layer of the film zone plate in the shot image according to the proportional function.

Preferably, the specific formula for correcting the thickness of each layer of the film zone plate in the shot image according to the proportional function is as follows:

wherein y is the thickness of each layer of the film zone plate after correction, and delta D₁＝D₁-D′₁，ΔD₂＝D₂-D′₂，D₁Is a first upper end thickness, D₂Is a first lower end thickness, D'₁Is a second upper end thickness, D'₂And the thickness of the second lower end is n, the total number of film layers of the multilayer film zone plate is n, and the thickness of each film zone plate in the shot image is x.

An X-ray multilayer film zone plate-based correction system, comprising:

the plating module is used for plating N layers of periodic films on the upper end and the lower end of the multilayer film zone plate respectively; n is a positive integer greater than 2;

the X-ray reflection testing module is used for carrying out grazing incidence X-ray reflection testing on the plated N layers of periodic films and determining the periodic thicknesses of the N layers of periodic films plated at two ends, namely the thickness of the first upper end and the thickness of the first lower end;

the shooting module is used for shooting the multilayer film zone plate and the N layers of periodic films plated at two ends by using an electron microscope to obtain a shot image;

the thickness reading module is used for reading the thickness of each layer of the zone plate in the shot image and the thickness of the N layers of the periodic films plated at two ends; the read thickness of the N layers of periodic films plated at the two ends comprises a second upper end thickness and a second lower end thickness;

and the correcting module is used for correcting the thickness of each layer of the zone plate in the shot image according to the first upper end thickness, the first lower end thickness, the second upper end thickness and the second lower end thickness.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the invention discloses a correction method and a system based on an X-ray multilayer film zone plate, wherein the method comprises the following steps: plating N layers of periodic films on the upper end and the lower end of the multilayer film zone plate respectively; grazing incidence X-ray reflection test is carried out on the N layers of plated periodic films, and the periodic thickness of the N layers of plated periodic films at two ends is determined to be the first upper end thickness and the first lower end thickness; shooting the multilayer film zone plate and the N layers of periodic films plated at two ends by using an electron microscope to obtain a shot image; reading the thickness of each layer of the zone plate in the shot image and the thickness of the N layers of the periodic films plated at two ends; the read thickness of the N layers of periodic films plated at the two ends comprises a second upper end thickness and a second lower end thickness; and correcting the thickness of each layer of the zone plate in the shot image according to the first upper end thickness, the first lower end thickness, the second upper end thickness and the second lower end thickness. According to the invention, the periodic films are added at the upper end and the lower end of the multi-layer film zone plate, so that errors introduced during image shooting of an electron microscope are corrected, and the accuracy of positioning and thickness characterization of the electron microscope is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

Fig. 1 is a flowchart of a correction method based on an X-ray multilayer film zone plate according to an embodiment of the present invention;

fig. 2 is a block diagram of a multilayer film zone plate provided by an embodiment of the present invention;

fig. 3 is a structural diagram of a correction system based on an X-ray multilayer film zone plate according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention aims to provide a correction method and a correction system based on an X-ray multilayer film zone plate, which are used for correcting errors introduced during image shooting of an electron microscope and improving the accuracy of positioning and thickness characterization of the electron microscope.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.