In-situ testing method for material shear stress under double-beam system

Abstract

The application discloses a kind of in-situ testing methods of material shear stress under double-beam system, it is related to shear stress testing technical field, comprising the following steps: step one, with electron beam perspective analysis sample block, with ion beam imaging to determine processing area;Step two, ion beam processing microblock topography;Step three, mechanical hand assisted microblock extraction and finishing;Step four, with ion beam deposition microblock;Step five, ion beam processing shear sample;Step six, with electron beam perspective carries out pure shear test.The application provides a kind of method for determining critical shear stress on micro-nano scale to specific structure metal material, provides important support for regulating metal material plastic deformation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of shear stress testing, in particular to an in-situ testing method for quantitatively measuring the critical shear stress of a metal material under a specific slip system. BACKGROUND

[0002] Microelectronic devices and micro-electro-mechanical systems (MEMS / NEMS) are independent intelligent systems with feature sizes in the micron or even nanometer range. They have a wide range of applications in national economy and military systems due to their high integration and multi-functionality. Micro-nano components usually contain a large number of multi-phase material interfaces, and defects inevitably exist between the interfaces. The deformation mismatch of the two materials on the bi-phase interface will cause stress concentration at the interface, so the shear failure of the interface is an important factor for the delamination failure of microelectronic devices. These interface failures often lead to device scrap, thereby directly affecting the yield and service life of the devices. Therefore, in order to ensure the reliability and durability of micro-nano devices / systems, it is necessary to study the critical shear stress and shear deformation behavior of the interface bonding.

[0003] Unlike the traditional testing method of macroscopic bulk materials, the small volume of the sample in the experiment of nanomaterials brings a series of difficulties, such as the fixation and clamping of the sample, the application of effective load to the interface in the sample, and the accurate measurement of related mechanical quantities. These difficulties have resulted in a lack of data on the mechanical properties of the interface in nanomaterials, which has seriously hindered the development and application of microelectronic devices and micro-nano mechanical systems. The commonly used pulling method, peeling method, and eardrum method, etc. use off-site testing technology, and the interface bonding strength measured is still in the macroscopic range. The simulation from the theoretical point of view cannot estimate the actual critical shear stress containing defect structures. Therefore, it is necessary to develop an in-situ testing method for material shear stress under a double-beam system. SUMMARY

[0004] The purpose of the present application is to provide an in-situ testing method for material shear stress under a double-beam system, which can measure the critical shear stress of a specific microstructure of a metal material in a double-beam system (electron beam-ion beam).

[0005] To achieve the above purpose, the present application provides the following scheme:

[0006] The present application provides an in-situ testing method for material shear stress under a double-beam system, comprising the following steps:

[0007] Step one: analyze the sample block from the electron beam perspective and determine the processing area by ion beam imaging;

[0008] Step two: process the microblock morphology by ion beam;

[0009] Step three: mechanical hand assisted microblock extraction and finishing;

[0010] Step four, ion beam deposition micro-block;

[0011] Step five, ion beam processing shear sample;

[0012] Step six, electron beam perspective pure shear test.

[0013] Preferably, in the step one, the process of analyzing sample block with electron beam perspective and determining processing area with ion beam imaging is:

[0014] A1, observing sample block with electron beam perspective, scanning target area for EBSD analysis;

[0015] A2, determining the processing area where the target structure is located according to the EBSD analysis result;

[0016] A3, perspective to the target processing area, aligning electron beam and ion beam system;

[0017] A4, selecting processing area in SmartSEM program, ion beam rough processing scanning imaging.

[0018] Preferably, in the step one, the sample block material is metal material, and the sample block is EBSD sample prepared by mechanical polishing or mechanical-chemical polishing after heat treatment.

[0019] Preferably, in the A1, when scanning for EBSD analysis with electron beam perspective, the EBSD sample is fixed on the sample stage and rotated by 70°;

[0020] In the A3, when aligning electron beam and ion beam, the sample stage is rotated by 54°;

[0021] In the A4, when ion beam rough processing scanning imaging, the scanning voltage is 30kV and the scanning current is 30nA.

[0022] Preferably, in the step two, the process of ion beam processing micro-block morphology is:

[0023] B1, drawing processing area in SmartSEM program, setting processing program;

[0024] B2, cutting micro-block morphology with ion beam according to the program.

[0025] Preferably, in the B1, the processing area contains a square area with a length of 20μm and a width of 10μm;

[0026] In the B2, the cutting depth is 10-12μm, the sample stage inclination angle is 54°, the working voltage of ion beam is 30kV, and the working current of ion beam is 30nA.

[0027] Preferably, in the step three, the process of the mechanical hand assisting micro-block extraction and trimming is as follows:

[0028] C1, the ion beam cuts through the bottom of the micro-block;

[0029] C2, the mechanical hand is moved to contact one side of the micro-block, the mechanical hand is connected with one side of the micro-block by depositing Pt;

[0030] C3, the ion beam cuts off the part of the other side of the micro-block connected with the base of the sample block, and the mechanical hand is moved to extract the micro-block;

[0031] C4, the micro-block is trimmed once so that the bottom surface of the micro-block remains horizontal.

[0032] Preferably, in the C1, when the ion beam cuts through the bottom of the micro-block, the sample stage remains horizontal;

[0033] In the C4, when the micro-block is trimmed once, the mechanical hand is rotated by 36°.

[0034] Preferably, in the step four, the process of depositing the micro-block by the ion beam is as follows:

[0035] D1, the mechanical hand is moved so that the bottom surface of the micro-block is attached to the edge of the sample stage;

[0036] D2, one side of the micro-block is deposited by the ion beam, and the part of the mechanical hand connected with the micro-block is cut off after the deposition is completed;

[0037] D3, the micro-block is rotated by 180°, and the other side of the micro-block is deposited.

[0038] Preferably, in the step five, when the ion beam processes the shear sample, a shear sample with a specific shape is processed, and the shear sample has two critical sections;

[0039] In the step six, when the pure shear test is performed by the electron beam perspective, the pure shear test is performed in a displacement control mode, and the loading head used is adapted to the shear sample, that is, the size of the loading head is smaller than the distance between the two critical sections.

[0040] The present application has the following technical effects relative to the prior art:

[0041] The present application provides a micro-nano scale shear stress in-situ testing method, which gives an effective and systematic solution to a series of difficulties in micro testing, such as sample fixation and transfer, effective load applied to the critical section of the sample, and accurate measurement of related mechanical quantities.

[0042] The present application provides an accurate measurement method for micro-nano scale shear stress and interfacial bonding strength, which effectively makes up for the shortcomings of the prior art that adopts a single direction nano scale and other directions are still macro scale.

[0043] The present application provides an in-situ testing method of shear stress, which does not rely on the calculation of Schmid Factor, and the test result is more accurate and intuitive, and the test method is widely applicable. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0045] Figure 1 (a) in the figure is an embodiment of nickel-based alloy electron beam EBSD analysis diagram;

[0046] Figure 1 (b) in the figure is an ion beam determined processing area;

[0047] Figure 2 is a schematic diagram of ion beam processing microblock morphology;

[0048] Figure 2 (a) in the figure is to determine the processing area in SmartSEM, and (b) in the figure is the morphology after processing;

[0049] Figure 3 is an embodiment of mechanical hand assisted microblock extraction and finishing group diagram;

[0050] Figure 3 (a) in the figure is a schematic diagram of ion beam cutting through the bottom of microblock under the view of SmartSEM;

[0051] Figure 3 (b) in the figure is that the moving mechanical hand contacts one side of the microblock and connects through Pt deposition;

[0052] Figure 3 (c) in the figure is a mechanical hand assisted transfer microblock;

[0053] Figure 4 is a schematic diagram of shear sample size;

[0054] Figure 4 (a) in the figure is a front view of shear sample;

[0055] Figure 4 (b) in the figure is a top view of shear sample;

[0056] Figure 4 (c) in the figure is a schematic diagram of shear sample;

[0057] Figure 5The results of the shear stress test on metallic materials under a dual-beam system are shown. Detailed Implementation

[0058] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0059] The purpose of this invention is to provide an in-situ testing method for material shear stress in a dual-beam system, which enables the measurement of critical shear stress in metallic materials with specific microstructures in a dual-beam system (electron beam-ion beam).

[0060] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] like Figures 1 to 5 As shown: This embodiment provides an in-situ testing method for shear stress in nickel-based alloy materials using a dual-beam system, including the following steps:

[0062] Step 1: Analyze the sample block using an electron beam perspective and determine the processing area using ion beam imaging;

[0063] Figure 1 To determine the schematic diagram of the processing area, the sample surface needs to be mechanically polished or mechanical-chemically polished. After cleaning, it is fixed to the sample stage with conductive gel / conductive tape and placed in the SEM test chamber.

[0064] The workflow for analyzing the sample block using an electron beam perspective and determining the processing area using ion beam imaging is as follows:

[0065] A1. Determine the approximate orientation of the sample from a visual perspective, locate the area to be processed using the electron beam perspective, rotate the sample stage to 70°, and connect it to the EBSD system for Kikuchi flower pattern diffraction analysis. The analysis results are as follows: Figure 1 As shown in Figure (a);

[0066] A2. Identify grains with specific structures / orientations in the EBSD analysis results;

[0067] A3. With the viewpoint directed to the target processing area, the electron beam and ion beam systems are aligned;

[0068] A4. In the SmartSEM program (SmartSEM is the operating software for Zeiss scanning electron microscopes (SEM), compatible with Zeiss FIB-SEM instruments), select the processing area, rotate the sample stage to 54°, adjust the sample stage height so that the electron beam and ion beam have the same focal length and viewing angle, and use the ion beam to coarsely scan the target area. Determine the position of the target grain based on the grain boundaries, such as... Figure 1 As shown in Figure (b).

[0069] In A4, when the ion beam performs roughing scanning imaging, the scanning voltage is 30kV and the scanning current is 30nA.

[0070] Step 2: Ion beam processing of micro-bulb morphology;

[0071] Figure 2 The steps for ion beam fabrication of micro-bulk morphology are as follows:

[0072] B1. Draw the following in the SmartSEM program: Figure 2 The machining area shown in Figure (a) contains a square area with a length of 20 μm and a width of 10 μm, and the machining program is set there.

[0073] B2. Cut out shapes according to a program using an ion beam. Figure 2 The microparticle in Figure (b) was cut to a depth of 10-12 μm, with a stage tilt angle of 54°; the ion beam operating voltage was 30 kV, and the ion beam operating current was 30 nA. Figure 2 In Figure (b), the area on the right side of the microblock that is connected to the substrate is preserved to prevent the sample from sliding when cutting through the bottom of the sample and to facilitate the transfer of the sample by the robot arm; the large area removed below is intended to make the progress of cutting through the microblock visible.

[0074] Step 3: Extraction and trimming of micro-pieces with the assistance of a robotic arm;

[0075] Figure 3 The robotic arm-assisted micro-part extraction and trimming process is as follows:

[0076] C1. In the SmartSEM program, set up the operation to cut through the bottom of the micro-block, such as... Figure 3 As shown in Figure (a), the ion beam cuts through the bottom of the micro-block;

[0077] In C1, the sample stage is kept horizontal when the ion beam cuts through the bottom of the micro-bulb.

[0078] C2. After cutting through the bottom, move the robotic arm to the left side of the micro-particle and make contact with it. Introduce a gas-assisted deposition system to deposit Pt at the contact point between the robotic arm and the micro-particle. Figure 3As shown in Fig. b). After deposition, GIS is removed;

[0079] C3, cut through the right side of the micro-block under the ion beam view, and slowly lift the micro-block by moving the manipulator, as shown in Fig. c). Figure 3

[0080] C4, adjust the position of the manipulator, rotate 36°, and process the micro-block to the bottom under the ion beam view, to complete the first shaping of the micro-block.

[0081] Step four, deposit the micro-block by ion beam;

[0082] The process of depositing the micro-block by ion beam is as follows:

[0083] D1, slowly move the manipulator, and place the micro-block processed in step three on the edge of the upper surface of the sample stage, so that the bottom surface of the micro-block is in contact with the edge of the sample stage without lifting on both sides.

[0084] D2, use GIS to deposit the side of the micro-block and the sample stage, and after deposition, cut the deposition point of the micro-block under the ion beam view.

[0085] D3, rotate the micro-block by 180°, and deposit the other side of the micro-block by GIS.

[0086] In this embodiment, the ion beam for the target area is Pt deposition, the deposition thickness is 0.2-0.8 μm, the voltage is 30 kV, and the current is 100 pA.

[0087] Step five, process the shear sample by ion beam;

[0088] Figure 4 The structural parameters and schematic diagram of the shear sample, wherein a, c and e are all 5 μm, b is 10 μm, d is 9 μm, f is 20 μm, the micro-block in step four is on the upper surface of the sample stage, and the ion beam processing system cannot directly process the hollow shape, therefore, the sample stage is taken out and rotated to the front surface with the micro-block, and the edge of the micro-block is on the top surface. Under the ion beam view, the micro-block is first processed into a hollow structure in the shape of a door, and then the sample stage is restored to the position in step four, to process the shear sample with a specific shape, and the shear sample has two critical cross sections.

[0089] Step six, perform pure shear test under electron beam view;

[0090] Figure 5 ​The schematic diagram of the pure shear test result of the metal material under the double-beam system is shown in Fig. 1. The device used is a Hysitron Pico Indenter 88 in-situ mechanical testing platform (PI-88) developed by Bruker. The diamond indenter used in the test is a flat indenter with a taper of 60° and a diameter of 5 μm. The Young's modulus of the indenter is 1140 GPa, and the Poisson's ratio is 0.07. The indenter needs to be matched with the shear sample, that is, the size of the indenter is smaller than the distance between the two critical sections. A solid indenter is used to compress the center of the sample during the test. The pure shear test is performed by an electron beam, and the test is performed in a displacement control mode. After the pure shear test is completed, the slip deformation of the sample is observed by an electron beam, as shown in Fig. 2. Figure 5

[0091] The embodiment provides a method for measuring the shear stress of a specific region of a metal material in a double-beam system (ion beam-electron beam), realizes in-situ pure shear testing at a micro-nano scale, forms an effective scheme for micro-sample mechanical property testing, improves the accuracy of the test result, and provides an in-situ testing method for the study of the mechanical properties and plastic deformation mechanism of the material in multiple phases.

[0092] The in-situ testing method for quantitatively measuring the critical shear stress of a specific slip system of a metal material is disclosed. The testing method determines the behavior of the material under stress by manufacturing a micro shear sample on the surface of the material and measuring it in a double-beam system. The method can measure the critical shear stress of a metal material with a specific microstructure in a double-beam system (electron beam-ion beam). The method can reveal the slip deformation mechanism and the shear behavior of the two-phase interface of the material.

[0093] The embodiment can measure the critical shear stress of a specific cross section of a specific microstructure. The accurate measurement of the shear stress can be realized at a micro-nano level. An effective micro shear sample preparation method is designed through the research and practice of the double-beam system.

[0094] The principles and implementation modes of the present application are described in the specific examples in the specification. The above examples are only used to help understand the method of the present application and its core idea. For those skilled in the art, the specific implementation modes and application ranges can be changed according to the idea of the present application. In view of the above, the content of the specification should not be understood as a limitation of the present application.​

Claims

1. A method for in-situ testing of shear stress of a material under dual-beam system, characterized in that: The method comprises the following steps: Step one: analyzing the sample block in electron beam perspective and determining the processing area by ion beam imaging; In the step one, the process of analyzing the sample block in electron beam perspective and determining the processing area by ion beam imaging is as follows: A1, observing the sample block in electron beam perspective, and performing EBSD analysis on the target area; A2, determining the processing area where the target structure is located according to the EBSD analysis result; A3, rotating the sample stage to 54° to align the electron beam and the ion beam system; A4, selecting the processing area in the SmartSEM program, and performing coarse processing scanning imaging by the ion beam; Step two: ion beam processing micro block morphology; Step three: mechanical hand assisted micro block extraction and trimming; In the step three, the process of mechanical hand assisted micro block extraction and trimming is as follows: C1, cutting through the bottom of the micro block by the ion beam; C2, moving the mechanical hand to contact one side of the micro block, connecting the mechanical hand and the one side of the micro block by depositing Pt; C3, cutting off the part of the micro block connected with the sample block base on the other side, and moving the mechanical hand to extract the micro block; C4, trimming the micro block once to keep the bottom surface of the micro block horizontal; Step four: depositing the micro block by the ion beam; Step five: ion beam processing shear specimen; In the step five, when the ion beam processes the shear specimen, the shear specimen with a specific shape is processed, and the shear specimen has two critical cross sections; Step six: pure shear test in electron beam perspective; In the step six, when the pure shear test is performed in electron beam perspective, the pure shear test is performed in displacement control mode, and the loading head used is adapted to the shear specimen, that is, the size of the loading head is smaller than the distance between the two critical cross sections; After the pure shear test is completed, the slip deformation of the sample is observed by the electron beam.

2. The dual-beam system in-situ test method for material shear stress under the beam according to claim 1, characterized in that: In the step one, the sample block is made of metal material, and the sample block is an EBSD sample prepared by mechanical polishing or mechanical-chemical polishing after heat treatment.

3. The dual-beam system in-situ test method for material shear stress under shear stress according to claim 1, characterized in that: In the A1, when the electron beam perspective scanning is performed for EBSD analysis, the EBSD sample is fixed on the sample stage and rotated by 70°; In the A3, when the electron beam and the ion beam are aligned, the sample stage is rotated to 54°; In the A4, when the ion beam performs coarse processing scanning imaging, the scanning voltage is 30kV, and the scanning current is 30nA.

4. The dual-beam system in-situ test method for material shear stress under the beam according to claim 1, wherein: In the step two, the process of ion beam processing micro block morphology is as follows: B1, drawing the processing area in the SmartSEM program, and setting the processing program; B2, cutting out the micro block morphology by the ion beam according to the program.

5. The dual-beam system in-situ test method for material shear stress under the beam according to claim 4, characterized in that: In the B1, the processing area contains a square area with a length of 20μm and a width of 10μm; In the B2, the cutting depth is 10-12μm, the sample stage is inclined at an angle of 54°, the working voltage of the ion beam is 30kV, and the working current of the ion beam is 30nA.

6. The dual-beam system in-situ test method for material shear stress under shear stress according to claim 1, characterized in that: In the C1, when the ion beam cuts through the bottom of the micro block, the sample stage is kept horizontal; In the C4, when the micro block is trimmed once, the mechanical hand is rotated by 36°.

7. The dual-beam system in-situ test method for material shear stress under shear stress according to claim 1, wherein: In the step four, the process of depositing the micro block by the ion beam is as follows: D1, moving the mechanical hand to make the bottom surface of the micro block fit the edge of the sample stage; D2, depositing one side of the micro block by the ion beam, and cutting off the part connected with the mechanical hand after the deposition is completed; D3. Rotate the microblock 180°, depositing the other side of the microblock.

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