Method for measuring height of nanometer material by using elastic probe

Abstract

The method comprises the following steps: curing and copying a silane high-molecular prepolymer through a probe template to obtain the elastic probe, mounting the probe on a scanning probe microscope platform bracket, and controlling movement to irradiate the probe by using an LED light source. And recording a gray scale-time curve of the gray scale of the needle tip moving along with the probe, analyzing the initial position, the positions of a contact peak and a separation peak on the curve, and determining the time from contact to separation from the surface of the sample in the process of scanning each point by the probe. And converting the time into the height through a height calculation formula to obtain the height of the sample. The height calculation formula is H = (T1-T2) * V / 2, H is the height of the sample, T1 is the time of contacting the surface of the sample, T2 is the time of leaving the surface of the sample, and V is the moving speed of the elastic probe. The invention has the advantages of innovative principle, less material consumption and simple device manufacturing, provides a new method for measuring the height of the nano material, and has far-reaching significance for research and development and application of the nano material.

Description

Technical Field

[0001] The invention relates to a height measurement method, in particular to a method for using an elastic probe to measure the height of a nano material. Background Art

[0002] With the development and application of nanotechnology, nanotechnology has attracted more and more attention and financial investment. The characterization of nanostructures is the key and foundation of nanomaterial research. At present, scanning electron microscopes, transmission electron microscopes and scanning probe microscopes are commonly used to characterize the nano and micro structures of materials. However, these characterization methods are either limited by productivity and speed, or limited by longitudinal resolution. For industrial processes that require large-area rapid characterization and testing, such as failure analysis and defect detection in the manufacturing process of integrated circuits, the above-mentioned characterization methods are time-consuming and expensive.

[0003] Because microscopes are the most intuitive means of characterizing and studying nanotechnology, they have become a tool that scientists need in large numbers. For researchers engaged in micron / nano processing, they hope to quickly obtain a large-area morphology of the nanostructure on the sample surface to provide a reference for the material structure for their next experiment and application.

[0004] Silane polymer materials are highly transparent, easy to shape and modify, and are suitable as raw materials for manufacturing new probes. By pouring silane polymer prepolymer into the existing probe mold, a transparent elastic probe can be prepared. This probe can be applied to the scanning probe microscope platform to detect the surface morphology of nanomaterials. Compared with the original silicon and other hard probes, it is cheaper, easier to use, and has a wide range of applications.

[0005] The use of elastic probes to measure the height information of nanomaterials has a different measurement principle. It uses the deformable characteristics of elastic polymers and combines the change in the grayscale of the needle tip under the deformed state obtained by microscopic observation to determine the state of the probe measuring the sample, thereby measuring the height of the nanomaterial. Summary of the invention

[0006] The purpose of the present invention is to provide a method for measuring the height of nanomaterials using an elastic probe in order to solve the above-mentioned problems.

[0007] The present invention provides a method for measuring the height of nanomaterials using an elastic probe, comprising the following steps:

[0008] S1. Install the elastic probe on a microscope platform bracket, illuminate the elastic probe with an LED light source, and allow the elastic probe to scan and contact the sample surface. Observe and record the grayscale change of the tip of the elastic probe during the test through a microscope.

[0009] S2, obtaining a curve of the relationship between the grayscale of the needle tip and the test time of the elastic probe, and determining the position where the elastic probe contacts and leaves the sample surface through the positions of the contact peak and the separation peak in the curve;

[0010] S3. Obtain the time from contact to separation of each elastic probe from the sample during scanning each point, and obtain the height of the sample through a height calculation formula. The height calculation formula is: H = (T1-T2) × V / 2, wherein H is the height of the sample, T1 is the time of contact with the sample surface, T2 is the time of leaving the sample surface, and V is the moving speed of the elastic probe.

[0011] In some embodiments, the elastic probe is made of an elastic transparent polymer material, and the polymer material is made by configuring polydimethylsiloxane and a curing agent in a ratio of 10:1.

[0012] In some embodiments, the elastic probe is deformed when in contact with the sample surface, and the deformation magnitude is 0-20 μm.

[0013] In some embodiments, the moving speed of the elastic probe is constant, and the moving speed of the elastic probe is 1-10 μm / s.

[0014] In some embodiments, the method further includes detecting the grayscale change of the needle tip by taking a photo.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] First, this is the first time that a soft polymer probe is used to measure the height information of nanomaterials by photographing the grayscale changes at the tip of the probe. This is an innovative height measurement principle.

[0017] Secondly, the tip size of the elastic probe used is at the nanoscale, which can provide very high resolution. The study proposed a height calculation formula, explored and revealed the relationship between the height of the nanomaterial and the grayscale of the tip during the measurement process with the elastic probe, and enriched the research in the field of nanomaterial morphology characterization.

[0018] Finally, this probe is simple to prepare and low-cost, and the measurement system is simple and convenient to set up. It only requires LED light irradiation and camera shooting, and has no special requirements for the test environment, which is conducive to expanding the test scope. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A scanning electron microscope image of an elastic probe used for nanomaterial measurements.

[0020] Figure 2 Schematic diagram of the process of measuring nanomaterials using an elastic probe.

[0021] Figure 3 This is the grayscale change diagram of the needle tip position obtained by FDTD time-domain finite difference method simulation.

[0022] Figure 4 The grayscale time curves at two different positions of the probe are measured.

[0023] Figure 5 The continuous grayscale time curve is obtained by continuously measuring multiple positions of the probe in Example 3.

[0024] Figure 6 To read the time difference from the obtained grayscale time curve, combined with a scanning speed of 1μm / s, the height data graph is calculated. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0026] Example 1

[0027] Step 1: After the silane polymer prepolymer is solidified and replicated through the probe template, the probe is obtained, and the probe is installed on the scanning probe microscope platform bracket. The probe is illuminated by an LED light source, and the probe is manipulated to move at a speed of 5μm / s, and the grayscale changes of the needle tip are recorded from the microscope field of view.

[0028] Step 2: Draw a grayscale-time curve with the grayscale of the needle tip along with the probe test, mark the starting position, contact peak and separation peak on the curve, and determine the time a second from the probe contacting to separating from the sample surface during the scanning process of each point. Convert the time to height through the height calculation formula to get the sample height H = 2.5aμm.

[0029] Among them, Figure 1 Shown is a scanning electron microscope image of an elastic probe used for nanomaterial measurement; Figure 2 The figure shows a schematic diagram of the process of measuring nanomaterials with an elastic probe, wherein the probe moves from position 1 to position 2, the probe deforms respectively, and the grayscale of the needle tip position changes; Figure 3 As shown, the grayscale change of the needle tip position obtained by FDTD time-domain finite difference method simulation indicates that when the probe contacts the sample, the grayscale first decreases and then increases, and the grayscale change is the largest at the moment of contact and separation.

[0030] Example 2

[0031] Step 1: After the silane polymer prepolymer is solidified and replicated through the probe template, the probe is obtained, and the probe is installed on the scanning probe microscope platform bracket. The probe is irradiated with white light, and the probe is manipulated to move at a speed of 10μm / s, and the grayscale changes of the needle tip are recorded from the microscope field of view.

[0032] Step 2: Draw a grayscale-time curve with the grayscale of the needle tip along with the probe test, mark the starting position, contact peak and separation peak on the curve, and determine the time b seconds from the probe contacting to separating from the sample surface during the scanning process of each point. Convert the time to height through the height calculation formula to get the sample height H = 5bμm.

[0033] When the tip of the probe contacts or leaves the sample surface, the intensity of the light reflected from the tip of the probe will suddenly increase or decrease due to the deformable characteristics of the elastic polymer. In the process of peak identification, the peak position is accurately found through appropriate methods to determine when and where the probe contacts the sample surface. Figure 4 As shown in the figure, in one process, point c and point g respectively represent the time points of contact and separation between the probe and the sample, and point c, point d, point f and point g represent the time points of contact and separation twice. It can be found that the contact and separation time difference is different at different positions.

[0034] The time Tcg required for probe 1 to move from the initial contact position to the initial separation position is longer than the time Tdf required for probe 2 to move from the initial contact position to the initial separation position. This is because the probe undergoes two processes of contact and separation in the vertical direction, and half of the time difference multiplied by the speed of the probe is equal to the height of the concave area relative to the flat area. The height calculation formula is: H = (T1-T2) × V / 2, where H is the height of the sample, T1 is the time of contacting the sample surface, T2 is the time of leaving the sample surface, and V is the moving speed of the elastic probe.

[0035] Example 3

[0036] Step 1: After the silane polymer prepolymer is solidified and replicated through the probe template, the probe is obtained, and the probe is installed on the scanning probe microscope platform bracket. The probe is irradiated with white light, and the probe is manipulated to move at a speed of 1μm / s, and the grayscale changes of the needle tip are recorded from the microscope field of view.

[0037] Step 2: Draw a grayscale-time curve with the grayscale of the needle tip along with the probe test, mark the starting position, contact peak and separation peak on the curve, and determine the time from contact to separation of the probe from the sample surface during the scanning process of each point, which is 0.5 seconds. Convert the time to height through the height calculation formula to get the sample height H = 0.25μm.

[0038] like Figure 5As shown, for the sample of Example 3, the probe continuously measures a plurality of positions to obtain continuous grayscale time curves.

[0039] like Figure 6 The height data graph is shown by reading the time difference from the obtained grayscale time curve and calculating the height data by combining the scanning speed of 1μm / s.

[0040] Finally, it should be noted that: technicians in this industry should understand that the present invention is not limited to the above-mentioned implementation cases. The above-mentioned embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for measuring the height of nanomaterials using an elastic probe, characterized in that: The following steps are involved: S1. Install the elastic probe on a microscope platform bracket, illuminate the elastic probe with an LED light source, and allow the elastic probe to scan and contact the sample surface. Observe and record the grayscale change of the tip of the elastic probe during the test through a microscope. S2, obtaining a curve of the relationship between the grayscale of the needle tip and the test time of the elastic probe, and determining the position where the elastic probe contacts and leaves the sample surface through the positions of the contact peak and the separation peak in the curve; S3. Obtain the time from contact to separation of each elastic probe from the sample during scanning each point, and obtain the height of the sample through a height calculation formula. The height calculation formula is: H = (T1-T2) × V / 2, wherein H is the height of the sample, T1 is the time of contact with the sample surface, T2 is the time of leaving the sample surface, and V is the moving speed of the elastic probe.

2. The method for measuring the height of nanomaterials using an elastic probe according to claim 1, characterized in that: The elastic probe is made of an elastic transparent polymer material, and the polymer material is made by configuring polydimethylsiloxane and a curing agent in a ratio of 10:

1.

3. The method for measuring the height of nanomaterials using an elastic probe according to claim 2, characterized in that: The elastic probe is deformed when in contact with the sample surface, and the deformation size is 0-20 μm.

4. The method for measuring the height of nanomaterials using an elastic probe according to claim 1, characterized in that: The moving speed of the elastic probe is constant, and the moving speed of the elastic probe is 1-10 μm / s.

5. The method for measuring the height of nanomaterials using an elastic probe according to claim 1, characterized in that: It also includes detecting the grayscale changes of the needle tip by taking pictures.

Images