Coating device and coating method for TEM sample surface protection layer

Abstract

The invention provides a coating device and a coating method for a TEM sample surface protection layer, a light curing coating pen of the coating device is used for delineating a contour line of a to-be-protected area on the surface of a sample, and a light sensation positioning instrument is used for capturing an image of the surface of the sample so as to position the area and the position of the to-be-protected area; and the isolation coating assembly is used for spraying on the surface of the contour line to form an isolation belt, so that the subsequently sprayed epoxy resin material is prevented from overflowing. According to the method, the process of positioning the target area is manually drawn, so that the freedom degree of sample preparation protection is increased; and the part for spraying, curing and thinning resin is completed by a mechanical device, so that the risks of invalid accumulation of a protective layer and abnormal flowing of liquid resin are reduced. Besides, operations such as coating isolation and vibration defoaming which cannot be realized by conventional sample preparation protection are added, so that the range of a resin protection layer can be delineated, a tighter and uniformly-distributed protection coating can be produced, and subsequent TEM sample testing is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor sample preparation, and particularly to a coating device and a coating method for a surface protection layer of a TEM sample. Background Art

[0002] In failure analysis cases related to TEM sample preparation, covering a metal (such as platinum) coating or other protection means is an essential step to prevent sputtering contamination of the structure by gallium ions and to ensure that the bombardment of the ion beam on the sample surface does not change the morphology of the internal structure of the chip protection area. Depending on the fragility and material of the sample surface structure, different TEM sample protection methods with different elements and conditions need to be implemented respectively. Among them, drop-coating ion-thinned epoxy resin is a relatively mild and least likely to erode the sample structure protection means.

[0003] However, even so, since the ion-thinned epoxy resin still needs 15 minutes to fully cure at a high temperature of 150 °C, the resin layer generally drop-coated on the sample surface is difficult to stably cure in the required area, often accumulating and completely covering the sample surface structure, making it impossible to identify the target points of failure analysis by electron beam imaging. Moreover, during the curing process, the flowing resin may even break some fragile and protruding surface structures. The existing manual operation method is also difficult to ensure stable force application without touching the sample surface.

[0004] Therefore, how to stably form a protection layer within the designated area on the sample surface without overflowing is an urgent problem to be solved in the sample preparation process. Summary of the Invention

[0005] In view of the above-mentioned disadvantages of the prior art, the present invention provides a coating device for a surface protection layer of a TEM sample. The coating device includes a photo-curing paint pen, and an ultraviolet light irradiation lamp, a light-sensitive positioning instrument, and an isolation coating assembly located in a chamber;

[0006] The photo-curing paint pen is used to draw the contour line of the area to be protected on the sample surface. The contour line is a closed line type that is connected end to end. The paint of the photo-curing paint pen is a photo-curing material, which can be quickly cured under the irradiation of the ultraviolet light irradiation lamp; the ultraviolet light irradiation lamp is used to irradiate the sample surface to harden the photo-curing material, and at the same time as the illumination light source of the light-sensitive positioning instrument; the light-sensitive positioning instrument is used to capture the image of the sample surface and locate the area and position of the area to be protected according to the identified contour line; the isolation coating assembly is used to spray and form an isolation zone on the surface of the contour line according to the positioning information of the light-sensitive positioning instrument. The isolation zone is a retaining wall with a certain height, so as to prevent the epoxy resin material subsequently sprayed on the area to be protected from overflowing.

[0007] Optionally, it also includes a resin spraying component and a coating curing component located in the chamber;

[0008] The resin spraying assembly is used for spraying epoxy resin material in the area to be protected surrounded by the insulating tape, and the coating curing assembly is used for carrying samples and accelerating the curing of the epoxy resin material.

[0009] Optionally, the coating curing assembly includes a carrier, an auxiliary heat curing unit, a vibration defoaming unit and a centrifugal rotation unit. The auxiliary heat curing unit includes an electric heating wire installed in the carrier for heating the sample; the vibration defoaming unit includes a vibration motor installed in the carrier for vibrating the carrier to discharge bubbles inside the epoxy resin material; the centrifugal rotation unit includes a rotation motor installed in the carrier so that the carrier rotates around the center to evenly diffuse the epoxy resin material to the entire area to be protected.

[0010] Optionally, the coating of the photocurable coating pen includes a photoinitiator, a photocurable resin, a filler, and a diluent, and the refractive index of the filler is between 2.0 and 3.0.

[0011] Optionally, the filler includes graphite nanosheets, silicon carbide, and titanium dioxide.

[0012] Optionally, the ultraviolet irradiation lamp includes a shell, an ultraviolet light source, a reflector, a heat insulation layer, and a cooling unit, and the light emission band of the ultraviolet light source is the UVB band of 320 to 350 nm.

[0013] Optionally, the light sensing locator includes a light sensor for acquiring images and a processor for processing image signals.

[0014] Optionally, the protrusion height of the isolation zone relative to the sample surface is greater than 500 microns.

[0015] The present invention also provides a coating method using the coating device, comprising the following steps:

[0016] S1: Use a light-curing paint pen to draw a contour line on the chip surface in a closed pattern that is connected end to end and symmetrical relative to the center to circle the appropriate area to be protected, so that the target structure is as close to the center of the contour line as possible;

[0017] S2: Fix the sample with the outline painted on the stage of the coating curing component, then put the sample into the device cavity, start the ultraviolet light irradiation lamp or further start the auxiliary heat curing unit of the coating curing component; after irradiation for 1 minute, start the light sensing positioning instrument to capture the fluctuation of the sample surface reflectivity, and calculate the relative position of the chip surface outline and the device cavity, the total area of the area to be protected, and the center position of the area to be protected;

[0018] S3: Activate the isolation coating assembly, move the spray gun above the contour line, and further spray fast-curing coating on the cured contour line to increase its height to at least 500 microns, forming an isolation zone.

[0019] S4: Activate the resin spraying assembly, move the spray gun above the center position of the area to be protected, calculate the volume consumption according to the total area of the area to be protected obtained by the processor and the set required thickness of the protective film layer; then spray epoxy resin material downward at the center position of the area to be protected to form an uncured protective coating layer with a tendency to spread outward from the center.

[0020] Optionally, the following steps are further included:

[0021] S5: Activate the coating curing assembly. The auxiliary heat curing unit heats the cavity environment temperature to 150 - 175 °C to accelerate the curing of the liquid resin; the vibration defoaming unit makes the stage vibrate slightly up and down to make the bubbles inside the resin easier to discharge; the centrifugal rotation unit makes the stage rotate with a slow acceleration, and by the action of centrifugal force, the epoxy resin material is evenly spread over the entire area to be protected; 15 minutes after the coating curing assembly is activated, the epoxy resin material cures to form a protective layer, then the sample that has completed the sample protection is reset, the cavity is cooled by the cooling unit in the ultraviolet irradiation lamp, and finally the sample is taken out.

[0022] As described above, the present invention provides a coating device and a coating method for the surface protective layer of a TEM sample. The coating device includes a photo-curing coating pen, an ultraviolet irradiation lamp, a light-sensitive positioning instrument, a resin spraying assembly, an isolation coating assembly, and a coating curing assembly. The photo-curing coating pen is used to circle the contour line of the area to be protected on the sample surface, and the contour line can be quickly cured under the irradiation of the ultraviolet irradiation lamp. The light-sensitive positioning instrument is used to capture the image of the sample surface and locate the area and position of the area to be protected according to the recognized contour line. The isolation coating assembly is used to spray and form an isolation zone with a certain height on the surface of the contour line according to the positioning information of the light-sensitive positioning instrument, so as to prevent the epoxy resin material sprayed subsequently from overflowing. The resin spraying assembly is used to spray epoxy resin material on the area to be protected. The coating curing assembly is used to carry the sample and at the same time to accelerate the curing of the epoxy resin material, and finally form a protective layer within the area to be protected surrounded by the isolation zone.

[0023] The present invention hands over the process of positioning the target area to manual drawing, increasing the freedom of sample preparation protection and making the confirmation of the target area more user-friendly. The part of spraying, curing, and thinning the resin is completed by a mechanical device, reducing the risk of ineffective accumulation of the protective layer and abnormal flow of the liquid resin. During the process of coating the protective layer, the fully automatic coating device provided by the present invention additionally adds operations such as coating isolation and vibration defoaming that cannot be achieved by conventional sample preparation protection. It can delineate the range of the resin protective layer and produce a denser and more evenly distributed protective coating on the basis of the existing technology, facilitating subsequent TEM sample testing. Description of the Drawings

[0024] Figure 1 It shows a schematic diagram of each component of the coating device in Embodiment 1 of the present invention.

[0025] Figure 2 It shows a schematic diagram of the surface structure of the chip in Embodiment 1 of the present invention.

[0026] Figure 3 It shows a schematic diagram of the contour line delineated by the photo-curing coating pen in Embodiment 1 of the present invention.

[0027] Figure 4 It shows a schematic diagram of the relative positions of each component in Embodiment 1 of the present invention.

[0028] Figure 5 It shows a schematic diagram of the working states of the ultraviolet light irradiation lamp and the light-sensitive positioning instrument in Embodiment 1 of the present invention.

[0029] Figure 6 It shows a schematic diagram of the isolation coating component spraying the isolation zone in Embodiment 1 of the present invention.

[0030] Figure 7 It shows a schematic diagram of the resin spraying component spraying the epoxy resin material in Embodiment 1 of the present invention.

[0031] Figure 8 It shows a schematic diagram of the curing process of the coating curing component in Embodiment 1 of the present invention.

[0032] Figure 9 It shows a schematic diagram of the formed protective layer after curing in Embodiment 1 of the present invention.

[0033] Description of Component Labels

[0034] Sample 2; Contour line 22; Area to be protected 23; Ultraviolet light irradiation lamp 12; Light-sensitive positioning instrument 13; Resin spraying component 14; Isolation coating component 15; Coating curing component 16; Isolation zone 221; Epoxy resin material 21; Uncured protective coating 211; Protective layer 212; Vibration defoaming unit 162; Centrifugal rotation unit 161; Auxiliary heat curing unit 163. Detailed Description of the Invention

[0035] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0036] When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views showing the device structure will be enlarged locally out of the general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present invention here. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.

[0037] For convenience of description, spatial relationship terms such as "beneath", "below", "lower", "under", "above", "on" etc. may be used herein to describe the relationship between one element or feature shown in the drawings and other elements or features. It will be understood that these spatial relationship terms are intended to encompass other directions of the device in use or operation, in addition to the directions depicted in the drawings. Further, when a layer is referred to as being "between" two layers, it can be the only layer between the two layers, or there can be one or more intervening layers. As used herein, "between... and..." means including the endpoint values.

[0038] In the context of the present application, the structure in which the first feature is "above" the second feature may include embodiments where the first and second features are formed in direct contact, and may also include embodiments where additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0039] It should be noted that the illustrations provided in this embodiment only schematically illustrate the basic concept of the present invention. Therefore, only the components related to the present invention are shown in the illustrations, rather than being drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and proportion of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0040] Embodiment 1

[0041] As Figure 1 shown, this embodiment provides a coating device for the surface protective layer of a TEM sample. The coating device includes a photocuring paint pen 11, an ultraviolet light irradiation lamp 12, a photosensitive positioning instrument 13, a resin spraying assembly 14, an isolation coating assembly 15, and a coating curing assembly 16.

[0042] Refer to Figures 2 to 9, the photo-curing coating pen 11 is used to draw the contour line 22 of the area to be protected on the surface of the sample. The contour line 22 is a closed linear shape that connects the head and the tail. The coating of the photo-curing coating pen is a photo-curing material, which can be quickly cured under the irradiation of the ultraviolet light irradiation lamp 12. The ultraviolet light irradiation lamp 12 is used to irradiate the surface of the sample to harden the photo-curing material, and at the same time serves as the illumination light source of the photo-sensing positioning instrument 13. The photo-sensing positioning instrument 13 is used to capture the image of the surface of the sample, and locate the area and position of the area to be protected 23 according to the identified contour line 22. The isolation coating assembly 15 is used to spray and form an isolation zone 221 on the surface of the contour line 22 according to the positioning information of the photo-sensing positioning instrument 13. The isolation zone 221 is a cofferdam with a certain height, so as to prevent the epoxy resin material sprayed subsequently from overflowing. The resin spraying assembly 14 is used to spray the epoxy resin material 21 in the area to be protected. The coating curing assembly 16 is used to carry the sample, and at the same time is used for the accelerated curing of the epoxy resin material, and finally forms a protective layer 212 in the area to be protected 23 surrounded by the isolation zone 221.

[0043] The photo-curing coating pen 11 is an auxiliary tool independent of other components. The photo-sensing positioning instrument 13, the ultraviolet light irradiation lamp 12, the resin spraying assembly 14, and the isolation coating assembly 15 are all located above the coating curing assembly 16 to perform operations such as irradiation and spraying on the surface of the sample piece. The following is a detailed introduction to each component.

[0044] The coating of the photo-curing coating pen 11 is a photo-curing material. The photo-curing material is a composite material, including components such as photo-initiator, photo-curing resin, filler, and diluent. Thus, under the irradiation of ultraviolet light, it absorbs light energy, initiates chain polymerization and cross-linking reactions, and generates a grid-like solid. The photo-curing resin is the matrix component of the photo-curing material, accounting for 40% - 80%. Its type and content determine the bonding strength, flexibility, hardness, chemical resistance, and aging resistance and other properties after curing. Photo-curing resins usually include acrylate, epoxy resin, polyamide resin, etc. The photo-initiator is the key to photo-curing. It can bond the resins together and make them quickly cure under the action of light. The diluent can effectively adjust the system concentration, increase the cross-linking degree, and obtain better use performance.

[0045] For the selection of fillers, the fillers in this application do not use common materials such as calcium carbonate, barium sulfate, aluminum hydroxide, and silicon dioxide, but materials with a large refractive index difference from the photocurable resin and the diluent. Since the refractive indices of the photocurable resin and the diluent are between 1.4 and 1.6, and the refractive indices of materials such as calcium carbonate, barium sulfate, aluminum hydroxide, and silicon dioxide are also between 1.4 and 1.6, these fillers appear transparent in the photocurable material and have no covering power on the sample surface. When the light-sensing locator captures the image of the sample surface, the contour line cannot be clearly distinguished from other areas of the sample surface, resulting in ineffective recognition. In this application, fillers with a large refractive index difference from the photocurable resin and the diluent are selected, and the refractive index of the filler is between 2.0 and 3.0, such as graphite nanosheets, silicon carbide, titanium dioxide, etc. The large refractive index difference causes the light entering the photocurable material to deflect greatly at the interface of different materials, and it is difficult for the light to be continuously transmitted at the interface of different materials, resulting in difficulty for the light entering the photocurable material to exit, making the contour line appear significantly darker than other areas of the sample surface. Thus, the light-sensing locator can accurately identify the contour line based on the gray value of the captured image.

[0046] According to the Lorentz-lorenz formula, n 2 =(1 + 2R / V) / (1 - R / V); where n is the refractive index, R is the molar refraction of the constituent material groups, and V is the molar volume of the groups; the refractive index n is proportional to the refraction per unit molar volume. By adjusting the fillers in the photocurable material, the refraction per unit molar volume (i.e., R / V) of the photocurable material groups is made less than 0.3, and the refractive index n is less than 1.5. Explained from another perspective, the lower the refractive index of the material, the lower the reflectivity of the film layer, ultimately reducing the reflectivity of the scribed contour line, so that the light-sensing locator can accurately identify the contour line based on the gray value of the captured image.

[0047] Furthermore, the ultraviolet irradiation lamp 12 includes a housing, an ultraviolet light source, a reflector, a heat insulation layer, and a cooling unit. The emission wavelength band of the ultraviolet light source is preferably the UVB band, that is, a light source with a light wavelength of 320 to 350 nm. The ultraviolet light in this band has strong penetration and mainly acts on the surface curing of the curing material. Therefore, it is suitable for application scenarios with a relatively thin thickness or requiring rapid surface curing. Since the scribed trace of the photocurable coating pen is a relatively thin layer of material, selecting a UVB band ultraviolet light source can achieve rapid curing.

[0048] Meanwhile, the ultraviolet light source can also be used as the illumination light source of the light sensor locator. The ultraviolet light source and the light sensor locator are fixed on the lower surface of the housing. As a preferred solution, the incident direction of the ultraviolet light source forms a 45-degree angle with the sample surface, that is, the oblique incidence method is adopted to increase the brightness and darkness contrast of the images captured by the light sensor locator. The reflector can be used for optical path design to evenly irradiate the light onto the sample surface. The heat insulation layer can be used to isolate heat and maintain the high-temperature environment in the cavity during curing. The cooling unit (such as a fan) can quickly cool down the cavity.

[0049] Furthermore, the light sensor locator 13 is composed of a light sensor for acquiring images and a processor for analyzing and integrating optoelectronic signals. The two work together to check for sudden light energy loss or brightness and darkness changes on the sample surface, and calculate the coverage position and area of the contour line scribed by the photo-curing coating pen based on the collected light energy fluctuation signals, providing necessary positioning information for the subsequent automatic coating of the sample protection layer.

[0050] As an example, the process of the processor processing the image usually includes preprocessing and feature extraction. Preprocessing refers to preprocessing the original image to reduce noise and enhance image features. Common preprocessing methods include denoising, smoothing, and sharpening, etc. Feature extraction refers to extracting features related to the contour line from the preprocessed image. Common features include color, texture, shape, etc., so as to accurately identify the contour line. Regarding specific algorithms, there are already mature solutions in the prior art and will not be elaborated here.

[0051] Furthermore, the isolation coating assembly 15 is used to spray and form an isolation zone on the surface of the contour line according to the positioning information of the light sensor locator. The isolation zone is a cofferdam with a certain height. The protruding height of the isolation zone relative to the sample surface is more than 500 microns, so that the epoxy resin material injected into the cofferdam has sufficient surface tension to prevent overflow. The isolation zone is a fast-curing coating that can form a relatively thick three-dimensional height, and its main components include epoxy resin, drying agent, silane coupling agent, fiber filler, etc. During the formation of the isolation zone, the irradiation of the ultraviolet lamp 12 can also be used to accelerate curing.

[0052] The isolation zone is deposited based on the contour line, and the contour line is manually drawn, which can increase the freedom of sample preparation protection and make the delineation of the area to be protected more user-friendly. At the same time, the isolation zone is a cofferdam with a certain height, which can reduce the risk of ineffective accumulation of the protection layer and abnormal flow of the liquid resin, thereby protecting specific areas of the sample while avoiding damage to other areas.

[0053] Furthermore, the resin spraying assembly 14 is used to spray epoxy resin material in the area to be protected surrounded by the isolation belt, and the spray gun of the resin spraying assembly moves to the center of the area to be protected, and calculates the appropriate volume dosage according to the total area of the area to be protected obtained by the processor and the required protective film thickness set. According to the data, the ion-thinned epoxy resin material is sprayed downward at the center, and the inside of the area to be protected is covered as evenly as reasonably as possible, forming an uncured protective coating with a tendency to diffuse outward from the center.

[0054] Furthermore, the coating curing component 16 includes a carrier, an auxiliary heat curing unit, a vibration defoaming unit and a centrifugal rotation unit. The auxiliary heat curing unit can be an electric heating wire installed in the carrier, which is used to heat the sample and accelerate the curing of the epoxy resin material; the vibration defoaming unit can be a vibration motor installed in the carrier, which is used to vibrate the carrier to make the bubbles inside the epoxy resin material easier to discharge; the centrifugal rotation unit can be a rotating motor installed in the carrier, so that the carrier rotates around the center, and the epoxy resin material is evenly diffused to the entire area to be protected by the centrifugal force. With the continuous action of the coating curing component, the epoxy resin material gradually hardens to form a protective layer. During the curing process of the protective layer, the curing can also be accelerated by the irradiation of the ultraviolet lamp 12; at the same time, the contour line drawn by the light curing paint pen 11 and the insulation tape sprayed by the insulation coating component 15 can also be accelerated by the coating curing component 16.

[0055] During the curing process of the epoxy resin material by the coating curing assembly 16, the heat insulation layer in the ultraviolet lamp 12 can be used to isolate heat and maintain a high temperature environment in the cavity. In addition, after the coating curing assembly 16 has completed curing the epoxy resin material, the cooling unit (such as a fan) in the ultraviolet lamp 12 can quickly cool the cavity.

[0056] Embodiment 2

[0057] Based on the coating device in the first embodiment, this embodiment provides a coating method, comprising the following steps:

[0058] S1: Please refer to Figures 2 to 3 Before the sample protection begins, use a light-curing paint pen 11 to draw a contour line 22 on the chip surface in a closed pattern that is connected end to end and symmetrical relative to the center, avoiding areas that hinder the curing of the resin layer or have other sample preparation requirements, so as to circle a suitable area to be protected 23, and make the target structure as close to the center of the contour line 22 as possible.

[0059] S2: Please refer to Figures 4 to 5, fix the sample with the contour line 22 scribed on the stage of the coating curing assembly 16, then send the sample 2 into the device cavity, and start the ultraviolet light irradiation lamp 12 or further start the auxiliary heat curing unit of the coating curing assembly 16. After the irradiation lasts for 1 minute, start the light sensor locator 13 to start capturing the fluctuations in the surface reflectivity of the sample. The obtained data is uniformly imported into the processor for integration, and according to fixed formulas such as the reflection angle of light, calculate the relative position of the surface contour line 22 of the chip 2 and the device cavity, the total area of the area to be protected 23, and the relatively appropriate central position of the area to be protected 23.

[0060] S3: Please refer to Figure 6 , start the isolation coating assembly 15, move the spray gun above the contour line 22, and further spray a fast-curing coating on the cured contour line 22 to increase its height to at least 500 microns to form an isolation band 221. The isolation band 221 occupies a larger area compared to the contour line 22 to prevent the epoxy resin material injected into the isolation band 221 from overflowing.

[0061] S4: Please refer to Figure 7 , start the resin spraying assembly 14, move the spray gun above the central position of the area to be protected 23, and calculate the appropriate volume usage according to the total area of the area to be protected obtained by the processor and the set required thickness of the protective film layer. Spray the ion-thinned epoxy resin material 21 (M-Bond 610) downward at the central position according to the data, and reasonably cover the inside of the area to be protected 23 as much as possible to form an uncured protective coating layer 211 with a tendency to spread from the center outward.

[0062] S5: Specifically, please refer to Figures 8 to 9 , start the coating curing assembly 16. Among them, the auxiliary heat curing unit 163 heats the cavity environment temperature to 150 - 175 °C to accelerate the curing of the liquid resin; the vibration defoaming unit 162 makes the stage vibrate slightly up and down to make the bubbles inside the resin easier to discharge; the centrifugal rotation unit 161 makes the stage rotate with a slow acceleration, and by the action of centrifugal force, the epoxy resin material is evenly diffused to the whole of the area to be protected 23. Of course, during the process, the ultraviolet light source of the ultraviolet light irradiation lamp 12 can be started as needed for accelerated curing. After the coating curing assembly 16 is started for about 15 minutes, the epoxy resin material cures to form a protective layer 212, then return the chip 2 with the sample protection completed, use the cooling unit in the ultraviolet light irradiation lamp 12 to cool the cavity, and finally take out the stage to complete the coating protection.

[0063] In summary, the present invention provides a coating device and a coating method for a surface protective layer of a TEM sample. The coating device includes a photo-curing paint pen, an ultraviolet light irradiation lamp, a light-sensitive positioning instrument, a resin spraying assembly, an isolation coating assembly, and a coating curing assembly. The photo-curing paint pen is used to delineate the contour line of the area to be protected on the sample surface, and the contour line can be quickly cured under the irradiation of the ultraviolet light irradiation lamp. The light-sensitive positioning instrument is used to capture the image of the sample surface and locate the area and position of the area to be protected according to the identified contour line. The isolation coating assembly is used to spray and form an isolation band with a certain height on the surface of the contour line according to the positioning information of the light-sensitive positioning instrument, so as to prevent the epoxy resin material sprayed subsequently from overflowing. The resin spraying assembly is used to spray the epoxy resin material on the area to be protected. The coating curing assembly is used to carry the sample and at the same time accelerate the curing of the epoxy resin material, and finally form a protective layer within the area to be protected enclosed by the isolation band.

[0064] The present invention hands over the process of positioning the target area to manual drawing, increasing the freedom of sample preparation protection and making the confirmation of the target area more user-friendly; the part of spraying, curing, and thinning the resin is completed by a mechanical device, reducing the risk of ineffective accumulation of the protective layer and abnormal flow of the liquid resin. During the process of coating the protective layer, the fully automatic coating device provided by the present invention additionally adds operations that cannot be achieved by conventional sample preparation protection, such as isolation coating and vibration defoaming. It can delineate the range of the resin protective layer and can produce a more compact and evenly distributed protective coating on the basis of the existing technology, which is convenient for subsequent TEM sample testing.

[0065] The above embodiments are only illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A coating device for a surface protective layer of a TEM sample, characterized in that, The coating device includes a light-curing paint pen, and an ultraviolet light irradiation lamp, a light sensing locator, and an isolation coating component located in the chamber; The photocurable paint pen is used to draw the contour line of the area to be protected on the surface of the sample, and the contour line is a closed line connected end to end. The paint of the photocurable paint pen is a photocurable material, which can be quickly cured under the irradiation of the ultraviolet lamp; the ultraviolet lamp is used to irradiate the surface of the sample to harden the photocurable material, and at the same time serve as the lighting source of the photosensitive locator; the photosensitive locator is used to capture the image of the sample surface, and locate the area and position of the area to be protected according to the identified contour line; the isolation coating component is used to spray on the contour line surface according to the positioning information of the photosensitive locator to form an isolation belt, and the isolation belt is a cofferdam with a certain height, so as to prevent the epoxy resin material subsequently sprayed on the area to be protected from overflowing.

2. The coating device for the surface protective layer of the TEM sample according to claim 1, characterized in that: Also included is a resin spraying assembly and a coating curing assembly located in the chamber; The resin spraying assembly is used for spraying epoxy resin material in the area to be protected surrounded by the insulating tape, and the coating curing assembly is used for carrying samples and accelerating the curing of the epoxy resin material.

3. The coating device for the surface protective layer of the TEM sample according to claim 2, characterized in that: The coating curing assembly includes a carrier, an auxiliary heat curing unit, a vibration defoaming unit and a centrifugal rotation unit. The auxiliary heat curing unit includes an electric heating wire installed in the carrier for heating the sample; the vibration defoaming unit includes a vibration motor installed in the carrier for vibrating the carrier to discharge bubbles inside the epoxy resin material; the centrifugal rotation unit includes a rotation motor installed in the carrier so that the carrier rotates around the center to evenly diffuse the epoxy resin material to the entire area to be protected.

4. The coating device for the surface protection layer of the TEM sample according to claim 1, wherein: The coating of the photocurable coating pen comprises a photoinitiator, a photocurable resin, a filler, and a diluent, and the refractive index of the filler is between 2.0 and 3.

0.

5. The coating device for the surface protective layer of the TEM sample according to claim 4, wherein: The filler includes graphite nanosheets, silicon carbide and titanium dioxide.

6. The coating device for the surface protection layer of the TEM sample according to claim 1, wherein: The ultraviolet irradiation lamp comprises a shell, an ultraviolet light source, a reflector, a heat insulation layer, and a cooling unit. The light emission band of the ultraviolet light source is the UVB band of 320 to 350 nm.

7. The coating device for the surface protective layer of the TEM sample according to claim 1, characterized in that: The light sensing locator includes a light sensor for acquiring images and a processor for processing image signals.

8. The coating device for the surface protection layer of the TEM sample according to claim 1, wherein: The protrusion height of the isolation zone relative to the sample surface is more than 500 microns.

9. A coating method using the coating device according to any one of claims 3-8, characterized in that, The steps include: S1: Use a light-curing paint pen to draw a contour line on the chip surface in a closed pattern that is connected end to end and symmetrical relative to the center to circle the appropriate area to be protected, so that the target structure is as close to the center of the contour line as possible; S2: Fix the sample with the outline painted on the carrier of the coating curing component, then put the sample into the device cavity, start the ultraviolet light irradiation lamp or further start the auxiliary heat curing unit of the coating curing component; After irradiation for 1 minute, the light sensing locator is started to capture the fluctuation of the sample surface reflectivity, and calculate the relative position of the chip surface contour line and the device cavity, the total area of the area to be protected, and the center position of the area to be protected; S3: Start the isolation coating component, move the spray gun to the top of the contour line, and further spray the fast-curing coating on the solidified contour line to increase its height to at least 500 microns to form an isolation zone; S4: Start the resin spraying component, move the spray gun above the center position of the area to be protected, and calculate the volume consumption according to the total area of the area to be protected obtained by the processor and the set required thickness of the protective film layer. Then spray the epoxy resin material downward at the center position of the area to be protected to form an uncured protective coating with a tendency to spread from the center outward.

10. The coating method according to claim 9, characterized in that, It further includes the following steps: S5: Start the coating curing component. The auxiliary heat curing unit heats the cavity environment temperature to 150 - 175 °C to accelerate the curing of the liquid resin; the vibration defoaming unit makes the stage vibrate slightly up and down to make the bubbles inside the resin easier to discharge; The centrifugal rotation unit makes the stage rotate with a slow acceleration, and by the action of centrifugal force, the epoxy resin material is evenly spread to the entire area to be protected; 15 minutes after the coating curing component is started, the epoxy resin material cures to form a protective layer, then the sample with the sample protection completed is returned to its original position, the cavity is cooled by the cooling unit in the ultraviolet irradiation lamp, and finally the sample is taken out.

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