A method for removing a chip stopper layer

Abstract

The application discloses a chip barrier layer removing method, which comprises the following steps: coating silicon grease on one side surface of a first glass slide and a second glass slide respectively to obtain a first silicon grease layer and a second silicon grease layer; adhering one side surface of the barrier layer to one side surface of the first silicon grease layer; coating melted hot melt adhesive on one side surface of a metal layer so that the hot melt adhesive wraps the chip; adhering one side surface of the second silicon grease layer to one side surface of the hot melt adhesive to obtain a laminated structure; cooling the laminated structure until the hot melt adhesive solidifies; removing the first glass slide, the second glass slide, the first silicon grease layer and the second silicon grease layer to obtain an intermediate composite structure in which the chip is partially wrapped by the hot melt adhesive and the barrier layer is exposed; and grinding the barrier layer of the intermediate composite structure with a flannel repeatedly until the barrier layer is removed and the metal layer is exposed. The application increases the area of the chip by using the hot melt adhesive, improves the convenience of manually grinding and removing the barrier layer, and ensures the integrity and surface flatness of the chip.

Description

Technical Field

[0001] This invention relates to the field of semiconductor inspection technology, and in particular to a method for removing a chip blocking layer. Background Technology

[0002] In semiconductor failure analysis, physical delamination of the multilayer metal interconnect structure inside the chip is a key pre-sample preparation technique. Its core objective is to remove the oxide layer, metal layer, and barrier layer on the chip surface layer by layer to expose the underlying circuitry for observation and analysis using equipment such as scanning electron microscopes.

[0003] Currently, a typical delamination process for standard-sized chips involves first cleaning the chip, then placing it in a reactive ion etching (RIE) machine to remove the surface oxide layer using plasma etching, exposing the underlying metal layer. This metal layer is then removed using either chemical etching or RIE. It is well known that a barrier layer typically exists beneath the metal layer to prevent metal diffusion. A common method for removing this barrier layer is for engineers to manually polish the chip on a polishing table using polishing slurry.

[0004] However, manually polishing the barrier layer is extremely difficult, and the chip is prone to being lost or damaged. The chips are tiny and lightweight, making them prone to irregular rolling when held between the fingers or handled with polishing tools, failing to hold them stably on the polishing platform. This not only prevents the barrier layer from being effectively removed but also frequently causes the chip to accidentally bounce away, be lost, or even be directly damaged, rendering the sample unusable for failure analysis.

[0005] When manual polishing is not feasible, existing technologies can only resort to reactive ion etching or wet chemical etching to remove the barrier layer. However, both of these methods are isotropic or low-selectivity etching processes, leaving obvious trench-like marks on the chip surface. Especially at the interface between metal lines and interlayer dielectrics, uneven etching rates due to material differences can create significant steps or depressions. This uneven morphology causes regional undulations in the overall image, severely affecting focusing and imaging quality under a microscope, making the observation of fine underlying lines extremely difficult or even impossible.

[0006] For multilayer chips with two or more metal interconnect structures, the aforementioned morphological defects worsen, leading to misalignment during subsequent delamination. When removing the barrier layer beneath the first metal layer, if reactive ion etching or wet etching is used, the resulting deep trenches will be directly replicated onto the chip surface. When delaminating the second and deeper layers, these pre-existing deep trenches cause uneven delamination rates in different areas, leading to localized over-etching or under-etching, ultimately resulting in misalignment between the upper and lower layers—a phenomenon known as misalignment. Misalignment completely destroys the chip's vertical structural information, making it impossible to correctly interpret the three-dimensional interconnect relationships of the multilayer circuitry. Summary of the Invention

[0007] This invention provides a method for removing a chip barrier layer. By using hot melt adhesive, the chip area is increased, improving the convenience of manually grinding to remove the barrier layer, while ensuring the chip's integrity and surface flatness.

[0008] This invention provides a method for removing a barrier layer from a chip, wherein the chip comprises at least a metal layer and a barrier layer stacked sequentially; the removal method includes: A first glass slide and a second glass slide are provided, and silicone grease is coated on one side surface of the first glass slide and the second glass slide respectively to obtain a first silicone grease layer and a second silicone grease layer; The surface of the barrier layer facing away from the metal layer is bonded to the surface of the first silicone grease layer facing away from the first glass slide. Molten hot melt adhesive is applied to the surface of the metal layer opposite to the barrier layer, so that the hot melt adhesive encapsulates the chip; The second silicone grease layer is bonded to the surface of the second glass slide opposite to the second glass slide, and the hot melt adhesive is bonded to the surface of the hot melt adhesive opposite to the metal layer to obtain a laminated structure; wherein, the laminated structure sequentially includes the first glass slide, the first silicone grease layer, the chip, the hot melt adhesive, the second silicone grease layer, and the second glass slide; The laminated structure is cooled until the hot melt adhesive cures; Remove the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially wrapped by the cured hot melt adhesive and the barrier layer is exposed; wherein the coverage area of ​​the hot melt adhesive in the intermediate composite structure in the direction parallel to the chip surface is larger than the area of ​​the chip. The intermediate composite structure is subjected to repeated grinding of the barrier layer using a velvet cloth until the barrier layer is removed and the metal layer is exposed.

[0009] Optionally, the surface of the second silicone grease layer facing away from the second glass slide is bonded to the surface of the hot melt adhesive facing away from the metal layer to obtain a laminated structure, including: The surface of the second silicone grease layer facing away from the second glass slide is covered with the surface of the hot melt adhesive facing away from the metal layer; Pressure is applied to the surface of the second glass slide on the side opposite to the second silicone grease layer to cause the molten hot melt adhesive to flow, thereby obtaining the laminated structure with a smooth surface on each layer.

[0010] Optionally, before repeatedly polishing the barrier layer with a cloth until the barrier layer is removed and the metal layer is exposed, the intermediate composite structure further includes: A silica polishing slurry is dropped onto the fabric; wherein the particle size of the polishing particles in the silica polishing slurry is 0.05μm~0.2μm.

[0011] Optionally, after removing the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially encased by the cured hot melt adhesive and the barrier layer is exposed, the intermediate composite structure is further subjected to multiple abrasive polishing of the barrier layer using a cloth until the barrier layer is removed and the metal layer is exposed. The intermediate composite structure is cut so that the length of the cured hot melt adhesive in the direction parallel to the long side of the chip surface is 2mm to 5mm; and the length of the cured hot melt adhesive in the direction parallel to the short side of the chip surface is 2mm to 5mm.

[0012] Optionally, after removing the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially encased by the cured hot melt adhesive and the barrier layer is exposed, the intermediate composite structure is further subjected to multiple abrasive polishing of the barrier layer using a cloth until the barrier layer is removed and the metal layer is exposed. The intermediate composite structure is cut so that the cured hot melt adhesive is square, rectangular or circular.

[0013] Optionally, after repeatedly polishing the barrier layer with a cloth in the intermediate composite structure until the barrier layer is removed and the metal layer is exposed, the method further includes: The hot melt adhesive is heated to remove the hot melt adhesive covering the chip.

[0014] Optionally, the dimensions of the first glass slide and the second glass slide in the direction parallel to the chip surface are both greater than or equal to the dimensions of the first silicone grease layer and the second silicone grease layer; the dimensions of the first silicone grease layer and the second silicone grease layer in the direction parallel to the chip surface are both greater than the dimensions of the chip.

[0015] Optionally, the length of the long side of the chip in the direction parallel to the chip surface is L1, and the length of the short side of the chip in the direction parallel to the chip surface is L2, wherein L1≤528.7μm and L2≤445.62μm.

[0016] Optionally, the thickness of the hot melt adhesive is 150nm~250nm.

[0017] Optionally, the thickness of both the first silicone grease layer and the second silicone grease layer is 150μm~250μm.

[0018] The chip barrier layer removal method provided by this invention increases the chip area by using hot melt adhesive, improving the convenience of manual grinding to remove the barrier layer, while ensuring chip integrity and surface flatness. Furthermore, under room temperature conditions, the hot melt adhesive maintains a stable solid state, constraining the chip in a predetermined position and preventing it from loosening due to temperature fluctuations or slight external forces. Simultaneously, because the chip is reliably fixed before grinding, it maintains a flat posture throughout the grinding process, preventing rolling, shaking, or uneven stress, thus effectively avoiding mechanical damage. After grinding, the chip surface has a complete circuit structure and good flatness, without the obvious grooves or step morphologies left by traditional dry or wet etching methods. This results in clear and layered imaging under a microscope, facilitating rapid and accurate identification of circuit anomalies and fault location, fully meeting the requirements of high-standard failure analysis.

[0019] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic flowchart illustrating a method for removing a chip blocking layer according to an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the operation steps for a corresponding chip barrier layer removal method; Figure 3 This is a schematic diagram of the structure of a chip provided in an embodiment of the present invention; Figure 4 This is a top view schematic diagram of an intermediate composite structure provided in an embodiment of the present invention; Figure 5 A top view schematic diagram of a chip provided in an embodiment of the present invention; Figure 6 A schematic flowchart of another chip barrier layer removal method provided in an embodiment of the present invention; Figure 7 This is a schematic diagram of the chip structure after the chip barrier layer has been removed using existing technology; Figure 8 This is a schematic diagram of the chip structure after the chip barrier layer has been removed using the removal method provided in this application. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0023] The terminology used in the embodiments of this invention is for the purpose of describing specific embodiments only and is not intended to limit the invention. It should be noted that directional terms such as "upper," "lower," "left," and "right" described in the embodiments of this invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this invention. Furthermore, in the context, it should be understood that when referring to an element being formed "on" or "below" another element, it can be formed not only directly on or below the other element, but also indirectly on or below it through intermediate elements. The terms "first," "second," etc., are used for descriptive purposes only and do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0024] The term "comprising" and its variations as used in this invention are open-ended, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment".

[0025] It should be noted that the concepts of "first" and "second" mentioned in this invention are only used to distinguish the corresponding contents and are not used to limit the order or interdependence.

[0026] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0027] Figure 1 This is a flowchart illustrating a method for removing a chip blocking layer according to an embodiment of the present invention. Figure 2 for Figure 1 A schematic diagram illustrating the operational steps of a corresponding chip barrier layer removal method. Figure 3 This is a schematic diagram of a chip structure provided in an embodiment of the present invention, such as... Figure 1 , Figure 2 and Figure 3 As shown, the chip includes at least a metal layer 10 and a barrier layer 20 stacked sequentially. The removal method includes: S101. A first glass slide and a second glass slide are provided, and silicone grease is coated on one side surface of the first glass slide and the second glass slide respectively to obtain a first silicone grease layer and a second silicone grease layer.

[0028] refer to Figure 2 A1 and A2 are respectively coated with a layer of silicone grease on one side surface of the first glass slide 31 and the second glass slide 32 to obtain a first silicone grease layer 41 and a second silicone grease layer 42. The dimensions of the first glass slide 31 and the second glass slide 32 in the direction parallel to the chip surface are both greater than or equal to the dimensions of the first silicone grease layer 41 and the second silicone grease layer 42. The dimensions of the first silicone grease layer 41 and the second silicone grease layer 42 in the direction parallel to the chip surface are both greater than the size of the chip. This allows the first silicone grease layer 41 on the first glass slide 31 and the second silicone grease layer 42 on the second glass slide 32 to temporarily fix the chip during subsequent operations, thereby significantly increasing the manual operation area of ​​the chip and making it less prone to rolling or accidental loss during transfer and packaging, greatly reducing the risk of sample scrap. In an optional embodiment, the thickness of both the first silicone grease layer 41 and the second silicone grease layer 42 is 150μm to 250μm.

[0029] S102, the surface of the barrier layer facing away from the metal layer is bonded to the surface of the first silicone grease layer facing away from the first glass slide.

[0030] refer to Figure 2In A3, because the silicone grease has adhesive properties, the side of the chip barrier layer 10 facing away from the metal layer 20 is bonded to the side of the first silicone grease layer 41 facing away from the first glass slide 31. The chip can be well adsorbed on the first glass slide 31 through the first silicone grease layer 41. At the same time, the side of the chip metal layer 20 facing away from the barrier layer 10 can be gently pressed to make the chip barrier layer 10 completely adhere to the first silicone grease layer 41, thereby ensuring that the contact surface between the barrier layer 10 and the first silicone grease layer 41 is flat.

[0031] S103. Apply molten hot melt adhesive to the side of the metal layer away from the barrier layer, so that the hot melt adhesive wraps the chip.

[0032] refer to Figure 2 To increase the chip area for subsequent manual polishing, hot melt adhesive 50 can be melted into a liquid using a hot air gun and then applied to the surface of the metal layer 20 facing away from the barrier layer 10. This allows the hot melt adhesive 50 to encapsulate the chip, thereby increasing its area. In an optional embodiment, the thickness of the hot melt adhesive 50 is 150nm to 250nm.

[0033] S104. The surface of the second silicone grease layer facing away from the second glass slide is bonded to the surface of the hot melt adhesive facing away from the metal layer to obtain a laminated structure.

[0034] refer to Figure 2 In step A5, the surface of the second silicone grease layer 42 facing away from the second glass slide 32 is bonded to the surface of the hot melt adhesive 50 facing away from the metal layer 20 to obtain a laminated structure. The laminated structure sequentially includes a first glass slide 31, a first silicone grease layer 41, a chip, hot melt adhesive 50, a second silicone grease layer 42, and a second glass slide 32. At this time, the hot melt adhesive 50 and the chip are located between the first silicone grease layer 41 and the second silicone grease layer 42. Since the first silicone grease layer 41 and the second silicone grease layer 42 have adhesive properties, they can reliably fix the chip between them, thereby ensuring that the chip remains in a stable position during the subsequent curing process of the hot melt adhesive 50. At the same time, the first silicone grease layer 41 and the second silicone grease layer 42 do not stick to the hot melt adhesive 50, so the first silicone grease layer 41 and the second silicone grease layer 42 can be easily removed in subsequent steps.

[0035] S105. Cool the laminated structure until the hot melt adhesive cures.

[0036] Specifically, the laminated structure can be cooled at room temperature to allow the hot melt adhesive 50 to cure, thereby fixing the chip in the hot melt adhesive 50 and increasing the chip area.

[0037] S106. Remove the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially wrapped by the cured hot melt adhesive and the barrier layer is exposed.

[0038] refer to Figure 2 In A6, since the first silicone grease layer 41 and the second silicone grease layer 42 do not adhere to the hot melt adhesive 50, after the hot melt adhesive 50 cures, the first glass slide 31, the second glass slide 32, the first silicone grease layer 41, and the second silicone grease layer 42 in the laminated structure can be removed to obtain an intermediate composite structure in which the chip is partially wrapped by the cured hot melt adhesive 50 and the barrier layer 10 is exposed. Figure 2 As shown in A6, the hot melt adhesive 50 of the intermediate composite structure has a larger coverage area than the chip area in the direction parallel to the chip surface, thereby increasing the chip area and making subsequent manual polishing operations more convenient.

[0039] S107. For the intermediate composite structure, the barrier layer is ground multiple times with a cloth until the barrier layer is removed and the metal layer is exposed.

[0040] refer to Figure 2 With the A7 chip, after the chip area is effectively increased, the intermediate composite structure can be manually polished. The barrier layer 10 is repeatedly polished with a soft cloth until it is removed, exposing the metal layer 20. At this point, because the chip is easier to handle with fingers, the polishing direction can be adjusted during the polishing process, and the polishing frequency of the chip edges can be controlled. This ensures maximum chip flatness and prevents chip loss, improving work efficiency and quality control.

[0041] This invention increases the chip area by using hot melt adhesive, improving the convenience of manually removing the barrier layer while ensuring chip integrity and surface flatness. Furthermore, at room temperature, the hot melt adhesive maintains a stable solid state, constraining the chip in a predetermined position and preventing it from loosening due to temperature fluctuations or slight external forces. Simultaneously, because the chip is reliably fixed before grinding, it remains flat throughout the grinding process, preventing rolling, shaking, or uneven stress, thus effectively avoiding mechanical damage. After grinding, the chip surface exhibits a complete circuit structure and good flatness, without the obvious grooves or steps left by traditional dry or wet etching methods. This results in clear, layered imaging under a microscope, facilitating rapid and accurate identification of circuit anomalies and fault location, fully meeting high-standard failure analysis requirements.

[0042] Based on the above embodiments, the present invention proposes variant embodiments of the above embodiments. It should be noted that, in order to keep the description brief, only the differences from the above embodiments are described in the variant embodiments.

[0043] After step S106, removing the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially wrapped by cured hot melt adhesive and the barrier layer is exposed, step S107, before repeatedly polishing the barrier layer of the intermediate composite structure with a cloth until the barrier layer is removed and the metal layer is exposed, further includes: S1061. The intermediate composite structure is cut so that the length of the cured hot melt adhesive in the direction parallel to the long side of the chip surface is 2mm~5mm; the length of the cured hot melt adhesive in the direction parallel to the short side of the chip surface is 2mm~5mm.

[0044] Specifically, after obtaining the intermediate composite structure in which the chip is partially wrapped by cured hot melt adhesive 50 and the barrier layer 10 is exposed, the amount of hot melt adhesive 50 cannot be precisely controlled when it is applied to the side of the metal layer 20 facing away from the barrier layer 10. This may result in a larger size of the intermediate composite structure, increasing the difficulty of manual polishing. Therefore, before polishing, the intermediate composite structure can be trimmed so that the length of the cured hot melt adhesive 50 in the direction parallel to the long side of the chip surface is 2mm to 5mm, and the length of the cured hot melt adhesive 50 in the direction parallel to the short side of the chip surface is also 2mm to 5mm. This ensures that the size of the intermediate composite structure matches the size of the polishing machine, while also ensuring that the fingers can apply uniform pressure to the surface of the intermediate composite structure to keep the chip surface flat during polishing.

[0045] Further, in an optional embodiment, after step S106, removing the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially wrapped by cured hot melt adhesive and the barrier layer is exposed, in step S107, before repeatedly polishing the barrier layer of the intermediate composite structure with a cloth until the barrier layer is removed and the metal layer is exposed, the method further includes: S1062. Cut the intermediate composite structure so that the cured hot melt adhesive is square, rectangular or circular.

[0046] Specifically, Figure 4 This is a top view schematic diagram of an intermediate composite structure provided in an embodiment of the present invention, as shown below. Figure 2 and Figure 4 As shown, the cured hot melt adhesive 50 partially wraps the chip and exposes the barrier layer 10. When cutting the intermediate composite structure, the cured hot melt adhesive 50 can be square, rectangular or circular to facilitate manual grinding. This application does not specifically limit the shape after cutting.

[0047] It is understandable that after the intermediate composite structure is trimmed, the size of the cured hot melt adhesive 50 is still larger than the chip size, thereby increasing the chip area. In an optional embodiment, Figure 5 This is a top view schematic diagram of a chip provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the length of the long side of the chip in the direction parallel to the chip surface is L1, and the length of the short side of the chip in the direction parallel to the chip surface is L2, where L1≤528.7μm and L2≤445.62μm.

[0048] Optionally, Figure 6 This is a flowchart illustrating another method for removing a chip blocking layer provided by an embodiment of the present invention. This embodiment is a refinement of the above embodiment. Specifically, for step S104, bonding the surface of the second silicone grease layer away from the second glass slide to the surface of the hot melt adhesive away from the metal layer to obtain a laminated structure, it can be further refined as follows: The surface of the second silicone grease layer facing away from the second glass slide is covered with the surface of the hot melt adhesive facing away from the metal layer. Pressure is applied to the surface of the second glass slide on the side opposite to the second silicone grease layer to allow the molten hot melt adhesive to flow, thereby obtaining a laminated structure with a smooth surface for each layer.

[0049] Furthermore, in step S107, before repeatedly polishing the barrier layer with a cloth on the intermediate composite structure until the barrier layer is removed and the metal layer is exposed, the following steps are also included: Apply silica polishing slurry to a piece of velvet.

[0050] Furthermore, in step S107, after repeatedly polishing the barrier layer of the intermediate composite structure with a cloth until the barrier layer is removed and the metal layer is exposed, the process further includes: Heat the hot melt adhesive to remove the hot melt adhesive covering the chip.

[0051] For details not described in this embodiment, please refer to the foregoing embodiments. Figure 6 As shown, the removal method provided in this embodiment includes: S201. A first glass slide and a second glass slide are provided, and silicone grease is coated on one side surface of the first glass slide and the second glass slide respectively to obtain a first silicone grease layer and a second silicone grease layer.

[0052] S202, The side surface of the barrier layer away from the metal layer is bonded to the side surface of the first silicone grease layer away from the first glass slide.

[0053] S203. Apply molten hot melt adhesive to the side of the metal layer away from the barrier layer, so that the hot melt adhesive wraps around the chip.

[0054] S204. Cover the surface of the second silicone grease layer away from the second glass slide with the surface of the hot melt adhesive away from the metal layer.

[0055] S205. Apply pressure to the surface of the second glass slide on the side opposite to the second silicone grease layer to allow the molten hot melt adhesive to flow, thereby obtaining a laminated structure with a smooth surface for each layer.

[0056] Specifically, since the molten hot melt adhesive 50 is fluid, after the side of the second silicone grease layer 42 away from the second glass slide 32 is covered with the side of the hot melt adhesive 50 away from the metal layer 20, the molten hot melt adhesive 50 can be made to flow by gently pressing the side of the second glass slide 32 away from the second silicone grease layer 42, thereby making the surface of each layer in the laminated structure smooth.

[0057] S206. Cool the laminated structure until the hot melt adhesive cures.

[0058] S207. Remove the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially wrapped by the cured hot melt adhesive and the barrier layer is exposed.

[0059] S208. Apply silicon dioxide polishing slurry to a cloth.

[0060] The abrasive particles in the silicon oxide polishing slurry have a particle size of 0.05μm to 0.2μm. Because the cloth is soft and elastic, it can make flexible contact with the chip surface, avoiding chip breakage or surface scratches caused by hard polishing tools during the polishing process. Furthermore, the silicon oxide abrasive particles within this particle size range can uniformly and controllably remove the barrier layer material without leaving obvious mechanical scratches or grooves on the chip surface, ensuring the flatness of the circuit after delamination.

[0061] S209. For the intermediate composite structure, the barrier layer is ground multiple times with a cloth until the barrier layer is removed and the metal layer is exposed.

[0062] S210. Heat the hot melt adhesive to remove the hot melt adhesive covering the chip.

[0063] Specifically, after removing the blocking layer 10 of the chip, the hot melt adhesive 50 can be melted by heating, and then the chip wrapped by the hot melt adhesive 50 can be removed, thereby removing the hot melt adhesive 50 wrapped around the chip without damaging the chip.

[0064] Figure 7 This is a schematic diagram of the chip structure after the chip barrier layer has been removed using existing technology. Figure 8 This is a schematic diagram of the chip structure after the chip barrier layer has been removed using the removal method provided in this application, as shown below. Figure 7 and Figure 8As shown, after removing the chip barrier layer using existing removal methods, as Figure 7 In the 100 region of the chip, there are many grooves on the chip surface, and the whole image is uneven, which affects subsequent analysis. However, after removing the chip blocking layer using the removal method provided in this application, the chip surface remains flat, making the chip clear and layered under the microscope. This facilitates the rapid and accurate identification of circuit abnormalities and the location of fault points, and can fully meet the high standard of failure analysis requirements.

[0065] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, combinations, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A method for removing a chip blocking layer, characterized in that, The chip includes at least a metal layer and a barrier layer stacked sequentially; the removal method includes: A first glass slide and a second glass slide are provided, and silicone grease is coated on one side surface of the first glass slide and the second glass slide respectively to obtain a first silicone grease layer and a second silicone grease layer; The surface of the barrier layer facing away from the metal layer is bonded to the surface of the first silicone grease layer facing away from the first glass slide. Molten hot melt adhesive is applied to the surface of the metal layer opposite to the barrier layer, so that the hot melt adhesive encapsulates the chip; The second silicone grease layer is bonded to the surface of the second glass slide opposite to the second glass slide, and the hot melt adhesive is bonded to the surface of the hot melt adhesive opposite to the metal layer to obtain a laminated structure; wherein, the laminated structure sequentially includes the first glass slide, the first silicone grease layer, the chip, the hot melt adhesive, the second silicone grease layer, and the second glass slide; The laminated structure is cooled until the hot melt adhesive cures; Remove the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially wrapped by the cured hot melt adhesive and the barrier layer is exposed; wherein the coverage area of ​​the hot melt adhesive in the intermediate composite structure in the direction parallel to the chip surface is larger than the area of ​​the chip. The intermediate composite structure is subjected to repeated grinding of the barrier layer using a velvet cloth until the barrier layer is removed and the metal layer is exposed.

2. The removal method according to claim 1, characterized in that, The second silicone grease layer is bonded to the surface of the second glass slide facing away from the second glass slide, and the hot melt adhesive is bonded to the surface of the hot melt adhesive facing away from the metal layer, to obtain a laminated structure, including: The surface of the second silicone grease layer facing away from the second glass slide is covered with the surface of the hot melt adhesive facing away from the metal layer; Pressure is applied to the surface of the second glass slide on the side opposite to the second silicone grease layer to cause the molten hot melt adhesive to flow, thereby obtaining the laminated structure with a smooth surface on each layer.

3. The removal method according to claim 1, characterized in that, For the intermediate composite structure, before repeatedly polishing the barrier layer with a velvet cloth until the barrier layer is removed and the metal layer is exposed, the process further includes: A silica polishing slurry is dropped onto the fabric; wherein the particle size of the polishing particles in the silica polishing slurry is 0.05μm~0.2μm.

4. The removal method according to claim 1, characterized in that, After removing the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially encased by the cured hot melt adhesive and the barrier layer is exposed, the intermediate composite structure is further subjected to multiple abrasive polishing of the barrier layer using a cloth until the barrier layer is removed and the metal layer is exposed. The intermediate composite structure is cut so that the length of the cured hot melt adhesive in the direction parallel to the long side of the chip surface is 2mm to 5mm; and the length of the cured hot melt adhesive in the direction parallel to the short side of the chip surface is 2mm to 5mm.

5. The removal method according to claim 1, characterized in that, After removing the first glass slide, the second glass slide, the first silicone grease layer, and the second silicone grease layer from the stacked structure to obtain an intermediate composite structure in which the chip is partially encased by the cured hot melt adhesive and the barrier layer is exposed, the intermediate composite structure is further subjected to multiple abrasive polishing of the barrier layer using a cloth until the barrier layer is removed and the metal layer is exposed. The intermediate composite structure is cut so that the cured hot melt adhesive is square, rectangular or circular.

6. The removal method according to claim 1, characterized in that, After repeatedly polishing the barrier layer with a cloth until the barrier layer is removed and the metal layer is exposed, the intermediate composite structure further includes: The hot melt adhesive is heated to remove the hot melt adhesive covering the chip.

7. The removal method according to claim 1, characterized in that, The dimensions of the first glass slide and the second glass slide in the direction parallel to the chip surface are both greater than or equal to the dimensions of the first silicone grease layer and the second silicone grease layer; the dimensions of the first silicone grease layer and the second silicone grease layer in the direction parallel to the chip surface are both greater than the dimensions of the chip.

8. The removal method according to claim 1, characterized in that, The chip has a long side length L1 in the direction parallel to the chip surface and a short side length L2 in the direction parallel to the chip surface, where L1 ≤ 528.7 μm and L2 ≤ 445.62 μm.

9. The removal method according to claim 1, characterized in that, The thickness of the hot melt adhesive is 150nm~250nm.

10. The removal method according to claim 1, characterized in that, The thickness of both the first and second silicone grease layers is 150μm to 250μm.

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