Method and process for forming and monitoring voids in dressers and polishing pads for CMP processes

Abstract

To provide a method and a process for forming and monitoring voids of a dresser and a polishing pad for a CMP process.SOLUTION: The dresser includes a substrate, a sheet-like body disposed on one surface of the substrate, and a modular polishing unit disposed on the sheet-like body, wherein the modular polishing unit is provided with a plurality of single units, the plurality of single units are disposed on the sheet-like body at intervals, each single unit has a convex portion, and the convex portions have different heights. The polishing pad is polished by the convex portion of each single unit of the dresser to form a polishing pad groove in which a zoned common height and a common surface are carved on the polishing pad, and a lateral shape of the polishing pad groove is formed by the auxiliary convex portion of each single unit. To effectively hold a polishing liquid, to effectively control the occurrence of thermal expansion due to the heat of a dresser and a polishing pad, to improve the influence of the defect of surface texture or the like, and to effectively reduce the cost of the whole CMP process.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a CMP process, an apparatus, and a monitoring method, and more particularly to a CMP process, an apparatus, a dresser, and a monitoring method for polishing pad quality that are convenient for piercing a polishing pad to form a regionalized common height and common surface groove on the polishing pad, remove glazing or dirt on the polishing pad, regenerate fluff to make the surface roughness of the polishing pad uniform, form a lateral shape of the polishing pad groove, and are advantageous for retaining a polishing liquid. [Background technology]

[0002] Chemical-mechanical polishing (CMP) is the primary wafer planarization process in semiconductor manufacturing. When the feature size of a semiconductor chip is less than 0.35 micrometers (μm), global planarization must be performed. CMP is currently the most efficient planarization technology in the world. As the linewidth of integrated circuits continues to shrink, the optical NA (numerical aperture) value in DUV (Deep Ultraviolet Lithography) / EUV (Extreme Ultraviolet Lithography) is significantly increased. As the NA value continuously improves, the depth of field becomes shorter and shorter. Therefore, the wafer planarization process must be performed before exposure, development, and etching. The CMP process uses a properly distributed dresser (or diamond disk) to recreate the surface shape of the polishing pad. For example, for EUV extreme ultraviolet light source technology, the depth of field (DoF) is expressed by the following formula: DoF=K λ / NA 2 Here, λ is the wavelength and NA is the numerical aperture. Assuming a fixed wavelength of 13.5 nm and an NA of 0.55, the depth of field must clearly be less than 15 nm. In other words, if the wafer cannot be polished to this flatness, exposure and development will fail. Furthermore, it is necessary to ensure the flatness of the wafer surface while maintaining the wafer material removal rate (MRR). Therefore, the height of the cone tip of the existing dresser is an extremely important factor. This is because it affects the depth, width, and amount of fuzz of the grooves generated when the existing dresser cuts the existing polishing pad, and whether the resulting surface fuzz can hold more chemical polishing fluid (or polishing fluid). Next, the common height of the cone tips of each area-forming module determines the coplanarity of the existing dresser. However, if the tip of the dresser particle is too high or the cross-sectional area is too large, the polishing pad 400 will form an excessively high protrusion 401 (which will further increase the unit pressure formed on the wafer contact surface), as shown in Figure 25, and will scratch the wafer surface.

[0003] Furthermore, as shown in FIG. 25, if the tip of one cone on the dresser is excessively higher than the tips of the other cones, an excessive protrusion 401 is generated on the existing polishing pad 400, causing indirect damage to the wafer. The protrusion 401 occurs when the tip of the existing dresser is pressed against the existing polishing pad 400. The polishing pad 400 is first deformed, and then the lateral movement causes a protrusion. Therefore, controlling the common height and coplanarity of the tips of the cones is one of the requirements for improving the dresser. Furthermore, during the CMP process, the existing dresser applies downward pressure and movement to form grooves in the existing polishing pad 400, which are then filled with a chemical polishing solution. Due to the relative movement between the wafer and the existing polishing pad 400, fine abrasive particles in the chemical polishing solution (or grinding solution) polish the wafer surface while oxidizing or corroding the metal. However, during the wafer polishing process, the chemical polishing solution is rapidly lost due to centrifugal force. The cost of polishing solution in the CMP process accounts for more than 50% of the total consumables. Therefore, to maintain the polishing solution on the polishing pad, the existing dresser must continuously create new voids in the polishing pad. This is the second requirement for improving the dresser. Furthermore, in the CMP process, as shown in Figure 26, chemical mechanical polishing is performed by pressing the dresser X and the wafer against the polishing pad 400. Over time, if the temperature of the polishing pad 400 exceeds 35°C, the variation in material removal rate (MRR) increases rapidly, thereby affecting the quality of wafer polishing.

[0004] Furthermore, during the CMP process, the relative movement between the existing dresser and the existing polishing pad 400 carves grooves in the polishing pad 400 and generates new surface fuzz. Therefore, the third requirement for improving the dresser is to control the protrusions 401 on the polishing pad 400 and reduce the overall roughness uniformity of the polishing pad 400.

[0005] Meanwhile, during the CMP process, the existing dresser is pressed against the existing polishing pad 400, forming grooves in the existing polishing pad 400. During this process, the existing polishing pad 400 is subjected to friction, deformation, tearing, and other forces due to the relative movement between the existing dresser and the existing polishing pad 400. Because the viscoelasticity of the existing polishing pad 400 includes the amount of deformation, the larger the cone angle of the existing dresser, the greater the reaction force against penetration into the existing polishing pad 400, making it difficult to control the penetration depth into the existing polishing pad 400. Furthermore, the other component force of the cone forms protrusions 401 at the edges of the grooves in the existing polishing pad 400, which has a significant impact on the flatness of the wafer surface. Therefore, the sharp protrusions on the diamond pyramid surface penetrate deeply into the polishing pad when pressed down, reducing deformation of the metal body and the polishing pad 400. This allows for qualitative and quantitative engraving of four-dimensional grooves, avoiding the use of conventional polishing pad 400 methods, such as the use of plastic microcellular foam injection molding techniques, such as the MuCell® supercritical microcellular foam injection molded polishing pad 400. In the polishing pad 400, irregular and non-uniform pores are formed during the cooling process after injection molding, making it difficult to control the overall deformation during polishing. This is the fourth requirement for improving the dresser.

[0006] From this information, along with the stress and strain diagram shown in Figure 27, the following simplified equation can be derived: σ=Fc / A where σ is the applied stress, Fc is the compressive force, and A is the cross-sectional area of ​​the test material. For a constant deformation rate, the strain is calculated using the following formula: ε=νΔt where ε is the strain, ν is the descent speed of the cone, and Δt is the deformation rate of the test piece after a certain time has passed. The line in the elastic region is before the maximum load is applied and is based on Hooke's law: σ(t)=E·ε(Δt) ε=v Δt / L0 σ=E·ε(t)=E·v·Δt / L0 E=σ / ε where σ is stress, E is Young's modulus, ε(t) is the strain that changes with time, v is a constant velocity, Δt is the elapsed time, and L0 is the original length.

[0007] However, although the relevant data can be calculated and obtained using the above relevant equations, the current operating mode cannot detect in a timely manner whether the surface texture of the existing polishing pad 400 and the tip of the cone of the existing dresser are worn, and adjustments can only be made when problems occur in subsequent processes, which will affect the quality of the polished wafers.

[0008] For example, Taiwan Patent No. 436375B, Taiwan Patent Application Publication No. 202004886A, Taiwan Patent No. I813551, and Taiwan Patent No. I741865 (IDS procedures are required for U.S. applications) state that while existing dressers are useful for improving the mechanical properties, surface shape, and porosity / fluffing of the PU polyurethane of existing polishing pads, they lack methods and related technologies for improving the problems of not being able to effectively control the polishing liquid retention method, thermal expansion of the dresser and polishing pad due to heat, and poor surface texture, etc., and these improvements are needed to manage the cost of the entire CMP process.

[0009] Furthermore, the aforementioned TW436375B, TW202004886A, TWI813551, and TWI741865 all demonstrate the polishing effect of diamond dressing on the mechanical properties, surface topography, and porosity / fuzz formation of PU polyurethane polishing pads. However, this function only satisfies requirements such as polishing pad groove engraving and debris removal. Cost control of the entire CMP process (e.g., flatness) and polishing fluid retention methods are lacking, making it impossible to effectively control polishing pad grooves qualitatively or quantitatively. Conventional polishing pad manufacturing methods use supercritical micro-foam injection molding, which results in the formation of pores of variable size after the polishing pad cools. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Taiwan Patent No. 436375 [Patent Document 2] Taiwan Patent Application Publication No. 202004886 [Patent Document 3] Taiwan Patent No. I813551 [Patent Document 4] Taiwan Patent No. I741865 Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, in view of the defects and inadequacies of the existing CMP process, the inventors of the present invention have, through continuous research and testing, developed the present invention, which can finally improve the existing defects.

[0012] The object of the present invention is to provide a CMP process, apparatus, and monitoring method that is convenient for piercing a polishing pad to form regionalized common height and common surface grooves on the polishing pad, removes gloss or dirt on the polishing pad, regenerates fuzz to uniform the surface roughness of the polishing pad, forms the lateral shape of the polishing pad grooves, and is advantageous for retaining polishing liquid. [Means for solving the problem]

[0013] In order to achieve the above object, the present invention provides: A substrate; At least one sheet-like body disposed on one surface of the substrate; a modular polishing unit disposed on the at least one sheet; Equipped with The modular polishing unit is provided with a plurality of individual units, the individual units being spaced apart on the at least one sheet-like body, each of the individual units having a protrusion, and the protrusions of the individual units having different heights.

[0014] The present invention further provides a tool comprising: a body provided with a working end and a working platform; a dresser provided at a processing end of the body for directing each of the single units on the at least one sheet-like material toward the processing platform; a polishing pad provided on a processing platform of the main body and performing polishing via the dresser; The present invention provides a CMP process apparatus comprising:

[0015] The present invention further comprises: providing the CMP process tool; driving the dresser to move and rotate toward the polishing pad with a working end of the body; a polishing pad groove having a common height and a common surface on the polishing pad by a protrusion of each of the single units of the dresser, and a lateral shape of the polishing pad groove on the polishing pad by a sub-protrusion of each of the single units; The present invention provides a CMP process comprising:

[0016] The present invention further comprises the steps of providing a CMP process tool; installing a lens module in the CMP process tool, the lens module using a metalens to observe microscopic features and perform 3D texturing and flatness monitoring of a surface by optical shear interference; Integrating an AI system to identify the polishing pad, polishing liquid, and wafer according to the refractive index, reflected light intensity, and scattering data; and training the AI ​​system to determine microscopic features and monitor the porosity of the polishing pad. A method for monitoring voids in a polishing pad in a CMP process is provided, comprising: [Effects of the Invention]

[0017] The above technical features allow the vertex of the upper module of the dresser for the CMP process of the present invention to be easily inserted into the polishing pad and to carve grooves in the polishing pad at a common height and surface. The dresser blade can remove glazing or dirt from the polishing pad and regenerate more fuzz during the dressing process, thereby maintaining a uniform polishing pad surface roughness. At the same time, the lateral shape of the polishing pad grooves is formed during the dressing process, thereby improving the polishing fluid retention and effectively retaining the polishing fluid. This effectively controls the thermal expansion of the dresser and polishing pad, improving the effects of poor surface texture, and effectively reducing the overall cost of the CMP process. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing an external appearance of a dresser for a CMP process according to the present invention. [Figure 2] 1 is a perspective external view of a first preferred embodiment of a sheet-shaped member of a dresser for a CMP process according to the present invention; [Figure 3] FIG. 10 is a partially enlarged perspective external view of a second preferred embodiment of a sheet-like body of a dresser for a CMP process according to the present invention. [Figure 4] FIG. 10 is a partially enlarged perspective external view of a third preferred embodiment of a sheet-like body of a dresser for a CMP process according to the present invention. [Figure 5] FIG. 10 is a top external view of a third preferred embodiment of a sheet-like body of a dresser for a CMP process according to the present invention. [Figure 6] FIG. 6 is a sectional side view of the third preferred embodiment of the sheet-like body of the dresser for a CMP process according to the present invention, taken along the AA section line in FIG. 5. [Figure 7] FIG. 10 is a partially enlarged sectional side view of a third preferred embodiment of a sheet-like body of a dresser for a CMP process according to the present invention. [Figure 8] FIG. 10 is a partially enlarged perspective sectional external view of a fourth preferred embodiment of a sheet-like body of a dresser for a CMP process according to the present invention. [Figure 9]FIG. 10 is a partially enlarged perspective sectional external view of a fifth preferred embodiment of a sheet-like body of a dresser for a CMP process according to the present invention. [Figure 10] FIG. 13 is a partially enlarged perspective external view of a sheet-like body of a dresser for a CMP process according to a sixth preferred embodiment of the present invention. [Figure 11] 1 is an explanatory view of an operation of using a polishing pad of the dresser for a CMP process of the present invention. FIG. [Figure 12] FIG. 10 is another explanatory view of the operation of using a polishing pad of the dresser for a CMP process of the present invention. [Figure 13] FIG. 10 is an external top view of another embodiment of the dresser for a CMP process of the present invention. [Figure 14] 10 is a partially enlarged perspective external view of a sheet-like body of another embodiment of a dresser for a CMP process according to the present invention. FIG. [Figure 15] FIG. 10 is a partially enlarged perspective external view of a sheet-like body of still another embodiment of a dresser for a CMP process according to the present invention. [Figure 16] FIG. 10 is another partially enlarged perspective external view of a sheet-like body of still another embodiment of a dresser for a CMP process according to the present invention. [Figure 17] 1 is an explanatory view of the operation of polishing a wafer in the CMP process apparatus of the present invention. [Figure 18] 10 is a diagram illustrating another operation of polishing a wafer in the CMP process apparatus of the present invention. FIG. [Figure 19] 1 is an explanatory view showing an operation of dressing a polishing pad of the dresser for a CMP process of the present invention. FIG. [Figure 20] 10 is another explanatory view of the operation of dressing a polishing pad of the dresser for a CMP process of the present invention. FIG. [Figure 21] 1 is an explanatory diagram of an operation in which a lens module is installed in the CMP process apparatus of the present invention. [Figure 22] 1 is a perspective view illustrating the appearance of a lens module of a CMP process apparatus according to the present invention; [Figure 23] 1 is a partially enlarged explanatory view showing the appearance of a CMP process apparatus according to the present invention in which a lens module is installed; [Figure 24]FIG. 1 is an explanatory diagram of an operation interface in which the AI ​​system of the CMP process equipment of the present invention performs recognition on an image. [Figure 25] 1A and 1B are explanatory views of an operation for dressing a polishing pad of a conventional dresser for a CMP process. [Figure 26] FIG. 1 is a graph showing the relationship between the material removal rate and the temperature when dressing the polishing pad of a dresser for a CMP process. [Figure 27] FIG. 1 is a diagram showing the relationship between stress and strain when dressing a polishing pad of a dresser for a CMP process. DETAILED DESCRIPTION OF THE INVENTION

[0019] The following will further explain the technical means adopted by the present invention to achieve the specified inventive objectives, in combination with the drawings and preferred embodiments of the present invention.

[0020] The present invention aims to provide a dresser for a CMP process, as well as a method and process for generating and monitoring voids in a polishing pad.

[0021] The present invention designs and manufactures a single crystal / polycrystalline diamond particle or a hard material module having a Vickers hardness of more than 1000 kgf / mm 2 on a dresser to fulfill the following functions of the dresser:

[0022] First, the highest point of the module on the dresser is convenient for piercing the polishing pad and allows for cutting polishing pad grooves at a common area and surface.

[0023] Here, a specific description of the common height or common surface of the cones in the CMP process can be given separately for the polishing pad and the dresser. 1. Common Height and Common Surface of the Polishing Pad: The raised protrusion of the polishing pad after the polishing pad has been dressed by the dresser is shown in Figure 25. When dressing the polishing pad 400 using the cone apex 310 on the dresser, the cone apex 310 on the dresser first approaches the polishing pad 400 from the far end. Following the downward pressure stroke W and the rotation of the polishing pad 400, the dresser begins to pierce the polishing pad 400 in the direction S by the movement of the swing arm. The outward shape of the cone apex 310 gradually deforms the polishing pad 400 downward along its path under the action of elastic and plastic stress. Due to the interaction between the plastic flow of the polishing pad 400 and the shape of the cone apex 310, the protrusion 401 generates a height (PLOW UP). This height and shape are completely affected by the shape of the cone apex 310, the rotation speed of the polishing pad applying the downward pressure, the movement of the swing arm (including the rotation speed of the dresser), and the physical properties of the polishing pad 400. When multiple pyramidal apexes 310 of the same height are engraved on the polishing pad 400 by the above-described motion, regionalized common-height or common-surface protrusions 401 are generated. As shown in FIG. 8 , the pyramidal apexes 310 generate protrusions 3101, 3111, and 3301 (textural pattern) and pyramidal surface portions 3102, 3112, and 3302 (surface morphology) during the engraving process. The protrusion 3101 shown in FIG. 9 is a variation of the protrusion 3101 in FIG. 8 . Strictly speaking, wafer grinding involves a fairly large area of ​​12 inches (300 mm range), and CMP equipment utilizes the large-area layout of the polishing pad 400 to grind wafers. When the diameter of the polishing pad 400 exceeds 700 mm, the wear rate varies with the radius of the circle, affecting the flatness results of the entire wafer. Therefore, to achieve high-precision wafer flatness, the common-height or common-surface protrusions 401 of the polishing pad 400 must be regionally corrected. The wafer can be ground by the minute gaps between the protrusions 401 and the abrasives in the polishing liquid.

[0024] 2. Common Height and Surface of the Dresser: The dresser described in this invention is formed by post-processing a high-hardness material, rather than hard solder. Examples include ultrafast laser processing, electron beam processing, plasma processing, and electrical discharge machining. For example, ultrafast laser processing (1064 nm, 1030 nm, <532 nm, etc.; the shorter the wavelength, the higher the processing accuracy; the scanning frequency is nanoseconds < picoseconds < femtoseconds; the higher the frequency, the lower the stored energy and the smaller the change in the physical properties of the material) is used to perform shape removal processing on single-crystal diamond, polycrystalline diamond, or materials with a Mohs hardness of 9.5 or higher. Ultrafast lasers can be used in combination with a galvanometer and workpiece to change the position of the workpiece on a 4- or 5-axis machining center, changing the processing path and allowing for instant processing of high-hardness materials in any shape and area. This is due to the benefits of a high-precision optical system (such as a high numerical aperture of the optical lens group). For example, the diamonds in the outer circle of the dresser are higher than the diamonds in the second and third inner circles. Each group in each region must have a common height (common height range: 3-10 μm). This allows the protrusions 401 on the polishing pad 400 to be machined and form a common surface with the same shape. Precision machining of 3D or larger shapes is also easily achieved. For example, the difference in common height between the diamonds in the first region and the diamonds in the second region is 5-20 μm, which is not constant and depends on the wafer flatness requirements. The results of the regionalized common surface of the polishing pad 400 are further monitored. If a 12-inch wafer is divided into eight regions by radius, the corresponding polishing pad 400 must have at least eight regions covering the wafer area. Area 8 and Area 7 are monitored for flatness, and the dresser must form a common surface between Area 8 and Area 7. That is, the diamond height in each area of ​​the diamond dresser is dressed (real-time laser correction) according to the flatness of the polishing pad 400, and a common surface is formed between the protrusions 401 in Area 8 and Area 7 of the polishing pad 400.

[0025] 3. Based on the above description, the common height and common surface of the regions can be set during the initial use of the dresser. After dressing the polishing pad 400 and grinding the wafer, flatness monitoring statistics are obtained and the laser real-time processing data of the common height and common surface of the regions of the diamond dresser is estimated. After laser real-time dressing of the diamond dresser, a wafer planarization target is formed. Therefore, the height of each region after laser real-time dressing of the diamond dresser is not necessarily the same as the original height; Area 7 may be lower than Area 8 and Area 6.

[0026] The second is the cutting edge, which removes glazing or dirt from the polishing pad 400 .

[0027] The third is to regenerate more fluff to make the surface roughness of the polishing pad 400 uniform.

[0028] Fourth, the lateral shape of the grooves in the polishing pad 400 is designed to facilitate retention of polishing fluid.

[0029] 1 to 3. FIG. 1 is a partial external view of an embodiment of a dresser 10 of the present invention. FIG. 2 is an external view of an embodiment of the arrangement of the upper modular cone of the dresser 10 of the present invention. FIG. 3 is a partially enlarged external view of an embodiment of the arrangement of the apex of the upper modular cone of the dresser 10 of the present invention. In some embodiments, the dresser 10 (or diamond disk) of the present invention is divided into multiple parts. The first part is a substrate 20 (a metal body, typically a corrosion-resistant stainless steel metal, e.g., 316 or 304) that can be fixed to the swing arm of a CMP device. The second part is a metal body on which multiple sheet-like bodies 30 are provided, protruding toward the polishing pad. The sheet-like bodies 30 may be partially coated with an acid- and alkali-resistant material, such as a diamond-like film or resin. The third part is a combination of the sheet-like bodies 30 and the metal body. The fourth part is a single-crystal / polycrystalline diamond or a diamond having a Vickers hardness of 1000 kgf / mm on the sheet-like body 30. 2 and the sheet-like body 30 is a sheet-like body (i.e., a single unit) having a Vickers hardness of 1000 kgf / mm or more. 2 The height, shape and mutual spacing of the modularized high hardness cones having a matrix formed by more than 1000 sheets or a single sheet are not limited here.

[0030] The sheets 30 are arranged in a circular pattern on the substrate 20 at intervals, each sheet 30 is provided with a modularized grinding unit 40, and each modularized grinding unit 40 is provided with a plurality of individual units 41, each individual unit 41 is provided with a protrusion 411, and each of the protrusions 411 may be a pyramid. These pyramids may be arranged radially and linearly at intervals on the sheet 30 as shown in Figures 1 and 2, or may be arranged in a matrix as shown in Figure 3, but are not limited to the above arrangements and may also be arranged randomly on the sheet 30.

[0031] Furthermore, the cone of the dresser 10 of the present invention is made of diamond, silicon dioxide, boron carbide, or the like, which has a Vickers hardness of 1000 kgf / mm 2 The cone of the dresser 10 is provided facing away from the substrate 20, but the shape is not limited to a pointed cone, and may be a point-like, planar, or linear end portion.

[0032] In the above embodiment, the substrate 20 of the dresser 10 of the present invention may be covered with resin by vapor deposition, sputtering, a diamond-like film, a colloidal spray, etc., to prevent the polishing liquid from oxidizing or corroding the metal object and adversely affecting wafer polishing. Furthermore, in the above embodiment, the multiple sheet-like bodies 30 on the dresser 10 of the present invention may be covered with resin by vapor deposition, sputtering, a diamond-like film, a colloidal spray, etc., to prevent the polishing liquid from oxidizing or corroding the metal object and adversely affecting wafer polishing.

[0033] In the above embodiment, the single crystal / polycrystalline diamond on the sheet 30 or the Vickers hardness is 1000 kgf / mm 2 The sheet-like body (i.e., the single unit 41) has a variety of matrix and modular cone height configurations and mutual spacings. Here, the single crystal / polycrystalline diamond sheet or the Vickers hardness of 1000 kgf / mm 2 The sheet-like body (i.e., the single unit, 41) having a Vickers hardness of 1000 kgf / mm is formed by a femtosecond laser (point or line laser) into a single crystal / polycrystalline diamond or 2 The sheet-like body is carved into modular shapes (geometric configurations) and heights exceeding 100cm.

[0034] In the above embodiment, the femtosecond laser (point or linear laser) is configured such that the linear laser beam is 0th order, ±1st order, ±2nd order, ±3rd order, etc., and a plurality of point light sources having the same energy are arranged in a linear light source or a matrix point light source via a diffraction element, and the Vickers hardness is 1000 kgf / mm or monocrystalline / polycrystalline diamond. 2 The method engraves shapes and heights in all directions on a sheet-like body exceeding 100 mm, and as shown in Fig. 4, by setting appropriate laser trajectories "1" and "2" using computer graphics, a main cone (i.e., convex portion 411) and a secondary cone (i.e., secondary convex portion 412) "3" can be created. Fig. 5 shows an explanatory top view of the cone-shaped body of the dresser 10 after laser processing, Fig. 6 is a side cross-sectional view of the cone-shaped body of the dresser 10 taken along the AA cutting line in Fig. 5, and Fig. 7 is an enlarged side cross-sectional view of a portion of one of the cones (right side) of the dresser 10.

[0035] Figures 8 and 9 are cross-sectional views of a cone-shaped surface machined using a multi-function femtosecond laser. The cone cutting edge 320 forms an angle with the surface 330, which is at least 1 degree. Figure 10 also shows the appearance of another cone after machining using a multi-function femtosecond laser. In Figures 8 and 9, 3101 / 3111, etc., are the cone-shaped side surfaces of the cone apex 310. The grooved side surface of the polishing pad can accommodate more polishing fluid and continuously compress and expand during the grinding process, forcing the polishing fluid from the gap between the wafer and the polishing pad. Therefore, the side surface of the diamond cone serves as the second element of the diamond dresser, retaining the polishing fluid on the polishing pad. In the cross-sectional view of Figure 9, H1 is one of the highest points of the common height of the dresser area, H3 is the lowest point of the sheet 30, and H2 / H4 are the heights of the protrusions on the sheet 30, which retain more polishing fluid due to their shape and surface tension.

[0036] In the above embodiment, the monocrystalline / polycrystalline diamond on the sheet 30 has various diamond particle heights, shapes, and spacings. The monocrystalline / polycrystalline diamond sheet is carved by applying diamond powder to the filament, with a 111 lattice, to create the shape and height of the monocrystalline / polycrystalline diamond (100 lattice). Because the 111 lattice is harder than the 100 lattice, the diamond material is removed. The filament coated with the 111 lattice diamond abrasive drives a new filament through a wheel-like structure to polish the 100 monocrystalline shape.

[0037] In the above embodiment, the single crystal / polycrystalline diamond or the Vickers hardness of the sheet-like body 30 is 1000 kgf / mm 2 The sheet-like body has various cone side shapes and mutual intervals. 2 Sheets with a Vickers hardness of 1000 kgf / mm or more can be formed by a femtosecond laser (point or line laser). 2 Engraving of shapes and heights of sheet-like objects exceeding this limit is performed.

[0038] In the above embodiment, the single crystal diamond on the sheet 30 has various diamond particle side shapes and spacing, and the single crystal diamond sheet is engraved with a single diamond shape and height using diamond powder (single or multi-wire) on the filament.

[0039] In the above embodiment, the Vickers hardness of the sheet 30 is 1000 kgf / mm 2 The sheet-like body can have, but is not limited to, various cone heights, various cone side shapes, and mutual spacing, and the required structure can be formed by 3D additive manufacturing.

[0040] In the above embodiment, the single crystal / polycrystalline diamond or the Vickers hardness of the sheet-like body 30 is 1000 kgf / mm 2The sheet-like bodies exceeding 310 are arranged at a certain ratio and set in a symmetrical pattern. Therefore, on both sides of the scribing direction of the higher cone tip, multiples of higher cone apexes 310 are required so that the lower cone cutting edges 320 can press against the polishing pad. One embodiment is an arrangement of 2x, 3x, 4x, ... < 20x. As shown in Figure 11, the cone apexes 310 and cone cutting edges 320 on the sheet-like body 30 form a gradient height that makes it easy to pierce the polishing pad, i.e., the gradient gradually increases toward the outside.

[0041] In the above embodiment, the single crystal / polycrystalline diamond or the Vickers hardness of the sheet-like body 30 is 1000 kgf / mm 2 The sheet-like material exceeding this is set in a linearly sloped pattern at a certain rate. When the dresser 10 is pressed against the polishing pad 50, the center protrudes, forming a gradient height as shown in FIG. 12. Because the depth of the protrusion of the polishing pad 50 is constant after the dresser 10 is pressed, the dresser 10 is designed to have a cone height such that the outer cone height is higher than the central cone height inside the dresser 10.

[0042] The sheet-like body 30 is made of diamond / polycrystalline diamond or has a Vickers hardness of 1000 kgf / mm 2 The sheet-like body having a Vickers hardness of 1000 kgf / mm or more is as described above, and the present invention is also applicable to a single crystal diamond / polycrystalline diamond or a sheet-like body having a Vickers hardness of 1000 kgf / mm or more in different functional regions by planning a laser path using a computer program. 2 The apex of the sheet-like body exceeding 1000 kgf / mm can be formed into the shape and height of a cone on each surface of the sheet-like body 30 under the movement of the multi-axial movement device. Also, as shown in FIG. 13, single crystal diamond / polycrystalline diamond or a diamond having a Vickers hardness of 1000 kgf / mm 2 A sheet-like body of more than 100 mm can be fixed on the substrate 20. In Fig. 14, the sheet-like body 30 has a partially expanded cone shape. In Figs. 15 and 16, the sheet-like body 30 has a partially expanded cone shape.

[0043] In a specific embodiment, the single crystal diamond / polycrystalline diamond on the sheet-like body 30 or the diamond having a Vickers hardness of 1000 kgf / mm 2 After more than 100 sheet-like objects are combined into a dresser or alone in a single system device, the height and x, y position information of the cone are detected by an optical imaging device, and the height is instantly corrected by a laser beam, thereby completing a dresser 10 having a common height and a common surface.

[0044] Therefore, the protrusions 3101 / 3111 (new groove side shapes) created by the present invention allow the polishing pad 50 to hold more polishing liquid and continuously deliver the polishing liquid from the gap between the wafer and the polishing pad 50 during the grinding process. Therefore, the side shape of the cone of the dresser 10 allows the polishing liquid to be retained in the polishing pad 50. As shown in FIG. 17, the convex portion 411 (cone) can carve, scrape, and form fluff in the polishing pad 50. As shown in FIG. 18, the minor convex portion 412 (minor cone) forms a hole in the side of the groove in the polishing pad 50. Furthermore, as shown in FIGS. 18 and 19, the side edges of the minor cone form a side gap in the groove in the polishing pad 50.

[0045] Due to the above technical features, the dresser 10 of the present invention can retain more polishing liquid after grinding the polishing pad 50, forming circulatory cooling and suppressing thermal expansion of the polishing pad 50, ensuring a smooth polishing result for the wafer. As can be seen from the relationship between temperature and material removal rate shown in FIG. 26, the present invention uses a three-dimensional or more dimensional operating mode in which the dresser 10 and the polishing pad 50 interact linearly and rotationally, allowing the dresser 10 to form side grooves with a three-dimensional or more dimensional structure on the polishing pad 50, allowing the dresser 10 to retain more polishing liquid and achieving a more stable overall material removal rate (MRR) than the existing dresser X.

[0046] When using the present invention, the cone apex 310 of the dresser 10 must be inserted into the polishing pad 50. At this time, the larger the contact area in the downward pressure direction, the greater the amount of deformation, but tearing is unlikely to occur. Therefore, the protrusion 3101 must first be torn, so that the polishing pad 50 can be smoothly torn in the downward pressure direction. As shown in Figure 20, due to the relative movement of the polishing pad 50 and the dresser 10, the raised burrs (in the direction of the arrow) on the polishing pad are aligned to the height of the cone cutting edge 320, and after the polishing pad burrs are pressed and removed, more fluff is formed.

[0047] Therefore, the protrusions 3101 / 3111 on the corner faces of the diamond cone protrude sharply, which is advantageous for precisely piercing the polishing pad 50 downward and horizontally. In addition, it becomes possible to reduce the angle design of the dresser 10, and the angle of the cone can be made sharper, which further increases the number of cones that can be arranged per unit area.

[0048] Importantly, this invention enables timely detection of the surface texture and flatness of the polishing pad 50 and the wear of the dresser 10 cone tip, thereby directly visualizing the CMP process. As shown in Figures 21, 22, and 23, the CMP equipment is equipped with an optical lens module 60 (i.e., an optical imaging device) for observation from above (to observe the wear state of the dresser cone) and below (to observe the 3D texture of the polishing pad surface). The optical lens module 60 uses a metalens 61 to observe the microstructure and monitor the 3D surface texture through optical shear interference. It also works in conjunction with an AI system (Weka / Deeplearnin4j / Saliency Map Viewer) to observe key regions of interest for the trained model in the input image, known as "model vision." The model determines the category of the input image based on these regions of interest and identifies objects such as the polishing pad and polishing fluid based on the object's refractive index, reflected light intensity, and scattering data. Then, an ultrafast laser is used to perform real-time regional shape correction of the dresser, achieving high-flatness wafer polishing. As shown in Figures 22 and 23, the optical lens module 60 is composed of one or more metalenses 61, and laser light is optically focused onto a shear-wave optical diffraction element. A CCD / CMOS sensor and diffraction element detect the shear-wave interference results at a certain distance and use them to reconstruct a 3D image. In this way, the surface geometry (flatness), groove depth, and uniformity of the polishing pad can be observed, and the common height of the dresser area of ​​the CMP equipment and the polishing pad's motion parameters and statistics can be adjusted. The optical lens module 60 is detected on a narrow line, its total thickness is less than 50 mm, and it can be embedded at any position in the equipment.

[0049] The first embodiment will be described below. First, the optical lens module 60 is used to identify the polishing pad 50, and a standard environment, such as reflectance, light intensity, and scattering, is established (at this time, the dresser 10 polishes the polishing pad 50 without providing a polishing liquid for the first time). This is recorded and saved as Reference 1. After entering an environment where a polishing liquid is provided, the optical lens module 60 is used to observe again (at this time, wafer grinding is not provided), and this is recorded and saved as Reference 2. After using References 1 and 2 to distinguish between an unpolished polishing pad 50 and a polished polishing pad 50 and establish basic data, the AI ​​system begins training and learning to identify the characteristics of the polishing pad 50 surface and the polishing liquid. This is the first stage of learning.

[0050] In the second stage, additional wafers 70 are ground. The periodic reciprocating detection positions are determined based on the data from the first stage. For example, before dressing the polishing pad 50, the 3, 6, 9, and 12 o'clock positions are selected, and images are captured and measured through comparative learning. Continuous learning by the AI ​​system enables the determination of the unevenness of fine features. As shown in Figure 24, the left image shows the actual state (original input image) of the holes (uneven areas) on the polishing pad. After learning, the AI ​​system recognizes the features as bright, dotted areas (as shown in the center image, this indicates the key area of ​​interest for the model, i.e., the salient image). Furthermore, overlaying the left and center images produces the overlay result shown in the right image, allowing for judgments to be made based on this image. This is useful for comparing the visual differences between the areas recognized by the human eye and the model, allowing for timely adjustment of polishing parameters for re-polishing the uneven areas. Furthermore, the software interface (deep learning UI interface) of the AI ​​system is used to train, validate, and adjust parameters for the model through the captured images. For example, some of the diagrams are used for training and learning of the AI ​​system, and the remaining diagrams are used for verifying the AI ​​system. Preferably, 60-70% of the diagrams are used for training and learning, and 30-40% of the diagrams are used for verification.

[0051] The optical lens module 60 can be preferably mounted on the rocker arm 11 of the dresser 10. Alternatively, it can be preferably observed from below through an opening (not shown) in the substrate 20 of the dresser 10. As shown in Figures 21, 22, and 23, the optical lens module 60 is composed of one or more metalenses 61, which optically focus laser light onto a shear light diffraction element. A CCD / CMOS sensor and a diffraction element detect the shear interference results at a certain distance and perform 3D image reconstruction based on the shear interference results. In this way, the groove depth and surface roughness of the polishing pad can be observed and the motion parameters of the dresser 10 and polishing pad 50 in the CMP apparatus can be adjusted. Figure 21 illustrates online detection of the optical lens module 60 in a narrow space. The overall thickness is less than 50 mm, allowing it to be installed at any position in the apparatus. The optical lens module 60 can also be equipped with a self-cleaning system, such as air, liquid, or ultrasonic, and software can determine whether the lens is dirty and trigger a self-cleaning operation.

[0052] In the present invention, the cone is not limited to a continuous surface of a geometric shape, but may also be a discontinuous surface. The cone is integrated with the sheet 30, and the sheet can be removed by a subtractive process such as a laser, or the cone shape can be grown on the sheet 30 by an additive method. The tip, cutting edge, or corresponding part (point, line, surface) of the cone is not limited. Furthermore, the substrate 20 refers to the metal body of the dresser 10, one end of which is connected and fixed to the device, and the other end of which is the sheet 30 and the cone on the sheet. [Explanation of symbols]

[0053] 10. Dresser 100 grids 11 Rocker arm 20 Substrate 30 Sheet-like body 310 Pyramid Apex 3101 Protrusion 3111 Protrusion 3102 Pyramidal surface 320 conical cutting edge 330 pages 40 Modular Grinding Unit 400 Polishing Pads 401 Protrusion 41 Single Unit 411 Convex 412 Sub-convex part 50 polishing pads 60 Optical Lens Module 61 Metalens 70 wafers

Claims

1. A substrate; At least one sheet-like body disposed on one surface of the substrate; a modular polishing unit disposed on the at least one sheet; Equipped with The modular polishing unit is provided with a plurality of individual units, the plurality of individual units being arranged at intervals on the at least one sheet-like body, and each of the individual units has a convex portion, and the convex portions of the individual units have different heights.

2. 2. The dresser for a CMP process according to claim 1, wherein height and position information of the convex portion of each single unit is detected through an optical imaging device, and height adjustment is performed to complete the regionalized common height and common surface of the dresser, and the range of the common height is set to 3 to 10 μm.

3. 3. The dresser for a CMP process according to claim 2, wherein at least one sub-protrusion is formed around the protrusion of each of the single units, and the height of the at least one sub-protrusion is lower than the height of the protrusion.

4. Each of the single units is made of a single crystal diamond, a polycrystalline diamond, or a diamond having a Vickers hardness of 1000 kgf / mm ２ 4. The dresser for a CMP process according to claim 3, wherein the dresser is a cone-shaped body made of a material exceeding 100%.

5. 5. The dresser for a CMP process according to claim 4, wherein the plurality of single units are arranged on the at least one sheet-like body at intervals in a linear pattern, a radial pattern, or a matrix pattern.

6. 6. The dresser for a CMP process according to claim 5, wherein each of the protrusions and each of the at least one sub-protrusion are formed on the single unit by a laser.

7. 6. The dresser for a CMP process according to claim 5, wherein each of the convex portions and each of the at least one sub-convex portion are formed by stacking on the single unit.

8. 2. The dresser for a CMP process according to claim 1, wherein the modular polishing unit has an array of convex portions whose heights gradually decrease from both sides toward the center.

9. 2. The dresser for a CMP process according to claim 1, wherein the modular polishing unit has an array of convex portions whose heights gradually decrease from the center to both sides.

10. a body provided with a working end and a working platform; a dresser according to any one of claims 2 to 9, provided at a processing end of the main body and configured to direct each of the single units on the at least one sheet-like body toward the processing platform; a polishing pad provided on a processing platform of the main body and performing polishing via the dresser; A CMP process apparatus comprising:

11. Providing a CMP process apparatus according to claim 10; driving the dresser to move and rotate toward the polishing pad with a working end of the body; a polishing pad groove having a common height and a common surface on the polishing pad by a protrusion of each of the single units of the dresser, and a lateral shape of the polishing pad groove on the polishing pad by a sub-protrusion of each of the single units; 1. A CMP process comprising:

12. Providing a CMP process apparatus according to claim 10; installing a lens module in the CMP process tool, the lens module using a metalens to observe microscopic features and monitor 3D surface texturing and flatness by optical shear interference; Integrating an AI system to identify the polishing pad, polishing liquid, and wafer by refractive index, reflected light intensity, and scattering data; training the AI ​​system to determine microscopic features and monitor the porosity of the polishing pad; 1. A method for monitoring voids in a polishing pad of a CMP process, comprising:

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