Diamond trimmer

Abstract

The diamond dresser comprises a ceramic substrate and a base body, tower bodies are arranged on the upper surface of the ceramic substrate in an array mode, and a diamond film protection layer is attached to the upper surface of the ceramic substrate; the ceramic substrate is arranged on the base body, and a brush is further arranged on the base body. According to the diamond dresser, the brush is arranged on the base body, scraps on the polishing pad are cleaned through the brush when the polishing pad is dressed, and the scrap cleaning capacity of the diamond dresser is enhanced.

Description

Technical Field

[0001] The present application relates to the technical field of chemical mechanical polishing, and in particular to a diamond dresser. Background Art

[0002] In the manufacturing process of semiconductor wafers, chemical mechanical polishing (CMP) is an essential process. The flatter the CMP surface, the thinner the line width that can be manufactured. With the advent of the era of feature line widths below 10 nanometers, the CMP process requires higher stability and yield. This requires that in addition to the high quality of the manufacturing equipment itself, the three major consumables of the CMP process, namely, slurry, pad, and diamond dresser, must also continuously improve their quality stability to meet the ever-increasing quality requirements.

[0003] The wafer CMP process uses a polishing pad and a polishing liquid (containing abrasive particles) to polish the wafer. The surface of the polishing pad needs to have a certain degree of roughness to facilitate the formation and flow of the polishing liquid flow layer. In addition, the protruding burrs contained in the surface roughness to a certain extent enable the wafer polishing to obtain a certain degree of surface material removal rate. However, foreign matter in the polishing process (abrasive particles in the polishing liquid, particles on the wafer surface, and broken polishing pad burr debris) will gradually fill the surface of the polishing pad, making its surface smooth and reducing the wafer surface material removal rate. Therefore, a dresser needs to be used to dress the polishing pad during the polishing process to remove foreign matter in the holes, but the existing dressers have poor cleaning effects. Utility Model Content

[0004] The present application provides a diamond dresser, which can solve the problem of poor foreign matter cleaning effect of the dresser in the related art.

[0005] The embodiment of the present application provides a diamond dresser, which includes: a ceramic substrate and a base body, wherein tower bodies are arranged in an array on the upper surface of the ceramic substrate, and a diamond film protective layer is attached to the upper surface of the ceramic substrate; the ceramic substrate is arranged on the base body, and a brush is also arranged on the base body.

[0006] In some embodiments, a plurality of ceramic substrates are disposed on the base, the plurality of ceramic substrates are equidistantly distributed around the center of the base, and the brush is located in the middle of the base.

[0007] In some embodiments, the ceramic substrate is cylindrical.

[0008] In some embodiments, a plurality of groups of ceramic substrates are disposed on the substrate, each group of ceramic substrates includes a plurality of ceramic substrates equidistantly distributed around the center of the substrate, and in the plurality of groups of ceramic substrates, the distance between each group of ceramic substrates and the center of the substrate is different, and the brush is located in the middle of the substrate.

[0009] In some embodiments, the ceramic substrate is in a fan-shaped ring shape.

[0010] In some embodiments, the tower body includes a flat tower and a pointed tower, the top of the flat tower is a plane, and the top of the pointed tower has a sharp corner.

[0011] In some embodiments, there is a height difference between the top of the flat tower and the top of the pointed tower.

[0012] In some embodiments, the tower body further includes a broken tower, and the broken tower is located at an edge of the upper surface of the ceramic substrate.

[0013] In some embodiments, the diamond film protective layer includes diamond particles, the diamond particles have a particle size of 1 to 5 microns, and the diamond film protective layer has a thickness of 2 to 20 microns.

[0014] In some embodiments, a boss is disposed on the ceramic substrate, and the tower body is disposed on the boss.

[0015] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0016] The embodiment of the present application provides a diamond dresser, wherein a brush is arranged on a base body, and when the polishing pad is dressed, the brush is used to clean the debris on the polishing pad at the same time, thereby enhancing the ability of the diamond dresser to clean the debris. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 A top view of the tower provided in an embodiment of the present application;

[0019] Figure 2 A cross-sectional view of a ceramic substrate having regularly arranged microstructures provided in an embodiment of the present application;

[0020] Figure 3 A top view of a diamond dresser provided in an embodiment of the present application;

[0021] Figure 4 A top view of a first ceramic substrate provided in an embodiment of the present application;

[0022] Figure 5 A top view of a second ceramic substrate provided in an embodiment of the present application;

[0023] Figure 6A top view of a third ceramic substrate provided in an embodiment of the present application;

[0024] Figure 7 A top view of a first diamond dresser provided in an embodiment of the present application;

[0025] Figure 8 A top view of a second diamond dresser provided in an embodiment of the present application.

[0026] In the figure: 1. ceramic substrate; 2. tower body; 20. spire; 21. flat tower; 22. broken tower; 3. base; 4. brush. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] The embodiment of the present application provides a diamond dresser, which can solve the problem of poor foreign matter cleaning effect of the dresser in the related art.

[0029] See also Figures 1 to 8 The embodiment of the present application provides a diamond dresser, which includes: a ceramic substrate 1 and a base 3, the upper surface of the ceramic substrate 1 is arrayed with tower bodies 2, and the upper surface of the ceramic substrate 1 is attached with a diamond film protective layer; the ceramic substrate 1 is arranged on the base 3, and the base 3 is also provided with a brush 4.

[0030] In the present application, a brush 4 is provided on the base 3, and the debris on the polishing pad is cleaned by the brush 4 while the polishing pad is being dressed, thereby enhancing the ability of the diamond dresser to clean the debris.

[0031] Furthermore, a boss is provided on the ceramic substrate 1, and the tower body 2 is provided on the boss; for some high-end CMP processes, in addition to ensuring no metal contamination, it is also necessary to more efficiently remove the debris on the pad during the CMP operation. Therefore, a brush 4 is provided on the base body 3, and the specific structure is to add a brush 4 in the center of the base body 3, and the height of the brush 4 is consistent with the height from the top of the tower body 2 to the lower surface of the ceramic substrate 1, so that the diamond dresser has an enhanced ability to remove debris on the pad.

[0032] Among them, the ceramic substrate 1 is made of ceramic powder. When the ceramic powder is made into the ceramic substrate 1, silicon carbide is selected as the base material of the ceramic substrate 1. Silicon carbide has the characteristics of high hardness, good heat resistance, good toughness and strong acid and alkali resistance. In addition, since silicon carbide and diamond are in the same main group (C, Si) of the periodic table and have similar thermal expansion coefficients, it can ensure that a chemical bond is formed between the two, the bonding force is strong, and it is not easy to fall off.

[0033] The ceramic substrate 1 is manufactured by a pressing process, and the pressing process is mainly achieved by pressureless sintering, wherein pressureless sintering refers to a method of sintering by heating a product under normal pressure.

[0034] Furthermore, the ceramic powder is a mixture of one or more of silicon carbide, boron carbide, diamond and phenolic resin, the purpose of which is to enhance the sintering strength and increase the initial nucleation density of the CVD coating. When the ceramic powder is a mixture of silicon carbide, boron carbide, diamond and phenolic resin, the ceramic powder includes 90-95% silicon carbide, 0.5-2% boron carbide, 0.1-0.5% diamond powder and 3-5% phenolic resin by weight percentage.

[0035] Preferably, in an embodiment of the present application, the tower body 2 is formed by laser engraving on the upper surface of the ceramic substrate 1. After laser engraving, the upper surface of the ceramic substrate 1 forms a group of regularly arranged pyramids with a diamond shape, that is, the tower body 2, and the tower body 2 is a hexagonal pyramid.

[0036] In this application, the laser power and engraving depth can be adjusted to ensure that the size of the processed tower body 2 is within the tolerance range of the micron level. By changing the parameters such as the size and height difference of the tower body 2, the characteristics of the dresser in the CMP process can be adjusted, especially affecting the removal rate (PCR) and the surface roughness (Ra) of the polishing pad.

[0037] The tower body 2 includes a flat tower 21 and a spire 20. For more details, see Figure 1 and Figure 2 As shown, the top of the flat tower 21 is a plane, and the top of the spire 20 has a sharp angle. And the entire tower body 2 includes 3 / 4 of the flat tower 21 and 1 / 4 of the spire 20.

[0038] In some embodiments, when the morphology of the tower body 2 after laser engraving is changed, the height of the tower body 2 in this embodiment is reduced by half compared to the above tower body 2, which can significantly reduce the removal rate (PCR) of the diamond dresser in the CMP process, and the roughness Ra of the polishing pad in the CMP process is also reduced;

[0039] In some embodiments, Figure 5As shown, compared with the tower body 2 described above, the height of the tower body 2 remains unchanged, so that the distance between two adjacent tower bodies 2 is enlarged to reduce the surface density, which can slightly increase the PCR of the dresser in the CMP process;

[0040] In some embodiments, Figure 6 As shown, the morphology of the tower body 2 after laser engraving is changed, and the distance between two adjacent tower bodies 2 is enlarged. The tower body 2 also includes a broken tower 22, and the broken tower 22 is located at the edge of the upper surface of the ceramic substrate 1, that is, a circle of broken towers 22 is designed at the edge of the ceramic substrate 1, which is analogous to the crushing material diamond used in ordinary dressers, and can significantly improve the PCR of the dresser in the CMP process.

[0041] The above embodiments are merely multiple possible implementations of the embodiments of the present application, and the embodiments of the present application are not limited thereto.

[0042] Preferably, in the embodiment of the present application, the diamond film protective layer deposited on the upper surface of the ceramic substrate 1 is a micron diamond film protective layer, the diamond film protective layer includes diamond particles, the diamond particle size is 1 to 5 microns, and the diamond film protective layer thickness is 2 to 20 microns. The micron-level diamond film coating is prepared by microwave plasma chemical vapor deposition (MPCVD). The preparation process is: first, the ceramic substrate 1 is ultrasonically cleaned with acetone alcohol, then ultrasonically nucleated in a diamond micropowder suspension, and the substrate is dried using a low-pressure, pure nitrogen flow, and then the ceramic substrate 1 is placed in an MPCVD (Microwave Plasma Chemical Vapor Deposition) cavity, and finally in a vacuum cavity with a high vacuum degree, a high-purity mixed gas of 5N-level methane and hydrogen is introduced, and the microwave energy transmitted to the reaction cavity by waveguide and antenna is used to excite the gas in the cavity so that it is ionized into plasma, and various neutral carbon-containing precursor active groups capable of depositing diamond film are generated, and the substrate is heated at the same time, and finally a diamond film is deposited on the ceramic substrate 1.

[0043] Due to the co-growth of multiple cores, the crystal surface formed is a diamond polycrystalline film, which is more wear-resistant than a single crystal film, and the size of polycrystalline diamond particles is micron-level, which improves the chip cutting ability. After coating, the pyramid structure carved out of the silicon carbide surface is still maintained, so the surface chemical properties of this dresser are stable and the wear resistance is improved. At the same time, the performance is always stable, ensuring that the dresser maintains high stability and life in the CMP (Chemical Mechanical Polishing) process.

[0044] Since silicon carbide contains diamond powder, it is easier to nucleate during the CVD (Chemical Vapor Deposition) coating process, which speeds up the deposition rate of polycrystalline diamond films and ensures uniform coverage.

[0045] The existing technology mainly uses hot-filament CVD, which has a simple device and low price. However, the performance of the filament will decay during the deposition process, resulting in unstable performance, and the quality of the diamond film is lower than that of other CVD methods. The filament uses tantalum wire, tungsten wire, etc., and a small amount of metal will be doped in the diamond film. The present invention uses microwave CVD, with stable deposition parameters and high-quality diamond films. It is characterized by non-polar discharge, no direct contact with the cavity, and no gas pollution and electrode pollution. For CMP high-end processes, the advantage of this method is that the prepared diamond film is of better quality and has stable and uniform parameters, which can better ensure that there is no metallization.

[0046] In the process of making the diamond dresser, it is also necessary to perform etching on the lower surface of the ceramic substrate 1. Etching the back side of the ceramic substrate 1, i.e., the lower surface, can increase the surface roughness and surface area, increase the contact area between the ceramic substrate 1 and the adhesive, and enhance the bonding strength between the ceramic substrate 1 and the stainless steel substrate 3.

[0047] Preferably, in the embodiment of the present application, the substrate 3 is made of stainless steel, and the stainless steel substrate 3 is passivated to prevent metal corrosion or rusting.

[0048] In this embodiment, the substrate 3 is a circular 304 stainless steel with a diameter of 108 mm and a thickness of 6 mm, and a hole is punched on the back side to be attached to the carrier arm of the CMP polisher.

[0049] In some possible embodiments, Figure 3 As shown, the ceramic substrate 1 is cylindrical and is mounted on a stainless steel base 3; the base 3 is divided into five equal parts with the center as the origin, and a plurality of ceramic substrates 1 are mounted on the base 3, at which time the ceramic substrates 1 are spaced equidistantly at 72°.

[0050] In some other possible embodiments, Figure 8As shown, the ceramic substrate 1 is a fan-shaped ring structure, and a plurality of groups of ceramic substrates 1 are arranged on the base 3, each group of ceramic substrates 1 includes a plurality of ceramic substrates 1 equally spaced around the center of the base 3, and the distance between each group of ceramic substrates 1 and the center of the base 3 is different. That is to say, a plurality of fan-shaped ring-shaped ceramic substrates 1 are assembled in a ring shape around the center of the stainless steel base 3, and the ceramic substrate 1 can be one layer or more layers, presenting a "Bagua" structure. Under the condition that the quality of the ceramic substrate 1 is certain, compared with the cylindrical ceramic substrate 1, the fan-shaped ring-shaped ceramic substrate 1 has a larger surface area, a stronger bonding strength with the stainless steel base 3, and a larger contact area with the grinding pad, which can speed up the grinding efficiency; on the other hand, the fan-shaped ring-shaped ceramic substrate 1 is thinner, and the total thickness of the manufactured diamond dresser is closer to the thickness of the traditional dresser, which is convenient for the replacement and use of CMP equipment.

[0051] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0052] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0053] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A diamond dresser, characterized in that: It includes: A ceramic substrate (1), wherein tower bodies (2) are arranged in an array on the upper surface of the ceramic substrate (1), and a diamond film protective layer is attached to the upper surface of the ceramic substrate (1); A base (3), the ceramic substrate (1) being arranged on the base (3), and a brush (4) being also arranged on the base (3); The tower body (2) comprises a flat tower (21) and a spire (20); the top of the flat tower (21) is a plane, and the top of the spire (20) has a sharp corner.

2. The diamond dresser according to claim 1, characterized in that: A plurality of ceramic substrates (1) are arranged on the base (3), the plurality of ceramic substrates (1) are distributed at equal distances around the center of the base (3), and the brush (4) is located in the middle of the base (3).

3. The diamond dresser according to claim 2, characterized in that: The ceramic substrate (1) is cylindrical.

4. The diamond dresser according to claim 1, characterized in that: A plurality of groups of ceramic substrates (1) are arranged on the base (3), each group of ceramic substrates (1) comprising a plurality of ceramic substrates (1) equidistantly distributed around the center of the base (3), and in the plurality of groups of ceramic substrates (1), the distance between the ceramic substrates (1) in each group and the center of the base (3) is different, and the brush (4) is located in the middle of the base (3).

5. The diamond dresser according to claim 4, characterized in that: The ceramic substrate (1) is in the shape of a sector ring.

6. The diamond dresser according to claim 1, characterized in that: There is a height difference between the top of the flat tower (21) and the top of the steeple (20).

7. The diamond dresser according to claim 1, characterized in that: The tower body (2) further comprises a breaking tower (22), wherein the breaking tower (22) is located at the edge of the upper surface of the ceramic substrate (1).

8. The diamond dresser according to claim 1, characterized in that: The diamond film protective layer comprises diamond particles, the diamond particles have a particle size of 1 to 5 microns, and the diamond film protective layer has a thickness of 2 to 20 microns.

9. The diamond dresser according to claim 1, characterized in that: The ceramic substrate (1) is provided with a boss, and the tower body (2) is arranged on the boss.

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