JP2010221386A - Substrate coating film, manufacturing method of substrate coating film, and cmp pad conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate coating film, a manufacturing method of the substrate coating film, and a CMP pad conditioner for reducing residual stress on an interface between a carbon film and a substrate, preventing the carbon film from generating a large crack or peeling from the substrate, and stably ensuring performance with a simple means. <P>SOLUTION: In the substrate coating film for coating a substrate, fine cracks 7 are formed by blasting on a carbon film 6 formed on a surface of the substrate by a vapor phase synthetic method. The fine crack 7 is formed at the density of 1-10 pieces/mm<SP>2</SP>, and has an average length set in the range of 1-15 μm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a base material coating film used for a tool, a member, or the like that requires mechanical properties such as wear resistance, hardness, and rigidity, a method for manufacturing the base material coating film, and the base material coating film The present invention relates to a CMP pad conditioner using

  In recent years, active research has been conducted on the use of carbon films (base coat films) made of diamond particles and DLC (diamond-like carbon) formed by vapor phase synthesis for electronic devices and tools. That is, by forming the carbon film on a tool, member, or the like, the mechanical properties such as wear resistance, hardness, rigidity, and the like required for the tool, member, etc. are met.

By the way, the carbon film formed so as to cover the base material usually has a relatively large residual stress along the bonding surface direction. This is due to the difference between the lattice constant of the crystals constituting the carbon film and the lattice constant of the crystals constituting the substrate, and the difference in the thermal expansion coefficients of the materials constituting the carbon film and the substrate. If the residual stress is large, for example, when a normal impact is applied to the joint surface with the base material, a relatively large crack is generated in the carbon film, or the carbon film is formed on the base material due to the large crack. There is a possibility that a problem of peeling from the substrate may occur.
In the following Patent Documents 1 and 2, techniques for reducing the residual stress generated in such a carbon film are proposed.
That is, Patent Document 1 proposes a technique in which a surface of a base material before film formation is distorted in advance, and stress generated in a carbon film covering the base material due to the strain is reduced.
Further, in Patent Document 2, the surface of the base material is formed in a convex shape in advance, and when the carbon film formed on the convex base material surface is peeled from the base material, the residual stress is low and the warpage is low. Techniques for obtaining a carbon film that does not easily occur have been proposed.

  On the other hand, with the progress of the semiconductor industry, there is an increasing need for high-precision finishing of metals, semiconductors, ceramics, and other surfaces. In particular, for semiconductor wafers, surface integration on the order of nanometers is required as well as the degree of integration. Has been. In order to cope with such high-precision surface finishing, CMP (Chemical Mechanical Polish) polishing using a porous CMP pad is generally performed on a semiconductor wafer.

  A CMP pad used for polishing a semiconductor wafer or the like is clogged or compressively deformed as the polishing time elapses, and its surface state gradually changes. As a result, undesired phenomena such as a decrease in polishing rate and non-uniform polishing occur. By using a CMP pad conditioner and grinding the surface of the CMP pad, the surface state of the CMP pad is kept constant and good polishing is achieved. The device is maintained to maintain the state.

  Such a CMP pad conditioner has, for example, a disk-shaped substrate (base material) and a plurality of cutting blades formed on the surface of the substrate facing the CMP pad side. These cutting blades are covered with the carbon film made of diamond particles to ensure sharpness and wear resistance.

Japanese Patent No. 3202932 Japanese Patent Laid-Open No. 05-306195

  As described above, in the techniques described in Patent Documents 1 and 2, residual stress generated in the carbon film by preliminarily distorting the base material or forming the base material in a convex shape. However, every time the film formation conditions change, the amount of distortion of the substrate and the convex curvature radius must be changed, which is a problem that the control is very troublesome. It was.

  The present invention has been made in view of such circumstances, and it is possible to reduce residual stress at the interface between the carbon film and the substrate by simple means, and a large crack is generated in the carbon film or peeled off from the substrate. It is an object of the present invention to provide a substrate coating film, a method for producing the substrate coating film, and a CMP pad conditioner that can prevent the occurrence of the problem and stably ensure performance.

In order to solve the above problems, the present invention proposes the following means.
That is, the base material coating film of the present invention is characterized in that a crack is formed by blasting on a carbon film formed on the surface of the base material by a gas phase synthesis method.

  According to the base material coating film of the present invention, when the carbon film is formed on the surface of the base material by the vapor phase synthesis method, residual stress is generated along the bonding surface with the base material on the carbon film. However, after that, the carbon film that covers the base material is subjected to a blasting process, and innumerable micro cracks are formed on the surface, so that the stress along the joint surface between the base material and the carbon film is released. . Therefore, only a small stress remains on the base material coating film after the blast treatment.

The cracks are preferably formed at a density of 1 to 10 pieces / mm ² .
Thereby, a residual stress can be made smaller and desired abrasion resistance and rigidity can be ensured.

Moreover, it is preferable that the average length of the crack is set to 1 to 15 μm.
Thereby, a residual stress can be made smaller and generation | occurrence | production of a big crack can be prevented.

  The manufacturing method of the base material coating film of this invention is a manufacturing method of the base material coating film for manufacturing the base material coating film of any one of Claims 1-3, Comprising: Gas phase A carbon film forming step of forming the carbon film on the surface of the substrate made of ceramics by a synthesis method, and a blasting step of projecting ceramic fine particles onto the carbon film formed on the surface of the substrate. Features.

  The CMP pad conditioner of the present invention is a CMP pad conditioner that performs grinding on a CMP pad disposed opposite to the substrate by using a cutting blade protruding from the surface of the substrate, wherein the claim is placed on the surface of the cutting blade. The substrate coating film according to any one of 1 to 3 is formed.

  According to the CMP pad conditioner of the present invention, since the cutting edge is coated using the above-mentioned base material coating film, the cutting edge is enhanced and the rigidity of the cutting edge is ensured, and the grinding performance for the CMP pad is ensured. Will improve. In addition, since the generation of large cracks and peeling of the substrate coating film is prevented, the tool life is extended, and the CMP pad can be ground stably over a long period of time. The occurrence of scratches can be prevented.

  According to the present invention, the residual stress at the interface between the carbon film and the base material can be reduced by simple means, preventing large cracks in the carbon film or peeling of the carbon film from the base material, resulting in long-term performance. It is ensured stably over time. Moreover, the micro crack formed in the carbon film can also be used as a cutting blade.

It is a top view of CMP pad conditioner of an embodiment of the present invention. It is a front view of CMP pad conditioner of an embodiment of the present invention. It is an enlarged view of the III circle part of FIG. It is sectional drawing to which a part of FIG. 3 was expanded. FIG. 5 is a view taken in the direction of arrow V in FIG. 4.

A CMP pad conditioner according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a plan view of a CMP pad conditioner, and FIG. 2 is a front view of the CMP pad conditioner.
As shown in these drawings, the CMP pad conditioner 1 has a substantially disk shape and has a substrate (base material) 2 that rotates around a central axis (not shown). The substrate 2 is made of a ceramic material such as silicon carbide (SiC) or silicon nitride (Si ₃ N ₄ ).
The substrate 2 includes a disk-shaped substrate body 3 and a mound 4 formed on the surface of the substrate body 3 so as to protrude outward.

  The mound 4 is formed one step higher than the other part of the substrate 2, and is formed in a truncated cone shape, for example. For example, the mound 4 is set to have a height of about 0.5 to 300 μm and a radius of about 0.5 to 3 mm. Further, although only nine mounds 4 are shown in FIG. 1 for ease of viewing in the drawing, in practice, for example, when the substrate 2 is 4 inches, about 100 to 200 are formed. .

Cutting blades 5 are formed on the mound 4 as shown in FIGS. 3 and 4, and these cutting blades 5 are used to grind a CMP pad (not shown) disposed facing the substrate 1. Apply.
The cutting blade 5 has, for example, a polygonal pyramid shape, a polygonal column shape, a conical shape, a truncated conical shape, or the like, and is formed so as to protrude outward. For example, about 1 to 20 cutting blades 5 are formed on one mound 4.

  A carbon film 6 made of, for example, a diamond film is formed on the surface of the cutting blade 5, and the cutting blade 5 is reinforced by this. The carbon film 6 is formed so as to cover the mound 4 including the cutting edge 5 in the figure, but it is sufficient that the carbon film 6 is formed so as to cover at least a portion that becomes the cutting edge 5. The film thickness of the carbon film 6 is set to about 3 to 20 μm, for example.

The carbon film 6 is formed on the surface of the substrate 2 by a vapor phase synthesis method, and minute cracks 7 are formed on the surface by blasting. The minute cracks 7 have an average length of 1 to 15 μm, an average depth of 1 to 10 μm, and a density of 1 to 10 pieces / mm ² so as not to reach the bottom surface of the carbon film 6. Is set to about.

Next, a method for manufacturing the CMP pad conditioner 1 will be described.
First, the substrate 2 is prepared. A mound 4 may be formed integrally with the substrate body 3 in advance on the substrate 2 at the time of molding. Alternatively, the mound 4 and the substrate body 3 may be formed separately, and the mound 4 may be appropriately bonded with an adhesive or the like in a subsequent process. You may attach to the board | substrate body 3 with a fixing means.
Further, the mound 4 is formed with a portion that becomes the cutting edge 5 protruding in a predetermined shape.

Next, a carbon film 6 is formed on the surface of the portion to be the cutting edge 5 by a CVD method using a reaction vessel composed of a gas phase synthesis method hot filament furnace (carbon film forming step).
Specifically, in the reaction vessel, the methane (CH ₄ ) concentration is set to about 1%, and a diamond film is formed on the portion that becomes the cutting edge 5 in this environment.

  In addition, since it is sufficient that the carbon film 6 is formed at least in a part to be the cutting edge 5, masking is performed on other parts on the substrate 2, and a part of the carbon film 6 different from the cutting edge 5 is masked in a later process. It may be removed together. Further, if it is more troublesome to form the carbon film 6 only on the portion that becomes the cutting edge 5, the carbon film 6 is formed on the entire surface of the mound 4 or on the entire surface of the substrate 2 as shown in the illustrated example. May be.

  Next, a blasting process (blasting process step) in which ceramic fine particles made of SiC fine particles having an average particle diameter of about 50 to 500 μm are projected onto the carbon film 6 formed on the surface of the substrate 2 at a predetermined air pressure for 2 to 10 seconds. )I do. Thereby, minute cracks 7 having a predetermined average length are generated at a predetermined density on the surface of the carbon film 6. Also in this case, it is sufficient to perform the blasting process on at least the carbon film 6 formed on the surface of the cutting edge 5.

According to the CMP pad conditioner 1 configured as described above, since the micro crack 7 is generated in the carbon film on the surface of the cutting edge 5, the stress along the bonding surface of the carbon film 6 with the base material is released.
Therefore, even when a strong impact in the normal direction is applied to the joint surface between the carbon film 6 and the substrate 2, relatively large cracks do not occur in the carbon film 6. In addition, it is possible to avoid the occurrence of a problem that the carbon film 6 is peeled off from the substrate 2 with such a large crack. As a result, the bonding strength of the carbon film 6 to the substrate 2 is dramatically increased.
Further, since the minute cracks 7 are formed at a density of 1 to 10 pieces / mm ² and the average length is set to 1 to 15 μm, the residual stress is reduced and desired wear resistance is achieved. And rigidity can be secured.

That is, if the density of the minute cracks 7 is lower than 1 piece / mm ^{2, the} stress generated in the carbon film itself cannot be released and a relatively large stress remains. On the other hand, if the density of the cracks 7 is higher than 10 pieces / mm ² , the mechanical strength of the carbon film itself is weakened, and desired wear resistance and rigidity cannot be obtained.
If the average length of the cracks 7 is shorter than 1 μm, the stress generated in the carbon film itself cannot be released, and a relatively large stress remains generated. On the other hand, if the average length of the crack 7 is longer than 15 μm, the impact resistance becomes weak, and even if a relatively small impact in the normal direction is applied to the joint surface of the carbon film 6 with the substrate 2, May occur.
In addition, along with the formation of the crack 7 in the carbon film 6, an edge portion is formed around the crack 7, and this edge portion can be used as a sub-cutting blade.

  In this embodiment, since the cutting blade 5 is provided on the mound 4 protruding upward from the substrate body 3, compared with the case where the cutting blade 5 is provided on the flat substrate body 3 without having a mound, Even when contacting a relatively soft CMP pad, the cutting blade 5 can be prevented from being solid and the contact pressure of the cutting blade 5 with respect to the CMP pad can be increased.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, this invention is not limited to these embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
For example, in the said embodiment, although the example which uses a base-material coating film for the cutting blade 5 of CMP pad conditioner 1 was shown, not only this but a base-material coating film, such as a drill, an end mill, a bite, etc. It can also be used for a cutting tool or a member such as an electronic device.
In the above embodiment, an example of forming the substrate 2 with silicon carbide (SiC) or silicon nitride (Si 3 _{N 4),} without being limited thereto, to form a substrate with other ceramic materials Also good.
Moreover, in the said embodiment, when forming the crack 7 in the carbon film 6, it demonstrated as an example what is called a pneumatic shot blast which projects the projection material which consists of ceramic fine particles with compressed air, However, It is limited to this Alternatively, the crack 7 may be formed by mechanical blasting using the centrifugal force of the blades or wet blasting in which a projection material is mixed with liquid and projected.

Moreover, in the above-described embodiment, the example using ceramic fine particles was described as the projecting material when performing the blasting process. However, the present invention is not limited thereto, and fine particles of other materials may be used as the projecting material. good.
Moreover, in the said embodiment, although the example which forms a diamond film on the surface of the cutting blade 5 was shown, it is not restricted to this, For example, it is a carbon film other than diamond films, such as DLC, 6 may be configured.
In the embodiment, the case where the mound 4 is provided on the substrate 2 has been described as an example. However, the present invention is not limited to this, and the present invention can also be applied to the CMP pad conditioner of the substrate 2 that does not have the mound 4. It is.

Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to this embodiment.
As an example, first, a substrate 2 made of ceramics such as SiC or Si3N4 was prepared. A mound 4 is formed on the substrate 2, and a portion to be a cutting edge 5 is formed on the mound 4 so as to protrude into a predetermined shape.

A methane (CH ₄ ) concentration of 1% was set on the surface of the substrate 2 by a CVD method using a vapor phase synthesis method hot filament furnace, and a diamond film as a carbon film 6 was formed to a thickness of 10 μm.
Next, blasting was performed on the diamond film formed on the surface of the substrate 2 by projecting SiC fine particles having an average particle diameter of several hundreds of μm at an air pressure of 8 kg / cm ² for about 5 seconds. As a result, minute cracks 7 having an average length of 1 μm were formed on the surface of the diamond film at a density of 1 piece / mm ² .

  Thus, since the micro crack 7 was formed in the diamond film, a compressive stress of 500 MPa was generated in the diamond film before the blasting process. However, after the blasting process, the compressive stress could be reduced to 100 MPa.

1 CMP pad conditioner 2 Substrate (base material)
3 Substrate body 4 Mound 5 Cutting blade 6 Carbon film 7 Crack

Claims (5)

A substrate coating film for coating a substrate,
A substrate coating film, wherein a crack is formed by blasting on a carbon film formed on a surface of the substrate by a gas phase synthesis method. ^2. The substrate coating film according to claim 1, wherein the cracks are formed at a density of 1 to 10 pieces / mm ² .   The base coating film according to claim 1 or 2, wherein the crack has an average length set in a range of 1 to 15 µm. A method for producing a substrate coating film for producing the substrate coating film according to any one of claims 1 to 3,
A carbon film forming step of forming the carbon film on the surface of the base material made of ceramics by a vapor phase synthesis method;
And a blasting step of projecting ceramic fine particles onto the carbon film formed on the surface of the base material. A CMP pad conditioner that uses a cutting blade protruding from the surface of the substrate to grind the CMP pad disposed opposite to the substrate,
A CMP pad conditioner, wherein the substrate coating film according to any one of claims 1 to 3 is formed on a surface of the cutting blade.

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