JP2006130586A - Cmp conditioner and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain stable dressing performance over a long period of time while securing grinding performance to a polishing pad. <P>SOLUTION: Among a number of diamond abrasive grains, a group of diamond abrasive grains having a higher percentage content of diamond abrasive grains where the proportion of area occupied by crystal orientation 111 face is larger than that of the other faces is selected, and this group of diamond abrasive grains are dispersed in a plating liquid to be plated on the surface 2 of a base material 1 dipped in a plating solution, whereby among a number of diamond abrasive grains plated on the surface 2 of the base material 1, the proportion of diamond abrasive grains A1, A2, A4 to A6, A8, A9, the crystal orientation 111 faces (a) of which are oriented substantially parallel to the surface 2 of the base material 1 ranges from 65 to 95%, and the X-ray reflection intensity of the crystal orientation 111 face of the diamond abrasive grains is 2500 CPS or more. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a CMP conditioner used for dressing (sharpening) a polishing pad of a CMP (Chemical Mechanical Polishing) apparatus for polishing a semiconductor wafer or the like, and a method for manufacturing the same.

As this type of CMP conditioner, for example, in Patent Document 1, a plating layer having convex protrusions is provided on the surface of the base material of the CMP conditioner, and one diamond abrasive grain is plated on each of the convex protrusions by plating. There have been proposed ones that are fixed, that is, glued and distributed. Further, in Patent Document 2, as a diamond grindstone used for grinding itself of a silicon wafer or the like, a base (base material) is a prismatic diamond tip or a rough diamond with a plurality of flat working surfaces having the same crystal orientation in a row. In addition, Patent Document 3 discloses a plurality of substantially octahedral diamond abrasive grains in contact with the polishing pad, and contact surfaces facing each of the polishing pads are parallel to the polishing pad. A CMP conditioner arranged as described above has been proposed.
JP 2002-326165 A JP-A-11-156728 JP 2000-84831 A

  However, in the CMP conditioner described in the above-mentioned Patent Document 1, since the sharp tips that become the cutting edges of the diamond abrasive grains are all attached so as to face the direction perpendicular to the action surface on the surface of the plating layer, dressing Although the dressing performance is high with excellent sharpness at the beginning, the sharpness of the sharp cutting edge is lost early due to wear of the abrasive grains, resulting in a significantly shortened conditioner life.

  Therefore, particularly when diamond abrasive grains are deposited on the above-described CMP conditioner, it is desirable to align the crystal orientation of the diamond abrasive grains as described in Patent Document 2 above. 3, the crystal plane of the octahedral diamond abrasive grains, that is, the crystal orientation 111 of the diamond crystal is parallel to the polishing pad, that is, parallel to the surface of the base material. Stable dressing performance over a long period of time by suppressing the shape change of the contact surface due to abrasive wear by allowing the ridgeline portion of this facing crystal orientation 111 plane and other surfaces around it to act as a cutting edge It was said that it was more desirable in obtaining. Here, as a method of measuring the crystal orientation of such diamond abrasive grains, for example, a method of measuring the X-ray reflection intensity of the crystal face of the diamond abrasive grains by a pole measurement method is known.

  However, the crystal orientations of the diamond abrasive grains are aligned as in Patent Document 2, and in particular, as in Patent Document 3, the crystal orientation 111 plane of each of the approximately octahedral diamond abrasive grains is used as a contact surface so as to be parallel to the polishing pad. In the arranged CMP conditioner, high X-ray reflection intensity is obtained for the crystal orientation 111 plane and the dressing performance is stabilized as described above. However, all the abrasive grains always have the contact surface from the beginning of dressing. In addition to contact with the polishing pad only by surface contact due to the above, the above-mentioned ridge line portion acting as a cutting edge of the abrasive grains becomes obtuse and the sharpness is impaired, so that the obtained dressing performance itself is never high. Therefore, in such a CMP conditioner, since the polishing pad is only dressed endlessly with poor dressing performance, the pad grindability is impaired, resulting in poor pad cleaning, that is, lack of sharpness, and the semiconductor polished in the CMP apparatus. There is a possibility that defects such as scratches may occur on the wafer.

  Further, in Patent Document 2, 1 mm to 2 mm square prismatic diamond chips and 1.5 mm to 2 mm triangular triangular diamond stones are used as abrasive grains. In Patent Document 3, diamond abrasive grains having a large particle size of 500 μm to 3000 μm are used. Is used. However, in the CMP conditioner in which all the abrasive grains having such a large particle diameter are attached so that the contact surface thereof is parallel to the polishing pad as described above, the area of the contact surface itself of each abrasive grain also increases. For this reason, the pressure with which the abrasive grains press the polishing pad during dressing is dispersed, and the pad grindability is further impaired, and the occurrence of scratches due to poor cleaning becomes more prominent.

  Further, in such diamond grains having a large grain size, the crystals are sufficiently grown, so that the prisms or triangular plate-like chips as in Patent Document 2 or the rough or octahedral shape as described in Patent Document 3 are used. However, it is relatively easy to obtain such an abrasive grain and it is relatively easy to process into such a shape. For example, the shape varies from a shape close to a regular octahedron having a large proportion of the area occupied by the above-described crystal orientation 111 plane to a shape close to a substantially regular hexahedron having a large area ratio occupied by the crystal orientation 100 plane. It is.

  And, since commercially available artificial diamonds and the like have various shapes, if diamond abrasive grains having a small particle size are used in an attempt to reduce the area of the contact surface of each abrasive grain, For example, as in Patent Document 3, it is extremely difficult to attach all the crystal orientations such that the plane of the crystal orientation 111 is parallel to the polishing pad. Incidentally, such a commercially available artificial diamond abrasive is directly dispersed in the plating solution and immersed in the substrate, and adhered by fixing the diamond abrasive while depositing a plating phase on the surface by electrolytic plating, In a conventional CMP conditioner manufacturing method using a general electrolytic plating method, an X-ray reflection intensity of only about 1500 CPS can be obtained for the crystal orientation 111 plane.

  In Patent Document 2, first, diamond abrasive grains are regularly arranged on the base coated with an adhesive by using tweezers or a suction-type holding tool so that the crystal orientation is aligned, and then an extra adhesive is attached. After removing, a manufacturing method is adopted in which a plating film is grown and adhered by electroplating. However, it is extremely inefficient to fix the abrasive grains on the base one by one with tweezers in this way, and when arranging diamond chips having a large particle size of about 1 mm to 2 mm as described above, It is extremely difficult to regularly arrange diamond abrasive grains having a small particle diameter in this way.

  On the other hand, in the manufacturing method described in the cited document 3, the diamond-shaped grains forming the substantially octahedron are filled in an inversion-type fixing surface immersed in a plating solution and temporarily fixed, and then a fixing layer is formed by electroforming or the like. Then, after bonding to the pedestal, the inverted mold is removed to expose the diamond abrasive grains, so that the crystal orientation 111 plane of the abrasive grains in close contact with the fixed surface of the inverted mold is parallel to the polishing pad as a contact surface. I am doing so. However, in Patent Document 3 using diamond abrasive grains having a grain size as large as 500 μm to 3000 μm and having a shape close to a regular octahedron, the area of the crystal orientation 111 plane also increases, so this crystal orientation 111 is relatively easy. The surface can be temporarily fixed so as to be in close contact with the fixed surface of the inversion type, and the contact surface can be made parallel to the polishing pad. When used, it is not possible to obtain a high X-ray reflection intensity with respect to the crystal orientation 111 plane in the same manner as in the conventional method for manufacturing a conventional CMP conditioner.

  The present invention has been made under such a background, and provides a CMP conditioner capable of obtaining stable dressing performance over a long period of time while ensuring grindability for a polishing pad, and a method for manufacturing the same. It is intended to provide.

  In order to solve the above problems and achieve such an object, the CMP conditioner of the present invention is a CMP conditioner in which a large number of diamond abrasive grains are deposited on the surface of a substrate, Among the diamond abrasive grains, the ratio of the diamond abrasive grains whose crystal orientation 111 plane is oriented substantially parallel to the surface of the substrate is in the range of 65 to 95%, and the X of the crystal orientation 111 plane of the diamond abrasive grains The line reflection intensity is 2500 CPS or more. Further, in the method for manufacturing a CMP conditioner of the present invention, among a large number of diamond abrasive grains, diamond abrasive grains in which the area ratio occupied by the crystal orientation 111 plane is larger than the other planes (hereinafter referred to as main abrasive grains). Selecting a group of diamond abrasive grains having a higher content than the other groups, dispersing the group of diamond abrasive grains in a plating solution, and depositing on the surface of the substrate immersed in the plating solution. Features.

  First, in the CMP conditioner manufacturing method of the present invention, the group of diamond abrasive grains selected from a large number of diamond abrasive grains and dispersed in the plating solution includes all the surface areas of the individual abrasive grains. The main abrasive grains in which the ratio of the area occupied by the crystal orientation 111 plane is larger than the area ratio occupied by all other surfaces other than the crystal orientation 111 plane is constituted by all the remaining diamond abrasive grains in the large number of diamond abrasive grains. When the main abrasive grains are grounded and bonded to the substrate surface, the main abrasive grains try to take a more stable posture. The tendency that one of the crystal orientation 111 planes having a larger area ratio than the other planes tends to adhere to the substrate surface substantially in parallel is increased. Here, since the crystal orientation 111 plane of the diamond crystal is arranged so as to form a regular octahedron plane structure as described above, the crystal orientation 111 plane in close contact with the substrate surface side of the diamond abrasive grain is opposite to the crystal orientation 111 plane. The other crystal orientation 111 plane parallel to this is oriented so as to face the base material surface substantially parallel to the base material surface.

  However, as described above, commercially available artificial diamond and the like are mixed in various shapes, and among the group of diamond abrasive grains, there are abrasive grains other than the main abrasive grains. Although the content rate is lower than that of the group, there is a possibility of mixing, such abrasive grains, the crystal surface having a large area ratio other than the crystal orientation 111 plane is in close contact with the substrate surface side, and is grounded. Tends to be oriented so that crystal planes other than the crystal orientation 111 plane on the opposite side face the front side. In addition, among a group of diamond abrasive grains dispersed in the plating solution, some main abrasive grains are adhered with other crystal faces directed toward the substrate surface, while abrasive grains other than the main abrasive grains. However, in some cases, the crystal orientation 111 plane is directed toward the surface side, and, in addition to any of the crystal surfaces directed to the front side as described above, the ridge line portion between the crystal faces is directed to the front side. There are also abrasive grains that are glued.

  However, among the group of diamond abrasive grains thus bonded, the crystal orientation 111 plane is directed to the front side substantially parallel to the substrate surface as described above, and other crystal planes other than the crystal orientation 111 plane are The ratio of the ones directed to the front side and the ones protruding from the ridge line portions other than these can be adjusted, for example, by adjusting the content of the main abrasive grains in the group of diamond abrasive grains, It can be generally controlled. And, since the content of main abrasive grains in at least this group of diamonds is higher than that in the other groups, the crystal orientation 111 plane is a base material rather than the one in which commercially available artificial diamond is simply dispersed and adhered in the plating solution. It is possible to increase the proportion of diamond abrasive grains that are oriented substantially parallel to the surface.

  Therefore, for example, in the CMP conditioner of the present invention manufactured by such a manufacturing method, among the many diamond abrasive grains adhered to the surface of the substrate as described above, the crystal orientation 111 plane is the surface of the substrate. The ratio of the diamond abrasive grains oriented substantially parallel to the surface is in the range of 65 to 95%, which is sufficiently larger than that produced by the above-mentioned Patent Document 1 and the conventional general production method. Thus, the crystal orientation of all the abrasive grains can be made uniform, and in particular, as in Patent Document 3, each crystal orientation 111 plane can be made smaller than that arranged so as to be all parallel to the polishing pad.

  On the other hand, the remaining diamond abrasive grains are composed of those in which the other crystal faces are directed to the front surface side of the base material and those in which the ridge lines between the crystal faces are projected to the front side. Therefore, the ridge line portion from which the latter diamond abrasive grains protrude can be caused to act as a cutting blade, and the grindability of the polishing pad can be ensured. Therefore, according to the CMP conditioner of the present invention, stable dressing performance over a long period of time can be achieved by the diamond abrasive grains having the crystal orientation 111 plane substantially parallel to the base material surface that is deposited in a large proportion as described above. The polishing pad of the CMP apparatus can be dressed at a high polishing rate by the diamond abrasive grains protruding from the above ridge line portion and being attached while extending the life of the conditioner. It is possible to reliably prevent the occurrence of scratches or the like on the semiconductor wafer.

  Here, when the proportion of the diamond abrasive grains in which the crystal orientation 111 plane is oriented substantially parallel to the substrate surface is below the above range, the other crystal planes and the ridge line portions are directed to the substrate surface front side. This increases the ratio, and there is a risk that the dressing performance cannot be stabilized over a long period of time. On the other hand, if the ratio of the diamond abrasive grains whose crystal orientation 111 plane is substantially parallel to the substrate surface and is oriented on the front side becomes excessive as the above range is exceeded, the dressing performance becomes stable but the high polishing rate In the CMP conditioner of the present invention, the crystal orientation 111 plane is oriented substantially parallel to the surface of the base material, so that the polishing ability of the polishing pad is impaired and scratches may occur. The ratio of the diamond abrasive grains to be made is in the range of 65 to 95%. Further, according to the CMP conditioner thus configured, the ratio of the abrasive grains in which the crystal orientation 111 plane is oriented substantially parallel to the surface of the base material and faces the front side is larger than those in Patent Document 1 and the conventional CMP conditioner. Therefore, a high X-ray reflection intensity can be obtained with respect to the crystal orientation 111 plane, but for the same reason as described above, the X-ray reflection intensity of the crystal orientation 111 plane of the diamond abrasive grains is 2500 CPS or more.

In order to reliably prevent the deterioration of the grindability of the polishing pad while further stabilizing the dressing performance for a long period of time, the X-ray reflection intensity of the crystal orientation 111 plane of the diamond abrasive grains is different from that of other crystal planes such as crystal The X-ray reflection intensity on the azimuth 110 plane is preferably in the range of 10 to 230 times. Further, in the CMP conditioner of the present invention, the number of diamond abrasive grains adhered to the substrate surface is such that the ratio of the diamond abrasive grains whose crystal orientation 111 plane is oriented substantially parallel to the substrate surface is within the above range. a abrasive grains number that may, theoretically, 25 if abrasive grain size of # 100 / mm ² or more, the abrasive grains of grain size in the case of # 200 97 / mm ² or more, the abrasive grains If the particle size is # 325, it should be 201 pieces / mm ² or more. Actually, depending on the size of the conditioner base material surface, the type of polishing pad, the required dressing performance, etc. Many diamond abrasive grains are deposited.

  On the other hand, also in the manufacturing method of the present invention, a large number of diamond abrasive grains means that, for example, when manufacturing the above-described CMP conditioner of the present invention, all of the numerous diamond abrasive grains before selection are the main abrasive grains. If these are all selected as the group of diamond abrasive grains, and all of the group of diamond abrasive grains are adhered to the substrate surface, theoretically, the number per unit area with respect to the same grain size as above However, in practice, the group of diamond abrasive grains is selected from more diamond abrasive grains. In order to select a group of diamond abrasive grains in which the content of the main abrasive grains is higher than that of the other groups as described above, from among such a large number of diamond abrasive grains, particularly abrasive grains such as commercially available artificial diamonds. For example, it is possible to select each abrasive grain while checking the shape of each abrasive grain with a magnifying glass or microscope, but this is inefficient. It is desirable to roll the one group of diamond abrasive grains and select from the other group of diamond abrasive grains.

  That is, other crystal planes other than the crystal orientation 111 plane, such as the crystal orientation 100 plane, take a regular hexahedron plane structure arrangement as described above, and thus vibrate in the diamond abrasive grains having a large area ratio. If the abrasive grain rolls, it will be difficult to stably roll when the other surface comes into surface contact with the upper surface of the vibration table. However, since the crystal orientation 111 plane has a regular octahedron plane structure arrangement, the area of each crystal orientation 111 plane is small if the grain size is the same, and the abrasive grains themselves have a number of faces. Since the shape becomes closer to an infinite sphere, the main abrasive grains having a larger area ratio of the crystal orientation 111 plane than the other planes are once in contact with the upper surface of the vibration table. It is easy to roll by continuing to give vibration. Therefore, the main abrasive grains are selected so as to have a higher content than the other groups by collecting those separated from other groups by rolling while applying vibration to the numerous diamond abrasive grains. Thus, the group of diamond abrasive grains can be obtained reliably and easily.

  Further, when the group of diamond abrasive grains is selected by applying vibration in this manner, the content of the main abrasive grains contained in the group of diamond abrasive grains is determined by the grain size or grain size (average of the abrasive grains). Depending on the particle size) and the time during which vibration is applied, it can be generally controlled as described above. In other words, it is possible to control the content of the main abrasive grains in one group of diamond abrasive grains to a substantially predetermined content ratio higher than that of the other groups by adjusting the vibration time even for abrasive grains having a small grain size. Accordingly, even in a CMP conditioner manufactured by depositing a group of diamond abrasive grains having such a small particle size, the diamond abrasive in which the crystal orientation 111 plane is oriented substantially parallel to the substrate surface It becomes possible to control the ratio of the grains within the above-described range.

  Therefore, especially in the CMP conditioner of the present invention manufactured by such a manufacturing method, the grain size of the abrasive grains is, for example, from 1 mm to 2 mm or 1.5 mm to 2 mm in Patent Document 2 or from 500 μm to 3000 μm in Patent Document 3. Even if it is reduced, the above-described effects can be surely achieved, and by reducing the grain size, the individual diamond abrasive grains whose crystal orientation 111 plane is substantially parallel to the substrate surface, Since the area of the crystal orientation 111 face directed to the front surface of the base material is also reduced, it is possible to prevent the pressure with which the abrasive grains press the polishing pad during dressing from being dispersed. Therefore, according to such a CMP conditioner of the present invention, the pad grindability can be improved even by diamond abrasive grains whose crystal orientation 111 surface is directed to the front side substantially parallel to the substrate surface. A high pad polishing rate can be maintained over a long period of time, and a conditioner that is practically excellent in tool life can be provided.

  Even when the grain size of the abrasive grains is reduced in this way, if this is not sufficiently smaller than the grain sizes of Patent Documents 2 and 3, for example, there is a possibility that such an effect cannot be reliably achieved. . However, on the other hand, even if the grain size of this abrasive grain becomes too small, the area of the crystal orientation 111 face directed to the surface side of the substrate surface is also reduced, thereby reducing the grindability due to abrasive wear. May occur at an early stage, or the abrasive grains may easily fall off, and the above-described excellent tool life may not necessarily be obtained. For this reason, the size of the abrasive grains depends on the polishing rate according to the type of pad to be dressed, etc., but the particle size ranges from # 80 to # 500, and the particle size (average particle size) is 250 to 250. The range of 30 μm is desirable.

  On the other hand, in the production method of the present invention, the surface of the base material is coated with a mask having a plurality of holes of equal size prior to the deposition of the group of diamond abrasive grains. In this hole, only diamond abrasive grains having a particle size smaller than the inner diameter are adhered, so that in the above-mentioned group of diamond abrasive particles dispersed in the plating solution, abrasive grains having extremely large particle sizes are present. Even if it mixes, it can avoid that this abrasive grain adheres to the base-material surface. For this reason, it is possible to prevent a situation in which the polishing pad is damaged by the abrasive grains having such a large particle diameter.

  And since the abrasive grains to be adhered in the hole portion tend to come into contact with the base material surface in close contact with the crystal surface having a large area ratio in order to take a stable posture as described above, as a result In the part, approximately equal numbers of diamond abrasive grains corresponding to the particle diameter are deposited. Therefore, in the CMP conditioner manufactured in this way, the diamond abrasive grains are approximately equal in number for each of a plurality of regions of the same size defined on the substrate surface corresponding to the holes. In other words, the number of abrasive grains to be adhered to each of the regions can be controlled based on the size of the hole and the size of the abrasive grains. It is possible to reliably maintain an appropriate polishing rate according to the type of the material and to obtain uniform dressing performance over the entire surface of the substrate.

  When the group of diamond abrasive grains is adhered to the substrate surface by electrolytic plating, an insulating material is used as the masking, so that a plating phase is deposited on the surface of the masking or the abrasive grains are wrinkled. Therefore, the polishing pad can be dressed by a CMP conditioner whose surface is covered with a mask. Of course, the masking may be peeled off from the surface of the substrate after coating the insulating mask on the surface of the substrate and depositing the diamond abrasive grains.

  Furthermore, in the manufacturing method of the present invention in which the surface of the base material is coated with the masking having the holes as described above and the abrasive grains are adhered, the diamond grinding is performed after the base surface is coated on the surface of the base material coated with this masking. By depositing the grains, the diamond abrasive grains are deposited at a position protruding one step from the surface of the substrate in the hole by the thickness of the layer of the base plating. Therefore, in the CMP conditioner of the present invention manufactured as described above, the plurality of regions defined by the holes are protruded one step from the surface of the base material, and the group of diamond abrasive grains are formed on the plurality of regions. In particular, when the masking is peeled off as described above, grinding waste generated during dressing is smoothly discharged through the space between the protruding regions and the base is used. The grinding liquid can be evenly distributed over the entire material surface, and more efficient dressing can be promoted.

  1 to 5 illustrate one embodiment of a CMP conditioner manufacturing method according to the present invention. Of these, FIGS. 4 and 5 show the present invention manufactured by the manufacturing method according to this embodiment. 1 shows an embodiment of a CMP conditioner. In the manufacturing method of the present embodiment, the base material 1 made of a metal material such as stainless steel is first processed into a disk shape, and one of the circular surfaces is smoothed as a surface 2 of the base material 1 by machining. Next, a mask 4 having a plurality of holes 3 of the same size as shown in FIG. 1 is formed on the surface 2 by attaching a masked dry film made of an insulating material such as acrylic. Cover. Here, the hole 3 is, for example, a circular hole formed so as to penetrate the masking 4, and is formed at equal intervals in a lattice or zigzag arrangement.

  Thus, the base material 1 to which the masking 4 has been applied is pretreated. In this pretreatment, the substrate 1 is first immersed and washed in an acid-based degreasing bath, then washed with pure water, drained, and then seeded to enable Ni electrodeposition. Perform strike plating. In this strike plating, the substrate 1 is immersed in a Ni plating solution to form a thin strike plating layer (not shown) having a high current density of about 1 μm to 5 μm on the surface 2, provided that the strike plating layer is It is not formed in the portion covered with the insulating masking 4 but only in the portion of the surface 2 in the hole 3 exposed in the Ni plating solution.

  Next, the base material 1 that has been pretreated in this manner is washed again with pure water, drained, and subjected to base plating. That is, in this base plating treatment, the substrate 1 was connected to the cathode and immersed in a sulfamic acid Ni solution (plating solution) so that the surface 2 faced up, and was similarly immersed in the sulfamic acid Ni solution. By passing an electric current between the anode and the anode, it is formed on the surface 2 in the hole 3 except for the portion covered with the masking 4 of the surface 2 of the substrate 1 as shown in FIG. A base Ni plating layer 5 is formed on the strike plating layer. The base Ni plating layer 5 has a thickness of 10 μm to 20 μm, which is thicker than the strike plating layer and thinner than the thickness of the masking 4, and is a base Ni plating formed in each hole 3. The thicknesses of the layers 5 are substantially equal to each other, and the upper surfaces thereof are substantially parallel to the surface of the substrate 1.

  And if the foundation | substrate Ni plating layer 5 of predetermined thickness is formed, a diamond abrasive grain will be disperse | distributed to the said sulfamic-acid Ni liquid as a plating liquid, and the surface 2 of the base material 1 immersed in this plating liquid Of these, the diamond abrasive grains are deposited on the base Ni plating layer 5 other than the one coated with the masking 4. At this time, in the present embodiment, the diamond abrasive grains include a number of diamond abrasive grains. Then, a group of diamond abrasive grains is selected so that the main abrasive grains are contained at a higher content than the other groups, and this group of diamond abrasive grains is dispersed in the plating solution to form the surface 2 of the substrate 1. Wear it. Further, in the present embodiment, in order to select such a group of diamond abrasive grains, the above-described many diamond abrasive grains are dispersed on a vibrating table and are caused to roll by applying vibrations. A selection is made from another group of diamond abrasive grains.

  This shaking table has, for example, a bowl-shaped concave portion that has a stepped cross section and gradually falls downward from the outer peripheral side toward the inner peripheral side, so that horizontal vibration is applied. Yes, commercially available artificial diamond abrasive grains having a predetermined particle size are dispersed on the flat stepped surface above the concave portion to give vibration. Then, among abrasive grains of various shapes included in such a commercially available artificial diamond having a relatively small grain size, diamond abrasive grains having a large area ratio occupied by other faces other than the crystal orientation 111 face, for example, crystal orientation 100 Abrasive grains having a large surface area ratio have a shape closer to a regular hexahedron since the crystal plane 100 has a regular hexahedron plane structure. However, when it is placed in surface contact with the flat step surface of the vibration table, it becomes difficult to roll any more and remains on the upper side of the recess.

  On the other hand, the main abrasive grains in which the ratio of the area occupied by the crystal orientation 111 plane is larger than that of other surfaces in the surface area of the abrasive grains, the crystal orientation 111 plane has a regular octahedral plane structure. Therefore, for example, it is easier to roll by vibration than abrasive grains having a large proportion of the crystal orientation 100 plane having the regular hexahedron plane structure as described above, that is, any crystal orientation 111 plane is in surface contact with the step surface of the vibration table. Even if it is mounted, it rolls relatively easily by giving further vibration. Therefore, such main abrasive grains roll down sequentially from the stepped surface on the outer periphery of the recess and continue to fall to the stepped surface on the lower side of the inner periphery by continuing to give vibration, and finally the bowl-shaped recess Therefore, by collecting such abrasive grains, one group of diamond abrasive grains can be removed from the other diamond abrasive grains by collecting such abrasive grains. The content of the main abrasive grains contained in this group of diamond abrasive grains can be made higher than that of the other groups.

  Furthermore, the content of the main abrasive grains in the group of diamond abrasive grains selected in this way can be generally controlled by the grain size of the abrasive grains and the vibration time for selecting the group of diamond abrasive grains. In other words, depending on the period and amplitude of vibration applied, when the same vibration is applied on the same vibration table, the smaller the grain size, the easier the main abrasive grains to roll and the longer the vibration time. Since the main abrasive grains can be more reliably rolled and separated from other abrasive grains, the content of the main abrasive grains in the selected group of diamond abrasive grains can be increased. Since the relationship between the grain size and the vibration time and the content of main abrasive grains in the selected group of diamond abrasive grains can be obtained experimentally, it adheres to the surface 2 of the substrate 1. By adjusting the vibration time according to the particle size of the diamond abrasive grains to be performed, it becomes possible to select a group of diamond abrasive grains in which the main abrasive grains have a substantially predetermined content. The grain size of the abrasive grains is desirably set to a predetermined grain size within a range of # 80 to # 500 (an average grain size of 250 to 30 μm).

  When a group of diamond abrasive grains thus selected is dispersed in the plating solution, the abrasive grains settle while floating in the plating solution, and in the hole 3 of the masking 4 on the surface 2 of the substrate 1 as shown in FIG. The ratio of the main abrasive grains in the diamond abrasive grains to be grounded is substantially equal to the above-described content ratio of the main abrasive grains in the group of diamond abrasive grains. In FIG. 3, for the purpose of explanation, all of the main abrasive grains A1 to A9 having a larger area ratio occupied by the crystal orientation 111 plane a than other planes are side faces of the octahedron formed by the plane structure of the crystal orientation 111 plane a. Based on the visual shape, it is shown by a rhombus with a diagonal line connecting the obtuse angle part. Particularly, in a commercially available artificial diamond having a small particle size, a shape close to a regular octahedron, that is, the crystal orientation 111 plane Even if the area ratio occupied by this crystal orientation 111 plane is large, for example, it has a pair of octagonal crystal orientation 111 planes parallel to each other and other crystal planes are arranged around it. As described above, the main abrasive grains include those that are deformed into various shapes, such as abacus balls.

  Further, in FIG. 3, the ratio of the area occupied by the crystal orientation 100 plane for all the abrasive grains B1 to B3 other than the main abrasive grains A1 to A9 among the group of diamond abrasive grains grounded on the base Ni plating layer 5. This is represented by a square based on the side view shape of a regular hexahedron formed by the plane structure of the crystal orientation 100 plane b, and other abrasive grains other than the main abrasive grains are represented in this way. From a shape close to a regular hexahedron having a large ratio of the crystal orientation 100 plane, a shape deformed more than this, and a crystal plane other than these crystal orientation 111 plane and crystal orientation 100 plane, for example, the crystal orientation 110 plane This includes abrasive grains of various shapes such as those having a large area ratio. Further, when the abrasive grains are dispersed in the plating solution in this way, the main abrasive grains and other abrasive grains are attached to the masking 4 other than the base Ni plating layer 5 on the surface 2 of the base material 1. These abrasive grains are not shown in FIG.

  Since the main abrasive grains A1 to A9 and the other abrasive grains B1 to B3 tend to take a stable posture when the individual abrasive grains are grounded on the underlying Ni plating layer 5, most of them are area ratios. The main abrasive grains have a crystal orientation 111 plane a as in the main abrasive grains A1, A2, A4 to A6, A8, A9 shown in FIG. For example, other abrasive grains having a large area ratio occupied by the crystal orientation 100 plane, such as the abrasive grains B1 and B3 shown in FIG. The layer 5 is placed in close contact with the upper surface. However, some of the many abrasive grains dispersed in the plating solution include, for example, ridges between crystal surfaces of the abrasive grains, such as the main abrasive grains A3 and A7 and other abrasive grains B2 in FIG. In other words, there are some which are grounded so that the corners other than the crystal face are directed to the front side (upper side in FIGS. 1 to 5) of the surface 2 of the substrate 1.

  Although not shown in the drawing, a crystal plane other than the crystal orientation 111 plane having a large area ratio among the main abrasive grains is grounded to the upper surface of the underlying Ni plating layer 5 and is a plane other than the crystal orientation 111 plane on the opposite side. May be directed to the surface 2 surface side, conversely, the crystal orientation 111 plane in which the area ratio is small even in abrasive grains other than the main abrasive grains is grounded to the upper surface of the underlying Ni plating layer 5 and the opposite crystal orientation 111 plane is Some are face up. Furthermore, as described above, diamond abrasive grains having a particularly small particle diameter take various shapes. Therefore, even if an abrasive grain in which any crystal face is in close contact with the upper surface of the underlying Ni plating layer 5 is grounded, In some cases, the opposite side becomes a ridge line portion between crystal faces and protrudes to the surface 2 front side of the substrate 1.

  However, among the abrasive grains thus grounded on the surface 2 of the substrate 1 (in this embodiment, further on the underlying Ni plating layer 5 in the hole 3 of the masking 4), the main abrasive grains A1, A2 in FIG. , A4 to A6, A8, A9 and the like, with the crystal orientation 111 plane a facing the front side in parallel with the surface 2 of the substrate 1, and other crystal orientation 100 plane b such as abrasive grains B1 and B3 The ratio of the crystal surface facing the front side parallel to the surface 2 and the one having the ridge line portion between the crystal surfaces facing the front side like the main abrasive grains A3, A7 and abrasive grains B2 are dispersed in the plating solution. The above-mentioned group of diamond abrasive grains is assumed to have a high content of main abrasive grains with a large area ratio occupied by the crystal orientation 111 plane, and such main abrasive grains are likely to be scattered in a stable posture as described above. As shown in FIG. 3, the crystal orientation 111 plane a is substantially parallel to the surface 2 of the substrate 1. It becomes large proportion of those towards. Moreover, the ratio of these three kinds of abrasive grains can be generally adjusted according to the content ratio by controlling the content ratio of the main abrasive grains in the group of diamond abrasive grains as described above. In the manufacturing method of the present embodiment, the ratio of the crystal orientation 111 plane a that is substantially parallel to the surface 2 of the substrate 1 is in the range of 65 to 95%.

  Furthermore, in the present embodiment, the masking 4 having a plurality of holes 3 of the same size is coated on the surface 2 of the base material 1, and a predetermined Ni plating layer 5 is formed on the base Ni plating layer 5 formed in the holes 3. When the abrasive grains having a particle size of 1 are grounded, approximately the same number of abrasive grains are accommodated in each hole 3. That is, if the diameter of the circular hole 3 is not less than the average grain size of the abrasive grains and is about twice as large, the abrasive grains are accommodated one by one in the hole 3 and are grounded to the base Ni plating layer 5. If the average particle size is about 2 to 3 times larger than the average particle size, approximately two abrasive grains are accommodated in the hole 3 and grounded on the underlying Ni plating layer 5 as shown in FIG. It will be. However, even if the diameter of the hole 3 is more than twice the grain size of the abrasive grains, if one abrasive grain contacts the center in the hole 3 first, the next abrasive grain becomes difficult to ground, Since three or more abrasive grains may be accommodated when abrasive grains having a small particle diameter are concentrated in one hole portion 3, the same number of abrasive grains may not necessarily be accommodated in all the hole portions 3. Good.

  Next, when the group of abrasive grains dispersed in the plating solution is grounded on the surface 2 of the base material 1, the current is further passed through the base material 1, whereby the abrasive grains and the base Ni are shown in FIG. An Ni plating layer 6 having a thickness of about 10 μm to 20 μm is grown around the contact portion with the plating layer 5 to fix the abrasive grains, that is, adhere. However, at this time, the Ni plating layer 6 does not grow on the insulating masking 4, and therefore, the abrasive grains adhering to the masking 4 are not fixed. And the base material 1 to which the abrasive grains are fixed by the Ni plating layer 6 in this way is pulled up from the plating solution and washed with pure water, thereby surplus abrasive grains and the like adhering to the masking 4 The diamond abrasive grains are removed, and then immersed in a plating solution (sulfamic acid Ni solution) in which the abrasive grains are not dispersed, and an electric current is passed, so that a Ni plating layer 6 further grows and the Ni plating layer 6 is ground. Grain is embedded.

  When the Ni plating layer 6 has grown to a predetermined thickness in this way, the substrate 1 is lifted from the plating solution, washed with water, and dried to finish the manufacturing method, and the CMP conditioner as shown in FIG. Although the substrate 1 may be manufactured, the substrate 1 is subsequently immersed in an electroless plating tank, and an Ni plating layer is further formed on the Ni plating layer 6 by electroless plating in which the growth of Ni plating is faster than the electrolytic plating. It may be grown to adjust the protruding amount of diamond abrasive grains. Further, in the case where only the protrusion amount is adjusted in this way, or in the case where the production is finished as shown in FIG. 4, the surface 2 of the base material 1 remains covered with the masking 4. Thus, as shown in FIG. 5, a plurality of regions L of the same size defined on the surface 2 of the base material 1 corresponding to the positions where the holes 3 of the masking 4 are opened are the underlying Ni plating layer. The CMP conditioner may be manufactured so as to protrude one step from the surface 2 by 5 and to which a substantially equal number of diamond abrasive grains are deposited for each region L.

  Therefore, in the CMP conditioner according to the embodiment of the present invention manufactured as described above, either the mask 4 shown in FIG. 4 remains covered or the mask 4 shown in FIG. 5 is peeled off. Of the diamond abrasive grains adhered to the surface 2 of the substrate 1, the ratio of the diamond abrasive grains whose crystal orientation 111 plane is oriented substantially parallel to the surface 2 of the substrate 1 is 65 to 95%. Scope. Here, FIG. 6 and FIG. 7 show X-rays of diamond abrasive grains that are bonded by the CMP conditioner of the embodiment manufactured as described above and the CMP conditioner manufactured by a conventional general manufacturing method. The reflection intensity was measured, but in this embodiment, as shown in FIG. 6, the X-ray reflection intensity of the crystal orientation 111 plane was 2500 CPS or more and was about 13 times the X-ray reflection intensity of the crystal orientation 110 plane. On the other hand, in the conventional CMP conditioner, as shown in FIG. 7, the X-ray reflection intensity of the crystal orientation 111 plane is about 1700 CPS, which is only about 7 times that of the crystal orientation 110 plane.

  Thus, in the CMP conditioner having the above-described configuration, the ratio of diamond abrasive grains in which the crystal orientation 111 plane is oriented substantially parallel to the surface 2 of the substrate 1 is 65 to 95%, which is higher than that of the conventional CMP conditioner. In addition, since the X-ray reflection intensity of the crystal orientation 111 plane is 2500 CPS or more, stable dressing performance can be obtained over a long period, while the crystal orientation 111 plane of all the abrasive grains is the surface 2 In other words, the ridge line portion between the crystal faces is the surface of the abrasive grains other than the abrasive grains in which the crystal orientation 111 plane is attached in parallel with the surface 2. The above-mentioned dressing performance itself can be improved by causing the ridge line portion to act as a cutting edge by the abrasive grains protruding and glued to the front side of No. 2. That is, since the high dressing performance obtained in this way can be stably maintained over a long period of time, the grindability of the polishing pad is not impaired in the CMP apparatus while extending the life of the conditioner. A high polishing rate can be maintained, and the occurrence of scratches due to poor cleaning of the pad can be reliably prevented.

  Here, when the ratio of the diamond abrasive grains in which the crystal orientation 111 plane is oriented substantially parallel to the surface 2 of the substrate 1 exceeds the above range, the ridge line portion acting as a cutting edge protrudes to the front side of the surface 2 and is attached. As a result, the proportion of abrasive grains is relatively reduced, and the high polishing rate and dressing performance as described above cannot be obtained. On the other hand, if this ratio falls below the above range, or the X-ray reflection intensity of the crystal orientation 111 plane is less than 2500 CPS, conversely, the ridge line portion protrudes to the front side and the crystal orientation 100 plane that does not contribute to life extension The ratio of abrasive grains in which other crystal planes such as the 110 plane and the like are parallel to the surface 2 increases, and the polishing rate is extremely lowered in a short time, so that the conditioner must be replaced. In order to prevent such a problem from occurring more reliably and achieve the above-described effect, the ratio of the abrasive grains in which the crystal orientation 111 plane is substantially parallel to the surface 2 of the substrate 1 is within the above range. Of these, the X-ray reflection intensity on the crystal orientation 111 plane is preferably about 10 to 230 times the X-ray reflection intensity on the crystal orientation 110 plane.

  In the present embodiment, the grain size of the diamond abrasive grains thus attached to the surface 2 of the base material 1 is in the range of # 80 to # 500, and therefore the crystal orientation 111 plane is substantially parallel to the surface 2. Since the area itself of the crystal orientation 111 surface facing the surface 2 of the abrasive grain and contacting the polishing pad can be reduced, the pressure that the conditioner presses the pad during dressing is dispersed. Therefore, it is possible to maintain a higher polishing rate over a long period of time. Here, when the grain size is less than # 80 and the grain size of the abrasive grains is increased, such an effect cannot be obtained. Conversely, when the grain size becomes finer than # 500, the abrasive grains are polished. The portion in contact with the pad becomes too sharp and wear tends to occur, or the abrasive grains easily fall off, and the polishing rate may be lowered early.

  On the other hand, in the manufacturing method for manufacturing such a CMP conditioner, the main abrasive grains having a large area ratio occupied by the crystal orientation 111 plane are selected from a large number of diamond abrasive grains so as to have a higher content rate. Since a group of diamond abrasive grains is selected and dispersed in the plating solution and adhered to the surface 2 of the base material 1, a CMP conditioner that exhibits the above-described excellent effects can be obtained relatively easily. However, it can be reliably manufactured. Further, in the manufacturing method of the above embodiment, in order to select a group of diamond abrasive grains in this way, the main abrasive grains are rolled and separated by applying vibration to the large number of diamond abrasive grains. By controlling the content of the main abrasive grains in a group of diamond abrasive grains, the above ratio of the abrasive grains in which the crystal orientation 111 plane in the CMP conditioner is parallel to the surface 2 of the base material 1 is also more reliably described above. Such an excellent CMP conditioner can also be efficiently manufactured because it is possible to adjust the range.

  Moreover, in the manufacturing method of this embodiment, after covering the surface 2 of the base material 1 with the masking 4 in which a plurality of holes 3 having the same size are formed, the group of diamond abrasive grains is adhered. In the CMP conditioner thus manufactured, approximately equal numbers of abrasive grains corresponding to the size and particle size (particle size) of the hole 3 are adhered to the region L corresponding to the hole 3. The Rukoto. That is, in the above-described manufacturing method, it is possible to control the surface 2 of the conditioner so that a desired number of abrasive grains can be more securely adhered to a desired position even if a plurality of them are provided. In the manufactured CMP conditioner, when the holes 3 and the regions L are arranged at equal intervals in a lattice shape or a zigzag manner as in this embodiment, each abrasive grain acts equally on the polishing pad. This makes it possible to dress the entire pad evenly and uniformly. This is the same even when the conditioner with the masking 4 shown in FIG. Depending on the type of pad and the like, the holes 3 and the regions L may be arranged at unequal intervals.

  Further, in the present embodiment, the substrate 1 whose surface 2 is covered with the masking 4 with the hole 3 is first subjected to the base plating, and then the abrasive particles are dispersed and adhered to the plating solution. By this base plating, a base Ni plating layer 5 is formed on the surface 2 in the hole 3, and the abrasive grains are adhered to the upper surface thereof. Therefore, in the CMP conditioner manufactured in this way, even when the masking 4 is used while being covered as shown in FIG. 4, the abrasive grains are reliably projected from the surface of the masking 4 to polish the pad. On the other hand, when the masking 4 is peeled and used as shown in FIG. 5, the region L on which the abrasive grains are attached protrudes one step from the surface 2 of the substrate 1. Thus, a large space can be secured between the adjacent regions L. For this reason, during dressing, chips generated by polishing can be discharged through this space and the grinding fluid can be supplied to the abrasive grains in the region L inside the surface 2, and further excellent dressing performance can be obtained for a long time. Can be obtained.

It is sectional drawing of the surface 2 of the base material 1 to which the masking 4 was given explaining one Embodiment of the manufacturing method of the CMP conditioner of this invention. It is a figure which shows the state which gave the base plating to the base material 1 shown in FIG. FIG. 3 is a view showing a state in which a group of diamond abrasive grains are grounded on a surface 2 of a base material 1 shown in FIG. 2. It is a figure which shows one Embodiment of the CMP conditioner of this invention which made the Ni plating layer 6 grow from the state shown in FIG. It is a figure which shows other embodiment of the CMP conditioner of this invention which peeled the masking 4 from the state shown in FIG. It is a figure which shows the result of having measured the X-ray reflection intensity of the diamond abrasive grain in the CMP conditioner of embodiment shown in FIG. It is a figure which shows the result of having measured the X-ray reflection intensity of the diamond abrasive grain in the CMP conditioner manufactured by the conventional general method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Surface of the base material 3 Hole part 4 Masking 5 Base Ni plating layer 6 Ni plating layer L The area | region defined by the surface 2 of the base material A1-A9 The crystal orientation 111 surface occupies rather than another surface Diamond abrasive grains with a large area ratio (main abrasive grains)
a crystal orientation 111 plane B1 to B3 diamond grains having a larger area ratio of the crystal orientation 100 plane than other planes b crystal orientation 110 plane

Claims (9)

  A CMP conditioner in which a number of diamond abrasive grains are deposited on the surface of a substrate, and among these diamond abrasive grains, a diamond abrasive having a crystal orientation 111 plane oriented substantially parallel to the surface of the substrate. A CMP conditioner, wherein the proportion of grains is in the range of 65 to 95%, and the X-ray reflection intensity of the crystal orientation 111 plane of the diamond abrasive grains is 2500 CPS or more.   2. The CMP conditioner according to claim 1, wherein the X-ray reflection intensity of the crystal orientation 111 plane of the diamond abrasive grains is in the range of 10 to 230 times the X-ray reflection intensity of the crystal orientation 110 plane. .   The CMP conditioner according to claim 1 or 2, wherein a particle size of the group of diamond abrasive grains is in a range of # 80 to # 500.   4. The diamond abrasive grains are adhered in approximately equal numbers for each of a plurality of regions having the same size defined on the surface of the substrate. 5. A CMP conditioner as described.   The CMP conditioner according to claim 4, wherein the plurality of regions are protruded from the surface of the base material by one step.   From a large number of diamond abrasive grains, a group of diamond abrasive grains in which the content ratio of the diamond abrasive grains whose crystal orientation 111 plane is larger than the other planes is higher than the other groups is selected, and this group of diamonds is selected. A method for producing a CMP conditioner, characterized in that abrasive grains are dispersed in a plating solution and adhered to the surface of a substrate immersed in the plating solution.   7. The plurality of diamond abrasive grains are dispersed on a vibrating table and given vibration, whereby the group of diamond abrasive grains is rolled and selected from the other group of diamond abrasive grains. A process for producing a CMP conditioner according to claim 1.   8. The CMP according to claim 6, wherein a mask having a plurality of holes of the same size is coated on the surface of the base material before the diamond abrasive grains are deposited. 9. Conditioner manufacturing method. 9. The method of manufacturing a CMP conditioner according to claim 8, wherein the diamond abrasive grains are adhered after applying a base plating to the surface of the base material coated with the masking.

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