JP2003071718A - Cmp conditioner, method for arranging hard abrasive grain used in cmp conditioner and method for manufacturing cmp conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide stable CMP conditioner characteristics and to relieve slurry or the like in polishing without forming relief groove or the like on a support member. SOLUTION: This CMP conditioner of polishing cloth for a semiconductor substrate is composed of the support member 1 and plural diamond grains 2 brazed on a surface of the supporting member 1. Plural straight lines or curved lines radially extending from a center of the support member 1 are laid out on the surface of the disk-shaped support member 1 and the diamond grains 2 are arranged on the straight lines or the curved lines. The diamond grains 2 are arranged in such a manner that density of the diamond grains 2 at edge parts is smaller than that at a center par of the support member 1. Since area where no diamond grain 2 exists is secured in radial shape on the surface of the support member 1, slurry can be relieved outward from the support member 1 in polishing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CMP conditioner used for removing clogging of a polishing cloth for a semiconductor substrate and removing foreign matters, a method for arranging hard abrasive grains used for the CMP conditioner, and a CMP conditioner. The present invention relates to a conditioner manufacturing method.

[0002]

2. Description of the Related Art CM is used for polishing wafers.
A polishing method called P (Chemical Mechanical Polishing) has been proposed. CMP makes it possible to ensure both the polishing rate and the defect-free material to be polished by superimposing a chemical polishing action on a mechanical polishing action to achieve a polishing process for a silicon wafer. Widely used in.

Further, in recent years, with the high integration of devices, it is necessary to polish the wafer surface or the surface of a semiconductor substrate having a conductor / dielectric layer formed on the wafer surface at a predetermined stage of manufacturing an integrated circuit. Has become. The semiconductor substrate is
Polished to remove surface defects such as high bumps, scratches, roughness. This step is typically performed during the formation of various devices and integrated circuits on the wafer. In this polishing step, it is necessary to have both a polishing rate and no defect, as in the finishing polishing step for a silicon wafer.
The introduction of the chemical slurry provides chemical and mechanical planarization that gives the semiconductor surface a greater polishing removal rate and defect-free properties.

As an example of the CMP process, as shown in FIG. 8, silica particles having a particle size of, for example, about 5 to 300 nm are suspended in an alkaline solution of caustic soda, ammonia, amine and the like to chemically adjust the pH to about 9 to 12. Slurry 10
1 and a polishing cloth 102 made of polyurethane resin or the like are used. At the time of polishing, polishing is performed by bringing the semiconductor substrate 103 into contact with the polishing cloth 102 at an appropriate pressure while spreading the chemical slurry 101, and relatively rotating the semiconductor cloth 103 as indicated by an arrow in the figure.

As a method for conditioning the polishing cloth 102, while the water or the chemical slurry 101 is being flown through the polishing cloth 102, conditioning is performed using a CMP conditioner to eliminate clogging of the polishing cloth 102 and remove foreign matters. Had been removed. Conditioning using a CMP conditioner is performed by bringing the CMP conditioner into contact with the polishing cloth 102 after polishing the semiconductor substrate 103, or at the same time as polishing the semiconductor substrate 103 and at a position different from the position where the semiconductor substrate 103 abuts. At this position, the CMP conditioner is brought into contact with the polishing cloth 102.

[0006]

In a conventional CMP conditioner used for conditioning a polishing cloth, as shown in FIG. 9, diamond grains 202 as hard abrasive grains are manually formed on the surface of a disc-shaped support member 201. These diamond grains 202 were fixed after being distributed evenly by being dispersed. However, in this case, no matter how carefully the diamond particles 202 are sprayed, the diamond particles 202 are non-uniformly distributed, causing a difference between the CMP conditioner solids, and hindering the development of stable CMP conditioner characteristics. .

Further, in the conventional CMP conditioner, since the escape of the slurrue is poor, the micro scratches are increased. Further, in order to improve the escape of the slurry, as shown in FIG. 10, a relief groove 203 for allowing the chemical slurry 101 to escape is formed in the support member 201,
During polishing, the chemical slurry 10 is passed through the relief groove 203.
It was supposed to miss 1. However, the support member 201
If the escape groove 203 is formed in the groove, the CMP conditioner characteristics may be adversely affected, and it takes time to process the escape groove, resulting in a cost increase.

The present invention has been made in view of the above points, and it is possible to obtain stable CMP conditioner characteristics and to escape slurry during polishing without forming relief grooves. The purpose is to reduce.

[0009]

A CMP conditioner of the present invention is a CMP conditioner comprising a support member and a plurality of hard abrasive grains provided on the surface of the support member, wherein the surface of the support member is a CMP conditioner. The above is characterized in that the plurality of hard abrasive grains are regularly arranged and arranged so that the density decreases from the inside to the outside of the support member.

Another CMP conditioner of the present invention is
A CMP conditioner comprising a support member and a plurality of hard abrasive grains provided on the surface of the support member, wherein a region where the plurality of hard abrasive grains do not exist on the surface of the support member is substantially radial. The feature is that it is secured in.

The method for arranging hard abrasive grains used in the CMP conditioner of the present invention is a thin plate-like arrangement in which a plurality of through holes are formed regularly and arranged so that the density decreases from the inside to the outside. It is characterized in that it has a procedure of positioning the members on the array surface and a procedure of inserting hard abrasive grains into the through holes of the array member.

In another method of arranging hard abrasive grains used in a CMP conditioner of the present invention, a procedure for arranging a thin plate-shaped array member in which a plurality of through-hole-free regions are secured substantially radially on the arrayed surface. And a procedure of inserting hard abrasive grains into each through hole of the array member.

Another method of arranging hard abrasive grains for use in a CMP conditioner of the present invention is a holding member in which a plurality of hard abrasive grains are regularly arranged and arranged so that the density decreases from the inside to the outside. And the procedure of transferring the hard abrasive grains held by the holding member to the surface of the support member constituting the CMP conditioner.

According to another method of arranging hard abrasive grains for use in a CMP conditioner of the present invention, a plurality of hard abrasive grains are held by a holding member in a state where a region where a plurality of hard abrasive grains do not exist is substantially radially secured. And a procedure of transferring the hard abrasive grains held by the holding member to the surface of the support member that constitutes the CMP conditioner.

In the method for manufacturing a CMP conditioner of the present invention, the hard abrasive grains are arranged on the surface of the support member by using the method for arranging the hard abrasive grains used in the CMP conditioner, and then the hard abrasive grains are removed. It is characterized in that it adheres to the surface of the support member.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION With reference to the drawings, a CMP conditioner for a polishing cloth for semiconductor substrates, a method for arranging hard abrasive grains used in the CMP conditioner for a polishing cloth for semiconductor substrates, and a CMP conditioner manufacturing method according to the present invention will be described below. The embodiment will be described.

The CMP conditioner will be described with reference to FIG. As shown in the figure, diamond grains 2 are fixed as hard abrasive grains on the surface of a disc-shaped support member 1 made of stainless steel or the like.

2 and 3 show the outline of the arrangement of the diamond grains 2 on the surface of the support member 1. In the example shown in FIG. 2, a plurality of straight lines (dotted line L) radially extending from the center of the disc-shaped support member 1 are considered, and the diamond grains 2 are arranged on these straight lines. CMP done this way
In the conditioner, the diamond grain 2 is the support member 1
Are arranged so that the density decreases from the inner side to the outer side, and the diamond grains 2 are formed on the surface of the support member 1.
The area where no is present is secured radially.

Further, in the example shown in FIG. 3, a plurality of curves (dashed line L) extending radially from the center of the disc-shaped supporting member 1.
, The diamond grains 2 are arranged on these curves. In such a CMP conditioner, the diamond grains 2 are arranged so that the density decreases from the inner side to the outer side of the support member 1, and on the surface of the support member 1, regions where the diamond grains 2 do not exist are radially formed. Will be secured. The term “substantially radial” as used in the present invention includes not only the case of linear emission as shown in FIG. 2 but also the case of curved emission as shown in FIG.

The actual diamond grains 2 are much smaller than the support member 1, but the diamond grains 2 are shown in a large size in FIG. 1 and FIGS. . Also, regarding the number of straight lines and curves, radiation is made in a more dense state.
Now, let me briefly explain.

The method of arranging the diamond grains 2 will be described below with reference to FIGS. In this embodiment,
The diamond grains 2 are arranged by the following two methods.

In the first method, as shown in FIG. 4, the adhesive 4 is applied to the surface of the supporting member 1 provided with the brazing material 3. Then, the array plate 5 is placed on the surface of the support member 1 coated with the adhesive 4 and masked.

As shown in FIG. 5, the array plate 5 is formed with through holes 6 for arraying the diamond grains 2. That is, the through holes 6 are arranged in the array plate 5 in the same manner as the array shown in FIGS. Through hole 6 diameter X
Is 1.0D <with respect to the size D of the diamond grain 2.
Since X <2.0D, one or more diamond grains 2 are prevented from simultaneously entering one through hole 6. A shatterproof wall 5a is provided around the array plate 5.

As shown in FIG. 4, diamond grains 2 are scattered on the array plate 5 with the array plate 5 placed on the surface of the support member 1. At this time, appropriate vibration is applied to the array plate 5 so that the diamond grains 2 enter all the through holes 6. Diamond grains 2 in all through holes 6
If the invades, the extra diamond grains 2 on the array plate 5 are removed by using a brush or the like. After that, when the array plate 5 is removed from the surface of the support member 1, the diamond grains 2 become
It will remain on the surface of the support member 1 in the state of being arranged as shown in FIGS.

After the diamond grains 2 are arranged on the surface of the support member 1 as described above, the diamond grains 2 are fixed by single layer brazing. During this brazing, the adhesive 4 applied to the surface of the supporting member 1 is sublimated by heating the brazing material 3 and does not remain on the surface of the supporting member 1.

In the first method, instead of the array plate 5, a mesh woven with wires may be used. That is, the openings of the mesh are used as the through holes 6 in the array plate 5, and the diamond grains 2 are put into the openings to be arrayed on the surface of the support member 1.

In the second method, instead of directly arranging the diamond grains 2 on the surface of the supporting member 1 as in the first method, the diamond particles 2 are once arranged on a holding member such as an adhesive sheet and then supported. The transfer is performed on the surface of the member 1.

As shown in FIG. 6A, the array plate 7 includes
A recess 8 for arranging the diamond grains 2 is formed. That is, the recesses 8 are arranged on the array plate 7 in the same manner as the arrays shown in FIGS. The diameter X of the recess 8 is 1.0D <with respect to the diamond grain size D.
Setting X <2.0D is the same as the through hole 6 described in the first method.

The diamond grains 2 are scattered on the array plate 7. Also at this time, as described in the first method,
Appropriate vibration is applied to the array plate 7 so that the diamond grains 2 enter all the recesses 8. All recesses 8
If the diamond grains 2 have entered, the extra diamond grains 2 on the array plate 7 are removed using a brush 9 or the like.

Next, the adhesive sheet 10 is attached to the surface of the array plate 7 where the recess 8 is opened. Then, as shown in FIG. 6B, when the adhesive sheet 10 is peeled off by reversing the arrangement plate 7 upside down, the diamond particles 2 are held in the adhesive sheet 10 in an arrayed state. Become.

The pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet 10 holding the diamond grains 2 is bonded to the surface of the support member 1 coated with the adhesive 4. Therefore, as shown in FIG. 7, one end of the diamond grain 2 is the adhesive sheet 10
Side, the other end is in a state of being supported by the surface side of the support member 1. After that, the diamond grains 2 can be arranged on the surface of the support member 1 by leaving the diamond grains 2 on the surface side of the support member 1 and removing only the adhesive sheet 10.

As a method of removing only the pressure sensitive adhesive sheet 10, for example, the solubility of the adhesive material of the pressure sensitive adhesive sheet 10 and the solubility of the adhesive agent 4 on the support member 1 side may be made different. In this case, if the environment in which the adhesive agent of the pressure-sensitive adhesive sheet 10 is melted in the state shown in FIG. Only the adhesive sheet 10 can be removed.

After the diamond grains 2 are arranged on the surface of the supporting member 1 as described above, the diamond grains 2 are fixed by single layer brazing. During this brazing, the adhesive 4 applied to the surface of the supporting member 1 is sublimated by heating the brazing material 3 and does not remain on the surface of the supporting member 1.

In the second method, the array plate 7 is provided with a recess 8
However, it may be a through hole. In this case, if the support member 1 shown in FIG. 4 is changed to the pressure-sensitive adhesive sheet 10, the diamond particles can be arranged on the pressure-sensitive adhesive sheet 10, so that it can be transferred to the surface of the support member 1.

As described above, according to this embodiment,
Since the diamond grains 2 are regularly arranged, CM
There is no solid difference between P conditioners, and stable CMP conditioner characteristics can be obtained. Further, by arranging the diamond grains 2 substantially radially from the center of the supporting member 1, the density is reduced from the inside to the outside of the supporting member 1, and the region where the diamond grains 2 do not exist is radially arranged. Therefore, the slurry can be released toward the outside of the supporting member 1 during polishing, and micro scratches can be reduced. Further, since it is not necessary to perform a special process for releasing the slurry on the support member 1, it is possible to reduce the labor and cost of the process.

In this embodiment, the diamond grains 2 are used as the hard abrasive grains in the present invention, but other materials such as cubic boron nitride, boron carbide, silicon carbide or aluminum oxide may be used. It may be.

The diamond grains 2 may be fixed to the support member 1 by a method other than brazing, such as nickel electrodeposition.

Here, as a preferred example, a method of fixing diamond grains by brazing will be described.
As a brazing material, a melting point 650 containing 0.5 to 20 wt% of one or more selected from titanium, chromium, or zirconium.
By using an alloy of ℃ to 1200 ℃, a carbide layer of the metal is formed at the interface between the diamond grains and the brazing alloy. The content of at least one selected from titanium, chromium, and zirconium contained in the brazing material to 0.5 to 20 wt% means that the content of the metal is less than 0.5 wt% at the interface of the diamond-brazing alloy. This is because the carbide layer is not formed, and when 20 wt% is added, a carbide layer showing sufficient bonding strength is formed.

The brazing alloy has a melting point of 650 ° C. to 1200 ° C.
The alloy of is that at a brazing temperature of less than 650 ° C,
This is because it is not preferable because the bonding strength cannot be obtained and the brazing temperature exceeding 1200 ° C. deteriorates the diamond. As the brazing alloy, for example, a nickel (Ni) -based alloy containing the above components can be preferably used.

A suitable brazing alloy thickness is 0.2 to 1.5 times the thickness of diamond grains. This is because if the thickness is too thin, the bonding strength between the diamond and the brazing alloy will be low, and if it is too thick, the brazing material and the supporting member will easily peel off.

The diameter of diamond grains is 50 μm to 300 μm.
It is preferably set to μm. This is because fine diamond particles having a particle size of less than 50 μm cannot provide a sufficient polishing rate, tend to agglomerate, and easily fall off. Also, with coarse-grained diamond grains of more than 300 μm, stress concentration during polishing becomes large and the diamond grains are likely to fall off.

[0042]

As described above, according to the present invention, CM
Since there is no difference in solid state between P conditioners and stable CMP conditioner characteristics can be obtained,
It is possible to realize a stable mass production CMP process. Further, the slurry can be released at the time of polishing, micro scratches can be reduced, and it is not necessary to perform special processing for that purpose on the supporting member, so that the labor and cost of processing can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a CMP conditioner.

FIG. 2 is a diagram showing an example of an array of diamond grains 2.

FIG. 3 is a diagram showing an example of an array of diamond grains 2.

FIG. 4 is a diagram for explaining a method of arranging diamond grains 2 according to the first method.

FIG. 5 is a diagram for explaining an array plate 5.

FIG. 6 is a diagram for explaining a method of arranging diamond grains 2 according to a second method.

FIG. 7 is a diagram for explaining a method of arranging diamond grains 2 according to a second method.

FIG. 8 is a diagram for explaining a CMP process.

FIG. 9 is a diagram for explaining a conventional CMP conditioner.

FIG. 10 is a schematic view showing a CMP conditioner having relief grooves 203 formed therein.

[Explanation of symbols]

1 Support member 2 diamond grains 3 brazing material 4 adhesive 5 array board 5a Scatter prevention wall 6 through holes 7 Array board 8 recess 9 brush 10 Adhesive sheet 101 chemical slurry 102 polishing cloth 103 semiconductor substrate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Setsuo Sato             20-1 Shintomi, Futtsu City Nippon Steel Co., Ltd.             Inside the surgical development headquarters (72) Inventor Ryuichi Araki             20-1 Shintomi, Futtsu City Nippon Steel Co., Ltd.             Inside the surgical development headquarters F-term (reference) 3C047 EE18 EE19                 3C058 AA07 AA09 AA19 CB02 CB10                       DA12                 3C063 AA10 AB05 BB02 BC02 BG07                       EE26 FF23

Claims (13)

[Claims] 1. A CMP conditioner comprising a support member and a plurality of hard abrasive grains provided on the surface of the support member, wherein the plurality of hard abrasive grains are regularly formed on the surface of the support member. The CMP conditioner is characterized in that the density is reduced from the inside to the outside of the support member. 2. The hard abrasive grains are arranged substantially radially from the center of the support member.
The CMP conditioner described in 1. 3. A CMP conditioner comprising a support member and a plurality of hard abrasive grains provided on the surface of the support member, wherein the plurality of hard abrasive grains are present on the surface of the support member. CM characterized in that the non-existing area is secured in a substantially radial manner
P conditioner. 4. The C according to claim 1, wherein the hard abrasive grains are diamond grains.
MP conditioner. 5. A melting point 650 containing 0.5 to 20 wt% of at least one selected from titanium, chromium, and zirconium.
C. to 1200.degree. C., the diamond particles are single-layered or brazed to the supporting member made of a metal and / or alloy, and titanium, chromium, or zirconium is used at the interface between the diamond particles and the alloy. The CMP conditioner according to claim 4, wherein a carbide layer of a selected metal is formed. 6. The CMP conditioner according to claim 5, wherein the alloy having a melting point of 650 ° C. to 1200 ° C. is a nickel-base alloy. 7. A procedure for regularly arranging a thin plate-shaped array member having a plurality of through holes arranged so that the density decreases from the inner side to the outer side on the surface to be arrayed, and the array. A method of arranging hard abrasive grains for use in a CMP conditioner, comprising the step of inserting hard abrasive grains into each through hole of a member. 8. A procedure of arranging a thin plate-shaped array member in which a plurality of through holes do not exist substantially radially on the array surface, and hard abrasive grains are inserted into each through hole of the array member. A method of arranging hard abrasive grains for use in a CMP conditioner, comprising: 9. The method of arranging hard abrasive grains for use in a CMP conditioner according to claim 7, wherein the surface to be arranged is a surface of a support member that constitutes a CMP conditioner. 10. A procedure of holding a plurality of hard abrasive grains on a holding member in a state where they are regularly arranged in such a manner that the density decreases from the inner side to the outer side, and the hard abrasive grains held by the holding member. Is transferred to the surface of the support member constituting the CMP conditioner, and a method of arranging hard abrasive grains for use in the CMP conditioner. 11. A procedure for holding a plurality of hard abrasive grains on a holding member in a state where a plurality of hard abrasive grain-free regions are substantially radially secured, and a hard abrasive grain held by the holding member, A procedure for transferring to the surface of a support member constituting a CMP conditioner, and a method for arranging hard abrasive grains for use in a CMP conditioner. 12. The holding member is provided with a first bonding means for holding the hard abrasive grains, and the supporting member is provided with a second bonding means on the surface thereof. The method of arranging hard abrasive grains for use in a CMP conditioner according to claim 10 or 11, characterized in that the properties are different. 13. After arranging the hard abrasive grains on the surface of the support member by utilizing the arranging method of the hard abrasive grains used in the CMP conditioner according to any one of claims 7 to 12, A method for manufacturing a CMP conditioner, characterized in that the hard abrasive grains are fixed to the surface of the support member.