JP2008055593A - Diamond conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diamond conditioner capable of attaining high practicality and a long life. <P>SOLUTION: This conditioner conditions a surface state for a polishing cross used in a CMP device for polishing a semiconductor wafer. This conditioner includes a disc-shaped conditioner substrate 2 and a plurality of concentric band-shaped diamond abrasive grain adhesive portions 4A, 4B and 4C provided on the conditioner substrate 2 and partitioned by ring-shaped recess grooves 3. Diamond abrasive grains 6A, 6B and 6C are made to adhere to the diamond abrasive grain adhesive portions 4A, 4B and 4C through an adhesion layer. The diamond abrasive grains 6A, 6B and 6C different in type are made to adhere to surfaces of the respective diamond abrasive adhesive portions 4A, 4B and 4C. The surface of the conditioner after the adhesion of the diamond abrasive grain is adjusted so as to form a roughly flat surface. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a diamond conditioner for adjusting the surface condition of a polishing loss used in a CMP apparatus (chemical mechanical polishing machine) for polishing a semiconductor wafer.

  A semiconductor wafer is manufactured by slicing a silicon ingot having crystal growth in a cylindrical shape with a predetermined thickness. The semiconductor wafer sliced into a disk shape is sent to processing steps such as STD, ILD, W, and Cu processes. In these processes, the semiconductor wafer is chemically and mechanically polished by a CMP apparatus.

  The CMP apparatus etches a semiconductor wafer and performs chemical polishing using an alkali solution, an acid solution, a solution containing a neutral chelating agent, or the like. Further, mechanical polishing is performed using fine particle silica or the like (free abrasive grains). This polishing accuracy greatly affects the quality of the semiconductor wafer.

  The CMP apparatus polishes a semiconductor wafer chucked by a chuck mechanism by pressing it onto a polishing cloth. The polishing cloth is stretched on the upper surface of the disc-shaped polishing plate. The polishing plate is rotated by a rotating mechanism on the lower surface side. The chuck mechanism is fixed to the lower end of the spindle shaft that moves up and down above the polishing plate. The spindle shaft rotates in the opposite direction to the polishing plate. The semiconductor wafer chucked by the chuck mechanism is pressed against the polishing cloth while being rotated by the spindle shaft. During the polishing process, a slurry in which fine particle silica or the like is mixed with an alkali solution or the like is dropped onto the polishing cloth.

When a polishing cloth is used for a long time in a CMP apparatus, the flatness of the polishing surface is lowered and clogging occurs. At the same time, the polishing accuracy and polishing efficiency of the semiconductor wafer are reduced. Therefore, a conditioner that adjusts the surface state of the polishing cloth is used. The conditioner has a disk shape and rotates so as to be pressed onto the polishing cloth. The arm that supports the conditioner moves the conditioner on the polishing cloth. By this operation, the conditioner uniformly contacts the entire surface of the polishing cloth. The conditioner cuts the surface of the polishing cloth to create a new surface and optimizes the surface roughness. Conditioners are required to have efficient conditioning performance and durability. These techniques are described in the following documents (see Patent Documents 1 to 4).
Japanese Patent Laid-Open No. 11-300601 Japanese Patent Laid-Open No. 2001-341061 JP 2003-25230 A JP 2003-94332 A

  The conventional conditioner described above has a drawback that if the polishing performance of the polishing cloth is further stabilized, the polishing condition is not sufficient for the demand and the life is short. An object of the present invention is to provide a diamond conditioner with high practicality and a long life.

The present invention solves the above problems by the following configurations.
<Configuration 1>
A conditioner for adjusting the surface state of a polishing cloth used in a CMP apparatus for polishing a semiconductor wafer, comprising a disk-shaped conditioner substrate and a ring-shaped groove provided on the conditioner substrate. A plurality of concentric belt-shaped diamond abrasive bonded portions separated from each other, and diamond abrasive particles bonded to the surface of these diamond abrasive bonded portions via an adhesive layer, and each diamond abrasive bonded portion A diamond conditioner characterized by adhering different types of diamond abrasive grains and adjusting the surface of the conditioner after the diamond abrasive grains adhesion to form a substantially flat surface.

  Since a plurality of concentric belt-shaped diamond abrasive bonding portions are provided and different types of diamond abrasive particles are bonded to each other, the surface roughness can be optimized while suppressing abrasion of the polishing cloth.

<Configuration 2>
The diamond conditioner according to Configuration 1, wherein a ring-shaped concave groove is formed on a surface of the conditioner substrate to form a plurality of concentric band-shaped diamond abrasive bonding portions.

  The conditioner can be an integrated and robust structure.

<Configuration 3>
In the diamond conditioner according to Configuration 1, each of the diamond abrasive bond portions is formed by an annular block, is fitted into a recessed portion formed on the conditioner substrate, and is fixed by bolting or an adhesive. Diamond conditioner characterized by that.

  The diamond abrasive-bonded portion constituted by the annular block can be easily and easily replaced, and has good maintainability.

<Configuration 4>
In the diamond conditioner according to Configuration 1 or 2, an outer peripheral belt-shaped portion, an inner peripheral belt-shaped portion, and a central circular portion, which are separated from each other by a ring-shaped groove, are provided on the conditioner substrate. A diamond conditioner characterized in that a diamond grain having a grain size of # 400 to # 80 according to JIS standards is adhered to the belt-like portion, and a diamond grain having a particle size smaller than that of the outer belt-like portion is adhered to the inner belt-like portion. .

  A new surface can be quickly formed on the polishing cloth with diamond grains having a large particle diameter on the outer periphery and finely finished with diamond grains having a small particle diameter on the inner periphery.

<Configuration 5>
In the diamond conditioner according to Configuration 1 or 2, an outer peripheral belt-shaped portion, an inner peripheral belt-shaped portion, and a central circular portion, which are separated from each other by a ring-shaped groove, are provided on the conditioner substrate. A diamond conditioner characterized in that a diamond abrasive grain having a grain size larger than that of the outer peripheral band-shaped portion is bonded to the band-shaped portion in accordance with JIS standard # 400 to # 80 particle size, and the inner peripheral band-shaped portion. .

  A new surface can be made with diamond grains having a small particle diameter on the outer periphery, and roughened with diamond grains having a large particle diameter on the inner periphery. Accordingly, the surface roughness can be adjusted to be sufficiently rough while minimizing the wear of the polishing cloth.

<Configuration 6>
In the diamond conditioner according to Configuration 1 or 2, an outer peripheral belt-shaped portion, an inner peripheral belt-shaped portion, and a central circular portion, which are separated from each other by a ring-shaped groove, are provided on the conditioner substrate. A diamond conditioner characterized in that blocky diamond abrasive grains are bonded to the band-shaped portion, and sharp diamond abrasive particles are bonded to the inner band-shaped portion.

  Blocky diamond abrasive grains have lower edge sharpness than sharp diamond abrasive grains. In addition, the former is mechanically damaged and is less likely to fall off than the latter. Accordingly, the polishing cloth having a rough surface is first shaved with blocky diamond abrasive grains and then finished with sharp diamond abrasive grains. This improves the durability of the conditioner.

<Configuration 7>
In the diamond conditioner according to the sixth aspect, blocky diamond abrasive grains are bonded to the outer band, sharp diamond grains are bonded to the inner band, and the inner band is bonded to the outer band. A diamond conditioner characterized by adhering diamond abrasive grains having a particle size smaller than that of the belt-shaped portion.

  Sharp diamond abrasive grains are made larger to improve durability.

<Configuration 8>
In the diamond conditioner according to the sixth aspect, blocky diamond abrasive grains are bonded to the outer band, sharp diamond grains are bonded to the inner band, and the inner band is bonded to the outer band. A diamond conditioner characterized by adhering diamond abrasive grains having a particle size smaller than that of the belt-shaped portion.

  It can be finely finished with diamond grains having a small inner diameter.

<Configuration 9>
In the diamond conditioner according to Configuration 1 or 2, the conditioner substrate is provided with an outer peripheral belt-shaped portion, an inner peripheral belt-shaped portion, and a central circular portion that are separated from each other by a ring-shaped concave groove. The size was selected so that the width of the outer band was 2 or more, 30 or less, the width of the inner band was 2 or more and 50 or less, and the radius of the central circle was 20 or more when the radius of the substrate was 100. Diamond conditioner characterized by that.

  If the radius of the center circle is less than 20, the peripheral speed of the center is slow, so that sufficient conditioning cannot be performed. The width of the outer peripheral belt-like portion and the inner peripheral belt-like portion may be selected in accordance with the assignment of making a new surface on the polishing cloth with the outer peripheral belt-like portion and finishing with the inner peripheral belt-like portion.

<Configuration 10>
The diamond conditioner according to Configuration 9, wherein the inner circumferential strip has a longer radial dimension than the outer circumferential strip.

  In order to sufficiently exhibit the finishing function of the polishing cloth, it is preferable that the width of the belt-like portion on the inner periphery is wider.

<Configuration 11>
The diamond conditioner according to any one of Items 1 to 9, wherein the outer peripheral band-shaped portion has a tapered surface on the outermost periphery, and diamond abrasive grains are bonded to the Taber surface. .

  When the conditioner substrate is pressed against the polishing cloth, the taber surface first contacts the polishing cloth. Therefore, the polishing efficiency is increased because the diamond abrasive grains are bonded here.

<Configuration 12>
The diamond conditioner according to the eleventh aspect, wherein a diamond abrasive having a larger particle diameter than that of the other surface is bonded to the taber surface.

  Since this portion is subjected to the most mechanical stress, diamond grains having a high strength and a large grain size are bonded.

<Configuration 13>
The diamond conditioner according to any one of the constitutions 1 to 9, wherein diamond abrasive grains are bonded to the upper and side surfaces of each band-like portion separated by a ring-shaped concave groove.

  Thereby, a diamond abrasive grain can be firmly fixed to the edge of a groove | channel. Further, the substrate surface can be used widely and effectively.

<Configuration 14>
A polishing cloth conditioner in a CMP apparatus for polishing a semiconductor wafer, comprising a disk-shaped conditioner substrate and a short arc-shaped continuous ring formed on the outer periphery of the conditioner substrate and integrally formed on the outer periphery. A plurality of diamond abrasive grains bonded to each other, a plurality of short arc-shaped diamond abrasive bonds formed in a spiral shape inside a plurality of short arc-shaped diamond abrasive bonds continuous with the ring, and the plurality of diamond abrasive grains A plurality of types of diamond abrasive grains that are bonded via an adhesive layer to the upper surface and the upper side surface of the bonding portion, and bonding the different types of diamond abrasive grains to the plurality of diamond abrasive bonding portions, A diamond conditioner characterized in that the surface of the conditioner after adhering the diamond abrasive grains is flush.

Hereinafter, embodiments of the diamond conditioner of the present invention will be described in detail with reference to the drawings. 1 is a plan view of a diamond conditioner of Example 1. FIG.
FIG. 2 is a cross-sectional view of the main part of the diamond conditioner of Example 1.
FIG. 3 is a cross-sectional view of a main part of the diamond conditioner according to the second embodiment.
FIG. 4 is a cross-sectional view of the main part of the diamond conditioner of Example 3.
FIG. 5 is a cross-sectional view of the main part of the diamond conditioner of Example 4.
FIG. 5 is a plan view for explaining an arrangement example of the diamond abrasive grain bonding portion of the fifth embodiment.
FIG. 6 is a perspective view of an example of a CMP polishing apparatus using a diamond conditioner.
8 and 9 are explanatory views for demonstrating the operational effects of the above diamond conditioner.

  The CMP polishing apparatus (chemical mechanical polishing machine) shown in FIG. 6 polishes the semiconductor wafer W using a polishing cloth C. The diamond conditioner 1 conditions the polishing cloth C. The polishing process of the semiconductor wafer W includes ILD, STI, and Cu processes. The CMP polishing apparatus requires different polishing conditions for each process.

  As shown in FIG. 6A, the CMP polishing apparatus rotationally drives a polishing plate B provided at the upper end of the rotation axis A by the rotation axis A. A polishing cloth C is stretched over the polishing plate B. Above the polishing plate B, a vertically movable spindle shaft D that rotates in the direction opposite to the rotation shaft A is disposed. The semiconductor wafer W is chucked by the chuck mechanism E provided at the lower end of the spindle shaft D. The semiconductor wafer W and the polishing plate B are rotated while dripping a slurry in which fine particle silica or the like is mixed with an alkali solution or the like onto the upper surface of the polishing cloth C. In this way, the semiconductor wafer W is subjected to CMP polishing.

  When the polishing cloth C is subjected to CMP polishing for a long time, the flatness of the polishing surface decreases. In addition, clogging occurs. This causes a decrease in polishing accuracy and polishing efficiency of the semiconductor wafer W. Therefore, an arm F that protrudes from the side of the polishing plate B to above the polishing cloth C and can be moved back and forth is provided. A rotating shaft is provided at the tip of the arm F, and the conditioner 1 is fixed to the lower end of the rotating shaft. Then, the conditioner 1 is rotated while advancing and retreating at least the range from the outer periphery of the polishing plate B to the vicinity of the center. Thus, the condition of the polishing cloth C is adjusted by the conditioner 1.

  As shown in FIG. 6B, the conditioner 1 is pressed against the polishing cloth C in a slightly inclined state and moves in the direction of the arrow 10. First, when viewed in the direction of travel of the conditioner 1 (the direction of the arrow 10), the front outer peripheral edge is in contact with the polishing cloth. Thereafter, the outer peripheral portion of the conditioner 1 contacts the polishing cloth. The outer peripheral part of the conditioner 1 contributes to the process of making a new surface of the polishing cloth. Subsequently, the inner peripheral portion of the conditioner 1 is in contact with the polishing cloth. The finishing process is performed here. The rear portion of the conditioner 1 in the traveling direction contributes to the finishing process.

  As shown in the plan view of FIG. 1 and the longitudinal sectional view of FIG. 2, the conditioner substrate 2 has a disk shape in which ring-shaped concave grooves 3 are formed at two locations. This is made of, for example, a metal such as stainless steel or alumina ceramic. It can also be made of hard plastic.

  The plurality of diamond abrasive grain bonding portions 4 are formed concentrically on the surface of the conditioner substrate 2 with the ring-shaped groove 3 therebetween. In the example of this figure, the ring-shaped concave grooves 3 are cut in two places. As a result, a circular diamond abrasive bonding portion 4A located at the center side, an outer band-like diamond abrasive bonding portion 4B, and an outermost band-like diamond abrasive bonding portion 4C are formed.

  In the embodiment shown in FIG. 1, the ring-shaped concave grooves 3 are cut at two locations. However, it can be one or three. In the case of one place, the diamond abrasive grain adhesion part is 2. In the case of three places, there will be four diamond abrasive joints. As will be described later, diamond abrasive grains need not be bonded to the circular portion at the center. When the conditioner is started by pressing the diamond conditioner against the polishing cloth, the entire surface is slightly bent by the pressing force. That is, the diamond conditioner is elastically deformed by the pressing force. A disk with an annular groove is more easily elastically deformed by a pressing force than a disk without a groove at all. The two ring-shaped grooves are boundary portions where the grain size of the diamond abrasive grains changes. Here, the disk is bent. If it carries out like this, the inner peripheral part can heighten the effect which determines the finishing surface roughness of polishing cloth.

  The plurality of types of diamond abrasive grains 6A, 6B, and 6C are artificial diamond abrasive grains. The diamond abrasive grains 6A, 6B, and 6C of the diamond abrasive grain bonding portions 4A, 4B, and 4C have different particle sizes, for example. For example, the hardness is different even if the particle size is the same. For example, one of the particles has a round shape and the other has a sharp corner. In this way, the types are made different. A particle having a round shape is called a blocky one, and a particle having a sharp corner is called a sharp one. From the blocky to the sharp with the same granularity, for example, those listed in the catalog of Diamond Innovation International may be selected.

  Diamond abrasive grains 6 </ b> A, 6 </ b> B, and 6 </ b> C are bonded to the upper surface and the side surface of each diamond abrasive bonding portion 4 via an adhesive layer 5. As shown in FIG. 2 etc., the taper surface is formed in the outer peripheral edge part of the diamond abrasive grain adhesion part 4 located in the outermost periphery. Diamond abrasive grains 6C are also bonded to the upper side of the tapered surface via the adhesive layer 5.

  In this embodiment, even if different types of diamond abrasive grains 6A, 6B, and 6C are bonded to the upper surfaces of the respective diamond abrasive bond portions 4A, 4B, and 4C, the surface of the diamond conditioner 1 after bonding is the same. It is adjusted to be in the same plane. For this reason, in this example, the height of the surface of the substrate 2 is adjusted. Actually, the difference in height is sufficiently acceptable up to about 0.5 mm. Therefore, the surface of the diamond conditioner 1 only needs to form a substantially flat surface. If the difference in the outer diameter of each diamond abrasive grain does not exceed about 0.5 mm, there is no need to adjust the height of the substrate. Furthermore, the ring-shaped concave groove is not necessarily formed by cutting on the substrate. When different types of diamond abrasive grains 6A, 6B, and 6C are bonded in an annular shape with a predetermined interval, a concave groove is automatically formed between them. This can also be called a ring-shaped groove.

The significance of bonding different types of diamond abrasive grains will be described below.
(Example 1) First, in the first example, blocky diamond abrasive grains are bonded to the outer peripheral band-shaped portion, and sharp diamond abrasive grains are bonded to the inner peripheral band-shaped portion. Since the circular portion located at the center side has a low rotation speed and a small polishing effect, the diamond abrasive grains need not be bonded. In the next example, diamond abrasive grains having a particle size of # 400 or more and # 80 or less in accordance with JIS standards are adhered to the outer peripheral belt-like portion, and diamond particles having a particle size larger than the outer peripheral belt-like portion are bonded to the inner peripheral belt-like portion. If it exceeds # 400, the polishing effect is too small. In addition, if it is # 80 or less, the surface roughness after finishing becomes too rough, so this range is suitable. In the JIS standard, the particle sizes from # 400 to # 80 have an average particle size of about 45 μm to about 250 μm. Preferably, the average particle size is different by 20% or more. When the average particle size is less than 20%, the difference in effect does not appear sufficiently as compared with the case where the same type of diamond abrasive is used.

  Focusing on the particle size of the diamond abrasive grains fixed on the conditioner surface, the larger the particle size, the rougher the surface roughness of the finished polishing cloth. The larger the abrasive grain size, the faster the polishing cloth is cut. The larger the grain size of the abrasive grains, the rougher the surface roughness after finishing of the polishing cloth. However, it is a precondition that the diamond abrasive grains are manufactured under substantially the same conditions.

  Focusing on the surface state of diamond abrasive grains, sharper ones with higher surface sharpness are better. For example, diamond abrasive grains with a large amount of impurities have many irregular irregularities on the surface and high surface sharpness. Even if the abrasive grains have the same particle size, the polishing cloth is cut faster when the surface sharpness is higher than the blocky one with lower surface sharpness. The surface roughness of the polishing cloth after finishing becomes rougher when the surface sharpness is higher. Also, the diamond abrasive grains 6 having a hard hardness have a high polishing ability, and those having a soft hardness have a low polishing ability.

  When conditioning the surface of the polishing cloth, first, a rough surface is cut by a predetermined amount to obtain a new surface, and then finished to the desired surface roughness. Conventionally, a single disk with uniform homogeneous diamond grains fixed on the entire surface was used. However, for example, if a rough surface is cut to the finish only with diamond grains having a large particle size, the polishing cloth is excessively shaved when a new surface is put out, and the polishing cloth is consumed heavily. That is, the polishing cloth is shaved too much before finishing.

  Therefore, the polishing cloth with a rough surface is first ground with blocky diamond abrasive grains on the outer periphery, and then finished with sharp diamond abrasive grains on the inner periphery. Alternatively, a new surface of the polishing cloth is first formed with diamond abrasive grains having a small particle diameter on the outer periphery, and then a finishing process is performed with diamond having a large particle diameter on the inner periphery. This improves the durability of the conditioner. In either case, the surface roughness at the finish can be adjusted to be sufficiently rough while minimizing abrasion of the polishing cloth.

  The diamond abrasive grains adhered to the belt-like portion on the outer periphery of the conditioner substrate 2 are in contact with the polishing cloth at a high speed and at a high pressure. Further, the vibration in the direction perpendicular to the polishing cloth surface is more intense near the outer periphery of the conditioner substrate 2 than near the inner periphery. Accordingly, the diamond abrasive grains are mechanically damaged and easily fall off. However, diamond grains having a small particle diameter or blocky diamond grains have a higher mechanical strength than diamond grains having a large particle diameter or sharp diamond grains. Also, the mechanical resistance when cutting the polishing cloth is small. Therefore, durability is high. The strength of the entire substrate is also averaged, and the overall durability is improved.

  For example, in an ILD process in a CMP polishing apparatus, a high polishing rate for the semiconductor wafer W is required. If the surface roughness of the polishing cloth C is increased, the polishing rate of the semiconductor wafer W is increased. Large diamond grains and sharp diamond grains have a high mechanical load and are easy to fall off and wear heavily. Accordingly, this causes a scratch on the semiconductor wafer W after being processed by the CMP polishing apparatus.

  Therefore, as described above, diamond abrasive grains having a small particle diameter or blocky diamond abrasive grains are arranged on the belt-like portion on the outer periphery of the substrate. For example, MBG680 (manufactured by Diamond Innovation International, average particle size X = 160 μm) was used as a blocky diamond abrasive. Further, MBG620 (the same, average particle diameter X = 160 μm) was used as sharp diamond abrasive grains.

  As described above, the scratch of the semiconductor wafer W was overwhelmingly less than that in the case where MBG620 (made by Diamond Innovation International) was used on the entire surface of the substrate. When sharp diamond abrasive grains MBG620 were used for the inner peripheral band-like portion, the surface roughness of the finished polishing cloth C was almost the same.

  It should be noted that when making a new surface on the polishing cloth with the belt-like portion on the outer periphery, it is necessary to adjust the excessive cutting. For this reason, it is preferable to select the width of the belt-like portion so that the inner belt-like portion has a longer radial dimension than the outer belt-like portion. More specifically, when the radius of the conditioner substrate is 100, the width of the outer band is 2 to 30, the width of the inner band is 2 to 50, and the radius of the central circle is 20 or more. It is preferable to select the size so that If the width of the outer band is 2 or less, the meaning of providing the outer band disappears. If the width of the outer peripheral strip portion exceeds 30, the effective width of the inner peripheral strip portion becomes too narrow. If the width of the inner peripheral belt-like portion is less than 2, the meaning of providing the inner peripheral belt-like portion is lost. If the width of the inner peripheral band portion exceeds 50, an effective outer peripheral band portion is not provided. The radius of the central circle is automatically determined by the remaining part of the outer and inner belts.

(Example 2) Further, in the STI process in the CMP polishing apparatus, it is required that the semiconductor wafer W has fewer scratches. In addition, there is a demand for a conditioner with a longer life. Therefore, in the prior art, it is conceivable to use MBG680 having a smaller particle diameter instead of MBG620 as diamond abrasive grains. However, the conditioner using only MBG680 has a drawback that the polishing rate is slow.

  Therefore, diamond abrasive grains having a small particle diameter (average particle diameter X = 90 μm) were used for the outer peripheral band-shaped portion, and diamond abrasive grains having a large particle diameter (X = 160 μm) were used for the inner peripheral band-shaped portion. Thereby, the mechanical strength of the strip | belt-shaped part of the outer periphery of a conditioner increased, and the scratch reduced. In addition, since the surface roughness of the polishing cloth C can be sufficiently roughened by the diamond grains having a large particle diameter on the inner peripheral belt-like part, the polishing rate of the semiconductor wafer W by the boring cloth is also increased. In addition, the overall processing speed is improved, and the life of the conditioner is approximately doubled.

(Example 3) On the other hand, in the Cu process of the CMP polishing apparatus, dishing and erosion are problems. It is known that the finer the surface roughness of the polishing cloth C, the less the dishing and erosion. However, for example, when fine diamond abrasive grains (for example, average particle diameter X = 10 μm) are used, although there is little dishing and erosion, there is a problem that the life of the diamond conditioner becomes extremely short.

  Therefore, in this example, diamond abrasive grains having a large particle diameter (eg, average particle diameter X = 40 μm) are used for the outer peripheral band-shaped portion, and diamond abrasive grains having a small particle diameter (for example, Average particle size X = 10 μm) is used. It is preferable to bond them with their heights substantially equal. With this configuration, dishing and erosion can be reduced to almost the same level as when only fine diamond abrasive grains (eg, average particle diameter X = 10 μm) are used. In addition, the life of the diamond conditioner has been doubled.

  In practice, it is preferable to bond diamond abrasive grains having a particle size of # 400 to # 80 according to JIS standards to the outer peripheral belt-like portion and a particle size smaller than that of the outer peripheral belt-like portion to the inner peripheral belt-like portion. The reason is the same as in Example 1. If it exceeds # 400, the polishing effect is too small. In addition, if it is # 80 or less, the surface roughness after finishing becomes too rough, so this range is suitable. Preferably, the average particle size is different by 20% or more. When the average particle size is less than 20%, the difference in effect does not appear sufficiently as compared with the case where the same type of diamond abrasive is used. For example, # 200 diamond abrasive grains 6 are used in a circular diamond abrasive grain bonded portion at the center side. The diamond abrasive grains of # 120 are used for the diamond abrasive-bonding portion 4 of the belt portion on the inner periphery. The diamond abrasive grain 6 of # 80 is used for the ring-shaped diamond abrasive grain adhesion part 4 of the belt-like part of the outer periphery. Thereby, the target performance was able to be obtained.

  Further, as shown in FIG. 2 and the like, diamond abrasive grains 6A, 6B, and 6C are bonded via an adhesive layer 5 on the upper surface and the side surface of each diamond abrasive bonding portion 4. A tapered surface is formed on the outer peripheral edge of the diamond abrasive grain bonding portion 4 located on the outermost periphery. Diamond abrasive grains 6C are also bonded to the upper side of the tapered surface via the adhesive layer 5. As described with reference to FIG. 6B, the outer peripheral edge and the outer peripheral edge of the diamond conditioner 1 become edges, and the surface of the polishing cloth C is polished. Furthermore, it can grind even the edge of the outer periphery of a strip | belt-shaped part, or the edge of the outer periphery of a circular-shaped diamond abrasive bond part. In other words, the entire surface of the substrate 2 can be efficiently used for polishing.

  As shown in FIG. 3, the diamond abrasive grain bonding portions 4D, 4E, and 4F are formed by annular blocks, and concave portions 3D, 3E, and 3F are formed on the conditioner substrate 2. The diamond abrasive grain bonding portions 4D, 4E, and 4F are fitted into the recessed portions 3D, 3E, and 3F. Both are fixed by bolting or an adhesive. As described above, the diamond abrasive grain bonded portions 4D, 4E, and 4F configured by the annular block can be easily and easily replaced, and thus have a feature of good maintainability.

  In Example 1, the diamond abrasive grains 6A, 6B, and 6C bonded to the diamond abrasive bond portions 4A, 4B, and 4C have different particle sizes. And the difference in the size of the grains was absorbed by adjusting the heights of the diamond abrasive grain adhesion portions 4A, 4B, 4C, and the surface of the conditioner 1 was flattened. In Example 3 shown in FIG. 4, the surface of the conditioner 1 was made flat by adjusting the thickness of the adhesive layer 5 of the adhesive.

  In Example 2, the diamond abrasive grains 6D, 6E, and 6F bonded to the diamond abrasive bond portions 4D, 4E, and 4F have different particle sizes. Then, the difference in the size of the grains was absorbed by adjusting the height of the block-shaped diamond abrasive grain adhesion portions 4D, 4E, and 4F, and the surface of the conditioner 1 was flattened. In Example 4 shown in FIG. 5, the thickness of the adhesive layer 5 of the adhesive was adjusted to flatten the surface of the conditioner 1.

  In Example 5, as shown in FIG. 6, a plurality of short arc-shaped diamond abrasive bonding portions 4 </ b> G and 4 </ b> H are disposed on the surface of the disk-shaped conditioner substrate 2. These diamond abrasive grain bonding portions 4 are formed on the surface of the conditioner substrate 2 so as to bulge together. Further, in the outer periphery of the conditioner substrate 2, the diamond abrasive bond portions 4G are arranged in a ring shape. Furthermore, inside the conditioner substrate 2, diamond abrasive bond portions 4 </ b> H are arranged in a spiral shape.

  Here, the diamond abrasive grains that adhere to the diamond abrasive-bonding portion 4G located on the outer periphery and the diamond abrasive particles that adhere to the diamond abrasive-bonding portion 4H located on the inner side are of different types. Thus, the same function as in the above embodiment can be exhibited.

  FIG. 8 is an explanatory diagram showing the relationship between the display surface roughness and the polishing time. The vertical axis of the graph of FIG. 8 indicates the surface roughness Ra, and the horizontal axis indicates the polishing time (hr). The numerical value on the right is a JIS representation of the particle size of the diamond abrasive grains in the outer band and the inner band. For example, SD100-SD60 means that diamond abrasive grains of # 100 are used for the outer band and # 60 diamond bands are used for the inner band. SD100 (outside only) indicates that the diamond abrasive grains are not adhered to the inner circumferential strip. The graph of FIG. 8 demonstrates that the surface roughness after finishing of the polishing cloth is determined by the grain size of the diamond abrasive grains in the inner peripheral band-like portion. FIG. 9 is an explanatory view showing a change in the polishing rate of the polishing cloth. The vertical axis of the graph in FIG. 8 indicates the polishing rate (μm / hr), and the horizontal axis indicates the polishing time (hr). The values on the right are the same as in FIG. The graph of FIG. 9 demonstrates that the polishing rate of the polishing cloth is also determined by the grain size of the diamond abrasive grains in the inner peripheral band-like portion.

1 is a plan view of a diamond conditioner of Example 1. FIG. 1 is a cross-sectional view of a main part of a diamond conditioner of Example 1. FIG. 6 is a cross-sectional view of a main part of a diamond conditioner of Example 2. FIG. FIG. 6 is a cross-sectional view of a main part of a diamond conditioner of Example 3. 6 is a cross-sectional view of a main part of a diamond conditioner of Example 4. FIG. FIG. 10 is a plan view for explaining an arrangement example of diamond abrasive bond portions of Example 5. It is a perspective view of the example of a CMP polisher using a diamond conditioner. It is explanatory drawing which shows the relationship between display surface roughness and grinding | polishing time. It is explanatory drawing which shows the change of the grinding | polishing speed | rate of polishing cloth.

Explanation of symbols

W Semiconductor Wafer C Polishing Cloth 1 Diamond Conditioner 2 Conditioner Substrate 3 Ring-shaped Concave 4 Diamond Abrasive Bonding Area 5 Adhesive Layer 6 Diamond Abrasive Grain

Claims (14)

A conditioner for adjusting the surface state of a polishing cloth used in a CMP apparatus for polishing a semiconductor wafer,
A disc-shaped conditioner substrate;
A plurality of concentric diamond abrasive bonding portions provided on the conditioner substrate and separated by a ring-shaped groove,
These diamond abrasive grains are provided with diamond abrasive grains bonded to the surface through an adhesive layer,
Each diamond abrasive grain adhesive part is bonded with different types of diamond abrasive grains,
A diamond conditioner characterized in that the surface of the conditioner after bonding of diamond abrasive grains is adjusted so as to form a substantially flat surface. The diamond conditioner according to claim 1,
A diamond conditioner, characterized in that a ring-shaped concave groove is formed on the surface of a conditioner substrate, and a plurality of concentric diamond abrasive bonding portions are formed. The diamond conditioner according to claim 1,
The diamond abrasive bonding portion is constituted by an annular block, and is fitted into a recessed portion formed on a conditioner substrate, and is fixed by bolting or an adhesive. The diamond conditioner according to claim 1 or 2,
On the conditioner substrate, there are provided an outer peripheral belt-like portion, an inner peripheral belt-like portion and a central circle portion, which are separated from each other by a ring-shaped concave groove,
Diamond with a grain size of # 400 to # 80 according to JIS standard, and a diamond grain having a particle size smaller than that of the outer band is bonded to the outer band. Conditioner. The diamond conditioner according to claim 1 or 2,
On the conditioner substrate, there are provided an outer peripheral belt-like portion, an inner peripheral belt-like portion and a central circle portion, which are separated from each other by a ring-shaped concave groove,
Diamond with a grain size of # 400 to # 80 in accordance with JIS standards, and diamond abrasive grains having a particle size larger than that of the outer band are bonded to the outer band. Conditioner. The diamond conditioner according to claim 1 or 2,
On the conditioner substrate, there are provided an outer peripheral belt-like portion, an inner peripheral belt-like portion and a central circle portion, which are separated from each other by a ring-shaped concave groove,
A diamond conditioner characterized in that blocky diamond abrasive grains are bonded to the outer band-shaped portion and sharp diamond abrasive particles are bonded to the inner band-shaped portion. The diamond conditioner according to claim 6,
Blocky diamond abrasive grains are bonded to the outer band, sharp diamond grains are bonded to the inner band, and the diamond band having a smaller particle diameter than the inner band is bonded to the outer band. Diamond conditioner characterized by adhering grains. The diamond conditioner according to claim 6,
Blocky diamond abrasive grains are bonded to the outer band, sharp diamond grains are bonded to the inner band, and the diamond band having a smaller particle diameter than the inner band is bonded to the outer band. Diamond conditioner characterized by adhering grains. The diamond conditioner according to claim 1 or 2,
On the conditioner substrate, there are provided an outer peripheral belt-like portion, an inner peripheral belt-like portion and a central circle portion, which are separated from each other by a ring-shaped concave groove,
When the conditioner substrate radius is 100, the width of the outer band is 2 to 30, the width of the inner band is 2 to 50, and the radius of the central circle is 20 or more. Diamond conditioner characterized by selection.   10. The diamond conditioner according to claim 9, wherein the inner circumferential strip has a longer radial dimension than the outer circumferential strip. 10. The diamond conditioner according to any one of claims 1 to 9,
A diamond conditioner characterized in that a taper surface is present at the outermost band in the outer band-like portion, and diamond abrasive grains are adhered to the taber surface. The diamond conditioner according to claim 11, wherein
A diamond conditioner characterized in that diamond abrasive grains having a grain size larger than those of other surfaces are bonded to the taber surface. The diamond conditioner according to any one of claims 1 to 9,
A diamond conditioner characterized in that diamond abrasive grains are bonded to the upper and side surfaces of each band-like portion separated by a ring-shaped concave groove.   A polishing cloth conditioner in a CMP apparatus for polishing a semiconductor wafer, comprising a disk-shaped conditioner substrate and a short arc-like shape formed on the outer periphery of the conditioner substrate and integrally formed on the outer periphery. A plurality of diamond abrasive grains adhering to each other, a plurality of short arc arc diamond adhering portions formed in a spiral shape inside the plurality of short arc arc diamond adhering portions connected in a ring, and the plurality of diamond abrasive grains A plurality of types of diamond abrasive grains that are bonded to each other through an adhesive layer on the upper surface and the upper side of the bonding portion, and different diamond abrasive grains are bonded to the plurality of diamond abrasive bonding portions, A diamond conditioner characterized in that the surface of the conditioner after adhering the diamond abrasive grains is flush.

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