WO2005023487A1

WO2005023487A1 - Polishing pad, and method and apparatus for producing same

Info

Publication number: WO2005023487A1
Application number: PCT/JP2004/008631
Authority: WO
Inventors: Tatsutoshi Suzuki
Original assignee: Toho Engineering Kabushiki Kaisha
Priority date: 2003-08-29
Filing date: 2004-06-18
Publication date: 2005-03-17
Also published as: JPWO2005023487A1

Abstract

A polishing pad having a novel structure is disclosed which enables to stably form a thin, generally uniform film of a slurry on the polishing surface, and thus enables to stably improve accuracy and efficiency in polishing of semiconductor substrates. A polishing surface (14) of a polishing pad (10) is provided with a circular groove (16) extending in the circumferential direction, while a communicating hole (24) is formed so as to penetrate through the polishing pad (10) in the thickness direction. The communicating hole (24) has an opening on the bottom of the circular groove (16).

Description

Specification

Polishing pad and method and apparatus for manufacturing the same

Technical field

The present invention relates to a polishing pad used in a polishing apparatus for polishing and flattening a substrate surface such as a semiconductor wafer in a semiconductor manufacturing process, and a method and an apparatus for manufacturing a powerful polishing pad. It is.

Background art

[0002] With the miniaturization and high integration of semiconductor integrated circuits, in order to form a flattened interlayer insulating film, to form a wiring having a damascene structure, or to form a Si with good surface flatness. In order to form an SOI (silicon on insulator) having a layer, the surface to be polished of a substrate such as a semiconductor wafer is pressed against the polishing surface of a polishing pad, and a polishing slurry is provided between the substrate and the polishing pad. The flattening technique by chemical mechanical polishing (CMP), which polishes the polished surface of the substrate by the relative movement of the substrate and the polishing pad while supplying, is widely used.

[0003] By the way, in the powerful chemical mechanical polishing method, in order to realize high integration and high precision of semiconductor devices by forming wirings having a complicated fine structure in multiple layers, (I) the entire surface of the wafer is required. There is a need for “polishing accuracy” for polishing wafers with high-precision flattening ability, and (Π) “polishing efficiency” for polishing wafers with excellent work efficiency. In addition, the demands for both of these have become stronger, especially in recent years with higher densities in semiconductor devices.

[0004] Therefore, in order to respond to such a demand, a polishing pad conventionally used for a chemical mechanical polishing apparatus is basically provided with a large number of small holes ゃ and linear concave grooves on a polishing surface thereof. In such a case, a rectangular or oblique lattice-like groove is formed. It is said that vigorous groove processing stabilizes the flow of the slurry and makes the polishing pressure uniform, and is effective in stabilizing the polishing characteristics. In addition, there is an advantage that a straight groove such as a lattice-shaped groove can be easily formed by milling or the like when forming.

[0005] In recent years, further improvement in polishing accuracy and further improvement in polishing performance have been attempted. For the purpose, an annular or spiral shape or the like, circumferential grooves extending in a circumferential direction of the polishing pad has been proposed (e.g., see Patent Documents 1 and 2.) ₀ That is, in such the above straight groove In addition, when the polishing pad is rotated, the polishing conditions in the radial direction of the polishing pad are large, and the holes and grooves on the polishing pad surface are easily clogged during the polishing process. This problem has been pointed out that the progress of clogging is likely to be uneven in the surface of the polishing pad. It is being done.

[0006] In spite of this, the demand for polishing accuracy and polishing efficiency of the polishing pad has been increasingly advanced, and the required level has been extremely rapidly updated. It is still not enough to provide such a circumferential groove. It is becoming difficult to achieve a polishing accuracy and a polishing efficiency that are satisfactory.

Patent Document 1: US Pat. No. 5,921,855

Patent Document 2: US Patent No. 5984769

Disclosure of the invention

Problems to be solved by the invention

[0008] Here, the present invention has been made in view of the above-mentioned circumstances, and a problem to be solved is that polishing accuracy and polishing efficiency for a semiconductor substrate can be further improved. It is another object of the present invention to provide a polishing pad having a novel structure, and an advantageous method of manufacturing a powerful polishing pad.

Means for solving the problem

[0009] In order to solve such problems, the present inventor first performed a number of simulations and experiments on various polishing pads provided with annular or spiral circumferential grooves. The study was repeated. As a result, they have come to know a new problem to be solved for the circumferential groove. That is, in the chemical mechanical polishing method, generally, a polishing slurry is supplied at a central partial force of the polishing pad, and the centrifugal force based on the rotation of the polishing pad passes through the polishing region of the semiconductor substrate and the outer periphery of the polishing pad. The fact that this fluidized slurry easily stayed inside the circumferential groove, which would be forced to flow to the side, became apparent. The retention of the slurry in such a circumferential groove is caused by the action direction of the centrifugal force exerted on the slurry with the rotation of the polishing pad and the circumferential recess formed on the polishing surface of the polishing pad. The fact that the circumferential walls of the grooves are substantially perpendicular to each other suggests that the effect of centrifugal force on the flow and inflow and out of the slurry in the circumferential grooves is unlikely.

[0010] Thus, if used slurry or polishing debris stays in the circumferential groove, the flow state of the slurry on the surface of the polishing pad is disturbed, making it difficult to ensure uniformity of the slurry composition. In addition, the reduction of the in-plane uniformity of the polishing and the attachment of the polishing debris are liable to occur, which adversely affects the polishing accuracy and the polishing stability. To put it the other way around, by reducing or eliminating the stagnation of the slurry in the circumferential groove, the polishing accuracy and stability of the polishing pad having the circumferential groove as described above are further improved. There is room for improvement.

[0011] In order to improve the fluidity of the slurry in the circumferential groove, for example, in a polishing pad, in addition to the circumferential groove extending in the circumferential direction, the polishing pad intersects with the circumferential groove that is strong. A force S that may form a radial groove extending in the radial direction of the polishing pad. Even if such a radial groove is formed, sufficient fluidity can still be provided to the slurry in the circumferential groove. It was not something.

[0012] Hereinafter, embodiments of the present invention made on the background of the above-described circumstances will be described. In addition, constituent elements adopted in each of the embodiments described below can be adopted in any combination as much as possible. In addition, aspects or technical features of the present invention are described in the entire specification and drawings without being limited to those described below, or an invention concept that can be understood by those skilled in the art from the descriptions. It should be understood that they are recognized based on

(Aspect 1 of the Present Invention Related to Polishing Pad)

Aspect 1 of the present invention relating to the polishing pad has a thin disk shape, the back surface of which is a mounting surface superimposed on a rotating plate of the polishing device, and the front surface has a polishing surface which exerts a polishing action on a semiconductor substrate. The polishing surface, wherein a circumferential groove extending in the circumferential direction is formed on the polishing surface, and a plurality of communication holes are formed so as to penetrate in the plate thickness direction. Is opened to the polishing surface side through the circumferential groove.

(Embodiment 2 of the present invention relating to polishing pad) Further, according to the present invention, as a second aspect, in the polishing pad according to the first aspect, at least a part of the plurality of communication holes has an inner portion extending from the mounting surface side of the polishing pad to the polishing surface side. A preferred embodiment is one in which a slurry for polishing is circulated toward the polishing pad to form a slurry supply hole for supplying the slurry onto the polishing surface of the polishing pad through the circumferential groove.

[0015] In the polishing pad having the structure according to the present embodiment, a circumferential groove opening in the polishing surface and a communication hole opened in the polishing surface through the circumferential groove are employed in combination with each other. It is being done. And since the communication hole which is strong is a slurry supply hole for supplying slurry, by supplying unused new slurry stably into the circumferential groove, the slurry in the circumferential groove is Circulation can be performed effectively. As a result, it is possible to effectively discharge used slurry and polishing debris remaining in the circumferential groove, which is likely to be generated due to the circumferential groove, and to use a new slurry for the inside of the circumferential groove. Can be satisfied. Therefore, the chemical uniformity of the slurry held in the circumferential groove can be maintained at a high level, and the effect of holding the slurry originally possessed by the circumferential groove can be maintained. The effect can be more effectively and stably exhibited. As a result, excellent polishing efficiency based on the edge action of the circumferential groove can be exerted substantially uniformly over a wide area, the force can be stably exhibited over a long period of time, and excellent polishing can be performed on the semiconductor substrate. Polishing can be performed with accuracy and polishing efficiency.

[0016] Further, in the polishing pad having the structure according to the present embodiment, since the communication hole serving as the slurry supply hole is opened to the polishing surface of the polishing pad through the circumferential groove, an unused portion is used. The new slurry is supplied to the inside of the circumferential groove first with the slurry supply hole, expanded in the circumferential direction, and then overflows the circumferential groove force so that the efficiency is improved over a wide area of the polishing surface. And uniformly supplied. As a result, the circumferential groove can be used as a supply port for uniformly supplying the slurry in the circumferential direction, and the slurry can be efficiently spread over a wide area of the polished surface even when the amount of the slurry supplied is small. It becomes possible to spread to. Therefore, the polishing conditions can be made uniform and stable over the entire polished surface, and highly accurate and highly efficient polishing of the semiconductor substrate as described above can be performed while suppressing the amount of slurry used. It is possible to perform it stably. [0017] Furthermore, as a synergistic effect of the effective circulation of the slurry inside the circumferential groove and the supply of the slurry after being expanded in the circumferential direction, the amount of slurry used on the polishing surface is reduced. By reducing the thickness of the slurry, the edge action of the circumferential groove can be more effectively exerted, and the polishing efficiency can be further improved.

(Embodiment 3 of the present invention relating to polishing pad)

Further, in a third aspect of the present invention, in the polishing pad according to the first or second aspect, at least a part of the plurality of communication holes has the inside thereof mounted from the polishing surface side of the polishing pad. An aspect in which the slurry for polishing is made to flow toward the surface side to form a slurry discharge hole for discharging the slurry from the polishing surface of the polishing pad through the circumferential groove is provided. It is preferably adopted.

[0019] That is, since the circumferential groove has a specific shape extending in the circumferential direction, the used slurry and polishing debris are less likely to be discharged by centrifugal force than the radial or lattice-shaped groove, and thus the circumferential groove has a specific shape. By providing a slurry discharge hole communicating with the circumferential groove, which is easy to stay, it is possible to effectively discharge the used slurry and polishing debris staying inside the circumferential groove.

[0020] The slurry may be discharged positively by using a discharge pump or the like, or may be discharged by letting the slurry fall by its own weight.

In the polishing pad according to this aspect, a mode in which the slurry supply hole is provided in addition to the slurry discharge hole is more preferably adopted. According to such an embodiment, it is possible to more advantageously circulate the used slurry and the unused slurry in the circumferential groove, and at the same time, to make a higher adjustment of the slurry layer thickness on the polishing pad surface. It becomes possible. In addition, when supplying and discharging the slurry, the amount and pressure of the slurry and the timing of the supply and discharge of the slurry can be mutually adjusted, so that the adjustment of the slurry fluidity on the polishing surface can be made larger. It can be performed with freedom and accuracy. The arrangement positions of the slurry supply holes and the slurry discharge holes are appropriately determined in consideration of various conditions such as a desired slurry layer thickness, the fluidity of the slurry to be used, and the rotation speed of the polishing pad. For example, when a plurality of circumferential grooves are formed, the through hole formed through one of the circumferential grooves is unified to either the slurry supply hole or the slurry discharge hole. May be Alternatively, both a slurry supply hole and a slurry discharge hole may be provided in one groove.

[0022] Further, the communication holes, which are the slurry supply hole and the slurry discharge hole, need not necessarily have all the communication holes opened through the circumferential groove and are opened on the polishing surface. It may be directly opened in an unformed area. In addition, the opening of the communication hole communicating with the circumferential groove may be arbitrarily adopted, such as the bottom surface and the side wall surface of the circumferential groove.

Further, as for the specific shape, size, structure, and the like of the circumferential groove and the communication hole, various configurations can be appropriately adopted, and some preferred embodiments are shown below. It should be understood that the present invention is not to be construed as limited by the embodiments. In addition, in one polishing pad, circumferential grooves and communication holes having different shapes and sizes from each other may be formed.

(Aspect 4 of the Present Invention Related to Polishing Pad)

A fourth aspect of the present invention relating to a polishing pad is the polishing pad according to any one of the first to third aspects, wherein a central portion of the polishing surface is formed with the circumferential groove. And a through-hole is formed in the central flat area so as to penetrate in the thickness direction, so that the slurry can be supplied to the polishing surface of the polishing pad through the through-hole. Is characterized.

[0025] Since the slurry is caused to flow toward the outer peripheral side of the polishing pad by the centrifugal force action due to the rotation of the polishing pad, the slurry immediately flows to the outer peripheral side at the central portion of the polishing pad, and the slurry is discharged. Although it is difficult to supply the slurry, in the polishing knot having the structure according to this aspect, the slurry can be stably supplied even to the central portion of the polishing pad where the slurry is difficult to be supplied. It is. In addition, it is of course possible to form a plurality of through holes in the central flat area and supply slurry to the polishing surface through these through holes. It is also possible to suck and discharge the slurry from the polishing surface through.

(Aspect 5 of the Present Invention Related to Polishing Pad)

Embodiment 5 of the present invention relating to a polishing pad is the polishing pad according to any one of Embodiments 1 to 4. A polishing pad, characterized in that the circumferential groove includes a plurality of annular grooves extending concentrically. In the polishing pad having the structure according to the present embodiment, the supply or discharge of the slurry through the communication hole acts on the polishing surface through the annular groove, and acts substantially uniformly over a wider range in the circumferential direction. It is possible to do. Furthermore, since a plurality of annular grooves are formed apart from each other in the radial direction of the polishing pad, it is possible to control the fluidity and improve the stability of the slurry in a wide area in the radial direction of the polishing pad. The effect as described above can be obtained.

More specifically, for example, by combining this aspect with the above-described aspect 2, by providing a slurry supply hole in the annular groove, the slurry supply hole force allows the discharged slurry to flow in the annular groove. After being squeezed and filled with the annular groove force slurry, it is possible to supply the slurry on the polishing surface of the polishing pad such that the slurry overflows from the annular groove. Therefore, the slurry can be supplied more uniformly and stably in the circumferential direction of the polishing pad. Then, by forming a plurality of annular grooves having such slurry supply holes at a distance from each other in the radial direction, it is possible to supply the slurry stably even in the radial direction of the polishing pad. In this embodiment, it is not necessary that all of the circumferential grooves formed on the polishing surface of the polishing pad be annular grooves of the same shape. It is also possible to form them together on the polished surface. In addition, it is not necessary that the annular grooves are formed at regular intervals in the radial direction of the polishing node, and the centrifugal force acting on the slurry flowing on the surface of the polishing pad need not be formed at regular intervals. It is also possible to form them at different intervals in consideration of the fluidity of the slurry.

(Aspect 6 of the Present Invention Related to Polishing Pad)

A sixth aspect of the present invention relating to a polishing pad is the polishing pad according to the fifth aspect, wherein among the plurality of annular grooves formed radially apart from each other on the polishing surface, different annular grooves are provided. By forming the slurry supply hole according to the second aspect and the slurry discharge hole according to the third aspect, the annular groove formed with the slurry supply hole and the annular shape formed with the slurry discharge hole are formed. Grooves are alternately arranged in the radial direction of the polishing pad.

[0029] In the polishing pad having the structure according to this embodiment, the slurry supply hole is formed in the same annular groove. In comparison with the case of forming a slurry discharge hole, the slurry supply hole force prevents the slurry supplied to the annular groove from being immediately discharged from the slurry discharge hole, and the slurry is moved along the annular groove in the circumferential direction. It can be spread over a wider area and can be efficiently supplied to the polished surface. Further, in the polishing pad of this aspect, most of the slurry discharged from the annular groove having the slurry supply hole spreads along the polishing surface by the action of centrifugal force accompanying the rotation of the polishing pad. Supplied to the polishing surface. After that, it is guided into another annular groove having a slurry discharge hole positioned on the outer peripheral side on the polishing surface and enters, and through the slurry discharge hole opened in this annular groove, the polishing pad and the force on the polishing pad are also eliminated along with the polishing debris. The Rukoto. This makes it possible to quickly remove used slurry and polishing debris from the polishing surface.

[0030] In this aspect, "alternately positioned in the radial direction" means that the annular groove provided with the slurry supply hole and the annular groove provided with the slurry discharge hole are arranged in the radial direction in a top view of the polishing pad. The positions and numbers of the slurry supply holes and the slurry discharge holes are not limited.For example, they may be located on a straight line in the radial direction, The number of the slurry supply holes and the number of the slurry discharge holes formed in each of the annular grooves may be different from each other. In addition, the annular groove provided with the slurry supply hole and the annular groove provided with the slurry discharge hole only need to be substantially alternately arranged in the radial direction. In addition, the slurry may be alternately formed by two strips, alternately formed by three or more strips, or may be supplied by different numbers of strips in the radial direction. The annular grooves provided with holes and the annular grooves provided with slurry discharge holes may be formed alternately.

(Embodiment 7 of the Present Invention Related to Polishing Pad)

A seventh aspect of the present invention relating to a polishing pad is the polishing pad according to any one of the first to sixth aspects, wherein the circumferential groove includes a spiral groove extending in a spiral shape. Is the feature. In the polishing pad having the structure according to the present aspect, one flow path which is directed toward the inner force and the outer peripheral direction of the polishing pad is formed, so that the fluidity of the slurry can be more advantageously secured.

[0032] It should be noted that the spiral spiral groove in the circumferential direction is not necessarily formed from the center of the polishing pad. For example, an intermediate partial force in the radial direction of the polishing pad can be formed. is there. Further, in this embodiment, a plurality of spiral grooves may be formed substantially in parallel. It is not necessary that all circumferential grooves formed on the polishing surface of the polishing pad have a spiral shape.For example, a spiral groove is formed in the central portion of the polishing pad, and a concentric circle is formed around the spiral groove so as to surround the spiral groove. It is also possible to form a plurality of circumferential concave grooves different from each other on the polishing surface, such as forming an annular groove having a shape.

(Embodiment 8 of the present invention relating to polishing pad)

Embodiment 8 of the present invention relating to a polishing pad is the polishing pad according to any one of Embodiments 1 to 7, wherein the polishing surface intersects with the circumferential groove and extends from a central portion to an outer peripheral portion on the polishing surface. It is characterized in that a cross-groove extending almost radially in a straight or curved shape by force is formed. In the polishing pad having the structure according to the present aspect, the flowability of the slurry in the circumferential groove is further improved by forming the flow path extending in substantially the same direction as the centrifugal force exerted on the slurry by the rotation of the polishing pad. Can be enhanced. As a result, it is possible to further reduce the retention of the used slurry and polishing debris in the circumferential groove. The above-mentioned communication hole (slurry supply hole and Z or slurry discharge hole) may be formed in the bottom of the cross groove as well.

(Embodiment 9 of the present invention relating to polishing pad)

An aspect 9 of the present invention relating to a polishing pad is the polishing pad according to any one of the aspects 1 to 8, wherein the communication holes are formed with a substantially uniform distribution density in a circumferential direction on the polishing surface. Is characterized. In the polishing pad having the structure according to the present embodiment, problems caused by uneven distribution of the communication holes, such as unevenness of slurry flow characteristics and mechanical characteristics such as uniform bending strength of the pad, are reduced. The stability and uniformity of the polishing characteristics can be improved.

[0035] In the present embodiment, the slurry supply holes are preferably formed with a substantially uniform distribution density in the circumferential direction. This makes it possible to supply the slurry substantially uniformly on the polishing surface of the polishing pad. Further, in this aspect, preferably, the slurry discharge holes are formed with a substantially uniform distribution density in the circumferential direction. As a result, the slurry supplied to the polishing surface can be discharged almost uniformly in the circumferential direction together with the polishing debris in the circumferential direction. More preferably, both of the slurry supply holes and the slurry discharge holes are formed with a substantially uniform distribution density in the circumferential direction. More preferably The distribution density of the slurry supply holes and the distribution density of the slurry discharge holes are set to be substantially the same.

[0036] When the slurry supply holes opened in the circumferential groove are formed at a substantially uniform distribution density in the circumferential direction, a polishing pad having a conventional structure in which radial or lattice-like grooves are formed is used. In comparison with the method, it is possible to stably supply a necessary and sufficient amount of slurry onto the polished surface, and it is possible to suppress the uneconomical effect of removing a large amount of slurry unused.

[0037] In this embodiment, the distribution density of the communication holes may be substantially uniform in the node / node radial direction. However, the communication density is considered in consideration of, for example, a change in the circumference and a difference in acting centrifugal force. The distribution density of the holes may be made different in the pad radial direction, for example, so that the distribution density becomes smaller toward the outer peripheral side. That is, considering the effect of centrifugal force exerted on the slurry by the rotation of the polishing pad and the fact that the slurry is caused to flow in the outer peripheral direction of the polishing pad, the distribution density of the powerful slurry supply holes and the slurry discharge holes is determined by the polishing density. Each area in the radial direction of the pad does not have to be even!

(Embodiment 10 of the present invention relating to polishing pad)

An aspect 10 of the present invention relating to a polishing pad is the polishing pad according to any one of the aspects 1 to 9, wherein at least one of the inner peripheral side wall surface and the outer peripheral side wall surface in the circumferential groove is provided. Is characterized in that it is inclined in the depth direction with respect to the central axis of the polishing pad, and the circumferential groove is an inclined groove. In the polishing pad having the structure according to the present aspect, by adopting the inclined groove having the inclined side wall surface, the polishing pad can be rotated with respect to the slurry or polishing debris existing in the circumferential groove. The resulting centrifugal force can act as a component force corresponding to the inclination angle of the inclined groove.

[0039] Thus, by appropriately adjusting the inclination angle and the inclination direction of the circumferential groove, the centrifugal force caused by the rotation of the polishing node can be more positively used. Specifically, for example, the fluidity of the slurry existing in the circumferential groove is further improved by adopting the outer circumferential side wall surface inclined toward the pad outer circumferential side with the bottom force of the circumferential groove also directed toward the opening. It can be done. Conversely, by adopting an outer peripheral side wall inclined toward the inner peripheral side of the pad from the bottom of the circumferential groove toward the opening, slurry and polishing debris that has entered the circumferential groove are retained. It can reduce the flow speed of the slurry and keep the polishing debris in the trapped state [0040] It is not necessary to incline the above-mentioned communication hole in accordance with the inclination angle of the circumferential groove. Specifically, even if the groove is a circumferential groove having an inclined side wall surface, a communication hole extending parallel to the center axis of the pad may be employed, and the inclination angle of any side wall surface in the inclined groove may be adopted. Accordingly, it is also possible to form the communication hole inclined with respect to the central axis of the polishing pad.

Further, the inclination direction and the inclination angle of the inclined groove do not need to be constant in one polishing pad, and may be formed with inclined grooves having different inclination directions and inclination angles. For example, it is also possible to form multiple circumferentially concave grooves spaced apart from each other in the radial direction of the polishing pad, and to make the inclination angles of the circumferentially grooved grooves different according to the distance from the central axis of the polishing pad. good. According to such an embodiment, the effect of the centrifugal force exerted on the slurry in the circumferential groove can be made substantially equal or more positively different over a wide range of the polishing pad.

(Aspect 11 of the Present Invention Related to Polishing Pad)

An eleventh aspect of the present invention related to a polishing pad is the polishing pad according to the tenth aspect, wherein, in the inclined groove, the inner peripheral side wall surface and the outer peripheral side wall surface are substantially parallel, and the groove width is substantially in the depth direction. It is characterized by being constant. In the polishing pad having the structure according to the present embodiment, even if the depth of the circumferential groove changes due to wear of the polishing pad as the polishing progresses, dressing of the polishing pad surface, or the like, the circumferential groove does not change. The groove width is kept substantially constant, and the polishing performance including the intended polishing efficiency and polishing accuracy can be maintained.

(Aspect 12 of the Present Invention Related to Polishing Pad)

A twelfth aspect of the present invention related to a polishing pad is the polishing pad according to the eleventh aspect, wherein the communication hole is formed to have an inner diameter smaller than the groove width of the inclined groove and opened to the bottom surface of the inclined groove. The inclined groove extends substantially in the thickness direction at substantially the same inclination angle as the inner peripheral side wall surface and the outer peripheral side wall surface, and extends toward the mounting surface to form an inclined hole. And In the polishing pad having the structure according to this aspect, since the communication hole and the circumferential groove are formed with the same inclination angle, the slurry is formed with a suitable fluidity. It can be supplied or discharged. Furthermore, when manufacturing a powerful polishing pad, it is possible to form a communication hole from the polishing surface side.For example, after cutting a circumferential groove, the hole is drilled while being supported by the same table as it is. This makes it possible to obtain suitable productivity. Not only the communication hole opened on the bottom surface of the inclined groove but also the communication hole opened directly on the polished surface at a portion where the above-mentioned circumferential groove is not formed can be formed as an inclined hole. It is.

(Aspect 13 of the Present Invention Related to Polishing Pad)

An aspect 13 of the present invention relating to a polishing pad is the polishing pad according to any one of the aspects 1 to 11, wherein the communication hole has an inner diameter larger than a groove width of the circumferential groove, and Force It is characterized in that it is formed with a depth dimension that does not reach the polished surface, and is a large-diameter hole opened in the circumferential groove. In the polishing pad having the structure according to this aspect, since the communication hole is formed by drilling the force on the mounting surface side of the polishing pad, the polishing surface of the polishing pad is formed in the step of forming the communication hole. There is no danger of damaging. Further, since the inner diameter of the communication hole is larger than the groove width of the circumferential groove, the communication hole can be reliably connected to the circumferential groove.

(Embodiment 1 of the present invention relating to a method for manufacturing a polishing pad)

According to a first aspect of the present invention relating to a method for manufacturing a polishing pad, there is provided a pad substrate made of a synthetic resin material having a thin disk shape when manufacturing the polishing pad according to any one of the first to thirteenth aspects. The back surface of the pad substrate is supported by being superimposed on a rigid rotating plate, and is rotated around the central axis of the pad substrate while being subjected to a cutting force in the circumferential direction on the surface of the pad substrate, thereby forming the circumferential concave portion. A turning step of forming a groove, and (b) a punching step of forming the communication hole by performing a punching process in a plate thickness direction while the pad substrate is supported in a fixed position. And

According to such a manufacturing method, a polishing pad having a structure according to the present invention as described above can be advantageously manufactured. In other words, in the polishing pad manufactured according to the present manufacturing method, as described above, the semiconductor substrate can be polished with excellent accuracy and efficiency while suppressing the amount of slurry used. However, by reducing the thickness of the slurry, the edge action of the circumferential groove can be more effectively exhibited. As a result, the polishing efficiency can be further improved.

[0047] In the present manufacturing method, the order of the turning step for forming the circumferential groove and the drilling step for forming the communication hole is not particularly limited, and can be appropriately selected by a person skilled in the art. Yes, any process may be performed first.

(Embodiment 2 of the present invention relating to a method for manufacturing a polishing pad)

A second aspect of the present invention relating to a method for producing a polishing pad is the method for producing a polishing pad according to the first aspect, wherein the turning step comprises: By turning while feeding the cutting blade obliquely at a predetermined inclination angle with respect to the rotation center axis of the pad substrate, the inclined groove is formed, while in the perforating step, the cutting is performed on the pad substrate with respect to the pad substrate. The inclined hole is formed by using a cutting drill having a rotating axis inclined in substantially the same direction as the feeding of the cutting blade, and feeding the cutting drill in the direction of the rotating axis to perform drilling. And According to this manufacturing method, it is possible to easily form the inclined grooves and the inclined holes having substantially the same inclination angle, and it is also possible to form a plurality of powerful inclined grooves and the inclined holes while keeping the inclination angle constant. It is easily possible.

(Embodiment 3 of the present invention relating to a method for manufacturing a polishing pad)

A third aspect of the present invention relating to a method for manufacturing a polishing pad is the method for manufacturing a polishing pad according to the first aspect, wherein, when manufacturing the polishing pad according to the thirteenth aspect, in the drilling step, The surface of the pad substrate is superimposed on a rigid support plate to be supported in a fixed position, and the back surface force of the pad substrate is subjected to drilling to a predetermined depth using a drill to form the large-diameter hole. Is the feature. According to this manufacturing method, by performing perforation processing from the back surface of the pad substrate, the surface of the pad substrate serving as a polishing surface is not roughened, and a polishing pad having a good polishing surface can be manufactured. It is.

(Aspect of the Present Invention Regarding Polishing Pad Processing Apparatus)

An aspect of the present invention relating to a polishing pad processing apparatus is a polishing pad processing apparatus for manufacturing the polishing pad according to any one of the above aspects 1 to 13, wherein (c) a synthetic resin material having a thin disk shape -Made node substrates are superimposed and fixedly supported (D) a table rotating means for rotating the circular table around a central axis, (e) table fixing means for fixing the circular table so that it cannot rotate, and (f) a circular table. A tool rest movable in three orthogonal directions of X-axis, Y-axis and Z-axis forces, (g) a cutting tool mounted on the tool rest, and (h) a drilling tool mounted on the tool rest. And (i) control means for controlling the position of the tool post in the orthogonal three-axis directions and for controlling the operation of the table rotation driving means and the table fixing means, and supporting the pad substrate. The circumferential groove can be formed by turning the rotated circular table by the table rotation driving means and turning the surface of the pad substrate with the cutting tool mounted on the tool rest. , The circular table That it has to be able to form the communication hole by drilling into the pad substrate in said drilling tool mounted on the blade material table under a state of being fixed at said table fixing means, characterized.

In the polishing pad processing apparatus having the structure according to the present embodiment, any of the polishing pads having the structure according to the present invention can be manufactured by a powerful processing apparatus. This makes it possible to reduce the cost of the work and increase the efficiency of the work.

(Aspect of the Present Invention Regarding a Method for Polishing a Semiconductor Substrate)

An aspect of the present invention relating to a method for polishing a semiconductor substrate is a method for polishing a semiconductor substrate using the polishing pad according to any one of Aspects 1 to 13 wherein a circumferential groove is formed. (I) the polishing slurry is continuously or intermittently supplied from the mounting surface side of the polishing pad through the communication hole at the same time as being supported from the mounting surface side and rotated about the rotation center axis. A slurry supply operation for supplying the slurry to the polishing surface through the circumferential groove; and (ii) discharging the slurry continuously or intermittently from the polishing surface through the communication hole to thereby discharge the slurry in the circumferential direction. By adopting at least one of the slurry discharge operation and the slurry discharge operation for discharging the polishing surface force through the concave groove, the semiconductor substrate as the workpiece is polished on the polishing surface. That exerts a use, and features.

[0053] In the polishing method according to the present embodiment, a polishing pad having a structure according to the present invention is used. This makes it possible to adjust the fluidity of the slurry on the polishing surface satisfactorily or to maintain the slurry in a stable state by using the circumferential grooves. As a result, the uniformity of the slurry composition and the like on the polished surface can be maintained, and the polishing quality of the semiconductor substrate can be improved. In addition, in the polishing method employing either the supply operation or the discharge operation of the slurry, by controlling the flow of the slurry on the polishing surface, it is possible to reduce the thickness of the layer while preventing the slurry from dying on the polishing surface. Can be done. Therefore, the edge effect of the circumferential groove in the polishing pad can be more effectively exerted, and the polishing efficiency can be further improved.

That is, in the polishing method employing the slurry supply operation, a small amount of slurry is also spread to the polishing surface after being widely spread in the circumferential direction by the circumferential groove, so that the thin slurry is applied to the wide polishing surface. Can be formed substantially uniformly. On the other hand, in the polishing method employing the slurry discharge operation, the slurry on the polishing surface can be almost uniformly discharged from the wide area in the circumferential direction through the circumferential groove. Thus, the flow of the thin layer slurry can be formed substantially uniformly, and even if a small amount of the slurry flows, it is also possible to avoid unnecessary accumulation of polishing debris and used slurry.

[0055] In the polishing method according to this aspect, an aspect in which both the slurry supply operation and the slurry discharge operation are combined is more preferably employed. By using the lid and combining them, the slurry flow on the polishing surface can be more efficiently controlled (adjusted) with great freedom, and the slurry flow on the polishing surface can be further increased. Because it can be produced stably. However, in the polishing method according to this embodiment, it is possible to employ only the slurry supply operation or the slurry discharge operation. In particular, when only the slurry discharging operation is employed, a conventionally known supply method in which the slurry is dropped on the polishing pad surface from above the polishing pad can be employed.

(Embodiment 1 of the present invention relating to a semiconductor substrate polishing apparatus)

According to a first aspect of the present invention relating to a semiconductor substrate polishing apparatus, (j) the polishing pad according to any one of the first to thirteenth aspects of the present invention relating to a polishing pad, and (k) the polishing pad is superposed and fixed. A polishing platen having a rigid disk shape having a fixing surface to be fixed; (1) platen rotation driving means for rotating the polishing platen around a central axis; and (m) an opening in the fixing surface of the polishing platen. Formed in the polishing pad And (n) slurry supply means for supplying a slurry for polishing to the communication hole of the polishing pad through the slurry introduction hole. When polishing the semiconductor substrate with the polishing pad fixed to the polishing platen by rotating the polishing platen by the platen rotation driving means, the polishing pad is fixed to the polishing pad through the slurry introduction hole and the communication hole. The slurry is supplied to the polishing surface through a circumferential groove.

In the polishing apparatus having the structure according to the present embodiment, the polishing pad having the structure according to the present invention can be effectively used. For example, the slurry introduction hole and the communication hole are connected on the mounting surface side of the polishing pad, and the slurry can be supplied so as to overflow from the bottom of the polishing surface through the communication hole and the circumferential groove. As a result, the amount of slurry used can be suppressed, and the thickness of the slurry can be reduced, so that effective polishing quality can be obtained.

[0058] The opening shape, the number, and the like of the slurry introduction holes that are opened on the fixing surface of the polishing platen that is strong are not limited at all. The slurry introduction hole can be formed to have the same shape as the opening shape of the mounting surface of the communication hole to be connected. Needless to say, a force, for example, a circumferential direction extending in the circumferential direction like the polishing pad to be mounted. If the groove is formed, the slurry introduction hole of the polishing plate can be connected to the communication hole of the polishing pad without performing circumferential positioning work when the polishing pad is mounted on the polishing plate. The number of slurry introduction holes is not limited at all, and need not be the same as the number of communication holes formed in the polishing pad to be mounted.

(Embodiment 2 of the present invention relating to a semiconductor substrate polishing apparatus)

A second aspect of the present invention relating to an apparatus for polishing a semiconductor substrate is (o) a polishing pad according to any one of the first to thirteenth aspects of the present invention, and (p) the polishing pad is superimposed. A polishing platen having a rigid disk shape having a fixing surface to be fixed, (q) platen rotation driving means for rotating the polishing platen around a central axis, and (r) a polishing platen on the fixing surface of the polishing platen. A slurry lead-out hole formed to be open and connected to the opening of the communication hole in the polishing pad to the mounting surface; and (s) polishing from the communication hole of the polishing pad through the slurry lead-out hole. And a slurry discharging means for discharging the slurry, wherein the polishing platen is rotationally driven by the platen rotation driving means. When polishing the semiconductor substrate with the polishing pad fixed to the polishing platen, the slurry is discharged from the polishing surface force through the circumferential groove of the polishing pad and the communication hole. It is characterized by having made it.

In the polishing apparatus having the structure according to the present embodiment, the polishing pad having the structure according to the present invention can be effectively used. For example, used slurry that has flowed into the communication hole can be discharged almost uniformly and effectively through a slurry outlet hole provided in the polishing platen in a wide circumferential area where the circumferential groove extends. I can do it. As a result, the thickness of the slurry can be reduced, and the uniformity of the composition of the slurry on the polishing surface can be maintained, so that effective polishing quality can be obtained. Here, as the slurry discharging means, a pump or the like may be provided to positively discharge the slurry, or the slurry may be discharged by falling due to its own weight.

[0061] The opening shape and number of the slurry outlet holes are not limited at all. Like the above-mentioned slurry inlet holes, the slurry outlet holes may be formed in a circumferential groove shape or the like. It is not necessary to form the same number of communication holes as formed in the pad.

(Embodiment 3 of the present invention relating to a semiconductor substrate polishing apparatus)

A third aspect of the present invention relating to an apparatus for polishing a semiconductor substrate is (t) a polishing pad according to any one of the above aspects 1 to 13 relating to a polishing pad, and (u) the polishing pad is superimposed. A polishing platen having a rigid disk shape having a fixing surface to be fixed, (V) platen rotation driving means for rotating the polishing platen about a central axis, and (w) a fixing plate on the polishing platen. A slurry introduction hole formed to be open and connected to the opening of the communication hole in the polishing pad to the mounting surface; and (X) the slurry introduction hole through the slurry introduction hole to the communication hole of the polishing pad. A slurry supply means for supplying a polishing slurry; and (y) an opening formed in the fixing surface of the polishing platen and connected to an opening of the communication hole in the polishing pad to the mounting surface. Slurry outlet holes, (Z) slurry discharge means for discharging a slurry for polishing from the communication hole of the polishing pad through the slurry outlet hole, wherein the polishing platen is rotationally driven by the platen rotation driving means, and the polishing platen is rotated. When polishing the semiconductor substrate with the fixed polishing pad, the slurry supply means cuts the semiconductor substrate through the communication hole of the polishing pad. Slurry for polishing is supplied to the polishing surface through the circumferential groove, and the slurry is discharged from the polishing surface through the communication hole by the circumferential groove force of the polishing pad by the slurry discharge means. The feature is that it is.

In the polishing apparatus having the structure according to the present embodiment, the polishing pad having the structure according to the present invention can be effectively used. For example, by using the above-mentioned slurry supply means and slurry discharge means together, while supplying the slurry stably through the circumferential groove, the used slurry is quickly discharged, and the slurry is more advanced. It is possible to maintain uniformity of the composition and to reduce the thickness of the slurry to obtain more effective polishing quality.

The invention's effect

As is clear from the above description, in the polishing pad having the structure according to the present invention, a circumferential groove extending in the circumferential direction is formed on the polishing surface, and the communication hole penetrates in the plate thickness direction. By forming a plurality of holes and opening the communication holes to the polishing surface side through the circumferential grooves, it is possible to advantageously generate circulation of used slurry and unused slurry in the circumferential grooves. I can do it.

[0065] Furthermore, the flow of the slurry supplied or discharged through the communication hole can be spread over a wide area in the circumferential direction of the polishing pad by using the circumferential groove, and can be generated substantially uniformly. .

[0066] Therefore, the uniformity of the composition of the slurry that can flow on the polishing surface of the polishing pad can be improved, and the slurry can be supplied or discharged more stably in the circumferential direction. Even when the thickness of the slurry layer is reduced, a stable slurry layer can be formed on the polished surface. As a result, the edge action of the circumferential groove can be more effectively exerted, and the polishing accuracy and polishing efficiency for the semiconductor substrate can be improved, and the polishing efficiency and quality of the semiconductor substrate can be improved. Become.

Brief Description of Drawings

FIG. 1 is a plan view showing a polishing pad as one embodiment of the present invention.

FIG. 2 is a partially enlarged plan view of the polishing pad shown in FIG. 1.

FIG. 3 is an enlarged longitudinal sectional view of an essential part showing a specific structure example of a circumferential groove preferably adopted in the polishing pad shown in FIG. 2. FIG. 4 is a schematic sectional view schematically showing a polishing apparatus that can be suitably used in the present invention.

FIG. 5 is a front view showing a processing machine that can be used when manufacturing a polishing pad having a structure according to the present invention.

FIG. 6 is a plan view showing a processing machine that can be used in manufacturing a polishing pad having a structure according to the present invention.

FIG. 7 is a side view showing an aspect in which a cutting tool is attached to the processing machine shown in FIG. 5

FIG. 8 is a front view showing an example of a cutting tool suitably used in manufacturing a polishing pad having a structure according to the present invention.

FIG. 9 is a side view showing an example of a cutting tool suitably employed in manufacturing a polishing pad having a structure according to the present invention.

FIG. 10 is an enlarged explanatory view of a main part showing a specific example of a cutting tool suitably employed for cutting a concave groove according to the present invention.

FIG. 11 is an explanatory diagram for explaining a step of forming a concave groove in a pad substrate using the cutting tool shown in FIG. 8.

FIG. 12 is a model diagram showing an ion blow passage and a vacuum suction device attached to the cutting tool shown in FIG. 9.

FIG. 13 is a side view showing a mode in which a boring tool is attached to the processing machine shown in FIG. 10.

FIG. 14 is an explanatory diagram for explaining a step of forming a communication hole in a pad substrate using a drilling tool.

FIG. 15 is a plan view showing a polishing pad as still another embodiment of the present invention.

FIG. 16 is a plan view showing a polishing pad as still another embodiment of the present invention.

FIG. 17 is an enlarged sectional view of a main part showing a polishing pad as still another embodiment of the present invention.

FIG. 18 is an enlarged sectional view of a main part showing a polishing pad as still another embodiment of the present invention. FIG. 19 is an enlarged sectional view of a main part showing a polishing pad as still another embodiment of the present invention.

FIG. 20 is a schematic sectional view showing an outline of a different embodiment of a polishing apparatus that can be suitably used in the present invention.

FIG. 21 is a schematic cross-sectional view schematically showing still another embodiment of a polishing apparatus that can be suitably used in the present invention.

Explanation of symbols

[0068] 10 Polishing pad

12 Pad board

16 Groove

24 Slurry flow hole

27 Center flat part

30 Polishing equipment

32 Platen

50 Processing equipment

52 yen tape

60A, B Turret

80 Controller

82 Cutting unit

84 bytes

101 Do, Linole

110 polishing pad

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 to 3 show a polishing pad 10 as a first embodiment of the present invention. FIG. 1 is a plan view of the polishing pad 10, and FIG. 2 is a partially enlarged plan view of the polishing pad 10. FIG. 3 is an enlarged sectional view of a main part of the polishing pad 10. This polishing pad 10 It is formed by a thin disk-shaped pad substrate 12 having a certain thickness dimension on the body. The pad substrate 12 is advantageously formed of, for example, a material selected from hard foamed or unfoamed urethane, silicone rubber, hard rubber, polytetrafluoroethylene, nylon, vinyl chloride, and a mixture thereof. . The thickness of the pad is not limited, and is appropriately set according to the material of the pad substrate 12, the material of the wafer to be processed, the required processing accuracy, and the like. In each of the accompanying drawings, the shapes and scales are exaggerated in order to facilitate understanding of the shapes of the grooves 16 and the slurry flow holes 24 described below. .

A concave groove 16 as a circumferential groove extending in the circumferential direction is formed on a surface 14 as a polishing surface, which is one surface of the pad substrate 12 to be pressed, around a central axis 18 of the pad substrate 12. A plurality of concentric circular grooves are formed and open on the surface 14.

[0072] Here, the concave groove 16 is an inclined groove having a specific inclined structure according to the present invention. Specifically, as shown in FIG. 3, the concave groove 16 is formed between an inner peripheral side wall surface (hereinafter referred to as “inner wall surface”) 20 and an outer peripheral side wall surface (hereinafter referred to as “outer wall surface”). 22) are inclined surfaces that are inclined by a predetermined angle: α (intersecting angle with a straight line parallel to the central axis 18 = α) with respect to the central axis 18 over the entire length in the circumferential direction. . In short, in the groove 16 shown in FIG. 3, the inner wall surface 20 and the outer wall surface 22 are parallel to each other, so that the groove 16 is formed not only in the circumferential direction of the groove 16 but also in the depth direction. The width of the groove 16 is substantially constant over the entire surface of the pad substrate 12, and the concave groove 16 is gradually separated from the central axis 18 toward the opening, and is directed obliquely outward in the radial direction of the pad substrate 12. To open

The bottom surface of the groove 16 may be a curved surface or a flat surface, which is not particularly limited in shape or the like. In the present embodiment, particularly, in the present embodiment, the bottom surface of the groove 16 is a pad. The flat surface is orthogonal to the center axis 18 of the substrate 12. By making the bottom surface of the groove 16 a flat surface substantially parallel to the surface of the pad substrate 12 as described above, even when the effective depth of the groove 16 is set to be large, the member thickness of the bottom wall of the groove 16 can be increased. , And good strength characteristics can be obtained.

The specific set values such as the dimensions and the inclination angle of each part of the concave groove 16 are determined by the material of the pad substrate 12. It is determined by comprehensively considering the quality, thickness dimensions, outer diameter dimensions, the material of the wafer to be polished, the shape and material of the metal wires formed on the wafer, and the required polishing accuracy. Although not particularly limited, generally, each value of the groove width: B, the depth: D, the radial pitch: P, and the inclination angle: α of the concave groove 16 is set within the following ranges. It is desirable.

[0075] 0.005mm ≤ B ≤ 3. Omm

0. lmm ≤ D ≤ 2. Omm

0. lmm ≤ P ≤ 3. Omm

0.5 degree ≤ α ≤ 30 degree

[0076] More preferably, it is set within the following range.

0.005mm ≤ B ≤ 2. Omm

(Even more preferably, 0.005mm ≤ B ≤ 1.0mm)

0. lmm ≤ D ≤ 1. Omm

0.2 mm ≤ P ≤ 2. Omm

1. 0 degree ≤ a ≤ 20 degree

(Even more preferably, 1.0 degrees ≤ a ≤ 15 degrees)

If the groove width of the groove 16 is too small, the effect of controlling the flow of the slurry due to the formation of the groove 16 is not easily exerted. While clogging is likely to occur, it is difficult to achieve a stable effect. On the other hand, if the groove width of the concave groove 16: B is too large, the contact surface pressure with the wafer at the edge portion (opening edge) of the concave groove 16 is reduced. This is because it is difficult to realize stable polishing, which is likely to increase and cause biting-like polishing or the like.

When the groove depth D of the concave groove 16 is too small, the slurry flow effect due to the formation of the inclined concave groove 16 is hardly exhibited, and the surface 14 of the polishing pad 10 The rigidity of the wafer becomes too large, and the contact surface pressure with the wafer becomes uniform as a whole, and the contact surface pressure with the wafer at the edge of the concave groove 16 does not sufficiently increase, so that effective polishing tends to be difficult. is there. On the other hand, if the groove depth D of the concave groove 16 is too large, the polishing pad 10 may be easily deformed and the surface 14 of the polishing pad 10 may be easily deformed with difficulty, and stick-slip may occur, resulting in unstable polishing. Easily. Further, if the radial pitch P of the concave grooves 16 is too small, the surface 14 of the polishing pad 10 that is difficult to manufacture is easily deformed or damaged, and stable polishing is hardly realized. On the other hand, if the radial pitch P of the grooves 16 is too large, it is difficult to control the flow of the slurry due to the formation of the grooves 16.

Further, if the inclination angle “a” of the inner and outer wall surfaces 20 and 22 is too small, it tends to be difficult to exert a slurry flow control effect or the like due to centrifugal force described later. On the other hand, if the inclination angle α of the inner and outer wall surfaces 20, 22 is too large, not only the manufacturing becomes difficult, but also the strength of the side wall portion of the concave groove 16 decreases, and the surface pressure distribution becomes difficult to stabilize. It may be difficult to obtain sufficient durability of No. 10.

As shown in FIGS. 2 and 3, a slurry flow hole 24 as a communication hole penetrates through the pad substrate 12 in the thickness direction of the pad substrate 12 and opens in the bottom surface of the concave groove 16. A plurality is formed. Each of the slurry flow holes 24 and the discharge port 25 to serve as a slurry supply hole is a discharge port 26 as a slurry discharge hole. In the present embodiment, the discharge port 25a and the discharge port 26a are concave. An opening is formed at the bottom of the groove 16. Here, the opening shape and the width dimension of the slurry flow hole 24 are not limited at all. For example, the opening shape is not limited to a circular shape such as a perfect circle and an ellipse, but may be a rectangular shape and other shapes as appropriate. In this embodiment, the discharge port 25a and the discharge hole 26a have the same structure as each other. The discharge port 25a and the discharge hole 26a are formed in a circular shape on the bottom surface of the concave groove 16, and the other opening is formed on the pad substrate. An opening is provided on the back surface 15 as a mounting surface of the device 12. The discharge port 25a and the discharge hole 26a are inclined holes having a circular cross section penetrating in the thickness direction of the pad substrate 12 at the same inclination angle as the inclination angle α of the concave groove 16. Further, the discharge port 25a and the discharge hole 26a are formed with a constant diameter dimension: φb, and the diameter dimension: <i) b is smaller than the groove width: B of the concave groove 16.

Further, in the present embodiment, the discharge as a slurry flow hole 24 which is opened directly without passing through the concave groove 16 is provided on an appropriate portion which does not overlap with the concave groove 16 on the surface 14 of the pad substrate 12. An outlet 25b and an outlet 26b are formed! The discharge port 25b and the discharge port 26b have substantially the same shape as the discharge port 25a and the discharge port 26a, and the discharge port 25b is a slurry supply hole, while the discharge port 26b is a slurry discharge hole. Te ru. [0083] Furthermore, a center flat portion 27 is formed in the center portion of the polishing pad 10 as a center flat region in which the concave groove 16 is not formed. A discharge port 25c and a discharge port 26c as 24 are formed and opened. In particular, in the present embodiment, the discharge port 25c is formed on the central axis 18 of the nod substrate 12. The discharge port 25c and the discharge port 26c do not have an inclination angle, have a constant diameter dimension: φ c, are formed so as to penetrate in the same direction as the axial direction of the pad substrate 12, and are formed on the surface 14 of the pad substrate 12. While the opening is formed in a circular shape, the other opening is a communication hole having a circular cross section opened on the back surface 15 of the pad substrate 12. However, the discharge port 25c and the discharge port 26c that are formed in the center flat portion 27 can also be formed with an inclination angle, and their diameters can be changed in the thickness direction by changing the diameter. Good.

As is clear from the above description, in the present embodiment, the discharge port 25 as a slurry supply hole and the discharge port 26 as a slurry discharge hole are formed as the slurry flow holes 24. As the outlet 25, a discharge port 25a opening through the concave groove 16, a discharge port 25b directly opening on the surface 14 of the pad substrate 12, and a discharge port 25c opening at the center flat portion 27 are provided. This is because a discharge port 26a that opens through the concave groove 16, a discharge port 26b that opens directly on the surface 14 of the pad substrate 12, and a discharge port 26c that opens in the center flat portion 27 are provided. These discharge ports 25 and discharge ports 26 are alternately opened in the radial direction of the surface 14 of the pad substrate 12. As a result, the used slurry can be discharged from the surface 14 of the polishing pad 10 before reaching the outer peripheral edge of the polishing pad 10, thereby effectively circulating the unused slurry and the used slurry, The layer thickness of the slurry supplied on the surface 14 of the polishing pad 10 can be adjusted to a higher degree. As is clear from FIG. 2, in FIG. 3, the discharge port 25 and the discharge port 26 are formed in a straight line extending in the radial direction to facilitate the description! When the discharge ports 26 and the discharge ports 26 are alternately formed in the radial direction, it is not always necessary to form them in a straight line.

In the present embodiment, as shown in FIG. 2, the slurry flow holes 24 are formed with a substantially uniform distribution density in each circumferential region on the surface 14 of the pad substrate 12. The distribution density of the slurry flow holes 24 is not particularly limited, Depending on the polishing characteristics and the like, it is also possible to form with an uneven distribution density. Further, since the circumferential length varies depending on the radial position of the node substrate 12, the number of the slurry flow holes 24 per unit angle around the central axis may be different at the radial position.

[0086] The polishing pad 10 provided with such concave grooves 16 is used for polishing a wafer or the like in substantially the same manner as in the past. Specifically, for example, a polishing apparatus 30 as shown in FIG. 4 can be suitably employed. The polishing apparatus 30 includes a platen 32 as a polishing platen. The platen 32 has a fixing surface 34 to which the polishing pad 10 is fixed by being superimposed or directly over an appropriate elastic pad or the like, and the polishing pad 10 is fixed to the fixing surface 34 by a tape, an adhesive, or the like. Or it is fixed on the mounting surface side by means such as negative pressure suction. The platen 32 is connected to a platen motor 36 as a rotation driving means so as to be driven to rotate around a central axis.

[0087] Here, the platen 32 is formed so as to be open to the slurry supply communication groove 38 as a slurry introduction hole and the force fixing surface 34. A plurality of strong slurry supply communication grooves 38 are formed on the fixing surface 34 of the platen 32 in a concentric shape extending in the circumferential direction with a width slightly larger than the opening on the back side of the discharge port 25 of the polishing pad 10. ing. A slurry supply channel 39 as a slurry supply means formed inside the platen 32 is opened and connected to an appropriate portion on the bottom surface of the slurry supply communication groove 38. The slurry supply flow path 39 is an internal space formed inside the platen 32, and the slurry stored in the slurry tank 41 is filled inside by the supply pump 40!

In addition, a slurry discharge communication groove 42 as a slurry outlet hole and a slurry discharge channel 43 as a slurry discharge means are formed in the platen 32 in addition to the slurry supply communication groove 38 and the slurry supply flow path 39. ing. The slurry discharge communication groove 42 and the slurry discharge channel 43 have substantially the same structure as the slurry supply communication groove 38 and the slurry supply channel 39, respectively, and are independent slurry discharge channels that are not connected to the slurry supply channel 39. Are formed. Also, the slurry in the slurry discharge channel 43 is positively discharged by being sucked by the discharge pump 44.The power discharge pump 44 discharges the slurry by its own weight, which is not necessarily required. You can do it!

Then, the polishing pad 10 is superimposed on the fixing surface 34 of the platen 32, The slurry supply communication groove 38 and the discharge port 25 of the polishing pad 10 are connected, and the slurry discharge communication groove 42 and the discharge port 26 are connected. Although not shown, it is not necessary that all the slurry supply communication grooves 38 and the slurry discharge communication grooves 42 are connected to the slurry circulation holes 24 of the polishing pad 10! The slurry supply hole 24 and the slurry supply communication groove 38 and the slurry discharge communication groove 42 and the slurry supply communication groove 38 and the slurry discharge communication groove 42 that are not connected to the slurry flow hole 24 may be present. . The openings of the slurry flow hole 24, the slurry supply communication groove 38, and the slurry discharge communication groove 42 are covered with the fixing surface 34 of the superposed platen 32 or the polishing pad 10. The Rukoto. Incidentally, the shape of the opening on the fixing surface 34 of the slurry supply communication groove 38 and the slurry discharge communication groove 42 is not limited, but a concentric circular shape extending in the circumferential direction as in the present embodiment is preferable. . When the lid and the polishing pad 10 are overlaid on the fixing surface 34 of the platen 32, the slurry supply communication groove 38 and the slurry discharge communication groove 42 can be connected to the slurry discharge hole 42 without performing the circumferential positioning of the slurry flow hole 24. Because.

On the other hand, a base support 45 is disposed above the platen 32, and the base support 45 can be relatively displaced in the approach Z separation direction with respect to the platen 32. A wafer 46 as a semiconductor substrate is superposed and fixedly supported on the surface of the base support 45 facing the platen 32. The support motor 47 drives the base support 45 to rotate. I have. Thus, the polishing pad 10 fixed to the platen 32 and the ueno 46 supported by the base support base 45 can be relatively rotated. It should be noted that the arrows indicating the rotation directions in the figures are merely examples, and the rotation directions are not limited at all.

[0091] With such a polishing apparatus 30, the polishing pad 10 is subjected to a polishing process. In addition, in such a polishing process, the polishing pad 10 and the wafer 46 are generally rotated around their rotation center axes, respectively, as in the past, so that the surface 14 of the polishing pad 10 and the wafer 46 are covered. Slurry is supplied between the opposing surfaces of the processing surfaces.

[0092] Here, the slurry supplied between the surface 14 of the polishing pad 10 and the opposing surface of the polishing surface of the wafer 46 is supplied from the slurry supply passage 39 formed in the platen 32 to the slurry supply communication groove. Fill the groove 16 through the discharge port 25 to which the slurry supply communication groove 38 connects through 38 After that, it is continuously or intermittently supplied to the surface 14 of the polishing pad 10. The slurry stored in the external slurry tank 41 is supplied to the slurry supply path 39 of the plate 32 by pressure feeding with a supply pump 40. Then, the slurry supplied to the surface 14 of the polishing pad 10 is spread on the surface 14 by the action of the centrifugal force accompanying the rotation of the polishing pad 10 around the central axis 18. As a result, compared with the conventional structure in which the slurry is dropped from above the polishing pad 10, the necessary and sufficient amount of the slurry on the surface 14 of the polishing pad 10 can be efficiently provided without using a large amount of slurry. It is possible to supply. Further, in the present embodiment, since the discharge port 25 is also formed on the central axis 18 of the polishing pad 10, it is sufficient even in the central portion of the polishing pad 10 that the slurry is hardly retained by the action of centrifugal force. In addition to providing a stable slurry, the distribution of the slurry around the circumference can be more advantageously achieved.

[0093] Further, used slurry used for polishing flowing on the surface 14 of the polishing pad 10 and polishing debris generated by the polishing are formed in the platen 32 from the discharge port 26 of the polishing pad 10. The slurry is continuously or intermittently discharged from the surface 14 through the slurry discharge channel 43. As a result, the surface of the slurry supplied between the polishing pad 10 and the wafer 46 can be maintained at a higher level by quickly discharging unnecessary used slurry and polishing debris from the surface 14 as well. Thus, superior polishing accuracy and polishing efficiency can be obtained.

[0094] Further, in the polishing pad 10 according to the present invention, the concave groove 16 opened in the pad surface 14 is formed such that the bottom force is gradually inclined outward in the radial direction with the force directed toward the opening. When the polishing pad 10 is rotated around the central axis 18, a centrifugal force exerted on the slurry filled in the concave groove 16 causes a component force in the direction flowing out of the concave groove 16. The opening force also flows out to the outer peripheral side of the polishing pad 10 with the fluid pressure of the slurry supplied from the bottom of the discharge port 25 and the force corresponding to the rotation speed of the polishing pad 10, and the polishing pad 10 Ueno, 46 will be made to flow between the opposing surfaces. In this way, in the groove 16, the slurry is actively supplied from the bottom and is spread in the circumferential direction, and is then substantially uniformly distributed over the entire circumference from the opening of the groove 16 to the outer peripheral side. It is leaked toward. Further, since the discharge port 25 is formed with the same inclination angle α as the concave groove 16, the component in the direction flowing out of the discharge port 25 is also applied to the slurry in the discharge port 25. This is advantageous in that the slurry can be supplied stably to the concave groove 16 and the surface 14 of the polishing pad 10.

[0096] As a result, efficient slurry inflow and outflow are performed in the concave groove 16, and a positive slurry flow is developed between the opposing surface of the polishing pad 10 and the wafer 46. In addition, the chemical polishing action of the slurry, which can be achieved not only by the mechanical polishing action of the slurry but also by the slurry, can be produced very efficiently and almost uniformly over the entirety, and effective polishing can be stably realized. .

[0097] As described above, by employing the inclined groove 16 and the slurry flow hole 24 inclined as described above, the slurry flow during polishing can be performed only by appropriately adjusting the inclination angle of the groove 16 and the slurry flow hole 24. The state can be controlled, and therefore, for example, in consideration of the characteristics of the slurry to be used, the characteristics of the target wafer, and various polishing conditions, the inclination angles of the concave groove 16 and the slurry flow hole 24 are considered. By adjusting the thickness, it is possible to easily realize the optimum polishing state.

[0098] Further, in the inclined groove 16, the side wall surfaces 20, 22 are parallel to each other not only in the circumferential direction but also in the depth direction, whereby the groove width dimension of the groove 16 is reduced. Therefore, even when the surface of the polishing pad 10 is worn or the surface layer is ground by dressing, the width of the concave groove 16 opening on the surface is maintained. If the dimensions are kept substantially constant and a stable polishing action can be exerted over a long period of time, there is another advantage.

[0099] Further, the diameter of the slurry flow hole 24 is not necessarily required to be constant, but in the present embodiment, the diameter of the slurry flow hole 24 is also the same as the groove 16 in the present embodiment. It is formed with approximately constant φ b and φ c throughout the depth direction. As a result, even when the discharge ports 25b and 25c and the discharge ports 26b and 26c that open on the surface 14 of the pad substrate 12 are formed, a stable polishing operation can be performed for a long period of time, as in the case of the concave groove 16. It can be demonstrated.

[0100] Note that the concave groove 16 and the slurry flow hole 24 having the above-described shapes are opposed to the node substrate 12. For example, it is possible to form such concave grooves and flow holes at the same time as the injection molding of the polishing pad 10 or to perform cutting using a rotary tool such as a milling tool. Although it is possible to form a concave groove, using a manufacturing apparatus equipped with a turning tool with a cutting edge and a drilling tool with a shape corresponding to the cross-sectional shape of the target circumferential groove, Is preferably formed by turning according to the manufacturing method described above.

[0101] More specifically, FIGS. 5 and 6 show a processing apparatus 50 suitable for manufacturing the polishing pad 10 having a structure according to the present invention. The processing device 50 has a circular table 52 having a flat support surface for fixedly supporting the pad substrate 12, and can be moved with respect to the circular table 52 in three orthogonal X-, Y- and Z-axis directions. Turrets 60A, 60B, cutting tools and drilling tools mounted on the powerful turrets 60A, 60B, and driving means for driving the turrets 60A, 60B and the rotary table 52, and further controlling their operation. It comprises a control device 80 as control means.

[0102] First, the circular table 52 will be described. The powerful circular table 52 can be driven to rotate around a central axis extending in the vertical direction (Z-axis direction) by a table rotation shaft 53, which is a table rotation driving means controlled by the C-axis. In addition, a fixing means (not shown) such as an electromagnetic brake is provided for preventing and fixing the rotation of the table rotation shaft 53 so as to be releasable. The circular table 52 is made of a light metal and a material that is not easily deformed by heat, such as an aluminum alloy, in order to fix the pad substrate and to enable quick starting and stopping. Materials may be suitably employed.

[0103] On the surface of the circular table 52, a plurality of suction holes 56 for fixing the pad substrate by negative pressure suction are formed at appropriate portions. The node substrate is suction-fixed to the surface of the rotary table 52 by suction under negative pressure through a powerful suction hole 56. Although not shown, the surface of the rotary table 52 is formed at a predetermined position thereof with a concave portion such as an escape groove or an escape hole when a cutting tool or a turning tool is used.

[0104] A pair of first guides 62A and 62B is provided on the bed 58 with the rotary table 52 interposed therebetween, and is guided by the pair of first guides 62A and 62B to be axially controlled. It has a gantry-type column 68. This gantry-type column 68 is a bridge between a column 70A guided by one first guide 62A and a column 70B guided by the other first guide 62B. And a cross rail 72 to be installed. Here, the gantry-type column 68 is driven by screw shafts 64A and 64B, guided by the pair of first guides 62A and 62B, and moves on the circular table 52 in the horizontal X-axis direction (up and down in FIG. 6). Direction). It should be noted that the gantry-type column 68 can also be integrally formed by welding or solid material.

Further, as shown in FIG. 5, on the bed 58, on both sides of the rotary table 52, a Y-axis direction (vertical direction in FIG. 5) and a Y-axis direction ( The pair of second guides 66A, 66B extend in the left-right direction (see FIG. 2). The saddles 74A, 74B are guided by the pair of second guides 66A, 66B, and are driven by screw shafts 76A, 76B to be movable in the horizontal Y-axis direction. I have.

[0106] Furthermore, the tool rests 60A and 60B are mounted on the saddles 74A and 74B, respectively. These tool rests 60A, 60B can be moved in the vertical Z-axis direction by motors 78A, 78B and a screw shaft (not shown), respectively. In particular, in the present embodiment, the balancer 79A, 79B is provided above the force saddles 74A, 74B to balance the weight when the tool rests 60A, 60B are moved, and is provided with smooth and precise in the Z-axis direction of the tool rests 60A, 60B. Good position control is possible. The tool rests 60A and 60B are appropriately provided with mounting holes 61A and 61B for mounting tools, respectively, so that tools can be mounted.

As described above, the X-axis movement of the gantry type column 68 by the first guides 62A and 62B, the Y-axis movement of the saddles 74A and 74B by the second guides 66A and 66B, and the Z-axis movement of itself The tool rests 60A and 60B can move in three orthogonal directions with respect to the rotary table 52. It should be noted that a linear motor may be used as the driving means of the tool rest 60, which can improve the positioning accuracy and the response speed.

The operation control and the position control of the rotary table 52 and the tool rests 60A and 60B are performed by the control device 80. The operation control of each member by the control device 80 is performed, for example, by feedback-controlling a step motor or the like as a driving unit for driving each operating member using a detection signal from a position sensor that detects the position of each member. This is performed by a known method. [0109] Further, the cutting tool and the turning tool can be appropriately attached to the tool rests 60A and 60B whose positions are controlled in the orthogonal three-axis directions as described above.

FIG. 7 shows an embodiment in which a cutting tool is mounted on a kafune apparatus 50. A cutting unit 82 as a cutting tool is mounted on a tool rest 60B shown in FIG. 7 using a mounting hole 61B.

. The cutting unit 82 has a tool holder 89 on which a cutting tool 84 as a cutting tool is mounted.

[0111] As the knot 84, for example, as shown in Figs. 8 and 9, a cutting edge 86 corresponding to the shape of the target groove is provided at an appropriate pitch: P on the leading edge. A blade tool tip is suitably employed. Such a multi-blade tool tip (bite) 84 is, for example, fitted and positioned on a positioning pin 92 fixedly mounted on a tool holder 89, held by a holding plate 90 and fixed with a bolt 94.

[0112] Here, as shown in Fig. 10, each of the cutting blades 86 is inclined with respect to the center axis of the tool holder 89 by an angle corresponding to a desired inclination angle of the concave groove 16 or the like: a It is only protruded at an angle. By using such a cutting tool having the inclined cutting edge 86, the cutting blade 86 is inclined with respect to the pad substrate 12 by an inclination angle: α, as shown in FIG. The turning process, in which the cutting process is repeatedly performed to trace the same cutting part with the cutting edge 86 protruding by a predetermined amount in the inclined protruding direction, while performing In the case of end grooves such as spiral grooves and spiral grooves, intermittent aspects such as reciprocating operation, etc. The inclined groove 16 having α can be advantageously formed by cutting. In particular, when forming an endless circumferential groove by performing continuous turning in the circumferential direction, the cutting height of the cutting blade 86 is not gradually increased, but is gradually increased. May be.

[0113] The feed operation with the inclined angle of the powerful cutting blade 86 includes X and Β or Υ and Β of the turret 60Ζ (in the mounting direction of the other blade tool tip 84 shown in the present embodiment, , Υ, and Ζ are adopted.) A force that can adopt the feed operation by binary control of the other. In addition, for example, a feed unit such as a screw mechanism in the protruding direction is provided in the cutting unit 82, and the feed operation is performed. This is also achieved by sequentially sending the cutting blades 86 in the projecting direction to the cutting unit 82 by means. Further, as shown in FIG. 12, the tool holder 89 in the present embodiment is provided with an ion blow passage 96 that extends straight through the inside of the tool holder 89, while the cutting blade 86 protrudes. A vacuum suction device 98 is mounted on the front side of the device.

More specifically, the ion blow passage 96 has an upper end connected to an external air blower for removing static electricity, and has a lower end protruding behind the cutting blade 86 at a lower end thereof. It is designed to open in a direction. Then, ions (hereinafter referred to as “ion blow”) supplied together with the compressed air from the external air blower for removing static electricity are inclined behind the cutting blade 86 at substantially the same angle as the cutting blade 86 and downward. It is being squirted. As a result, ion blow is directly sprayed onto the pat board 12 and its swarf (cut chips) cut by the cutting blade 86, thereby advantageously preventing the charging thereof, and the chip board of the swarf due to the charging. Adherence to the interior of the groove 12, in particular the groove 16, can advantageously be avoided.

It is desirable that the ejection direction of the ion blow be inclined forward in the cutting direction as shown in the figure. That is, simultaneously with the cutting of the groove in the pad substrate 12, it can be sent out in front of the cutting tool 84, whereby the adhesion of the chips into the groove can be more advantageously prevented. Here, as the air blow device for removing static electricity connected to the ion blow passage 96, various known air blow devices for removing static electricity can be adopted.

[0117] The vacuum suction device 98 is attached so that its opening is open near the front of the cutting blade 86, and vacuum suction of the chips that are sequentially fed in front of the cutting blade 86 is performed. The pulling device 98 makes it possible to immediately perform suction and recovery.

[0118] Power! In addition, as shown in FIG. 12 (b), the lower end of the ion blow passage 96 is inclined at the same angle as the inclination angle of the cutting blade 86 with respect to the central axis 18 of the pad substrate 12, whereby the cutting edge 86 is inclined. In addition, the ion blow can be advantageously applied also to the inner peripheral side wall surface and the bottom surface of the concave groove 16 that is undercut with respect to the surface 14 of the pad substrate 12, and the ion powder is charged by the chip on the surface. Adhesion can also be advantageously prevented.

Next, FIG. 13 shows an embodiment in which a drilling tool is mounted on the processing device 50. A piercing unit 100 as a piercing tool is attached to a tool rest 60B shown in FIG. 13 using a mounting hole 61B. The powerful drilling unit 100 has a drill 101 attached to the distal end thereof and includes an electric motor (not shown) for driving the drill 101. In addition, The knit 100 and the cutting unit 82 may be selectively mounted on one turret, but if there are two turrets 60A and 60B as in this embodiment, one of the Wear them one by one.

Here, as shown in FIG. 14, the drilling unit 100 is attached to the tool rest 60B such that the axial direction of the drill 101 is inclined at a predetermined angle with respect to the vertical direction. Thereby, the cutting edge of the tip of the drill 101 can be abutted against the bottom surface of the concave groove 16 at substantially the same inclination angle as the cutting tool with respect to the node substrate 12. Then, as a drilling step, the drill 101 is sent in the axial direction at the inclination angle to form a slurry flow hole 24 penetrating the node / node substrate 12 and having an inclination angle substantially equal to the concave groove 16. It has become so.

[0121] By the way, the same configuration as that of the cutting blade 86 described above can be adopted for the feed operation with the inclined angle of the powerful drill 101, and the two values of X and Z and Y and Z of the tool rest 60B can be adopted. It can also be realized by a feed operation by control or a feed means by, for example, a screw mechanism in the protruding direction.

[0122] Similarly to the above-described cutting unit 82, it is also possible to provide the above-described in-blowing passage 96 and the vacuum suction device 98 for the powerful perforating unit 100.

[0123] The cutting unit 82 and the drilling unit 100 are configured by a tool holder and a base for fixing a fixed tool such as a multi-edged tool or a single-edged tool to the tool rests 60A and 60B. For example, in addition to a tool holder or the like for fixing a rotary tool such as a drill as a drilling tool to the tool rests 60A and 60B, a tool having a driving unit such as an electric motor for driving a powerful rotary tool is also included.

[0124] That is, the tool post can be driven and displaced and controlled in the three orthogonal directions of X, Υ, and Z. A fixed tool or a rotating tool with a driving unit can be attached and detached as a tool unit. It is said that. Examples of the powerful tool unit include a groove milling unit, a cutting unit, and the like, in addition to the above-described cutting unit and punching unit.

[0125] Therefore, by using such a processing device 50, the polishing node 10 having the structure according to the present invention can be advantageously produced. The order of the turning step and the drilling step is not limited, and either step can be performed first. Essential In order to achieve this, a manufacturing method is also possible in which a slurry flow hole 24 is formed in a plurality of locations of the pad substrate 12 by a drilling process, and then a circumferential groove is formed at a position overlapping the slurry flow hole 24 by a turning process. is there.

Next, another specific embodiment of the groove 16 as a circumferential groove formed on the polishing pad is shown in FIGS. Note that each of these specific embodiments shows another form of the circumferential groove formed in the polishing pad, and has a structure similar to that shown in FIG. The same members and parts are denoted by the same reference numerals as those shown in FIG. 1 in the figure, and detailed description thereof is omitted. The specific embodiments described below do not indicate that the shape of the circumferential groove according to the present invention is limited to the following specific embodiments.

That is, the concave groove 112 as the circumferential groove of the polishing pad 110 according to the second embodiment of the present invention shown in FIG. It has a spiral shape with a gradually increasing radius of curvature. In the polishing pad 110 having such a structure, one flow path is formed toward the central portion of the polishing pad 110 and the outer peripheral portion thereof, and the flow force of the slurry is increased toward the outer peripheral side of the polishing pad 110. It can be secured more advantageously. Further, the intervals between the grooves in the radial direction may be equal or may be different in consideration of the flow characteristics of the slurry.

On the other hand, FIG. 16 shows a polishing pad 120 according to a third embodiment of the present invention. The polishing pad 120 has a concentric shape which is substantially the same as that of the polishing pad 10 according to the first embodiment, with respect to the shape of the groove 122 which is a circumferential groove. A cross groove 124 is formed so as to intersect with the groove 122 and extend in a curved shape from the central axis 18 toward the outer peripheral portion. The cross groove 124 is formed with a depth dimension substantially equal to the groove 122, and the width dimension, the depth dimension, the number, and the like are determined by the material of the pad substrate 12, the material of the wafer to be processed, It is set appropriately according to the required processing accuracy and the like. Also, in the cross groove 124, it is possible to form the slurry flow hole 24 that opens inside. Then, by forming the cross groove 124, the slurry in the cross groove 124 is effectively subjected to the action of the centrifugal force, and is allowed to flow toward the outer peripheral side of the polishing pad 120 with good fluidity. As a result, the used slurry and polishing debris already used for polishing can be removed from the surface of the polishing pad 120. 14 It is also possible to efficiently discharge the power.

[0129] The forces described above in detail for some embodiments of the present invention are merely examples, and the present invention is not to be construed as being limited in any way by the specific description in the powerful embodiments. Not. In addition, the present invention can be implemented in an embodiment in which various changes, modifications, improvements, etc. are added based on the knowledge of those skilled in the art, and such an embodiment does not depart from the gist of the present invention. It goes without saying that any of them are included in the scope of the present invention.

For example, as shown in FIG. 17, the slurry flow hole 24 is not necessarily formed with the inclination angle of the inner and outer wall surfaces 20 and 22 of the concave groove 16: α. When formed as an inclined groove having a constant inclination angle, the slurry circulation hole 24 can be formed with a different inclination angle in some cases. In this embodiment, the slurry circulation hole 24 is , Are formed without an inclination angle. Further, in the present embodiment, a discharge port 25a as a slurry supply hole and a discharge hole 26a as a slurry discharge hole are also opened on the inner side wall surface 20 as a side wall surface of the concave groove 16. When forming the slurry flow holes 24 in such an embodiment, either of a drilling process with a surface force of the pad substrate 12 and a drilling process from the back surface of the pad substrate 12 can be adopted. Further, as is clear from the present embodiment, even if the inclination direction of the concave groove 16 gradually approaches the central axis 18 as it goes to the opening, it can be opened by applying force diagonally inward in the radial direction of the pad substrate 12. good.

Further, as shown in FIG. 18, it is also possible to form a slurry flow hole 24 penetrating through the pad substrate 12 with an inner diameter larger than the opening width of the concave groove 16. In such an embodiment, a larger amount of slurry can be supplied in a short time to the inside of the concave groove 16 and to the polishing pad surface, and clogging of the slurry is effectively prevented. Further, when forming the slurry flow hole 24 in such an embodiment, it is possible to perform the drilling process with any force on the front and back surfaces of the pad substrate 12 without having to tilt the drill at the time of drilling.

Further, as shown in FIG. 19, the slurry flow hole 24 is formed to have an inner diameter larger than the width of the concave groove 16 and a depth not extending from the back surface 15 to the front surface 14 of the nod substrate 12. It is also possible to adopt a mode in which it is formed as a large-diameter hole and connected to the concave groove 16. Also in this mode, the use of large-diameter holes effectively prevents clogging of the slurry. . A powerful polishing pad can be manufactured by making a hole from the back surface 15 of the node substrate 12 without roughening the front surface 14 which is a polishing surface.

[0133] As described above, the concave groove 16 of the polishing pad to which the present invention is applied has, for example, an inwardly inclined form toward the center of the pad from the bottom to the opening as shown in FIG. For example, as shown in FIG. 19, a non-inclined mode that opens in the pad central axis direction can be appropriately adopted. In particular, the use of concave grooves 16 inclined inward as shown in Fig. 17 makes it possible to suppress the flow of slurry on the polishing pad surface, and to actively polish polishing debris with the concave grooves 16. It becomes. Of course, in one polishing pad, the inclination angle of the concave groove 16 formed on the surface may be made different from at least one of the circumferential direction and the radial direction. Also, when the concave groove 16 having an inner slope is employed, the inclination angle is not particularly limited. Furthermore, the inner peripheral side wall surface and the outer peripheral side wall surface of the concave groove 16 do not necessarily have to be parallel. For example, as described in Japanese Patent Application Laid-Open No. 2003-165049, the surface gradually widens from the bottom to the opening. An open cross-sectional shape or the like can also be adopted. Also, as described in, for example, US Pat. No. 5,984,769, the planar shape of the concave groove 16 has a large number of circumferentially curved wavy shapes and circumferentially intermittent bow-shaped concave grooves. Various modes can be adopted. When a plurality of these grooves 16 are formed, the slurry flow holes 24 need not necessarily be formed by opening all the grooves 16. A recessed groove 16 that does not communicate with the opening may be formed.

[0134] Furthermore, in the present invention, the substantially parallel side walls of the inclined groove employed in the present invention are not required to have the same inclination angle in a strict sense. It should be understood that there is an allowable range of parallelism between the side walls of the inclined groove in consideration of the material of the wafer, etc., and that both side walls of the inclined groove are deep with respect to the center axis of the node substrate. It should be understood that they are inclined in the same direction.

[0135] In addition, in the above-mentioned polishing apparatus 30 as a polishing apparatus using such a polishing pad 10, the slurry supplying means and the slurry discharging means are both provided, but either one of them is used. It is also possible to provide only one. For example, FIG. 20 shows a polishing apparatus 130 configured with only the slurry discharge means, and FIG. 21 illustrates only the slurry supply means. 1 shows a polishing apparatus 150 configured as described above. In the polishing apparatus 130 and the polishing apparatus 150 described below, the same reference numerals as those in the above-described polishing apparatus 30 denote the same structures as those in the above-described polishing apparatus 30, and a detailed description thereof will be omitted.

[0136] The polishing apparatus 130 is provided with a slurry discharge tank 132 as a slurry discharge means formed inside the platen 32 with respect to a slurry discharge communication groove 42 as a slurry outlet hole opened in the fixing surface 34 of the platen 32. A communication hole extending from is connected. The slurry discharge tank 132 is an internal space formed in the platen 32, and is communicated with the outside by one or more slurry discharge pipes 134 that also extend an appropriate force of the slurry discharge tank 132. As is clear from FIG. 20, the polishing pad 10 in the present embodiment does not have the slurry supply port 25 in FIG. 2, and all of the penetrated slurry flow holes 24 serve as color discharge holes. The outlet is 26.

[0137] In the polishing process using the polishing apparatus 130, the slurry dropped from the supply nozzle 136 onto the surface 14 of the polishing pad 10 is subjected to the centrifugal force generated by the rotation of the polishing pad 10 as in the related art. It is spread on the surface 14 and supplied between the surface 14 of the polishing pad 10 and the surface to be processed of the ueno 46.

[0138] The slurry used for polishing and polishing debris generated by the polishing flow from the discharge port 26 formed in the polishing pad 10 to the slurry discharge tank 132 through the slurry discharge communication groove 42 of the platen 32. I'm sullen. Then, the slurry and the polishing debris flowing into the slurry discharge tank 132 are discharged to the outside of the platen 32 through a slurry discharge pipe 134 formed at an appropriate portion of the slurry discharge tank 132. Incidentally, the polishing apparatus 130 does not include the discharge pump 44 as in the polishing apparatus 30 described above, and the slurry in the slurry discharge tank 132 can be discharged according to the drop of the slurry due to its own weight. It is also possible to positively discharge by connecting a pump.

On the other hand, FIG. 21 shows a polishing apparatus 150 configured to include only a slurry supply unit.

The polishing apparatus 150 is provided with a slurry supply communication groove 38 as a slurry introduction hole opened in the fixing surface 34 of the platen 32, and a slurry as a slurry supply means, which is an internal space formed inside the platen 32. A communication hole extending from the supply tank 152 is connected. Then, the polishing pad 10 was superimposed on the fixing surface 34 of the platen 32 to form the polishing pad 10. The slurry supply hole 24 and the slurry supply communication groove 38 formed in the platen 32 are connected. The polishing pad 10 according to the present embodiment is formed such that the opening size of the slurry flow hole 24 is substantially equal to the width dimension of the groove 16 serving as the circumferential groove, and the slurry flow hole 24 is formed. Each of the grooves 16 has no inclination angle, is formed in parallel with the central axis of the polishing pad 10, and all of the slurry flow holes 24 are formed as discharge ports 25 as power slurry supply holes. Further, a slurry supply communication groove 38c formed on the central axis of the platen 32 is connected to the discharge hole 25c formed on the central axis. As is apparent from FIG. 21, it is not necessary that all of the slurry flow holes 24 formed in the polishing pad 10 and the slurry supply communication grooves 38 formed in the platen 32 be connected to each other. Further, both the discharge hole 25c and the slurry supply communication groove 38c formed on the center axis are opened in a circular shape, so that the diameters of the forces are different from each other!

[0140] In the polishing apparatus 150 having the above-described structure, the slurry supplied from the slurry supply communication groove 38 is supplied by also supplying the bottom surface force of the circumferential groove 16 through the slurry flow hole 24 of the polishing pad 10. This makes it possible to spread the slurry on the polished surface with a smaller amount of use compared to the conventional structure in which the slurry is dropped and spread on the polished surface. Further, the circulation of the slurry in the circumferential groove 16 is effectively performed, and the uniformity of the composition of the slurry can be maintained at a higher level.

[0141] The ion blow passage 96 and the vacuum suction device 98 provided in the cutting unit 82 attached to the processing device 50 described above are not always necessary.

[0142] Further, the use mode of the polishing pad having the structure according to the present invention is not limited, and in various embodiments, including the slurry supply method, the semiconductor device using the polishing pad according to the present invention may be used. It goes without saying that the polishing pad according to the present invention can be polished for various workpieces including a substrate, and the applicable range of the polishing pad according to the present invention is not limited to the CMP method.

Claims

The scope of the claims

[1] A polishing pad that has a thin disk shape and has a back surface that is a mounting surface to be superimposed on a rotating plate of a polishing device, and a front surface that is a polishing surface that exerts a polishing action on a semiconductor substrate. In addition, a circumferential groove extending in the circumferential direction is formed on the polishing surface, and a plurality of communication holes are formed through the polishing surface in the thickness direction. The communication hole is formed in the circumferential groove. A polishing pad having an opening on the polishing surface side through the polishing pad.

[2] At least a part of the plurality of communication holes is provided with a polishing slurry flowing therethrough from the mounting surface side of the polishing pad toward the polishing surface side of the polishing pad, so that the circumferential groove is formed. 2. The polishing pad according to claim 1, wherein the polishing pad is formed as a slurry supply hole for supplying the slurry onto the polishing surface of the polishing pad.

[3] At least a part of the plurality of communication holes is formed such that the polishing slurry flows from the polishing surface side of the polishing pad toward the mounting surface side of the polishing pad, so that the circumferential groove is formed. 3. The polishing pad according to claim 1, wherein the polishing pad is formed as a slurry discharge hole for discharging the slurry from above the polishing surface of the polishing pad.

[4] A central portion of the polishing surface is a central flat area where the circumferential groove is not formed, and a through hole penetrating in the thickness direction is formed in the central flat area. 4. The polishing pad according to claim 1, wherein the slurry can be supplied to the polishing surface of the polishing pad through a hole.

5. The polishing pad according to claim 1, wherein the circumferential groove includes a plurality of concentric annular grooves.

[6] The slurry supply hole according to claim 2 and the slurry according to claim 3 for different annular grooves among the plurality of annular grooves formed radially apart from each other on the polishing surface. Forming a discharge hole so that the annular groove in which the slurry supply hole is formed and the annular groove in which the slurry discharge hole is formed are alternately arranged in the radial direction of the polishing pad; Item 6. The polishing pad according to Item 5.

7. The polishing pad according to claim 1, wherein the circumferential groove includes a spiral groove extending in a spiral shape.

[8] On the polishing surface, the central partial force crosses the circumferential groove and moves toward the outer peripheral portion. The polishing pad according to any one of claims 1 to 7, wherein a cross-shaped groove extending substantially radially in a linear shape or a curved shape is formed.

9. The polishing pad according to claim 1, wherein the communication holes are formed with a substantially uniform distribution density in a circumferential direction on the polishing surface.

[10] At least one of the inner peripheral side wall surface and the outer peripheral side wall surface in the circumferential groove is inclined in the depth direction with respect to the central axis of the polishing pad, and the circumferential groove is inclined. 10. The polishing pad according to claim 1, wherein the polishing pad is formed as an oblique groove.

11. The polishing pad according to claim 10, wherein in the inclined groove, the inner peripheral side wall surface and the outer peripheral side wall surface are substantially parallel, and a groove width is substantially constant in a depth direction.

[12] The communication hole is formed with an inner diameter smaller than the groove width of the inclined groove and opened at the bottom surface of the inclined groove, and the inclination angle of the inclined groove is substantially the same as that of the inner peripheral side wall surface and the outer peripheral side wall surface. 12. The polishing pad according to claim 11, wherein the polishing pad extends in a thickness direction of the plate so as to face the mounting surface, and is formed as a slanted hole.

[13] The communication hole is formed to have an inner diameter larger than the groove width of the circumferential groove, and to have a depth not extending from the mounting surface to the polishing surface, and to be opened in the circumferential groove. 12. The polishing pad according to claim 1, wherein the polishing pad has a large diameter.

[14] In producing the polishing pad according to any one of claims 1 to 13,

The back surface of the pad substrate made of a synthetic resin material having a thin disk shape is supported by being superposed on a rigid rotating plate, and is rotated around the central axis of the pad substrate in the circumferential direction with respect to the surface of the pad substrate. A turning step of forming the circumferential groove by performing a cutting process;

A perforation process of forming the communication holes by performing perforation processing in a plate thickness direction under a state where the pad substrate is supported in a fixed position.

A method for manufacturing a polishing pad, comprising:

[15] In producing the polishing pad according to claim 12,

In the turning step, the inclined groove is formed by turning while feeding the cutting blade obliquely at a predetermined inclination angle with respect to the rotation center axis of the pad substrate, thereby forming the inclined groove. Sending the cutting blade to the pad substrate 15. The polishing method according to claim 14, wherein the inclined hole is formed by using a cutting drill having a rotating shaft inclined in substantially the same direction as that of the cutting hole and feeding the cutting drill in the direction of the rotating shaft to perform drilling. Pad manufacturing method.

[16] In producing the polishing pad according to claim 13,

In the drilling step, the surface of the pad substrate is superimposed on a rigid support plate to be supported in a fixed position, and the back surface force of the pad substrate is also drilled to a predetermined depth using a drill. 15. The method for producing a polishing pad according to claim 14, wherein a diameter hole is formed.

[17] A polishing pad processing apparatus for manufacturing the polishing pad according to any one of claims 1 to 13,

A rigid circular table on which a pad substrate made of a synthetic resin material having a thin disk shape is superimposed and fixedly supported;

Table rotation driving means for driving the rotary table to rotate about a central axis; table fixing means for fixing the rotary table so that it cannot rotate;

A turret movable in three orthogonal directions of X-axis, Y-axis and Z-axis forces with respect to the rotary table;

A cutting tool mounted on the tool post,

A drilling tool mounted on the tool post,

Control means for controlling the position of the tool post in the orthogonal three-axis directions and for controlling the operation of the table rotation driving means and the table fixing means;

By rotating the circular table supporting the pad substrate with the table rotation driving means and turning the surface of the pad substrate with the cutting tool mounted on the tool rest, While the circumferential groove can be formed, while the circular table is fixed by the table fixing means, the communication hole is formed by piercing the pad substrate with the piercing tool mounted on the tool post. A polishing pad processing apparatus characterized in that a polishing pad can be formed.

[18] A method for polishing a semiconductor substrate using the polishing pad according to any one of claims 1 to 13, wherein a circumferential groove is formed, While supporting the polishing pad from the mounting surface side and rotating the polishing pad about a rotation center axis,

A slurry supply operation of supplying the slurry to the polishing surface through the circumferential groove by continuously or intermittently supplying a polishing slurry to the mounting surface side force of the polishing pad through the communication hole;

At least one of a slurry discharge operation and a slurry discharge operation that discharges the slurry through the circumferential groove by continuously or intermittently discharging the slurry through the communication hole. A polishing method for a semiconductor substrate, wherein a polishing action is exerted on a semiconductor substrate as a workpiece on the polished surface by adopting the method.

[19] The polishing pad according to any one of claims 1 to 13,

A polishing platen having a rigid disk shape having a fixing surface to which the polishing pad is superimposed and fixed;

Platen rotation driving means for rotating and driving the polishing platen around a central axis; and an opening formed in the fixing surface of the polishing platen, wherein the communication hole in the polishing pad has an opening to the mounting surface. A slurry introduction hole to be connected,

Slurry supplying means for supplying a slurry for polishing to the communication hole of the polishing pad through the slurry introduction hole,

When polishing the semiconductor substrate with the polishing pad fixed to the polishing platen by rotating and driving the polishing platen by the platen rotation driving means, the polishing pad is fixed to the polishing pad through the slurry introduction hole and the communication hole. The polishing apparatus for a semiconductor substrate, wherein the slurry is supplied to the polishing surface through a circumferential groove.

[20] The polishing pad according to any one of claims 1 to 13,

Platen rotation driving means for rotating and driving the polishing platen around a central axis; and an opening formed in the fixing surface of the polishing platen, wherein the communication hole in the polishing pad has an opening to the mounting surface. A slurry outlet hole to be connected; Slurry discharging means for discharging a polishing slurry from the communication hole of the polishing pad through the slurry outlet hole,

When polishing the semiconductor substrate with the polishing pad fixed to the polishing platen by rotating the polishing platen by the platen rotation driving means, the polishing pad is fixed to the polishing pad through the slurry outlet hole and the communication hole. The polishing apparatus for a semiconductor substrate, wherein the slurry is also discharged from the polishing surface through a circumferential groove.

[21] The polishing pad according to any one of claims 1 to 13,

Slurry supplying means for supplying a polishing slurry to the communication hole of the polishing pad through the slurry introduction hole;

A slurry outlet hole formed in the polishing platen so as to open to the fixing surface and connected to an opening of the communication hole in the polishing pad to the mounting surface;

Slurry discharging means for discharging a polishing slurry from the communication hole of the polishing pad through the slurry outlet hole,

When the polishing platen is rotationally driven by the platen rotation driving means and the semiconductor substrate is polished by the polishing pad fixed to the polishing platen, the slurry supply means transmits the polishing pad through the communication hole of the polishing pad. A polishing slurry is supplied to the polishing surface through the circumferential groove, and the polishing surface force is applied to the polishing surface through the communication hole by the slurry discharging means. An apparatus for polishing a semiconductor substrate, wherein the semiconductor substrate is discharged.