JP2014008693A - Method of manufacturing polishing pad molding die, polishing pad molding die manufactured by the same method, and polishing pad manufactured by the same die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a polishing pad molding die in which a polishing pad that performs a flattening work highly accurately and highly efficiently is manufactured, a polishing pad molding die manufactured by the method, and a polishing pad manufactured by the die.SOLUTION: A method of manufacturing a polishing pad molding die 10 for a polishing pad 13 on which a micro pattern α having fine protrusions 12 arranged thereon has: a master die fabrication process of fabricating a master die 26, on which a micro pattern β having an inverted concavo-convex relationship with the micro pattern α is formed, on one side of a substrate 21; a positive slave die fabrication process of fabricating a positive slave die 27, on the surface layer of which a micro pattern γ is formed, by using the master die 26; a negative slave die fabrication process of fabricating a negative slave die 18, on the surface layer of which a micro pattern δ is formed, by using the positive slave die 27; and an assembly process of arraying and fixing the negative slave die 18 on a base 17 while facing the surface layer on which the micro pattern δ is formed upward to constitute the polishing pad molding die 10.

Description

The present invention relates to a method of manufacturing a polishing pad molding die for manufacturing a polishing pad that performs high-precision and high-efficiency flat processing of a member requiring high flatness such as a semiconductor substrate, and a polishing pad manufactured by the method. The present invention relates to a molding die and a polishing pad manufactured with the die.

Conventionally, a polishing pad for a semiconductor substrate is formed, for example, by pouring urethane foam into a mold and curing it to form a foamed urethane block, and then cutting a flat plate having a predetermined thickness (for example, 1 mm) from the obtained block. A polishing pad was manufactured. For this reason, the manufactured polishing pad does not have high flatness, and before starting polishing, dressing (also called conditioning) using a diamond grindstone or the like is performed to make the polishing pad have high flatness. It was equipped. However, the pad surface state after dressing is unstable and easily fluctuates, and further, the surface state of the polishing pad after processing varies greatly between processes. The fine uneven pattern formed on the surface of the polishing pad by dressing dominates the operation of holding the slurry containing the abrasive on the surface of the polishing pad and supplying fresh slurry to the surface to be polished of the semiconductor substrate. Although this is a factor, the dressing method cannot always form a uniform fine uneven pattern on the surface of the polishing pad, and the semiconductor substrate cannot be stably subjected to high-precision flat processing. is there.

Furthermore, since the abrasive material and shavings accumulate during polishing in the holes that appear in the surface layer of the polishing pad due to the urethane foam, the removal performance of the shavings generated from the semiconductor substrate gradually increases. As a result, the supply performance of fresh slurry to the surface to be polished of the semiconductor substrate is lowered, which causes a problem that the polishing rate is lowered. For this reason, the surface of the polishing pad is periodically ground to form a new surface, but the cavities in the urethane foam vary in size and are not evenly distributed. Each time the surface of the pad is ground to form a new surface, the size distribution and dispersion state of the holes appearing on the surface change, and the polishing performance of the polishing pad cannot always be kept constant.

Therefore, for example, in Patent Document 1, the base of the polishing pad is formed of a non-foamed member made of a material excellent in affinity with the slurry, and a fine concavo-convex pattern is formed on the surface of the base using photolithography technology. It is disclosed that a polishing pad is manufactured by doing so. Since the polishing pad is formed with a non-foamed member, there is no possibility that abrasives or shavings may accumulate in the surface layer part during polishing, and the fine uneven pattern on the surface of the polishing pad is formed using photolithography technology. A constant fine concavo-convex pattern can always be formed, and the retention of the slurry on the surface of the polishing pad and the supply of fresh slurry to the surface to be polished of the semiconductor substrate can be stably achieved.

Japanese Patent No. 4845347

However, the polishing pad of Patent Document 1 has a problem that the productivity of the polishing pad is remarkably reduced because a fine uneven pattern is formed on the surface layer portion of each polishing pad to be manufactured using a photolithography technique. . Moreover, since the manufacturing process of a polishing pad is comprised from the process of manufacturing the main body of a polishing pad, and the process of forming a fine unevenness | corrugation pattern in the surface of a main body, a manufacturing process becomes complicated, manufacturing requires time, and manufacture There is a problem that costs increase.

Therefore, as an example of a fine uneven pattern on the surface of a single crystal silicon wafer used for a semiconductor substrate by utilizing MEMS (microelectromechanical system) technology, an inverted pyramid (for example, a square having a side of 7 μm and a depth of 7 μm) is used. It is conceivable to form a pattern in which 4.9 μm regular quadrangular pyramid holes are arranged at regular intervals (for example, 5 μm), and to use this silicon wafer as a molding die for manufacturing a polishing pad. That is, a resin plate (for example, a urethane resin plate) is pressed against a silicon wafer formed with side-by-side pyramid-shaped holes, and heated while being pressed to partially soften the surface layer of the resin plate. By entering the reverse pyramid-shaped hole, it is possible to form a micro uneven pattern in which pyramidal protrusions are arranged at regular intervals on the surface layer portion of the resin plate. However, since the size of a single crystal silicon wafer that can be used is limited to the size of a single crystal silicon rod supplied for manufacturing a semiconductor substrate, a micro uneven pattern is formed on a resin plate having a size required as a polishing pad. There is a problem that silicon wafers are hard and brittle, so that they are inferior in durability for repeated use.

The present invention has been made in view of such circumstances, and it is possible to easily and inexpensively manufacture a polishing pad that performs high-precision and high-efficiency flat processing of a member that requires high flatness, such as a semiconductor substrate. It is an object of the present invention to provide a method for producing a polishing pad molding die, a polishing pad molding die produced by the method, and a polishing pad produced by the die.

The manufacturing method of the polishing pad molding die according to the first invention that meets the above-mentioned object is used when performing flat processing of a plate-like workpiece, and a fine convex portion P is set on one surface side. A manufacturing method of a polishing pad molding die used for manufacturing a polishing pad in which micropatterns α arranged in a dispersed manner are formed,
A resist mask having a hole having the same size as the bottom of the fine projection P is provided on one surface side of the single crystal substrate in accordance with the arrangement of the fine projection P of the micropattern α. Etching is performed on one surface side of the substrate through a mask, and the fine concave portion Q in which the concave-convex relationship is reversed on the one surface side of the substrate is the fine convex portion P of the micropattern α. A parent mold production step of producing a parent mold in which micropatterns β are distributed and arranged in accordance with the arrangement of
The micro pattern β of the parent mold is transferred to form a micro pattern γ in which fine convex portions R having the same dimensions as the fine concave portions Q and having the concave and convex relations reversed are arranged at positions corresponding to the fine concave portions Q. A positive mold production process for producing a positive mold,
The positive pattern micropattern γ is transferred, and micropatterns δ having the same dimensions as the microprotrusions R and having the concave and convex relations inverted are dispersedly arranged at positions corresponding to the microprotrusions R. A negative child mold production process for producing a negative child mold formed with
Assembling to form the polishing pad molding die by placing the negative mold on the surface side where the micropattern δ is formed, and arranging and fixing the negative molds side by side on the base. Process.

In the method for producing a polishing pad molding die according to the first invention, the negative mold is a flat metal formed by plating with the surface side of the positive mold on which the micropattern γ is formed as a base surface. The board | substrate which has a member and to which the said negative child type | mold is fixed can be made into a flat plate.

In the method for manufacturing a polishing pad molding die according to the first invention, the negative mold is curved in an arc shape with the surface side of the positive pattern on which the micropattern γ is formed being radially inward, An arc-shaped metal member formed by plating with the surface side on which the micropattern γ is formed as a base surface, and the base to which the negative mold is fixed is a curvature on the radially inner side of the arc-shaped metal member And a roll having the same curvature.

The polishing pad molding die according to the second invention that meets the above object is manufactured by the method for manufacturing a polishing pad molding die according to the first invention.

The polishing pad according to the third aspect of the invention that meets the above object is manufactured using the polishing pad molding die according to the second aspect of the invention.

In the polishing pad according to a third aspect of the invention, the substrate is a silicon flat plate obtained by cutting a (100) plane from a single crystal silicon rod grown in the [100] direction, and the resist mask is the silicon flat plate. The fine convex portion P is a regular quadrangular pyramidal microprojection, and the length of one side of the bottom surface of the regular quadrangular pyramidal microprojection is 0.1 to 30 μm, and the adjacent regular quadrangular pyramid The distance between the fine projections is preferably 1 to 30 μm.

In the method for manufacturing a polishing pad molding die according to the first invention, the fine concave portion Q is a resist mask in which holes having the same dimensions as the bottom of the fine convex portion P are formed in accordance with the arrangement of the fine convex portions P. Therefore, a micro pattern β obtained by accurately inverting the micro pattern α can be formed on the parent mold. A positive pattern formed by transferring the parent micropattern β is formed with a micropattern γ (and therefore identical to the micropattern α) in which the micropattern β is accurately inverted. In the negative mold produced by transferring γ, an accurate micro pattern δ (and therefore identical to the micro pattern β) in which the micro pattern γ is accurately inverted is formed. By arranging and fixing a plurality of negative molds produced on a substrate having a desired area, an accurate micropattern δ (micropattern β) can be formed over the desired area. As a result, a polishing pad molding die for molding a polishing pad having a desired area can be easily and inexpensively manufactured.

In the method for manufacturing a polishing pad molding die according to the first invention, the negative mold has a flat metal member formed by plating with the surface side on which the positive micropattern γ is formed as a base surface. In this case, a durable negative child mold having an accurate micro pattern δ can be produced efficiently and inexpensively. And when the base | substrate to which a negative mold is fixed is a flat plate, the polishing pad shaping die which can manufacture a large sized polishing pad can be manufactured easily and cheaply.

In the method for manufacturing a polishing pad molding die according to the first invention, the negative mold is curved in an arc shape with the surface side on which the positive micropattern γ is formed radially inward, and the micropattern γ In the case of having an arc-shaped metal member formed by plating with the formed surface side as a base surface, a durable negative mold having an accurate micropattern δ can be produced efficiently and inexpensively. And, when the base on which the negative mold is fixed is a roll having the same curvature as the curvature of the arcuate metal member in the radial direction, it is possible to manufacture a long (band-shaped) polishing pad having a desired width. A simple polishing pad mold can be easily and inexpensively manufactured.

In the polishing pad molding die according to the second invention, micropatterns α in which fine convex portions P are dispersed and arranged at intervals set on one surface side of a polishing pad material having a desired dimension can be easily provided. In addition, since it can be formed efficiently, it is possible to manufacture a polishing pad having a desired dimension capable of performing flat processing with high precision and high efficiency at a low cost.

Since the polishing pad according to the third invention has an accurate micro pattern α, when polishing is performed by pressing the polishing pad against the material to be polished, the polishing pad is formed on the polishing pad on the polishing surface of the material to be polished. The slurry containing the abrasive present in the gaps between the fine protrusions P is brought into contact with the polishing surface of the material to be polished efficiently through contact with the top of the fine protrusion P. Can do. Furthermore, when the slurry is continuously supplied during polishing, the supplied slurry passes through the gaps of the fine protrusions P, so that fresh slurry can always be brought into contact with the polishing surface of the material to be polished, The shavings generated at the time of polishing can be removed by mixing in the slurry flow. As a result, it is possible to perform the flat processing of the material to be polished with high precision and high efficiency.

In the polishing pad according to the third aspect of the invention, the substrate is a silicon flat plate obtained by cutting a (100) plane from a single crystal silicon rod grown in the [100] direction, with the resist mask being a (100 ) Provided on the surface, and the fine convex portion P is a regular quadrangular pyramidal microprojection, the length of one side of the bottom surface of the regular quadrangular pyramidal microprojection is 0.1 to 30 μm, and the distance between adjacent regular quadrangular pyramidal microprojections Is 1-30 μm, the slurry present in the gap surrounded by the adjacent regular quadrangular pyramidal microprotrusions can be moved along the slope of the regular quadrangular pyramidal microprotrusions, which is efficient for the polishing surface of the material to be polished. Can be contacted with fresh slurry. As a result, the entire surface to be polished can be uniformly polished.

It is explanatory drawing of the polishing pad mold which concerns on the 1st Embodiment of this invention, and the polishing pad manufactured with the metal mold | die. (A) is a top view of a polishing pad, (B) is a perspective view of the fine convex part formed in the polishing pad. It is explanatory drawing which shows the condition at the time of grinding | polishing using a polishing pad. (A), (B) is explanatory drawing of the parent mold preparation process in the manufacturing method of the same polishing pad molding die. (A)-(C) are explanatory drawings of the positive child mold production process, the negative child mold production process, and the assembly process in the manufacturing method of the same polishing pad molding die, respectively. It is explanatory drawing of the polishing pad mold which concerns on the 2nd Embodiment of this invention, and the polishing pad manufactured with the metal mold | die. (A), (B) is explanatory drawing of the parent mold preparation process in the manufacturing method of the same polishing pad molding die. (A)-(C) are explanatory drawings of the positive child mold production process, the negative child mold production process, and the assembly process in the manufacturing method of the same polishing pad molding die, respectively.

Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIGS. 1 to 3, the polishing pad molding die 10 according to the first embodiment of the present invention is a flat surface of a semiconductor substrate 11 (for example, a silicon wafer) that is an example of a plate-like object to be polished. An example of a fine protrusion P having a top height H of 0.1 to 20 μm, for example, on one surface side (the side in contact with the surface to be processed of the semiconductor substrate 11 during flat processing) used when processing. The regular quadrangular pyramidal microprotrusions 12 (slope angle θ = 30 to 80 degrees), the distance D between the apexes of adjacent regular quadrangular pyramidal microprojections 12 is 1.1 to 60 μm, and the bottom of the regular quadrangular pyramidal microprojections 12 is 1 A polishing pad on which a micropattern α formed by arranging (distributed arrangement) side by side with a length L of 0.1 to 30 μm and an interval G between the bottom surfaces of adjacent regular quadrangular pyramidal microprotrusions 1 to 30 μm is formed. 13 is a mold for manufacturing 13. Details will be described below.

The polishing pad molding die 10 is a plastic workable flat plate (for example, a polyether ether ketone (PEEK) plate, which is an example of a thermoplastic resin, which is softened), which is a material of the polishing pad 13, An upper die 14 that forms a micropattern α on one side of the flat plate, for example, an upper surface side, and a lower die 15 that places and supports the flat plate is provided. Here, the upper die 14 has a pattern forming portion 16 that presses the upper surface of the flat plate to form the micropattern α on the upper surface side by plastic working, and an upper die main body 17 that holds the pattern forming portion 16. Yes. Further, the pattern forming portion 16 is arranged (fixed) on the upper die main body 17 with the side portions being in close contact with each other, and a plurality of negative die dies 18 that press the flat plate integrally to form the micropattern α. Have.

Each negative mold 18 is an example of a fine recess S, and has a shape in which the concavo-convex relationship with the regular quadrangular pyramidal microprotrusions 12 is inverted, and a regular quadrangular pyramid fine depression having a bottom depth K of 0.1 to 20 μm. A micro pattern δ (a pattern in which the concavo-convex relationship is reversed with respect to the micro pattern α) is formed, in which 19 is arranged side by side with an interval E between the bottoms of the adjacent regular quadrangular pyramid-shaped fine depressions 19 being 1.1 to 60 μm. ing. Moreover, the length M of one side of the opening 20 of the regular quadrangular pyramid-shaped fine recess 19 existing side by side on the surface side (the lower surface side of the upper die 14) of the negative die 18 (pattern forming portion 16) is 0.1. The interval J between the openings 20 is 1 to 30 μm.

With the above configuration, when the upper die 14 is pressed against the softened flat plate placed on the lower die 15 from above, a part of the material constituting the flat plate constitutes the micro pattern δ. Since the regular quadrangular pyramid-shaped fine depression 19 enters the regular quadrangular pyramid-shaped fine depression 19 from the opening 20 of each regular quadrangular pyramid-shaped recess 19, the upper die 14 is filled after the inside of the regular quadrangular pyramid-shaped fine depression 19 is filled with a part of the material constituting the flat plate. Is moved upward and away from the flat plate, the regular quadrangular pyramidal microprotrusions 12 formed from the material entering the regular quadrangular pyramid-shaped recess 19 are arranged side by side on the upper surface side of the flat plate. α is formed. And the polishing pad 13 is obtained by cooling the flat plate in which the micro pattern (alpha) was formed to a hardening state.
When the upper die 14 is pressed against the flat plate, the distance between the upper surface of the lower die 15 and the lower surface of the upper die 14 is made constant so that the top of each regular quadrangular pyramidal fine protrusion 12 and the lower surface of the polishing pad 13 are fixed. Can be a constant value (the thickness of the polishing pad 13 is uniform). Thereby, when the semiconductor substrate 11 and the polishing pad 13 are brought into contact with each other, the contact surface of the semiconductor substrate 11 with the polishing pad 13 can be made parallel to the lower surface of the polishing pad 13.

Next, a method for manufacturing the polishing pad mold 10 according to the first embodiment of the present invention will be described.
As shown in FIGS. 4A and 4B, the manufacturing method of the polishing pad molding die 10 is performed using a single crystal substrate, for example, a (100) plane from a single crystal silicon rod grown in the [100] direction. A resist mask 23 in which a square hole 22 having the same size as the bottom surface is formed in a region corresponding to the bottom surface of the regular quadrangular pyramidal fine protrusions 12 of the micro pattern α is provided on one side of the silicon flat plate 21 cut out as a cutting surface; Etching utilizing the difference in removal processing speed determined for each crystal plane of the silicon flat plate 21 is performed through the resist mask 23, which is an example of the fine concave portion Q, and the concave-convex relationship with the regular quadrangular pyramidal fine protrusion 12 is inverted. A regular quadrangular pyramid-shaped depression 24 (slope angle φ is 30 to 80 degrees) composed of etch pits having a depth of 0.1 to 20 μm at the bottom is the distance E between the bottoms of adjacent regular quadrangular pyramid-shaped depressions 24. The side-to-side length M of the opening 25 of the regular quadrangular pyramid-shaped fine depression 24 is 0.1 to 30 μm and the interval J of the opening 25 is 1 to 30 μm. A parent mold manufacturing step for manufacturing the parent mold 26 on which the micropattern β is formed. In the micro pattern β, the regular quadrangular pyramidal micro-dents 24 are distributed and arranged in accordance with the arrangement of the regular quadrangular pyramidal microprotrusions 12 of the micro pattern α.

In addition, as shown in FIGS. 5A to 5C, the manufacturing method of the polishing pad molding die 10 is molded using the parent mold 26, and the micropattern β is transferred (the micropattern β and the uneven relationship). And a positive die 27 made of a plate-like resin member in which micropatterns γ in which regular tetragonal pyramidal fine projections 29, which are an example of the fine convex portions R, are arranged on one surface layer are formed. It has a child mold manufacturing process. Further, the manufacturing method of the polishing pad molding die 10 is constituted by a regular quadrangular pyramid-shaped fine recess 19 formed by plating on the surface layer of the positive die 27 on which the micropattern γ is formed, and having the concavo-convex relationship reversed with the micropattern γ. The negative mold 18 having a plated metal part 31 (for example, nickel, cobalt, cobalt-nickel alloy, cobalt-phosphorus alloy, etc.), which is an example of a flat metal member having the micropattern δ formed on the surface layer, is produced. The negative mold producing process and the upper mold main body 17 made of a flat plate which is an example of a base while the negative mold 18 is brought into contact with the sides of the negative mold 18 with the surface layer on which the micropattern δ is formed facing up. The upper die 14 of the polishing pad molding die 10 is formed by arranging and fixing on a stainless steel plate, a plain steel plate, an alloy steel plate, a cast iron plate, a non-ferrous metal plate such as aluminum, etc. And a assembling step of. Details will be described below.

(1) Parent mold manufacturing process As shown in FIG. 4A, a resist layer (for example, acrylic resin, epoxy resin, etc.) is formed on one (100) surface of the cut silicon flat plate 21; A resist mask 23 is formed by forming the holes 22 using a lithography technique. A resist layer is also formed on the other (100) surface and the side of the silicon flat plate 21. Next, an etching solution is brought into contact with one (100) surface of the silicon flat plate 21 through a resist mask 23. For example, potassium hydroxide or tetramethylammonium hydroxide is used as the etching solution. The etching solution comes into contact with the exposed portion of the silicon flat plate 21 exposed from the hole 22 of the resist mask 23. In the exposed portion, the silicon hydroxide formed by the reaction with the etching solution dissolves in the etching solution, so that etching proceeds. Etch pits are formed.

Here, when the (100) plane of the silicon flat plate 21 is etched, since the etching rate of (111) in which silicon atoms are densely packed is the slowest, the etching proceeds while being controlled by the etching rate of (111). To do. For this reason, the shape of the formed etch pit is a regular quadrangular pyramid with the length of one side of the bottom being the same as the length of one side of the square-shaped hole 22 and the inclined surface having the (111) plane. Then, after etching for a predetermined time, the etching solution is removed from the silicon flat plate 21 and the silicon flat plate 21 is washed, so that the concave-convex relationship between the regular quadrangular pyramidal fine protrusions 12 on one (100) surface of the silicon flat plate 21 is obtained. Can be formed. The micropattern β is formed of the regular quadrangular pyramid-shaped fine depressions 24 in which are inverted. Next, the resist mask 23 is dissolved and removed in a chemical (for example, TMAH (tetramethylammonium hydroxy solution), KOH (potassium hydroxide solution), EDP (ethylenediamine / pyrocatechol solution), etc.), thereby removing FIG. ), The parent mold 26 is obtained.

(2) Positive mold manufacturing process As shown in FIG. 5A, when the positive mold 27 is manufactured from a flat resin member using the parent mold 26, a thermoplastic resin (for example, silicone, When using fluororesin, PEEK (polyetheretherketone), etc., a flat resin member heated to a softening temperature is placed on a molding table (not shown), and the parent mold 26 is placed from above. Press. When a thermosetting resin (for example, epoxy resin, urethane resin, polyester resin, etc.) is used as the resin member, the resin member is poured onto a molding table (not shown) without heating, and the master mold 26 is pushed from above. Hit it. As a result, a part of the flat resin member enters the regular square pyramid-shaped fine recess 24 from the opening 25 of the regular quadrangular pyramid-shaped recess 24, so that the inside of the regular quadrangular pyramid-shaped recess 24 is filled with a part of the resin member. Then, when the parent mold 26 is moved upward and separated from the resin member, the upper surface side of the resin member is formed from the resin member that has entered the regular quadrangular pyramid-shaped fine recess 24, and the regular quadrangular pyramid-shaped recess 24 and the unevenness are formed. The regular quadrangular pyramidal microprotrusions 29 (and therefore the same shape as the regular quadrangular pyramidal microprotrusions 12) whose relations are reversed are arranged side by side (distributed arrangement), and the positive die 27 having the micropattern γ is formed. .

Further, when a curable resin (for example, silicone, fluorine resin) or a photocurable resin (for example, an acrylic resin that is cured by irradiation with ultraviolet rays) is used as the resin member, a mold (FIG. (Not shown), a resin member was injected into the mold, a part of the resin member was caused to enter the regular quadrangular pyramid-shaped fine recess 24 through the opening 25 of the regular quadrangular pyramid-shaped recess 24, and the resin member was cured. Thereafter, when the resin member is taken out from the mold, the regular quadrangular pyramidal microprotrusions 29 formed from the resin member that has entered the regular quadrangular pyramid-shaped recess 24 are arranged side by side on the upper surface side of the resin member. A positive die 27 having a pattern γ is formed.

(3) Negative child mold production process As shown in FIG. 5B, when producing the negative child mold 18 from the positive mold 27, first, a metal is formed on the surface layer on which the micro pattern γ of the positive mold 27 is formed. The electrode layer 30 made of is formed by PVD (for example, vapor deposition). Here, the metal constituting the electrode layer 30 needs to have good adhesion to the plated metal portion 31 constituting the negative mold 18, and for example, nickel, gold, silver, copper, or the like is used. Can do. Next, on the electrode layer 30 (using the surface of the electrode layer 30 as a base surface), a negative metal mold 18 is formed by forming a plated metal portion 31 having a thickness of, for example, 0.1 to 5 mm by electroplating. can get.

Then, after the negative mold 18 is separated from the positive mold 27, the surface of the plated metal portion 31 (the surface opposite to the electrode layer 30) is polished to adjust the thickness of the negative mold 18. Here, since the micro pattern γ of the positive die 27 is transferred to the electrode layer 30 formed on the positive die 27, the negative quadrangle fine protrusions 29 (positive square pyramidal fine protrusions) are transferred to the negative die 18. 12) and the concave-convex relationship is inverted, the bottom depth K is 0.1 to 20 μm, the length M of one side of the opening 20 is 0.1 to 30 μm, and the distance J between the openings 20 is 1 to 30 μm. Are arranged side by side with an interval E between 1.1 to 60 μm (that is, at the position corresponding to the regular quadrangular pyramidal microprotrusions 29). The same size as the pyramidal fine protrusions 29 and the regular quadrangular pyramid-shaped depressions 19 are dispersed and arranged), and the micropattern δ is formed.

(4) Assembly process As shown in FIG. 5C, when the upper mold 14 is constructed from the negative mold 18, the negative mold 18 is placed with the surface layer on which the micropattern δ is formed facing upward. The 18 side parts are arranged side by side on the lower surface of the upper die main body 17 and fixed. Here, when the negative mold 18 is placed in close contact with the upper mold body 17, the interval E between the bottoms of the adjacent regular quadrangular pyramid-shaped depressions 19 across the boundary between the adjacent negative molds 18 is the negative mold. It adjusts so that it may become the same value as the space | interval E 'of the bottom part of the adjacent regular square pyramid-shaped fine dent 19 in 18. Thereby, the continuity of the micro pattern δ can be ensured between the adjacent negative molds 18.

Next, the operation of the polishing pad 13 produced using the polishing pad molding die 10 will be described.
Since the polishing pad 13 is manufactured by pressure molding by sandwiching a plastically workable flat plate from above and below using the upper mold 14 and the lower mold 15, the polishing pad 13 has high flatness. Further, as shown in FIGS. 2A, 2B, and 3, on one side of the polishing pad 13, the height H of the top is 0.1 to 20 μm, and the length L of one side of the bottom is 0. .1-30 μm regular quadrangular pyramidal microprotrusions 12 (slope angle θ = 30-80 degrees), the distance D between the apexes of adjacent regular quadrangular pyramidal microprojections 12 is 1.1-60 μm, and adjacent regular quadrangular pyramidal microprotrusions There are formed micropatterns α arranged so that 12 intervals G are 1 to 30 μm. For this reason, as in the past, a series of operations in which a flat plate that is the base material of the polishing pad is cut out from the material for the polishing pad and dressing that requires skill (ensuring the flatness of the polishing pad and forming a fine uneven pattern) is performed. Is no longer necessary. As a result, the semiconductor substrate 11 can be flattened quickly and the polishing performance of the polishing pad 13 can always be kept constant.

When the semiconductor substrate 11 is flattened, the semiconductor substrate 11 is supported by the tops of the regular quadrangular pyramidal microprotrusions 12 constituting the micropattern α of the polishing pad 13, and the gap between the regular quadrangular pyramidal microprotrusions 12. Since there is a slurry (containing an abrasive) dripped from above the central portion of the polishing pad 13, it is always possible to bring the slurry into contact with the lower surface (surface to be polished) of the semiconductor substrate 11. it can. Further, since the gaps between the regular quadrangular pyramidal microprotrusions 12 are continuous, the shavings generated during the polishing are supplied with new slurry to the polishing pad 13 and the outer periphery of the polishing pad 13 together with the used slurry. Can be discharged to the outside of the polishing pad 13. Note that since the pores do not exist in the material forming the polishing pad 13, the shavings do not enter the polishing pad 13. As a result, the supply of fresh slurry to the surface to be polished of the semiconductor substrate 11 and the removal of shavings from the surface to be polished can be efficiently performed, and the semiconductor substrate 11 has a high level while maintaining the polishing rate high. Precise flat processing can be performed stably.

As shown in FIG. 6, the polishing pad molding die 32 according to the second embodiment of the present invention performs flat processing of a semiconductor substrate 11 (see FIG. 3) that is an example of a plate-like object to be polished. The regular quadrangular pyramidal microprotrusions 33 (slope angle), which is an example of the fine convex portion P having a top height H of 0.1 to 20 μm, on one side (the side in contact with the surface to be processed of the semiconductor substrate 11). θ = 30 to 80 degrees), the distance D between the tops of adjacent regular quadrangular pyramidal projections 33 is 1.1 to 60 μm, and the length L of one side of the bottom surface of the regular quadrangular pyramidal projections 33 is 0.1 to 30 μm. This is a mold for manufacturing a belt-like polishing pad 34 on which a micropattern α formed by arranging and arranging the gaps G between the bottom surfaces of adjacent regular quadrangular pyramidal microprotrusions 1 to 1 to 30 μm. Details will be described below.

The polishing pad molding die 32 is a softened state by heating a plastically workable belt plate 35 (for example, a polyether ether ketone (PEEK) belt plate which is an example of a thermoplastic resin) as a material of the belt-like polishing pad 34. A pair of upper and lower rolls 36 and 37 that form a micropattern α on one side of the band plate 35, for example, the upper surface side. Here, a gap having a distance corresponding to the thickness of the belt-like polishing pad 34 is provided between the upper and lower rolls 36 and 37 and rotates in opposite directions at the time of pressurization. The upper roll 36 includes a pattern forming portion 38 that presses the upper surface of the band plate 35 to form the micropattern α on the upper surface side by plastic working, and a roll body 39 that holds the pattern forming portion 38. Yes. Further, the pattern forming portion 38 is disposed (fixed) on the outer peripheral portion of the roll main body 39 with the side portions being in close contact with each other, and a plurality of negatives forming the micropattern α by pressing the strip plate 35 integrally. A child mold 40 is provided.

The negative mold 40 is an example of a fine recess S, and has a shape in which the concavo-convex relationship with the regular quadrangular pyramidal microprotrusions 33 is inverted, and a regular quadrangular pyramid-shaped depression having a bottom depth K of 0.1 to 20 μm. 41 is formed, and a micro pattern δ (a pattern in which the concavo-convex relationship is inverted with respect to the micro pattern α) is formed by arranging and arranging the interval E between the bottoms of the adjacent regular quadrangular pyramidal micro dents 41 with 1.1 to 60 μm. Yes. Moreover, the length M of one side of the opening 42 of the regular quadrangular pyramid-shaped fine depression 41 existing side by side on the surface side of the negative die 40 (pattern forming portion 38) (the outer peripheral portion of the upper roll 36) is 0.1. The interval J between the openings 42 is 1 to 30 μm.

With the above configuration, when the upper roll 36 is pressed against the softened strip 35 inserted between the lower rolls 35 and 36 while rotating in opposite directions, the strip 35 is Since a part of the constituent material enters the regular quadrangular pyramid fine depression 41 from the opening 42 of the regular quadrangular pyramid fine depression 41 constituting the micro pattern δ, it passes between the upper and lower rolls 35 and 36. On the upper surface side of the strip 35, the regular quadrangular pyramidal microprojections 33 formed from the material that has entered the regular quadrangular pyramidal micro dent 41 are arranged side by side, and the micropattern α is formed. And after cooling and hardening the strip | belt board 35 (strip-shaped polishing pad 34) in which the micro pattern (alpha) was formed, the polishing pad 34a is obtained by cutting to a predetermined size.
The distance between the upper and lower rolls 35 and 36 is made constant, so that the distance between the top of each regular quadrangular pyramidal fine protrusion 33 and the lower surface of the belt-like polishing pad 34 is constant (accordingly, the polishing pad). 34a can be made uniform). Accordingly, when the semiconductor substrate 11 and the polishing pad 34a are brought into contact with each other, the contact surface of the semiconductor substrate 11 with the polishing pad 34a can be made parallel to the lower surface of the polishing pad 34a.

Next, a method for manufacturing the polishing pad molding die 32 according to the second embodiment of the present invention will be described.
As shown in FIGS. 7A and 7B, the manufacturing method of the polishing pad molding die 32 is performed using a single crystal substrate, for example, a (100) plane from a single crystal silicon rod grown in the [100] direction. On one side of the silicon flat plate 43 cut out as a cut-out surface, a resist mask 45 in which a square hole 44 having the same size as the bottom surface is formed in a region corresponding to the bottom surface of the regular quadrangular pyramidal microprojections 33 of the micro pattern α, Etching utilizing the difference in removal processing speed determined for each crystal plane of the silicon flat plate 43 through the resist mask 45 is an example of the fine concave portion Q, and the concave-convex relationship with the regular quadrangular pyramidal microprotrusion 33 is inverted. A regular quadrangular pyramid-shaped fine recess 46 (slope angle φ is 30 to 80 degrees) composed of etch pits having a depth of 0.1 to 20 μm at the bottom is the distance E between the bottoms of adjacent regular quadrangular pyramid-shaped recesses 46. The micropattern α and the concavo-convex relationship are reversed by arranging the length M of the side 47 of the opening 47 of the regular quadrangular pyramid 46 from 0.1 to 30 μm and the interval J of the opening 47 from 1 to 30 μm. A parent mold manufacturing step for manufacturing the parent mold 48 on which the micropattern β is formed.

Further, as shown in FIGS. 8A to 8C, the manufacturing method of the polishing pad molding die 32 is molded using the parent mold 48, and the micropattern β is transferred (the micropattern β and the concavo-convex relationship). The positive pattern forming step of manufacturing a positive mold 49 made of a flat resin member in which a micro pattern γ is formed on one surface layer, and the micro pattern γ is formed from the obtained positive mold 49. An example of an arc-shaped metal member in which a micropattern δ formed by plating on the surface layer on the radially inner side is curved with the surface layer side formed inward in the radial direction and the concavo-convex relationship with the micropattern γ is reversed is formed on the surface layer A negative mold producing process for producing a negative mold 40 having a certain plated metal portion 53 (for example, nickel, cobalt, cobalt-nickel alloy, nickel-phosphorus alloy, etc.); A roll body 39 which is an example of a base (for example, a stainless steel roll, a plain steel roll, an alloy steel roll, while the side portions of the negative mold 40 are brought into contact with each other with the surface layer on which the micropattern δ is formed facing up. A roll made of cast iron, a roll made of non-ferrous metal such as aluminum, etc.) and assembling the upper pad 36 of the polishing pad molding die 32 by fixing them side by side. Details will be described below.

(1) Parent mold production process As shown in FIG. 7A, a resist layer (for example, acrylic resin, epoxy resin, etc.) is formed on one (100) surface of the cut silicon flat plate 43, A resist mask 45 is formed by forming the hole 44 using a lithography technique. A resist layer is also formed on the other (100) plane of the silicon flat plate 43 and on the side portions of the silicon flat plate 43. Next, an etching solution is brought into contact with one (100) surface of the silicon flat plate 43 through a resist mask 45. For example, potassium hydroxide or tetramethylammonium hydroxide is used as the etching solution. The etching solution comes into contact with the exposed portion of the silicon flat plate 43 exposed from the hole 44 of the resist mask 45, and etching proceeds as silicon hydroxide formed by the reaction with the etching solution dissolves in the exposed portion. Etch pits are formed.

Here, when the (100) plane of the silicon flat plate 43 is etched, the etching speed of (111) is the slowest, so that the etching proceeds while being controlled by the etching speed of (111). For this reason, the shape of the formed etch pits is a regular quadrangular pyramid with one side at the bottom equal to the length of one side of the square-shaped hole 44 and the inclined surface having the (111) plane. Then, after performing etching for a predetermined time, the etching solution is removed from the silicon flat plate 43 and the silicon flat plate 43 is washed, so that a regular quadrangular pyramid constituting the micro pattern α is formed on one (100) plane of the silicon flat plate 43. It is possible to form a micro pattern β composed of a regular quadrangular pyramid-shaped depression 46 in which the concavo-convex relationship is reversed with the fine projection 33. Next, by removing the resist mask 45 by dissolving it in an organic solvent (for example, acetone or the like), a parent mold 48 is obtained as shown in FIG.

(2) Positive mold fabrication process As shown in FIG. 8A, when fabricating the positive mold 49 from a flat resin member using the master mold 48, a thermoplastic resin (for example, silicone, When using a fluorine-based resin, PEEK (polyether ether ketone), etc., a plate-like resin member heated to a temperature at which it becomes softened is placed on a molding table (not shown), and the parent mold 48 is placed from above. Press. As a result, a part of the flat resin member enters into the regular quadrangular pyramid fine recess 46 from the opening 47 of the regular quadrangular pyramid fine recess 46, so that the inside of the regular quadrangular pyramid fine recess 46 is filled with a part of the resin member. Then, when the parent mold 48 is moved upward and separated from the resin member, the upper surface side of the resin member is formed from the resin member that has entered the regular quadrangular pyramid-shaped fine recess 46, and is an example of the fine convex portion R. Thus, the regular quadrangular pyramid-shaped depressions 46 constituting the micropattern β and the regular quadrangular pyramid-shaped projections 51 whose concavo-convex relationship is reversed (the same shape as the regular quadrangular pyramid-shaped projections 33) are arranged side by side. A positive die 49 with γ is formed.

When a curable resin (for example, silicone, fluorine resin) or a photocurable resin (for example, an acrylic resin that is cured by irradiation with ultraviolet rays) is used as the resin member, a mold (see FIG. (Not shown), a resin member was injected into the mold, a part of the resin member was caused to enter the regular quadrangular pyramid-shaped fine recess 46 from the opening 47 of the regular quadrangular pyramid-shaped recess 46, and the resin member was cured. Thereafter, when the resin member is taken out from the mold, the regular quadrangular pyramidal microprotrusions 51 formed from the resin member that has entered the regular quadrangular pyramid-shaped recess 46 constituting the micropattern β are arranged side by side on the upper surface side of the resin member. As a result, a positive die 49 having a micro pattern γ is formed.

(3) Negative child mold manufacturing process As shown in FIG. 8B, when the negative child mold 40 is manufactured from the positive mold 49, first, the surface layer side of the positive mold 49 on which the micropattern γ is formed has a radius. An electrode layer 52 made of metal is formed on the surface layer by PVD (for example, vapor deposition). Here, the metal constituting the electrode layer 52 needs to have good adhesion to the plated metal portion 53 constituting the negative mold 40, and for example, nickel, gold, silver, copper, or the like is used. Can do. Next, the negative mold 40 is obtained by forming a plated metal portion 53 having a thickness of, for example, 0.1 to 5 mm by electroplating using the electrode layer 52 as a base layer.

Then, after separating the negative mold 40 from the positive mold 49, the surface of the plated metal portion 53 (the surface opposite to the electrode layer 52) is polished to adjust the thickness of the negative mold 40. Here, since the micro pattern γ of the positive die 49 is transferred to the electrode layer 52 formed on the positive die 49, the negative quadrilateral fine protrusions 51 (positive quadrangular pyramidal fine protrusions) are transferred to the negative die 40. 33) and the concavo-convex relationship is reversed, the depth K of the bottom is 0.1 to 20 μm, the length M of one side of the opening 42 is 0.1 to 30 μm, and the interval J of the openings 42 is 1 to 30 μm. Are arranged side by side with an interval E of 1.1 to 60 μm between adjacent bottoms of the regular pyramid-shaped fine dents 41, and a micro pattern δ is formed.

(4) Assembly process As shown in FIG. 8C, when the upper roll 36 is constructed from the negative mold 40, the negative mold 40 is formed with the surface layer on which the micropattern δ is formed facing upward. The side portions of the 40 are abutted and fixed on the lower surface of the roll body 39. Here, the radius of the roll main body 39 is adjusted so as to have the same curvature as the curvature inside the negative die 40 (plated metal portion 53) in the radial direction, and the negative die 40 is brought into close contact with the roll main body 39. In the case of disposing, the interval E ′ between the bottoms of the adjacent regular quadrangular fine pits 41 across the boundary of the adjacent negative child molds 40 is equal to the bottom of the adjacent regular quadrangular pyramidal micro dents 41 in the negative child mold 40. Adjustment is made so as to be equal to the interval E. Thereby, the continuity of the micro pattern δ can be secured between the adjacent negative molds 40.
The action of the polishing pad 34a produced using the polishing pad molding die 32 is the same as the action of the polishing pad 13 produced using the polishing pad molding die 10, and the description thereof will be omitted.

A polishing pad to be produced on one side of a silicon flat plate by cutting a silicon flat plate having a length of 200 mm, a width of 200 mm, and a thickness of 3 mm from the rod of single crystal silicon grown in the [100] direction as a cut surface. PLP-30 (commercially available product: manufactured by AZ Electronics Materials) is a resist mask having a plurality of square holes formed in accordance with the shape and distribution of the bottom surface of the regular quadrangular pyramidal microprotrusions of the micropattern α provided in Use to form. Here, the length of one side of the hole was 7 μm, and the distance between the holes was 5 μm. Next, etching was performed by immersing the silicon flat plate in an etching solution (2.38 wt% tetramethylammonium hydroxide aqueous solution) for a predetermined time to form a regular quadrangular pyramid-shaped fine depression having a depth of 4.94 μm and a slope angle of 55 degrees. . Then, after removing the silicon flat plate from the etching solution and cleaning it, the resist mask is dissolved and removed with acetone, whereby the length of one side of the opening of the regular quadrangular pyramid-shaped depression is 7 μm, A parent mold was obtained in which micropatterns β (in which the concavo-convex relationship with the micropattern α was inverted) arranged at intervals of 5 μm were formed.

Next, a polypropylene resin plate heated to 150 to 250 ° C. and placed in a plastic state is placed on a molding table, the parent mold is pressed from above, and the micro pattern β is transferred to the upper surface side of the polypropylene resin plate. A micro pattern γ was formed to produce a positive mold having a length of 200 mm, a width of 200 mm, and a thickness of 3 mm.
And after forming the electrode layer which consists of nickel by vapor deposition on the surface layer in which positive type micro pattern γ was formed, by forming the plating metal part which consists of nickel of thickness 1mm by electroplating, length 200mm, A negative child mold with a micro pattern δ formed in a size of 200 mm in width and 1 mm in thickness was produced.
Subsequently, the produced negative child molds are fixed side by side on the lower surface of the upper mold body made of stainless steel with the surface layer on which the micropattern δ is formed facing up and the side parts of the negative child molds being in contact with each other. An upper mold having a pattern forming portion having a length of 1000 mm and a width of 1000 mm was produced. And the polishing pad molding die was obtained by producing the lower die made of stainless steel with the size which becomes a pair with the upper die.

An upper die placed on a lower die of a polishing pad molding die on a polyether ether ketone plate (length 1000 mm, width 1000, thickness 4 mm) softened by heating to 400 ° C. And pressurizing and transferring the micro pattern δ to the upper surface side of the polyether ether ketone plate, thereby forming a micro pattern α composed of regular quadrangular pyramidal microprotrusions having a length of 1000 mm, a width of 1000 mm, and a thickness of 3 mm. A polishing pad was molded.
When the shape of the regular quadrangular pyramidal microprojections of the micropattern α formed on the obtained polishing pad was measured, the height of the regular quadrangular pyramidal microprojections was 4.8 to 5.1 μm with respect to the target of 4.94 μm, The length of one side of the base of the regular quadrangular pyramidal projections is 6.8 to 7.2 μm with respect to the target 7 μm, and the interval between the regular quadrangular pyramidal projections is 4.8 to 5.2 μm with respect to the target 5 μm. there were.

Using the obtained polishing pad, a silicon wafer with SiO ₂ (diameter 20 mm) was polished with a small polishing machine. In the polishing, the surface of the silicon wafer on which the micropattern α of the polishing pad is formed is brought into contact with rotation at a pressure of 34.5 kPa, and the silicon wafer is rotated at a rotation speed of 60 rpm and adjusted to pH 11. This was carried out while supplying a slurry in which 12.5 mass% of silica fine particles (abrasive) was dispersed in a potassium aqueous solution at 100 ml / min. The polishing rate at this time was 60 nm / min.

When a commercially available polishing pad was used to polish a silicon wafer of the same size under the same polishing conditions, the polishing rate was 50 nm / min, which was almost the same performance as the polishing pad of the present invention. .

As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included.
Further, the present invention also includes a combination of components included in the present embodiment and other embodiments and modifications.
For example, as a single crystal substrate, a flat plate cut out from a single crystal silicon rod grown in the [100] direction is used. For example, a flat plate cut out from a single crystal quartz block or a flat plate cut out from a sapphire block is used. You can also.

10: Polishing pad molding die, 11: Semiconductor substrate, 12: Regular pyramid-shaped fine protrusion, 13: Polishing pad, 14: Upper die, 15: Lower die, 16: Pattern molding part, 17: Upper die body, 18: Negative child type, 19: regular quadrangular pyramidal fine depression, 20: opening, 21: silicon flat plate, 22: hole, 23: resist mask, 24: regular quadrangular pyramidal fine depression, 25: opening, 26: parent mold, 27: positive Child mold, 29: regular quadrangular pyramidal microprotrusions, 30: electrode layer, 31: plated metal part, 32: polishing pad molding die, 33: regular quadrangular pyramidal microprotrusions, 34: strip-shaped polishing pad, 34a: polishing pad, 35 : Band plate, 36: Upper roll, 37: Lower roll, 38: Pattern forming part, 39: Roll body, 40: Negative child type, 41: Regular quadrangular pyramid fine depression, 42: Opening, 43: Silicon flat plate, 44: Hole, 45: resist mask, 6: depressions regular quadrangular pyramid shape fine, 47: opening, 48: parental, 49: Pojiko type, 51: regular quadrangular pyramid shape fine protrusions, 52: electrode layer, 53: plated metal part

Claims (6)

Used for flat processing of a plate-like material to be polished, and used for manufacturing a polishing pad in which micro-protrusions P are formed on one surface side and formed with micropatterns α dispersed and arranged at set intervals. A method of manufacturing a polishing pad molding die comprising:
A resist mask having a hole having the same size as the bottom of the fine projection P is provided on one surface side of the single crystal substrate in accordance with the arrangement of the fine projection P of the micropattern α. Etching is performed on one surface side of the substrate through a mask, and the fine concave portion Q in which the concave-convex relationship is reversed on the one surface side of the substrate is the fine convex portion P of the micropattern α. A parent mold production step of producing a parent mold in which micropatterns β are distributed and arranged in accordance with the arrangement of
The micro pattern β of the parent mold is transferred to form a micro pattern γ in which fine convex portions R having the same dimensions as the fine concave portions Q and having the concave and convex relations reversed are arranged at positions corresponding to the fine concave portions Q. A positive mold production process for producing a positive mold,
The positive pattern micropattern γ is transferred, and micropatterns δ having the same dimensions as the microprotrusions R and having the concave and convex relations inverted are dispersedly arranged at positions corresponding to the microprotrusions R. A negative child mold production process for producing a negative child mold formed with
Assembling to form the polishing pad molding die by placing the negative mold on the surface side where the micropattern δ is formed, and arranging and fixing the negative molds side by side on the base. And a method for producing a polishing pad molding die. 2. The method of manufacturing a polishing pad molding die according to claim 1, wherein the negative die is a flat metal member formed by plating with the surface side of the positive die on which the micropattern γ is formed as a base surface. And the base on which the negative mold is fixed is a flat plate. 2. The method of manufacturing a polishing pad molding die according to claim 1, wherein the negative die is curved in an arc shape with a surface side of the positive die on which the micropattern γ is formed being radially inward. An arc-shaped metal member formed by plating with the surface side on which the pattern γ is formed as a base surface, and the base to which the negative mold is fixed has a curvature on the radially inner side of the arc-shaped metal member, A method for producing a polishing pad mold, wherein the rolls have the same curvature. It manufactures with the manufacturing method of the polishing pad molding die of any one of Claims 1-3, The polishing pad molding die characterized by the above-mentioned. A polishing pad manufactured using the polishing pad molding die according to claim 4. 6. The polishing pad according to claim 5, wherein the substrate is a silicon flat plate cut out from a single crystal silicon rod grown in a [100] direction with a (100) plane as a cut surface, and the resist mask is made of the silicon flat plate. Provided on the (100) plane, the fine convex portion P is a regular quadrangular pyramidal microprojection, and the length of one side of the bottom surface of the regular quadrangular pyramidal microprojection is 0.1 to 30 μm, and the adjacent regular quadrangular pyramid shape A polishing pad, wherein the distance between the fine protrusions is 1 to 30 μm.

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