JP2000071168A - Method of flattening surface of workpiece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that reproduces the working surface of machined products and flattens the surface of workpieces. SOLUTION: For reproducing a working surface 18 of a machined product having the working surface 18 and an adjacent subordinate surface 24 both formed from a polymer matrix impregnated with polymer microelements 16 having a plurality of cavity spaces 22, the method of flattening the surface of workpieces places the product into contact with working environment, so that the shells of the polymer microelement 16 that lies about the working surface 18 are at least partly opened and that this polymer microelement 16 becomes less hard than the polymer microelement 16 that is buried in the subordinate surface 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for flattening the surface of a processed product such as a semiconductor device.

[0002]

2. Description of the Related Art Polishing and flattening of a conventional processed product (planariz)
The method of ing) has been performed with products such as polymeric substrates or polishing pads that are exposed to various operating conditions that affect the choice of substrate material. For example, the nature of the workpiece being polished, variations in polishing rate and pressure, temperature increases that occur during the polishing operation, and the nature of the polishing slurry used in the operation will affect the choice of substrate.

[0003] The prior art products generally have a multi-layer stack having non-uniform physical properties throughout their thickness.
er laminations) or stratified substrate
s). An example of a typical multi-layer pad commonly used to polish semiconductor devices is the Politex Supreme pad, available from Rodel Incorporat of Newark, Delaware.
ed). A typical Polytex Supreme Pad is 1mm made of polyester felt
It consists of a rigid but resilient porous bottom layer of from 2 to 2 mm thick and several layers containing polyurethane binder. about
A spongy, resilient, microporous urethane layer of 0.05 mm to 0.3 mm thickness is laminated on the bottom layer. The top layer has vertical, beveled pores, with a vertical urethane structure (v) in which the slope of the pores narrows toward the top of the pad.
ertical urethane structures). The top layer is very soft, porous and resilient. In a typical polishing operation, the top layer of such a multilayer pad wears rapidly. As the top layer wears and the subsequent layers are exposed, the polishing characteristics of the pad change, resulting in non-uniform polishing rates and non-uniform polishing characteristics on the workpiece surface.

[0004] Conventional polymer polishing pads are often
Has quality variability due to inaccurate control of polymerization and mixing and cutting and molding of the final pad product. Therefore,
Polishing characteristics, such as surface quality, material removal rate and planarization rate, provided to the workpiece being polished vary significantly between pad batches.

[0005]

SUMMARY OF THE INVENTION Therefore, the present invention
It is an object to provide a method for uniformly flattening the surface of a processed product.

[0006]

In order to solve the above-mentioned problems, the present invention employs the following technical means.

The method of flattening the surface of a workpiece according to the present invention is a method of impregnating a polymer matrix with a polymer microelement having a plurality of void spaces so as to have a working surface and a sub-surface adjacent to the working surface. The exposed product is brought into contact with the working environment to open at least a portion of the shell of the polymeric microelement located adjacent to the work surface, and the opened polymeric microelement is embedded in the sub-surface. The hardness is lower than that of the molecular microelement, so that the working surface of the product is regenerated.

The shell of the polymer microelement may be opened by slicing, grinding, cutting or drilling a part of the shell.

The polymer microelements located near the work surface are harder than the polymer microelements embedded in the sub-surface because at least a part of the shell is chemically changed by the work environment. Can be reduced.

[0010] A groove may be formed in a part of the work surface so that rigidity is reduced when the work surface comes into contact with the work environment.

Further, the processed product can be a semiconductor device.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

The method of flattening the surface of a workpiece according to the present invention is a method of impregnating a polymer matrix with a polymer microelement having a plurality of void spaces so as to have a working surface and a sub-surface adjacent to the working surface. The exposed product is brought into contact with the working environment to open at least a portion of the shell of the polymeric microelement located adjacent to the work surface, and the opened polymeric microelement is embedded in the sub-surface. The hardness is lower than that of the molecular microelement, and the work surface of the product is regenerated.

Referring to the accompanying drawings, generally like reference numerals indicate like elements, FIGS.
Examples of products used in the present invention are shown, labeled 5-9 and 11 with 10, 110, 210, 310 and 410.

The product 10 is preferably a substantially circular sheet or polishing pad 12 and is best shown in FIGS. Those skilled in the art will appreciate that the pad 12 may be, for example, substantially square, rectangular or any suitable shape as desired.

The product 10 or the like can be used as a polishing pad itself, or the polishing slurry can be used for semiconductor devices,
Silicon device, crystal, glass, ceramic,
It can also be used as a substrate in polishing operations used to apply the desired surface finish to polymeric plastics, metals, stones or other surfaces. The polishing pad 12, comprising the product 10, etc., can be used with lubricating oils, coolants and various polishing slurries that are well known to those skilled in the art and are readily available commercially.
Typical components of such slurries include liquid media such as water and oils, abrasives such as aluminum oxide, silicon carbide, silicon dioxide, cerium oxide and garnet, bases, acids, salts, surfactants, Alternatively, other agents depending on the nature of the processed product, or a combination thereof are included.

The product 10 and the like are, for example, wrapping
g), useful for changing the surface (also not shown) of a workpiece (not shown) by a polishing operation such as planarization, polishing or shaping. The workpiece to be polished preferably comprises a fragile material such as, for example, quartz, silicon, glass, electronic and optical substrates and high density multilayer electronic devices. The workpiece is a semiconductor device (not shown) consisting of multiple layers of polysilicon, thermal oxide, and metallic material, each layer being planarized before subsequent layers are deposited thereon.

As best shown in FIG.
10 is a polymer matrix that is preferably impervious to aqueous fluid slurries typically used in polishing and planarization operations.
Consists of The polymeric matrix 14 can be formed from urethanes, melamines, polyesters, polysulfones, polyvinyl acetates, fluorohydrocarbons, and the like, as well as analogs, mixtures, copolymers and grafts thereof. Those skilled in the art will appreciate that any other polymer having sufficient toughness and stiffness against grinding wear during the polishing operation can be used in a manner consistent with the spirit and scope of the present invention. It is. In a presently preferred form, the polymeric matrix 14 comprises a urethane polymer. The urethane polymer is preferably a polyether-based liquor such as a product of the Adiprene type commercially available from Uniroyal Chemical Co., Middlebury, CT.
idurethane). Preferred urethane prepolymers are about 9 to 9.3% by weight
Contains a free isocyanate. Other isocyanate bearing products and prepolymers can be used in a manner consistent with the spirit and scope of the present invention.

The urethane prepolymer preferably reacts with a polyfunctional hydroxyl compound such as a hydroxyl / amine or a mixed functional compound such as a hydroxyl / amine present in a polyfunctional amine, diamine, triamine or urethane / urea crosslinked network to form urea chemical bonds and It should allow the formation of a cured / crosslinked polymer network. As currently preferred, urethane prepolymers are available from Anderson Development, Adrian, Michigan.
product "Curene (R) 442" from evelopment Co.)
4,4′-methylene-bis [2-
Chloroaniline] ("MOCA").

As best shown in FIG. 1, the polymer matrix 14 is impregnated with a plurality of polymer microelements 16. Preferably, at least some of the polymeric microelements are generally flexible. Suitable polymeric microelements include inorganic salts, sugar and water-soluble gums and resins. Examples of such polymeric microelements include polyvinyl alcohol, pectin, polyvinyl pyrrolidone, hydroxyethylcellulose, methylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose. ), Hydroxypropylcellulose, polyacrylic acids, polyacrylamides, polyethylene glycol (poly)
ethylene glycols, polyhydroxyetheracrylites, starch, maleic acid copolymers, polyethylene oxide, polyurethane
lyurethanes), and combinations thereof. The microelements 16 can be chemically modified to alter solubility, swelling power and other properties, for example, by branching, blocking, and crosslinking.

In a presently preferred form, each of the polymeric microelements 16 has an average diameter of less than about 150 μm, and more preferably has an average diameter of about 10 μm. One skilled in the art will appreciate that the average diameter of the microelements can vary, and that the polymeric matrix 14 can be impregnated with microelements 16 of the same or different size or a mixture of different microelements 16 as needed.

In a presently preferred form, each of the polymeric microelements 16 is spaced from about 1 μm to about 100 μm. Preferably, the polymeric microelement
16 shall be distributed evenly by high shear mixing substantially throughout the polymer matrix 14. The resulting composite mixture is transferred to a conventional mold before the viscosity of the reactive urethane polymer becomes too large to allow for adequate blending of the microelements with the polymeric mixture. Those skilled in the art will appreciate that various thermosetting plastics and curing agents can change the low viscosity window at different temperatures. The resulting mixture gels in the mold for about 15 minutes. Gel times can vary based on factors such as temperature and the choice of polymer matrix and microelements. The mixture is then cured at about 200-225 ° F for about 4-6 hours and cooled to room temperature (about 70 ° F). The curing temperature may vary depending on factors among other things, the polymer matrix and the type of microelement used.

The resulting product 10 is removed from the mold, cut to a desired thickness by cutting, slicing, or the like, and then shaped to form a polishing pad 12. One skilled in the art will appreciate that the formed mixture may be cut, sliced, or otherwise processed according to the present invention to any thickness or shape as required.

Depending on the intended use or operation, the shape of at least some of the polymer microelements 16 may be entirely spherical as shown in FIG. Preferably, such microspheres are hollow, each sphere being about 0.1 μm
Have a shell thickness of

As best shown in FIG. 1, each polymeric microelement 16 has a void space 22 therein.
At least some of the polymeric microelements 16 preferably have a plurality of void spaces 22 therein, as best shown in FIG. Each void space 22 generally contains gas at a pressure above atmospheric pressure to help maintain the structural integrity of each of the microelements 16 ', 16 on both the working surface 18 and the subsurface 24 of the polymeric matrix 14. I have to.

The polymeric microelement can have a permeable or piercable shell 20, as best shown in FIG. 11, so that the void space 22 in the microelement 16 'can be Open.

As best shown in FIG. 1, a preferred embodiment of the product 10 is that when at least some of the polymeric microelements 16 'located on the work surface 18 come into contact with a work environment (not shown) or abrasive slurry. Softens. For example, a water-soluble cellulose ether, such as methyl cellulose, will dissolve as soon as it comes into contact with the water in the aqueous polishing slurry.

As best shown in FIG. 1, in another preferred embodiment, at least some of the polymeric microelements 16 'located on the work surface 18 expand immediately upon contact with the work environment. For example, long chain cellulose ethers expand as soon as they come in contact with the water of the aqueous polishing slurry.

The product 10 has a work surface 18 and a minor surface 24 adjacent thereto, as best shown in FIGS.
Preferably, work surface 18 is between about 5 μm and about 60 μm thick. The thickness of the product 10 is preferably about 300 μm in a direction generally perpendicular to the major plane (not shown) of the work surface 18.
m and about 400 μm.

An advantage of the present invention is that when the product 10 comes into contact with the working environment, the polymer microelements 16 ′ on the work surface 18 of the product 10 are open and smaller than the polymer microelements 16 embedded in the subsurface 24. Hardness is reduced. In addition, the reduced polymer microelements 16 ′ are part of the polymer matrix 14 surrounding the reduced hardness microelements.
The bearing capacity for 15 is reduced, thereby reducing the effective hardness of its surrounding portion 15 of the polymer matrix. Thus, at least two levels of hardness are created in the product 10 with the work surface 18 generally softer than the subsurface 24.

Another advantage of the present invention is that as the work surface 18 of the product wears, such as by contact with the work surface or work environment, the sub-surface 24 directly adjacent to the work surface 18 becomes a new work surface. And the two hardness levels are continuously regenerated,
This is to enable more uniform and consistent polishing of the workpiece and more uniform wear of the pad 12.

Hereinafter, a specific example of the product 10 will be described.
Note that the present invention is not limited to the following example.

[Product Specific Example 1] At a temperature of about 150 ° F., a polymer matrix was prepared by adding 2997 g of Uniroyal Adiprene L-325 polyether-based urethane prepolymer to 768 g of “Curene (R) ) Four
42 "(4,4'-methylene-bis [2-chloroaniline]
"MOCA"). At this temperature, the urethane / polyfunctional amine mixture has a pot life ("low viscosity region") of about 2.5 minutes.

Expancel having a void space containing gas at a pressure greater than atmospheric pressure during this low viscosity region
551 DE (Expancel 551 DE) hollow polymer microsphere 69g
Was blended at 3450 rpm using a high-speed shear blending and mixing device with the polymer mixture at 3450 rpm to distribute the microspheres throughout the polymer mixture uniformly. During a period of time and left for 15 minutes for gelling.

The mold was then placed in a curing oven, such as is commercially available from Koch Oven Corporation. The mixture is about oven
Cured at 200 ° F for about 5 hours. After curing, the power to the oven was turned off and the mixture was allowed to cool in the oven for about 4-6 hours until the temperature of the molded product 10 was about 70 ° F (room temperature). The molded product was then cut to form a polishing pad. The resulting average distance between the microspheres of the polishing pad 12 is about 75 μm and about 300 μm.
It seems to be between μm.

As shown in FIG. 4, when the pads are used to planarize a typical semiconductor device having patterns or chips spaced about 1 mm apart, the planarization rate (μm ⁻¹ ) increases with the Expancel. (Expancel) 20 microspheres embedded
The mill thickness urethane pad (indicated by a square symbol) is four times larger than a similar urethane pad without microspheres (indicated by a circle symbol). In other words, FIG. 4 shows that when a urethane pad in which microelements according to the present invention are embedded is used, a urethane pad 4 having no microelements is used.
Indicates that the device is planarized twice as fast.

As shown in FIG. 10, the specific gravity of the molded product decreases as the flow rate of the microspheres increases.
In general, it is preferred that the pad have a specific gravity of about 0.75 to about 0.8, which corresponds to a flow rate of about 53 g of Expancel microspheres per minute.

[Specific Example 2 of Product]
2997 g of Uniroyal Adiprene L-325 (Unir
oyal Adiprene L-325) 768 g of urethane
ne (R) 442 MOCA ”, and the urethane polymer was mixed with Air Products and Chemicals, Inc. of Allentown, PA.
Co., Ltd. was prepared by high-speed shear compounding with 87 g of partially acetylated polyvinyl alcohol powder, commercially available from Co., Ltd.). During the low viscosity region (2.5
Min), the mixture is poured into a mold in a manner similar to that of the product of Example 1 and, after gelling, in an oven at about 225 ° F. for about 6 hours.
Cured over time and allowed to cool to room temperature. Due to the much faster reaction with urethane amine groups (MOCA amino groups), it appears that essentially no reaction has occurred between the OH groups of the polyvinyl alcohol and the isocyanate groups of the urethane prepolymer.

[Specific example 3 of product]
3625 g of Adiprene L-213
Prepared in a similar manner to that of Example 1 by mixing with 930 g of "Curene® 442 MOCA". During the low viscosity region (approximately 2.5 minutes), Freeman Industries In Tuckahoe, NY
c.) 58 g of pectin powder, commercially available from), was high shear shear blended with the urethane polymer to evenly distribute the pectin powder throughout the urethane mixture. During the low viscosity region (2.
5 minutes), the resulting urethane / pectin mixture is poured into a mold in a manner similar to that shown in Example 1,
Cured on gelling at about 225 ° F for about 6 hours,
And was processed.

[Specific Example 4 of Product]
2997 g of Adiprene L-325 were added to BASF Chemicals Corp., Parisipanie, NJ or GAF Chemicals, Wayne, NJ.
Corp.), which was prepared by mixing with 65 g of polyvinylpyrrolidone powder for about 30 seconds to make a homogeneous formulation. "Curene (R) 442MOCA"
(768 g) was melted at a temperature of about 212-228 ° F., compounded with the urethane / polyvinylpyrrolidone mixture at high shear and poured into the mold during the low viscosity region, ie, before 2.5 minutes had elapsed. The resulting mixture was gelled in a manner similar to that shown in Example 1, heated to about 225 ° F. for about 6 hours, and cut into polishing pads.

[Specific Example 5 of Product]
3625 g of "Adiprene L-213" is replaced with 930 g of "Curen
e (R) 442 MOCA ". 65 g of white, free-flowing hydroxyethylcellulose (Union Carbide Chem, Danbury, CT) during the low viscosity region
icals and Plastics Corp.) was formulated with a urethane mixture. Hydroxyethylcellulose is insoluble in organic solvents but is soluble in warm or cold water. The composite mixture was then processed in a manner similar to that shown in Example 1.

In another example, best shown in FIGS. 5-9, the working surface 18 of the product 10 may further be provided with a mini or macro sized pattern or groove 26 comprising concave and / or convex portions or working structures 28. it can. The grooves 26 can be formed in at least a portion of the working surface 18 by mechanical grooving methods such as machining, embossing, turning, polishing, copying and laser machining. Those skilled in the art will appreciate that the grooves 26 can be formed by various other mechanical or chemical methods, such as, for example, etching.

By grooving the work surface 18, up to 50% or more of the surface can be exposed to facilitate removal of slag during polishing. In addition to this, the work surface
The grooving 18 enhances the polishing action by increasing the number of microelements 16 'exposed to the working environment. The groove 26 can be various patterns, contours, grooves, spirals, radii,
It can be formed in dots or any other shape. Grooving the working surface 18 of the pad 12 results in a series of changes in hardness on a microscopic scale. For example, the working structure 28 can be shaped to form a cone or tip having a harder core and a softer outer surface in addition to the harder subsurface 24.

Preferably, the working structures 28 are spaced at a distance between about 0.1 mm and about 10 mm and have a depth between about 1 mm and about 10 mm. Generally, the processing structure 28 has a first dimension
In the (first dimension), it is preferable to have a length smaller than about 1000 times the average diameter of the polymer microelement 16. It is also preferred that the working structure 28 has a depth that is less than about 2000 times the average diameter of the polymeric microelement 16.

As best shown in FIGS. 5 and 6, the working surface 18 can be provided with a mini-sized groove containing a working structure 28 having a width between about 1000 μm and 5 mm. Although the mini-sized grooves shown in FIGS. 5 and 6 have an eccentric circular pattern, those skilled in the art will appreciate that the mini-sized grooves can be spirals or other patterns, including those described above.

As best shown in FIGS. 7 and 8, the work surface 18 has a working structure each having a width greater than about 5 mm.
Macro-sized grooves, including 28, can be provided. FIG.
Although the mini-sized grooves are generally square grids, as shown at and 8, those skilled in the art will appreciate that the mini-sized grooves can be formed in any pattern, including those described above, as desired. .

The macro-sized and mini-sized grooves can be formed by typical machining methods such as embossing, turning, polishing, replication and laser processing and various other methods well known to those skilled in the art.

Product Example 6 Using a standard lathe and a single-tip tool, superimpose a circular and square grid pattern, respectively, on a work surface 18 vacuum-mounted on a rotating plate of a lathe or milling machine. As a result, the working surface 18 shown in FIGS. 5 to 8 was cut. Ganged cut
ting tools) or serrated teeth
A conventional milling machine having custom-built cutting combs spaced at regular intervals was used to machine the work surface 18 into the desired pattern.

As best shown in FIG. 5, an annular mini-sized groove is formed in the polishing pad to a depth of 1.397 mm.
Grooves having a pitch of (0.055 ") are formed, each groove having a depth of 0.356 mm (0.014"). As shown in FIG. 6, the shape of the groove is a buttress thread having a slope of 60 degrees toward the inner diameter of the pad.

The square grid macro-sized grooves 28 shown in FIGS. 7 and 8 are machined on a horizontal milling machine to a width of 0.8 mm.
Create multiple squares with a groove of 13mm (0.032 ") and a depth of 0.635mm (0.025").
[025] A machining structure 28) is defined.

As best shown in FIG.
Is about 1000 μm and 5
It is also possible to provide a mini-sized groove including a working structure 28 having a width between mm. Preferably, the micro-sized grooves are made in the form of a debris pattern on the work surface 18. As defined here, "fractal pattern
"n)" means a repetitive pattern having a repetitive processing structure in which the processing structures are different from each other. Debris pattern at Koch Island & Lake
Fragment pattern of Gosper Island
A deterministic or non-deterministic mathematical formula such as a variant (“Gosperpattern”) (shown in FIG. 9)
s). While suitable fragment models include round, spherical and Swiss cheese tremas, those skilled in the art will recognize that other suitable fragment patterns may be used in accordance with the present invention as needed. Preferably, the debris pattern is chaotic
Or a random form.

Product Example 7 As best shown in FIG. 9, the grooves or mini-sized grooves were machined into the polishing pad 12 using a typical carbon dioxide laser having a continuous wave output of 100 watts. . The power rating, power and beam focus are about 0.458 mm (0.018 ") deep and about 0.127 mm (0.005").
″) Selected to cut grooves with the following widths:
The mini-size groove is the Koch Island and
It was a Gosper Island deformation of the Lake (Koch Island & Lake) fragmentation pattern. The debris pattern image was electronically read and programmed into a conventional computer numerical controller that controlled the movement of the laser beam to form a debris pattern on the work surface 18 of the pad 12. Adhesive shield (adhesive) to prevent accumulation of gas traces
mask) was placed on the pad. The adhesive shield is simultaneously attached to the minor edge of the groove (attendant minor).
) Was also reduced.

Alternatively, or additionally, an isolated “mesa” pattern can be embossed on work surface 18 to form mini-sized grooves. For example, a conventional 30 ton press can be used to apply a pressure of about 25 tons to emboss a mini-sized groove on the work surface 18 of the pad 12. Heat can be applied to enhance the relief effect.

A method according to the invention for planarizing the surface of a semiconductor device, utilizing a product 10 or less according to the invention, is generally described below.

Referring to FIGS. 1-3, the method generally comprises an initial step of providing a product 10 or 110 comprising a polymeric matrix 14. The polymer matrix 14 is impregnated with a plurality of polymer microelements 16. The details of providing the polymer matrix 14 and impregnating the matrix 14 with the microelements 16 have been described above, and further discussion is deemed unnecessary and appears to be infinite.
Preferably, the working surface 18 of the product 10 or 110 is grooved,
The working structure 28 is formed to provide an enlarged working surface, and if the working surface is entirely flat, microelements that are not normally exposed are exposed to the working environment.

The present method makes at least a portion of the work surface 18 of the product 10 or 110 less than the polymer microelements 16 ′ on the work surface 18 of the product 10 or 110 where the polymer microelements 16 ′ are located on the adjacent minor surface 24. The method may further include contacting the work environment to reduce the hardness. For example work surface
A portion of the shell 20 of at least some of the polymeric microelements 16 located in the vicinity of 18 partially slices, alters a portion of the shell 20 by at least one of grinding, cutting and drilling, or chemically Alternatively, a part of the polymer micro element 16 ′ of the working surface 18 which is opened by softening and a part of the
Make the hardness less. How to work surface 18
The details as to whether the hardness of the polymeric element 16 'in can be reduced have been described above, and further discussion is deemed unnecessary and appears to be infinite.

The method includes contacting a surface (also not shown) of a semiconductor device (not shown) with at least a portion of the work surface 18 of the product such that the surface of the semiconductor device is sufficiently planarized. Is further provided. Product 10 or polishing pad 12 is mounted on a conventional polishing machine as is well known to those skilled in the art. Preferably, work surface 18 is oriented generally parallel to the surface of the semiconductor device to be planarized, for example, with straight or circular sliding contacts to planarize or grind the surface of the semiconductor device as needed. Shall be moved.

As the working surface 18 of the pad 12 is ground in sliding contact with the surface of the semiconductor device, a portion of the subsurface 24 is exposed and the microelements 16 of the subsurface 24 are ground or chemically The work surface undergoes a change or is softened to form a new work surface 18 having similar physical properties to the previously ground work surface. Thus, the work surface 18 in contact with the surface of the semiconductor device is substantially continuously regenerated and exerts a consistent flattening or polishing action on the surface of the semiconductor device.

The method according to the invention for regenerating the work surface 18 of a product according to the invention is described generally below.

Referring to FIG. 11, the method includes the steps of providing a product 410 or pad 12 comprising a polymeric matrix 14 and impregnating the matrix 14 with a plurality of polymeric microelements 16. Details of the steps for forming the product 10 have been described above, and further discussion is deemed unnecessary and appears to be infinite.

In the present method, at least a part of the shell 20 of at least a part of the polymer microelements 16 located near the work surface 18 is opened,
The method further includes the step of opening the microelements 16 so that the hardness of the microelements 16 is reduced. The step of opening the polymeric microelement may include at least one of slicing, grinding, cutting and drilling a portion of each of the shells 20 of the microelement 16. As best shown in FIG.
The shell 20 of the microelement 16 'on the work surface 18 is a combination (combi) of which a part is shown in section in FIG.
ned) can be pierced by pommelgation and piercing device 30; Apparatus 30 can be formed from any material that is sufficiently rigid to perforate work surface 18 and microelement 16, for example, stainless steel, aluminum, or other metals. Apparatus 30 includes a plurality of sharp tools or needles 32 for piercing at least a portion of shell 20 of polymeric microelement 16 located near work surface 18.

In addition to the needle 32, the device 30 includes at least one, and preferably a plurality of pads 34 that prevent the needle 32 from piercing too deep into the work surface 18. Preferably, the needle 32 pierces the working surface 18 at a depth of about 60 μm,
Those skilled in the art will appreciate that the depth of piercing of the device 30 can be any depth that increases or decreases from 60 μm as needed. For example, a long needle 32 can be used to pierce the working surface 18 to a depth greater than 60 μm.

Those skilled in the art will appreciate that the microelement 16 may be opened or the pad 12 may be pierced multiple times as needed.

In another example, at least a portion of the shell 20 of the polymeric microelement 16 located near the working surface 18 is partially embedded with the partially modified polymeric microelement 16 on the working surface 18. It is chemically changed or softened depending on the working environment so that the hardness is lower than that of the polymer microelement 16 which has been set. For example, polymer microelements
16 can be formed from a water-soluble cellulose ether comprising methyl cellulose or propyl methylcellulose that at least partially dissolves when contacted with a working environment containing water.

From the foregoing description, it can be seen that the present invention reduces the effective stiffness of a product that changes the surface of a workpiece, such as a semiconductor device, and a polymeric micro-element located on a portion of the work surface of such a product, It can be seen that there is provided a method of regenerating the work surface of such a product and flattening the surface of the semiconductor device using such a product.
The product can be used to polish or planarize substrates and other workpieces more quickly and uniformly.

It will be appreciated by those skilled in the art that other modifications can be made to the examples without departing from the broad inventive concept of the above examples. Thus, the invention is not limited to the disclosed examples,
It should be understood that it is intended to cover all modifications that fall within the spirit and scope of the invention as defined by the appended claims.

[0067]

The method for flattening a processed product according to the present invention comprises:
With the configuration as described above, the work surface of the product is regenerated and does not change significantly as the work surface comes into contact with the workpiece, so that the surface of the workpiece can be uniformly flattened.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a product used in the present invention.

FIG. 2 is a schematic sectional view of a modified embodiment of a product used in the present invention.

FIG. 3 is a schematic cross-sectional view showing a state in which a microelement on a product working surface is expanded when it comes into contact with a working environment in a modified embodiment of a product used in the present invention.

FIG. 4 is a graph of flattening ratio as a function of inter-pattern distance at the surface of a typical semiconductor device.

FIG. 5 is a schematic diagram of a modified embodiment of a mini-sized grooved pad used in the present invention.

FIG. 6 is an enlarged partial cross-sectional view of the pad, taken along line 6-6 of FIG.

FIG. 7 is a schematic diagram of a modified embodiment of a macro-sized grooved pad used in the present invention.

FIG. 8 is an enlarged partial cross-sectional view of the pad, taken along line 8-8 of FIG. 7;

FIG. 9 is a variation of a miniature fluted pad in a fractal pattern for use in the present invention.

FIG. 10 is a bar graph showing specific gravity as a function of microsphere flow rate for products used in the present invention.

FIG. 11 shows a part of a shell of a micro element on a work surface of a product used in the present invention, which is a pommelga.
te) Schematic diagram of the device to pierce.

[Explanation of symbols]

 10 Product 18 Working surface 16 Polymer microelement 20 Shell 24 Subsurface 22 Void space

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Roberts John V. Inventor. Eti. United States Delaware 19702 Newark West Country Lane 17 (72) Inventor McLane Harry George United States of America Delaware 19709 Middletown Sugar Pine Drive 257 (72) Inventor Jensen Elmir William United States of America Delaware 19720 Newcastle South Dupont Highway 325 (72) Inventor Badinger William D. Delaware, USA 19713 Newwork Beleved Road 451

Claims (5)

[Claims] 1. A method of impregnating a polymer matrix with a polymer microelement having a plurality of void spaces and having a work surface and a sub-surface adjacent to the work surface, the product being brought into contact with a work environment. At least a portion of the shell of the polymeric microelement located adjacent to the working surface is opened, wherein the opened polymeric microelement is less stiff than the polymeric microelement embedded in the sub-surface; A method of flattening the surface of a processed product, wherein the work surface is regenerated. 2. The shell of the polymer microelement,
The method of claim 1 wherein the shell is opened by any of slicing, grinding, cutting and drilling a portion of the shell. 3. The polymer microelement located near the working surface is harder than the polymer microelement embedded in the sub-surface by at least a part of the shell being chemically changed depending on the working environment. The method for flattening a surface of a processed product according to claim 1, wherein the surface is reduced. 4. The method for flattening a surface of a workpiece according to claim 1, wherein a groove is formed in a part of the work surface so that rigidity is reduced when the work surface comes into contact with the work environment. 5. The method for flattening a surface of a processed product according to claim 1, wherein the processed product is a semiconductor device.