CN1768417A - Polishing pad, process for producing the same and method of polishing therewith - Google Patents

Abstract

A polishing pad comprising fibers containing organic fibers and, retaining the fibers, a matrix resin, which at least after dressing, has at least organic fibers exposed on its surface of polishing object side. This polishing pad is capable of inhibiting the occurrence of minute polishing flaws on the polishing object and is capable of effecting flat polishing with a low load. Further, the polishing endpoint for polishing object can be controlled without any polishing flaw by means of a polishing condition detection system for polishing object utilizing an optical technique. Therefore, in, for example, the process for producing a semiconductor device, polishing with low load on interlayer insulating layers and excelling in flatness can be carried out, so that it becomes feasible to easily carry out a next-generation dual damascene process.

Description

Grinding pad, its manufacture method and the Ginding process that uses this grinding pad

Technical field

The present invention relates to be used for grinding pad, its manufacture method of the cmp (CMP) of semiconductor element manufacturing technology etc., the precise finiss in the hard disk manufacturing technology etc. and the Ginding process that uses this grinding pad.

Background technology

Present very lagre scale integrated circuit (VLSIC) tends to improve packing density, is is researching and developing various Micrometer-Nanometer Processing Technologies.Design standard has been the sub-half-micron level.One of technology that is developed for the miniaturization of satisfying this strictness requires has CMP (cmp).This technology is in the manufacturing process of semiconductor device, makes the layer planarization fully that applies exposure, alleviates the burden of exposure technique, thereby helps to stablize fabrication yield with high level, and it implements following grinding.Push grinding charge on grinding pad, the CMP lapping liquid of slurries shape is supplied with on the limit between grinding charge and grinding pad, and the limit is relatively slided grinding pad between grinding charge, thereby only critically removes the film on grinding charge surface with desired amount.Necessary technology when therefore, it is the planarization of carrying out for example interlayer dielectric and bpsg film, shallow-trench isolation etc.

For in the grinding pad of these CMP technology, the organic resin system grinding pad that uses foaming or do not foam (with reference to the scope and the background of invention of the letter of authorization requirement of the flat 8-511210 communique of Japanese Unexamined Patent Application Publication).For example, the general foaming polyurethane resin thin plate that is formed with concentric circles or clathrate ditch that uses.

The problem of this moment is the damage (grinding damage) to abradant surface of abrasive particle and lapping rejects.The situation of common foaming or the organic resin system grinding pad that do not foam is ground damage in order to reduce, and the hardness that reduces grinding pad is very effective.But if reduce this hardness, then grinding rate will descend, and then the depression of groove also tends to worsen.It is difficult satisfying these simultaneously.

On the other hand, distribution technology develops into the present flush type distribution that uses the employing dual-inlaid (dual-damascene) of advanced low-k materials to the low Cu of distribution metal use resistance, to interlayer dielectric as main flow from the A1 distribution at initial stage gradually.

In described dual-inlaid method, the selection of lapping liquid and the selection of grinding pad more and more become very important.Especially, compare with interlayer dielectric, metal is imbued with chemical reactivity, and soft, so cause defective because of grinding damage or corroding easily.On the other hand, easy deformation is that modulus of elasticity is more little more, and depression is just big more.But, if improve the modulus of elasticity of pad, then fill up hardness and generally can improve, thereby become the reason of defectives such as above-mentioned grinding damage.

In addition, for the technology that advanced low-k materials is applied to interlayer dielectric that is developing in recent years, owing to be accompanied by that the insulating barrier mechanical property descends or descend with the adaptation of metal, become the principal element that produces defective when grinding, the littler grinding system of mechanical load when therefore needing to grind.

And then, in the metal wiring grinding step and interlayer dielectric grinding step in these shallow-trench isolation operations, dual-inlaid method, when carrying out the CMP grinding, need correct amount of grinding management.As this method, except the strict control milling time, the method for the moment of torsion change that the pad the when motor that also has detection to drive lapping device is followed grinding and the friction of wafer change, and the method for mensuration grinding charge static capacity etc.But, but also possesses the lapping device of transducer that the wafer surface state variation of grinding is followed in optical detection in use, also have a kind of technology that is becoming main flow to be, from abradant surface irradiating laser or the infrared light of lapping device side process grinding pad to wafer, pass through grinding pad its reverberation of sensor once more, manage the grinding state of wafer by lapping device.Especially, shallow-trench isolation operation, dual-inlaid method etc. are owing to expose Obstruct membrane in wafer surface in grinding endpoint, so if use the light of appropriate wavelength when detecting, then can access the variation of big reflectivity, so this optical means is useful.In the grinding step of the dielectric film that does not have Obstruct membrane, can detect amount of grinding by the reverberation of wafer surface and catoptrical interference from the silicon layer under the dielectric film.As the representative example of the grinding pad that is used for this optical means, use the grinding pad that inserts the transparent window material that is used for seeing through light in the part of foaming polyurethane resin plate.In addition, also proposed to by polyurethane, Merlon, nylon, acrylate copolymer, polyester etc. not the grinding pad that constitutes of Foamex see through the technology (for example with reference to No. 5605760 specification of United States Patent (USP)) of light.But, the problem that exists in these grinding pads is in the optical mode endpoint detection, reduce when CMP grinds and grind damage and guarantee grinding rate, especially for inlaying process, it is important reducing because of grinding damage or corroding the defective that produces as mentioned above.

Summary of the invention

The present invention is exactly in order to address the above problem, and finishes by the structure of having studied various grinding pads.

The invention provides interlayer dielectric in semiconductor element manufacturing process, bpsg film, shallow-trench isolation with in the CMP technology of using in the planarization of dielectric film etc. and the formation of metal wiring portion etc., can effectively implement planarization and metal wiring and form, can suppress abradant surface simultaneously and produce damage or grinding pad, its manufacture method of insulating barrier generation unfavorable condition and the Ginding process that uses this grinding pad.And then, provide a kind of and be applicable to through grinding pad to grinding charge surface irradiation light such as semiconductor wafer, variation the having light transmission and can suppress grinding charge the grinding pad of damage and the Ginding process that uses this grinding pad to grind take place to grind of detecting its reflectivity with the grinding step of management grinding endpoint.

The present invention relates to as follows:

(1), grinding pad, it is characterized in that, by the fiber that contains organic fiber with keep the matrix resin of this fiber to constitute, and expose organic fiber at the grinding charge side surface at least.

(2), grinding pad, it is characterized in that by the fiber that contains organic fiber with keep the matrix resin of this fiber to constitute, and the grinding charge side surface after finishing is handled exposes organic fiber at least.

(3), above-mentioned (1) or (2) described grinding pad, it is characterized in that described matrix resin contains a kind of thermoplastic resin at least.

(4), each the described grinding pad in above-mentioned (1)～(3), it is characterized in that described matrix resin is made of the hemicrystalline thermoplastic resin.

(5), each the described grinding pad in above-mentioned (1)～(4), it is characterized in that, be dispersed with elastomer in the described matrix resin.

(6), above-mentioned (5) described grinding pad, it is characterized in that described elastomeric vitrifying transition temperature is below 0 ℃ or 0 ℃.

(7), each the described grinding pad in above-mentioned (1)～(6), it is characterized in that fiber is to be made of aromatic polyamide.

(8), each the described grinding pad in above-mentioned (1)～(7), it is characterized in that, contain the organic fiber of 1～50 weight %.

(9), each the described grinding pad in above-mentioned (1)～(8), it is characterized in that the diameter of organic fiber is 1mm or below the 1mm.

(10), each the described grinding pad in above-mentioned (1)～(9), it is characterized in that the length of organic fiber is 1cm or below the 1cm.

(11), each the described grinding pad in above-mentioned (1)～(10), it is characterized in that, keep polishing particles by the organic fiber that exposes at the grinding charge side surface.

(12), each the described grinding pad in above-mentioned (1)～(11), it is characterized in that the maximum exposed division length of the described organic fiber that exposes is 0.1mm or below the 0.1mm.

(13), above-mentioned (12) described grinding pad, it is characterized in that the described organic fiber that exposes is made of polyester.

(14), above-mentioned (12) or (13) described grinding pad, it is characterized in that, in matrix resin, be dispersed with the polyester fiber of chunky shape.

(15), above-mentioned (12) or (13) described grinding pad, it is characterized in that lamination has polyester non-woven fabric in matrix resin.

(16), each described grinding pad in above-mentioned (1), (2)～(4), (7), (9)～(11), it is characterized in that, it is to be applicable to the grinding pad that detects grinding endpoint at the grinding charge surface with optical mode in process of lapping, constitute by the matrix resin that does not foam in fact that contains 1～20 weight % organic fiber, have the function of conveying and maintenance grinding milk particle, and can see through the light of 190～3500nm range of wavelength.

(17), each described grinding pad in above-mentioned (1), (2)～(4), (7), (9)～(11), it is characterized in that, it is to be applicable to the grinding pad that detects grinding endpoint at the grinding charge surface with optical mode in process of lapping, comprise the part that can see through the light of 190～3500nm range of wavelength, this part is made of the matrix resin that does not foam in fact that contains 1～20 weight % organic fiber, and has the function of conveying and maintenance grinding milk particle.

(18), above-mentioned (16) or (17) described grinding pad, it is characterized in that described organic fiber is an aramid fiber.

(19), the manufacture method of grinding pad; it is characterized in that; it is to adhere on the platform and use; carrying out by the manufacture method of the grinding pad of the planarization of abradant surface, comprise mix the fiber that contains organic fiber and contain the matrix composition of thermoplastic resin and obtain mixture step, this mixture is made the step of spherolite or tablet and the step that this spherolite or tablet is processed into tabular or sheet by extrusion molding or injection molded.

(20), the manufacture method of grinding pad, it is characterized in that, it is to adhere on the platform and use, carrying out, comprise that step, the lamination of the fiber base material impregnation matrix resin combination that contains organic fiber being made resin impregnation sheet-like fiber base material contain the sheet-like fiber base material of this resin impregnation sheet-like fiber base material and implement the step that heating and pressurizing is shaped by the manufacture method of the grinding pad of the planarization of abradant surface.

(21), the manufacture method of above-mentioned (19) or (20) described grinding pad, it is characterized in that, further comprise the step that makes surperficial exposed fiber.

(22), Ginding process, it is characterized in that, with being pressed into of grinding charge above-mentioned (1) by abradant surface～

The organic fiber of the described grinding pad of each (18) exposes on the face, to by abradant surface and grinding pad between supply with lapping liquid on one side, grinding charge and pad are relatively slided, to grind by abradant surface.

(23), above-mentioned (22) described Ginding process, it is characterized in that described is by having covered conductor layer at the dielectric constant that is formed with distribution or groove on smaller or equal to 2.7 insulating barrier, having also had the laminate of copper layer to constitute by abradant surface.

(24), Ginding process, it is characterized in that, use each the described grinding pad in above-mentioned (16)～(18), detect grinding endpoint with optical mode.

The organic fiber that this is exposed to the surface, the stress between abrasive particle in the time of will relaxing grinding in the lapping liquid or foreign matter etc. and the grinding charge prevents that the grinding charge surface from producing damage.In addition, for the general grinding pad in the past that only constitutes by resin, the big ditch on foam hole or surface plays the effect of carrying and keeping the lapping liquid abrasive particle, but for grinding pad of the present invention, the organic fiber that is exposed to the surface has the ability of conveying and maintenance lapping liquid abrasive particle, and plays grinding rate and the effect that improves flatness of obtaining.

Embodiment

The structure of grinding pad of the present invention is by the fiber that contains organic fiber and keep the matrix resin of this fiber to constitute.Organic fiber can be the part of fiber or all, and fiber then except main organic fiber, can also contain inorfils such as glass fibre.

In addition, so long as the material that exposes organic fiber at least at the grinding charge side surface then be not particularly limited.Among the present invention, what is called is exposed the grinding charge side surface after organic fiber also comprises the finishing processing, promptly exposes organic fiber at least in use at least.

The structure of concrete grinding pad can be enumerated the structure that is dispersed with the chunky shape fiber in matrix resin, lamination has or not the structure of the fiber that spins cloth or woven cloths shape etc. in matrix resin.

As the matrix resin of the fiber that keeps grinding pad of the present invention, so long as common thermosetting resin and thermoplastic resin just can use with being not particularly limited.The resin that preferably belongs to the high classification of relative resilient modulus, for example the room temperature modulus of elasticity of solidfied material further is preferably greater than the resin that equals 0.5GPa more than or equal to the resin of 0.1GPa.If modulus of elasticity is little, then flatness tends to worsen.

As thermosetting resin, can use as epoxy resin such as bisphenol A type epoxy resin, cresols phenolic resin varnish type epoxy resins; Unsaturated polyester resin; Acrylic resin; Polyurethane resin etc.These can separately or mix two kinds or its with on use.When these thermosetting resins are epoxy resin, understand mixed curing agent, curing accelerator etc. usually.As curing agent, can use dicyan diamides, organic acid, organic acid anhydride, polyamines etc., curing accelerator can use as 2-ethyl-4-methylimidazole etc.

As thermoplastic resin, for example can enumerate Merlon, polymethyl methacrylate, AS (acrylonitritrile-styrene resin), ABS (acrylonitrile-butadiene rubber-styrol copolymer), polyethylene, polypropylene, polybutene, 4-methyl-amylene-1, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyester, polyamide, polyamidoimide, polyformaldehyde etc.These can separately or mix two kinds or its with on use.Especially, if the thermoplastic macromolecule resin who uses hemicrystalline then can obtain the grinding pad of the high-durability of abrasion performance excellence as matrix resin.

First execution mode of grinding pad of the present invention is the grinding pad that above-mentioned matrix resin contains a kind of thermoplastic resin at least.Here, as matrix resin, so long as contain a kind of thermoplastic resin at least, just can use, preferred principal component is a thermoplastic resin with being not particularly limited.

Second execution mode of grinding pad of the present invention is that above-mentioned maximum exposed division length at the organic fiber that is exposed by the abradant surface side surface is 0.1mm or the grinding pad below the 0.1mm.The maximum exposed division length of the organic fiber that exposes here, is meant length maximum in the length that is fixed on the part that the lip-deep fiber of grinding pad exposed in fact.In fact, can use about SEM lip-deep 5 places of observation pad such as (scanning electron microscopy) or with on carry out instrumentation.

The 3rd execution mode of grinding pad of the present invention is for being applicable to the grinding pad that detects grinding endpoint at the grinding charge surface with optical mode in process of lapping, part or all of this grinding pad is to be made of light that can see through 190～3500nm range of wavelength and the matrix resin that does not foam in fact that contains the organic fiber of 1～20 weight %, and has conveying and keep the function of grinding milk particle.

For matrix resin, especially in the above-described first embodiment, except above-mentioned thermoplastic resin, can also further mix crosslinked and uncrosslinked elastomer as additive, crosslinked polystyrene, crosslinked polymethylmethacrylaparticles etc., and be dispersed in the matrix resin.More preferably add the low elastomer of the thermoplastic elastomer (TPE) and the degree of cross linking.As elastomer,, be more preferably less than and equal 0 ℃ material so long as the vitrifying transition temperature smaller or equal to the material of room temperature, then can use with being not particularly limited.For example, can enumerate elastomers such as olefin-based elastomer, styrene series elastomer, ammonia ester based elastomers, ester based elastomers etc., alkenyl aromatic-conjugated diene copolymer, polyolefin copolymer etc.These elastomeric additions are many more, and then the resistance to impact of resin is just high more, and adhesiveness is strong more, simultaneously pad table and also can increasing with the frictional force of metal.

As the organic fiber in the grinding pad of the present invention, can use the fibrous material of making of aramid fiber, polyester, polyimides etc. widely.In addition, also can select, mix wherein two kinds or its with on use.

The viewpoint of the retentivity of abrasive particle particle is considered from the durability or the fiber of grinding pad separately preferred or principal component is that aramid fiber is an aromatic polyamide fibre, further preferred is aramid fiber separately.Be aramid fiber owing to compare with other general organic fibers, the hot strength height, during exposed fiber, fiber is stayed the surface easily, therefore, can keep the abrasive particle particle effectively so mechanically make grinding pad surface roughening of the present invention.In addition, also has the durability that improves grinding pad, the effect that increases the service life.Aramid fiber is particularly suitable for the situation of above-mentioned first and the 3rd execution mode.

Aramid fiber has a paratype and a bit-type and since contraposition be aramid fiber than between bit-type fiber mechanics intensity height and moisture absorption low, so more suitable.As contraposition is aramid fiber, can use commercially available Fanglun 1414 and polyparaphenylene's diphenyl ether terephthalamide fiber.

In addition, consider that preferred principal component is the fiber of polyester from the aspect of regulating maximum exposed length and surface roughness.This is because when exposing the fiber of this grinding pad, the shear strength of polyester fiber can reduce maximum exposed length less than the fiber of hard.Situation for the grinding pad of above-mentioned second execution mode is especially desirable.On the other hand, when using hard fibre such as other aramid fibers, polyimide fiber, can regulate maximum exposed length by the abrasive particle particle diameter that miniaturization is used.At this moment, the roughness on pad surface depends on above-mentioned abrasive particle particle diameter, therefore fill up self the surface concavo-convex will inevitably being affected and influence grinding rate.With respect to this, when using polyester, even use the abrasive particle of any particle diameter, exposed length is also almost constant.Therefore, the at random table of spacer self and roughness under the certain situation of fibre length.

Here, also can in polyester fiber, mix other above-mentioned hard fibre and use.At this moment, the ratio of hard fibre is suitably 40～100 weight %, is preferably 70～100 weight %, more preferably 80～100 weight %.If polyester fiber is many, then fiber exposes layer and can diminish, and on the contrary, if hard fibre is many, then can becomes and thickens, and tends to make flatness to worsen.

The suitable fiber that uses fiber footpath (diameter) smaller or equal to 1mm of organic fiber it is desirable to smaller or equal to 200 μ m.Be preferably 1～200 μ m, more preferably 5～150 μ m.If too thick, then mechanical strength will be too high, can become to grind damage or repair bad reason.If too thin, then operability will descend, and may descend owing to undercapacity causes the durability of pad.

Fibre length has no particular limits, and when grinding pad that fiber disperses with chunky shape in resin, preferably smaller or equal to 10mm, is more preferably less than and equals 5mm, more preferably 0.1～3mm.If too short, then the fiber that mechanically pad is exposed during surface roughening just can not remain on the pad effectively, if oversize, could thickening during then with mixed with resin and become and be difficult to moulding.These can use the mince that short fiber is cut into specific length, also can mix the material that uses multiple fibre length.

In addition,, can carry out the roughening of mechanicalness or chemical in advance to fiber surface, perhaps adopt coupling agent to carry out modification in order to improve the compatibility with resin.Consider from the operability aspect, can use the short fiber mince resin-coated and make the material of bundle with minute quantity.Here, it is so long as heating that can be when mixing with matrix resin or the shearing force that is applied, and the degree that makes the short fiber this degree in the matrix resin of being distributed to have confining force gets final product.

In addition, the grinding pad of nonwoven fabrics or woven cloths is arranged, when using nonwoven fabrics, can use the nonwoven fabrics that length is shaped to sheet at 1mm or the fiber same as described above more than the 1mm, the solvator of utilizing fiber self or adhesive for lamination.The adhesive that adhesive can use water-soluble epoxy resin adhesive etc. to be made of epoxy resin.When using adhesive, be not particularly limited, but be 3～20 weight portions preferably, more preferably 5～15 weight portions with respect to the fiber of 100 weight portions for its amount.In addition, long fibre is made the situation of the woven cloths of textile-like, be not particularly limited for method for weaving.Lamination has the grinding pad of this fiber to be particularly suitable for the grinding pad of second embodiment of the invention.

The above nonwoven fabrics and the Unit Weight of woven cloths are preferably 36～100g/m ², 55～72g/m more preferably ²

The content of above-mentioned organic fiber is not particularly limited, and to filling up the situation of all use chunky shape fibers, is preferably 1～50 all weight % of pad, more preferably 1～20 weight %, more preferably 5～20 weight %.If fibre weight is few, then the grinding of abradant surface damage will become significantly, if too much, then mouldability tends to variation.On the other hand, the situation of woven cloths and nonwoven fabrics is preferably more than and equals 50 weight %, more preferably 60～80 weight %.

Especially the situation of the 3rd execution mode, the content of the organic fiber of above-mentioned part with light transmission need be in the scope of the grinding state that does not hinder light transmission and can detect wafer.Thereby, be preferably 1～20 all weight % of grinding pad, more preferably 2～10 weight %.If fibre weight is few, then the grinding of abradant surface damage will become significantly, if too much, then mouldability tends to variation.

For above-mentioned grinding pad, method that can be by loosen collagen fibre and moulding in becoming the resin combination of matrix, the method for carrying out lamination after the woven cloths that contains fiber or nonwoven fabrics impregnating resin lacquer obtained prepreg wait and make, but be not limited to these methods.

Below, the manufacture method of grinding pad of the present invention is described.

First manufacture method comprises: mix the fiber contain organic fiber and matrix resin composition and obtain mixture step, this mixture is made the step of spherolite or tablet and is adopted extrusion molding or injection molded to be processed into the step of tabular or sheet this spherolite or tablet.Second manufacture method then comprises: step, the lamination of the fiber base material impregnation matrix resin combination that contains organic fiber being made resin impregnation sheet-like fiber base material contain the sheet-like fiber base material of this resin impregnation sheet-like fiber base material and implement the step that heating and pressurizing is shaped.Fiber base material preferably mainly contains polyester fiber.

Be used for making grinding pad of the present invention matrix resin composition modulator approach or with the mixed method of fiber, can use known method in the past, be not particularly limited.

Promptly, as first manufacture method directly with the chunky shape fiber dispersion in matrix resin composition the time, after for example each resin combination that forms matrix being mixed (do and mix) equably with Henschel mixer, high-speed mixer, drum mixer, ribbon mixer etc., with single shaft extruder or melting mixings such as biaxial extruder, Banbury.And then, add fiber melting mixing similarly.Spherolite or tablet are made in cooling then.When making water in the cooling, need intensive drying, dehydration.

The above-mentioned spherolite or the tablet that obtain are extruded, rolled with roll by mould with extrusion shaper once more, can make sheet or tabular shaping thing.

On the other hand, when matrix resin composition is liquid thermosetting resin composition,, pour into again after metal die etc. removes bubble by decompression by the chunky shape fiber is distributed in the liquid thermosetting resin composition with specified rate, be heating and curing, can make the shaping thing.It also can be with above-mentioned identical, and metal die is pressurizeed under heated condition and pours into and make.

In addition, above-mentioned second manufacture method also can adopt known method in the past, is particularly suitable for the manufacturing of the grinding pad of above-mentioned second execution mode.For example, when using woven cloths, nonwoven fabrics, prepare aforesaid resin impregnation sheet-like fiber base material or resin impregnation sheet-like fiber base material and resin and do not flood sheet fiber base material (being woven cloths or nonwoven fabrics) as fiber base material.It is integrated with them to be shaped by heating and pressurizing, can obtain the thing that is shaped.In addition, be formed on state that surface expose organic fiber preferably by not flooding the sheet fiber base material at least one surface configuration resin this moment.

Above-mentioned resin impregnation sheet-like fiber base material is the base material that resin is not flooded sheet fiber base material impregnating resin composition, is commonly referred to as prepreg.The manufacture method of prepreg is not particularly limited, and can be made into varnish by the above-mentioned matrix resin composition composition of dissolving in organic solvent, and impregnated in resin and do not flood heat drying behind the sheet fiber base material and obtain.For solvent types, so long as dissolving resin composition equably just can use with being not particularly limited.For example, can enumerate ketones such as methyl ethyl ketone, methyl iso-butyl ketone (MIBK), acetone; Lower alcohols such as ethanol, propyl alcohol, isopropyl alcohol; Amide-types such as dimethyl formamide, formamide etc., these materials also can mix use.With respect to the resin combination and the bonding agent that add up to 100 weight portions, the fiber content in the resin impregnation sheet-like fiber base material is preferably 60～140 weight portions, more preferably 90～120 weight portions.

In addition, do not flood sheet fiber base material shared ratio in all for resin, consider the fiber in the grinding pad content, especially will determine by the organic fiber content that is pressed in the superficial layer on the grinding charge.According to this method, can change the fiber content of grinding pad, therefore, do not need to change the resin content when making above-mentioned prepreg, and just can regulate by changing the usage ratio that resin do not flood the sheet fiber base material.

In heating and pressurizing was shaped, in general, heating-up temperature was generally 150～200 ℃, and pressure is 50～500kPa.These can suitably be regulated according to kind, the content of employed thermosetting resin.

These shaping things are suitably processed corresponding to the platform shape of given lapping device as required, can be obtained the grinding pad of end article.As the one example,, can make the end article grinding pad by above-mentioned sheet-like formed thing is cut into circle.

All thickness of grinding pad is preferably 0.1～5mm, more preferably 0.5～2mm.In addition, also can form concentric circles, clathrate etc. at the groove of processing such as the abradant surface use NC of above-mentioned pad rotating disk as the runner of lapping liquid and lapping rejects.

In order to obtain the grinding pad that exposes organic fiber at least at the grinding charge side surface of the present invention, handle the grinding charge side surface of pad as required, with exposed fiber.As the formation method of this exposed fiber, can adopt finishing to handle, promptly use grinding stone such as diamond to ream the resin on pad surface, with the method for exposed fiber.Also can use metal plug, metallic spatula, resin brush, glass or ceramic wafer to replace grinding stone.

In order to control the exposed length of fiber, need regulate their service condition well.Maximum exposed fiber length is influenced by the very big of fiber stiffness, if polyester fiber is used in pad, can regulate shortly easily.

The maximum length of the part that organic fiber exposes on the surface is that in general, practical is smaller or equal to 1mm, preferably smaller or equal to 200 μ m.More preferably 1～200 μ m, more preferably 10～150 μ m.If too short, then the retentivity of lapping liquid will descend and grinding rate is diminished; If oversize, then tend to flatness is brought bad influence.

Especially for the grinding pad of second embodiment of the invention, the maximum exposed division length of the above-mentioned organic fiber that exposes is smaller or equal to 0.1mm.Here, so long as maximum exposed division length just can use smaller or equal to 0.1mm with being not particularly limited, but be preferably 1～50 μ m, more preferably 1～25 μ m.If maximum exposed division length is oversize, then flatness will descend; If too little, then grinding rate tends to descend.

By this organic fiber that exposes at the grinding charge side surface, when grinding, can keep the polishing particles (abrasive particle) in the aftermentioned lapping liquid effectively.

The grinding pad of third embodiment of the invention then, is described.This grinding pad detects the amount of grinding of grinding charge with optical mode, managing its terminal point, and is keeping high grinding rate and inhomogeneity while, takes place in the time of can suppressing to grind to grind and damages.This formation can wait and realize by structure, resin composition, the filler of research grinding pad.

The structure of this grinding pad is that the material of grinding pad has the permeability of 190～3500nm range of wavelength light or the part of grinding pad are formed by the material that this has light transmission.The latter for example is configured as the parts of this grinding pad small pieces, is inserted on the part of other grinding pads that do not have sufficient light transmission as being used for seeing through the window portion of light.

Like this, because grinding pad or its part can see through the light of 190～3500nm range of wavelength, therefore through the abradant surface irradiates light of grinding pad, and detect the variation of its reflectivity, thereby can manage grinding endpoint to grinding charge.Among the present invention, the transmitance that the light that sees through 190～3500nm range of wavelength typically refers to this wavelength light of the grinding pad that exposes before the organic fiber or its part is 10～100%.Preferred this transmitance is 30～100%.

As the matrix resin of the material that is used to have such light transmission, preferably belong to the resin of the higher classification of modular ratio, each above-mentioned resin can use with being not particularly limited.If especially use the hemicrystalline thermoplastic macromolecule resin, then can obtain the grinding pad of the high-durability of abrasion performance excellence.In addition, this resin is preferably the form that does not have foam hole in fact.This is because the form with foam hole can hinder printing opacity, diminishes the wafer grinding status detection.As organic fiber preferred separately or main component be aramid fiber.

Manufacture method is identical with above-mentioned manufacture method, by each shaping thing is cut into circle etc. corresponding to the platform shape of regulation lapping device, can form grinding pad, perhaps this shaping thing is processed into small pieces, insert the low grinding pad of other light transmissions that has cut a part as light transmission window portion, formation can detect the grinding pad of light.For the latter's situation,, preferably insert the low grinding pad of the light transmission of window portion and form by the resin plate that contains organic fiber etc. too, but be not particularly limited for fiber content in order to improve effect of the present invention.In addition, the window portion of insertion need contact with grinding charge on the pad surface when grinding.This is because if the gap between window portion and the grinding charge is big, then lapping liquid can flow into, and causes seeing through the light generation scattering of coming, thereby hinders light to detect.The shape of window portion is not particularly limited, but its size needs to guarantee to carry out the area of the required light path of the subsidiary system works by rayed and detecting sensor constituted of lapping device that light detects, and is preferably about 0.1～10% all area of grinding pad surface.

Below, the Ginding process that uses grinding pad of the present invention is described.

Ginding process of the present invention is that grinding charge is pressed into by abradant surface that the organic fiber of arbitrary grinding pad exposes on the face in the invention described above, between by abradant surface and grinding pad, supply with lapping liquid on one side, grinding charge and pad are relatively slided, to grind by the Ginding process of abradant surface.

As grinding charge, can enumerate in the shallow-trench isolation operation as subtegulum: after making the device pattern that is shaped by silicon nitride film, etching Si exposed division is thereon by formation silicon oxide films such as TEOS (tetraethyl orthosilicate)-plasma CVD methods.In inlaying process, can enumerate in addition as subtegulum: can cover the obstruct electrically conductive film of peristome and inwall fully adopting dry etching to be formed with to grow up on the interlayer dielectric of through hole and distribution groove, and then the Cu film of growing up thereon, thereby imbed peristome fully.

The CMP lapping liquid that is used for Ginding process of the present invention is not particularly limited, for example, as the dielectric film lapping liquid, can enumerate the composition that to constitute by cerium oxide particles (ceria) or silica (silica) and dispersant and be distributed in the decentralized medium such as water, and then add additive and the material that obtains.As metal levels such as Cu lapping liquid, can enumerate abrasive particle, additive and anticorrisive agents such as silica, alumina, ceria, titanium oxide, zircon and germanium oxide are distributed in the water, and then add the formed lapping liquid of peroxide.As especially preferred colloidal silica particles of abrasive particle or aluminium oxide particles.In addition, the abrasive particle particle content is preferably 0.1～20 weight %.The manufacture method of this abrasive particle particle is not particularly limited, but its average grain diameter is preferably 0.01～1.0 μ m.If average grain diameter less than 0.01 μ m, then grinding rate can be too little, if surpass 1.0 μ m, then can cause damage easily.

The device that grinds is not particularly limited, and can use round supporting plate type lapping device, line style lapping device.For example, can use to have and be used for keeping the support of grinding charge and be stained with grinding pad and the common lapping device of the grinding plate of the motor that can change revolution etc. is installed.As the one example, the lapping device that can use (strain) ebara corporatlon to make: model EP0111.

Especially detect in the Ginding process of grinding pad of use the 3rd execution mode of grinding endpoint with optical mode, use this grinding pad, grinding charge and grinding pad are relatively slided, grind by abradant surface, pass through the light of grinding pad simultaneously, manage grinding endpoint by the variation that detects its reflectivity to the abradant surface illumination wavelength 190～3500nm of grinding charge.

When using the grinding pad of the 3rd execution mode, lapping device need have the device that is used for to platform irradiating laser that is stained with grinding pad and detection of reflected light as the MIRRA lapping device that U.S. Applied Material company makes.Grinding condition is not particularly limited, and can select optimum condition according to grinding object.For precision is ground well, in the shallow-trench isolation operation at the exposing of silicon nitride film, in inlaying process, detect the reflection of light that shines wafer surface at exposing of Obstruct membrane, thereby at lapping device side management grinding endpoint.At this moment, the program of control lapping process is to be encased in lapping device in advance.

For grinding pad of the present invention being fixed on the platform of lapping device, can be at the bonding agents such as using two-sided tape of tossing about of abradant surface.In addition, also can install across the liner of the low elastic modulus that constitutes by polyurathamc etc.

Grind for grinding pad and grinding charge relatively being slided at the state on the grinding pad of being pressed into by abradant surface with grinding charge, specifically can mobile grinding charge and grinding plate at least one.Except with the grinding plate rotation, can also rotate or sliding support grinds.In addition, can enumerate the Ginding process that makes the planetary rotation of grinding plate, make Ginding process that banded grinding pad moves with a direction linearity at length direction etc.Here, support can be the free position of fixing, rotate, shaking.These Ginding process are so long as make grinding pad and method that grinding charge relatively moves, then can be according to suitably being selected by abradant surface or lapping device.

Grinding condition is not particularly limited, but preferably suitably selects according to grinding charge.For example, be unlikely to fly out in order to make grinding charge, the rotary speed of grinding plate is preferably 200rpm or the following low speed rotation of 200rpm; The pressure that is applied to grinding charge then is preferably the pressure that does not produce damage after the grinding, for example preferably is about 50kPa or below the 50kPa when being copper by abradant surface.In addition, use when having the grinding charge of low-k interlayer dielectric film, be preferably 20kPa or below the 20kPa.

In the process of lapping, supply with lapping liquid to grinding pad with between continuously by abradant surface with pump etc.This quantity delivered is not particularly limited, but preferred grinding pad surface is covered by lapping liquid often.The pad that causes by grinding or expose the wearing and tearing of organic fiber, will keep from birth again by repairing.Grind the grinding charge after finishing, after preferably fully cleaning with flowing water, use drier etc. gets rid of attached to the water droplet on the abradant surface, and dry.

Below, a scheme as Ginding process of the present invention, form operation according to the distribution of semiconductor device, illustrate above-mentionedly to be intercepted conductor layer, the Ginding process that laminate constituted of metal level such as copper in addition by on the insulating barrier that is formed with distribution or groove, covering by abradant surface.

As above-mentioned metal level, can enumerate metals such as the group be made up of the oxide of the oxide of copper, copper alloy, copper, copper alloy (below be called copper and compound thereof), tungsten, tungsten alloy, silver, gold is the material of principal component, and copper such as preferably copper and compound thereof are the metal level of principal component.

As the obstruct conductor layer that is covered by metal level (below be called barrier layer), in above-mentioned metal, preferably for above-mentioned copper and compound thereof especially to the barrier layer of copper and copper alloy.Barrier layer is in order to prevent that metal level from spreading in dielectric film, and the adaptation that improves dielectric film and metal level forms.The composition of this conductor can be enumerated compounds such as tantalum, titanium, tungsten and their nitride, oxide, alloy etc.

Can enumerate the interlayer dielectric of silicon based coating or organic polymer films as dielectric film.Can enumerate silicon dioxide, fluorosilicate glass, be silicon based coating, carborundum and silicon nitrides such as the organic silicate glass that obtains of initiation material, silicon oxynitride, hydrogen silsesquioxanes as the silicon based coating with trimethyl silane or dimethoxy dimethylsilane.In addition, can enumerate all aromatic as organic polymer films is low-k interlayer dielectric film.The dielectric constant of especially preferred interlayer dielectric is smaller or equal to 2.7.

At first, interlayer dielectric such as lamination silicon dioxide on silicon chip.Then, by forming resist layer, known method such as etching at the recess (substrate exposed division) of interlayer dielectric surface formation predetermined pattern, are made the interlayer dielectric with protuberance and recess.On this interlayer dielectric, adopt surfacewise concavo-convex of vapour deposition method or CVD method, film forming is used for covering the barrier layers such as tantalum of interlayer dielectric.And then formation such as employing vapour deposition method, gold-plated method or CVD method are used for covering the metal levels such as copper of barrier layer, to fill described recess.

Then, use grinding pad of the present invention, the limit is supplied with the lapping liquid limit and is adopted CMP to grind the metal level (first grinding step) of this substrate surface.Thus, the barrier layer of on-chip protuberance is exposed to the surface, residual described metal film in the recess, the Wiring pattern that obtains expecting.When carrying out this grinding, it is also passable to grind away a part of protuberance barrier layer simultaneously with metal level.In second grinding step, but the lapping liquid of use grinding metal layer, barrier layer and interlayer dielectric adopts CMP to grind the metal level of described barrier layer that exposes and recess at least.Interlayer dielectric below the protuberance barrier layer exposes fully, and at the residual metal level that will become wiring layer of recess, exposes the section of barrier layer and finishes to grind when obtaining desired pattern in the boundary of protuberance and recess.Grinding pad of the present invention is used for second grinding step at least, preferably also is used for first grinding step as present embodiment.

More excellent flatness when finishing in order to ensure grinding also can further carry out grinding and (for example, in second grinding step, further append the situation of grinding in 50 seconds and just be called grinding 50% when the time that obtains desired pattern is 100 seconds.), be ground to the degree of depth of a part that comprises the protuberance interlayer dielectric.

Grinding pad of the present invention and the Ginding process that uses it, except above-mentioned buried insulating layer composite anti-blocking portion, mainly contain Cu, Ta, beyond the film of metal such as TaN and Al, can also be applicable to the silicon oxide film that grinding forms on the distributing board of regulation, glass, inorganic insulating membranes such as silicon nitride, the film that mainly contains polysilicon, optical glass such as photomask prism lens, inorganic conductive films such as ITO, the end face of the optic integrated circuit switching element light guide optical fiber that constitutes by glass and crystalline material, optics such as scintillator monocrystalline, the solid state laser monocrystalline, blue laser LED sapphire substrate, SiC, GaP, semiconductor monocrystals such as GaAs, magnetic device is with glass or alumina substrate, magnetic head etc.

Embodiment

Below, according to embodiment the present invention is described, but the present invention is not limited to these embodiment.

Embodiment 1

Organic fiber uses Fanglun 1414's (E.I.Du Pont Company's system trade name " Kevlar (Kevlar) ", fibre diameter 12.5 μ m, fibre length 3mm), matrix composition uses the ABS resin spherolite, use the extrusion shaper melting mixing, make tablet.Here, the Fanglun 1414 regulates to become 10 weight %.Tablet with large-sized drying machines 120 ℃ of dryings after 5 hours, with extrusion shaper and roll, making thickness 1.2mm and width is the sheet-like formed product of 1m.Form the ditch of the rectangular cross sectional shape of degree of depth 0.6mm, width 2.0mm in the above with 1 5mm clathrate at interval, cut into circle then.And then, at the bonding two-sided tape of opposition side of the face that has carried out ditch processing, make grinding pad.

Embodiment 2

Except matrix composition is weight ratio mix polyethylene, polypropylene, styrene series elastomer with 50: 50: 100, carry out similarly to Example 1, obtain grinding pad.

Embodiment 3

Except matrix composition is to use polypropylene, carry out similarly to Example 1, obtain grinding pad.

Comparative example 1

Except not using organic fiber, carry out similarly to Example 1, make grinding pad.

Comparative example 2

The polyurathamc system of preparation grinding pad.

Above-mentioned grinding pad is respectively installed on the platform of lapping device, uses sand paper finishing machine, the surface is carried out 30 minutes roughening with the #160 ciamond grinder.

The modulation of lapping liquid

As the lapping liquid that is used for copper, use no abrasive particle grinding agent (Hitachi Chemical Co., Ltd.'s system, the average grain diameter of trade name HS-C430 slurries), and therein adding offspring be the colloidal silica of 35nm be modulated into 0.37 weight % the abrasive particle grinding agent arranged.During use, the both is mixed into lapping liquid with volume ratio: aquae hydrogenii dioxidi=7: 3.

The grinding of substrate

Grinding pad and above-mentioned lapping liquid that use is made at embodiment and comparative example, grinding as described below does not have distribution or is formed with the silicon wafer substrate of distribution, measures grinding rate, grinds damage and as the depression of flatness index.

That is,, above-mentioned wafer is installed at the support that is stained with absorption layer that is used to install wafer of lapping device.And, on the grinding plate of described lapping device, stick to the grinding pad that embodiment and comparative example are made, make by abradant surface in the above and support is installed to lapping device down.Supply with above-mentioned lapping liquid with 150cc/ minute, with 38rpm rotation platform and wafer, with processing loading 4 * 10 ⁴Pa grinds, and estimates.Show the result in table 1.

The evaluation of grinding rate

What use was formed with the copper film of thickness 1 μ m and did not form distribution has a silica coating silicon wafer substrate (diameter 13cm), carries out grinding in 2 minutes.Measure resistance value with Na プ ソ Application Co., Ltd. system RT-7 model, calculate thickness, obtain the film thickness difference of CMP front and back, calculate the copper film thickness before and after grinding from resistivity.Show the result in table 1.

Grind the evaluation of damage

In-service evaluation the wafer of grinding rate, visual assessment damage.The result is shown in table 1 in the lump.

Zero: the damage by abradant surface after the grinding is less than 5

*: after the grinding by the damage of abradant surface more than equaling 5

Amount of recess

On silicon wafer, form the silicon dioxide film of thickness 300nm, in silicon dioxide, form the ditch of distribution density 50%, the degree of depth 0.5 μ m, adopt known sputtering method to form the nitrogenize tantalum film of thickness 50nm as barrier layer, similarly adopt sputtering method to form 1.0 μ m copper films, and adopt known heat treatment to imbed, formation has the silicon chip (diameter 13cm) of the surface configuration of distribution metal part (copper) width 100 μ m and the mutual strip pattern portion of arranging of the width 100 μ m of dielectric film (silicon dioxide) portion, prepares as grinding charge.

Use this grinding charge, carrying out two stages that the grinding by the grinding of copper film and barrier layer constitutes grinds, with contact pin type section difference meter (Veeco/Sloan corporate system Dektak3030),, measure film decrement for the distribution metal part of insulation membranous part from the surface configuration of above-mentioned strip pattern portion.The result is shown in table 1 in the lump.Here, " can't measure " in the table is expression, can't grind substrate because grinding rate is low or grind the too much and unmeasured state of damage.

The grinding pad of making at embodiment 1 and comparative example 1 is, matrix resin is identical, and difference is for containing or do not contain fiber.Grinding pad embodiment 1 of the present invention compares with the comparative example 1 that does not contain organic fiber, has suppressed the generation of damage, and is respond well.It is serious to grind damage in the comparative example 1, can't measure depression.Can know if use no abrasive particle grinding agent in an embodiment, then almost can't grind, and the high lapping device structure different with comparative example 1 or comparative example 2 of employing grinding rate just can grind.

Table 1

Pad	Grinding agent	Grinding rate (/minute)	Damage	Depression ()
					Embodiment 1	No abrasive particle grinding agent	50	○	Can't measure
The abrasive particle grinding agent is arranged	1000	○	300
				Embodiment 2		No abrasive particle grinding agent	70	○	Can't measure
The abrasive particle grinding agent is arranged	1000	○	300
					Embodiment 3	No abrasive particle grinding agent	40	○	Can't measure
The abrasive particle grinding agent is arranged	800	○	300
				Comparative example 1		No abrasive particle grinding agent	1000	×	Can't measure
The abrasive particle grinding agent is arranged	1500	×	Can't measure
					Comparative example 2	No abrasive particle grinding agent	2200	○	500
The abrasive particle grinding agent is arranged	2500	○	1100

Then, lapping liquid use in above-mentioned research grinding rate high the abrasive particle grinding agent arranged, and to make the processing loading be 2 * 10 ⁴Pa grinds in addition same as described abovely, and evaluation result is shown in table 2.Here, almost there be not the poor of grinding rate with above-mentioned grinding condition among the embodiment as can be recognized from Table 2, even low loading is that low-frictional force also can grind.On the other hand, if as the low loading of this condition, grinding rate is just extreme to descend in comparative example.

Table 2

Pad	Grinding rate (/minute)	Damage	Depression ()
				Embodiment 1	700	○	300
Embodiment 2	700	○	300
				Embodiment 3	700	○	300
Comparative example 1	400	×	Can't measure
				Comparative example 2	100	○	600

Can know from above-mentioned research,, just can when reducing, improve flatness when carrying out CMP the load of insulating barrier if use grinding pad of the present invention.

Then, utilize embodiment to illustrate to be applicable to through grinding pad to the semiconductor wafer surface irradiates light, detect of the present invention grinding pad of the variation of its reflectivity with the grinding step of management grinding endpoint, but the present invention is not limited to these embodiment.

Be prepared for making the following sheet material 1～3 of grinding pad.

Sheet material 1

Organic fiber uses Fanglun 1414's (E.I.Du Pont Company's system " Kevlar ", fibre diameter 12.5 μ m, fibre length 3mm), matrix resin uses AS resin spherolite (Japanese エ イ ア Application De エ Le Co., Ltd. system, trade name " ラ イ Star Network A-100PC); use the extrusion shaper melting mixing, make tablet.Here, the Fanglun 1414 regulates to become 5 weight %.Tablet with large-sized drying machines 120 ℃ of dryings after 5 hours, with extrusion shaper and roll, making thickness 1.2mm and width is the sheet-like formed product of 1m.

Sheet material 2

AS resin spherolite (the same) is used the extrusion shaper melting mixing, make tablet.This tablet with large-sized drying machines 120 ℃ of dryings after 5 hours, with extrusion shaper and roll, making thickness 1.2mm and width is the sheet-like formed product of 1m.This sheet material does not contain organic fiber.

Sheet material 3

Mixing contraposition is aramid fiber mince (fibre diameter 12.5 μ m, fibre length 5mm, E.I.Du Pont Company's system " Kevlar ") and contraposition be aramid fiber slurry (fibre diameter 1 μ m, fibre length 1mm, E.I.Du Pont Company's system " Kevlar ") and a position be aramid fiber mince (fibre diameter 25 μ m, fibre length 6mm, 280 ℃ of softening temperatures, Supreme Being people's (strain) makes " コ one ネ Star Network ス "), the 20 weight % aqueous solution of spray water dissolubility epobond epoxyn (110 ℃ of vitrifying transition temperatures, big Japanese ink chemical industry (strain) system, trade name " V コ one ト "), carry out (150 ℃ of heat dryings, 3min), and then, make it by (300 ℃ of temperature between a pair of hot-rolling, linear pressure 196kN/m) add hot compression, obtaining a position is that the thermal welding of aramid fiber mince is the nonwoven fabrics of aramid fiber mince in contraposition.Unit mass is 70g/m ², contraposition is that aramid fiber mince/contraposition is that an aramid fiber slurry/position is that the mixing quality ratio of aramid fiber mince/epobond epoxyn is 58/17/8/17.

Curing agent uses the dicyan diamides, and curing accelerator uses bisphenol A type epoxy resin (oiling シ エ Le (strain) system, trade name " the EP-828SK ") varnish that is mixed with 2-ethyl-4 methylimidazole.In order to regulate varnish,, use 20 weight portion curing agent, 0.1 weight portion curing accelerator, 40 weight portions methyl ethyl ketone as solvent for 100 weight portion bisphenol A type epoxy resins.

This varnish impregnation in described aramid fiber nonwoven fabrics, heat drying (170 ℃ 5min) are made prepreg.This prepreg is to regulate the resin adhesion amount to become 0.08mm for the heating and pressurizing thickness after forming.The content of aramid fiber nonwoven fabrics is 60 weight %.

Two surface configuration mould release films (polypropylene films of thickness 50 μ m) at the preimpregnation bed of material of overlapping 12 these prepregs, clamp with stainless steel mirror board, its many groups are put between the pressurization hot plate, and hot plate between across the padded coaming of the thickness 10mm that constitutes by layers of kraft paper, carry out heating and pressurizing shaping (170 ℃ of temperature, pressure 300kPa, time 120min), obtain the laminated board of thickness 1.0mm.

Embodiment 3

Use sheet material 1, be processed into the discoideus of φ 500mm, the lapping liquid of supplying with when Surface Machining is ground in order to make is through below the anchor clamps that are used for keeping wafer, ditch (clathrate below the inflow wafer, furrow width 2mm, ditch is 15mm at interval, ditch depth 0.6mm), make grinding pad at the face double-face adhensive tape of its opposition side.

Embodiment 4

Sheet material 1 processing growth 56mm, wide 19mm and on the angle, have the rectangle small pieces of radius (radius of curvature 1.0mm).Then, use sheet material 3, be processed into the discoideus of φ 500mm similarly to Example 3, carry out ditch processing on its surface.The scraping out long 56mm, wide 19mm and have the rectangular opening of radius same as described above at the angle of this plectane, and make length direction be in the radius side from the center towards the intermediate point of the radius of circumference.The foregoing rectangle small pieces that are made of sheet material 1 are inserted in hole at this plectane, as detecting the light light inlet window.At last make grinding pad at the opposition side double-face adhensive tape of ditch machined surface.

Example 1 in the past

Having prepared by polyurathamc is the grinding pad that resin constitutes, promptly have by long 56mm, wide 19mm and on the angle, have detection light that the rectangle transparent resin plate of radius constitutes commercially available product (thickness 1.2mm, ロ デ one Le corporate system " IC-1000/Suba-400 ") with light inlet window.

Comparative example 3

Sheet material 2 is carried out the processing identical with embodiment 3, and make grinding pad.

Reference example 1

Sheet material 3 is carried out the processing identical with embodiment 3, and make grinding pad.This grinding pad does not have the window portion as embodiment 4.

Measure these embodiment, the light transmittance of the grinding pad of example, reference example and comparative example in the past.For the grinding pad with light inlet window is to measure in window portion, then is to measure with the sheet material of grinding pad body for the grinding pad that does not have light inlet window.Use the system spectrophotometer UV-2200 of Shimadzu Seisakusho Ltd.'s (strain) to measure transmitance, setting and measuring wavelength is 670nm.Here, measured value is to use Lambert-Beer's law to be converted into the transmitance of thickness of slab 1mm.

Lapping device is to use U.S. Applied Material corporate system MIRRA machine, and each grinding pad is adhered to and is fixed on the platform of φ 500mm.Have and detect light and be aligned to the grinding pad of light inlet window, the window of the platform of lapping device and the window of grinding pad do not misplace.After adhering on the platform, the pad control member that is attached to this lapping device is installed rising sun ダ イ ヤ モ Application De (strain) system diamond dresser (abrasive particle: #170 has acrylic acid coatings), to each grinding pad with 9LB finishing 15 minutes.At this moment, observe the result of the surface state of each grinding pad, the grinding pad of embodiment 3 and reference example 1 can see that the surface exposed fiber (exposed length: about 500 μ m).The grinding pad of embodiment 4 also has window portion, and same exposed fiber (exposed length: about 500 μ m) all can be seen in the pad surface.The grinding pad of example 1 and comparative example 3 then be can't see this exposed fiber in the past.

These embodiment, structure, surface state and the light transmittance of the grinding pad of example, reference example and comparative example have in the past been summed up at table 3.

Table 3

	Structure	Windowless portion is arranged	Light transmittance (%)	Surface state
					Embodiment 3	Contain aramid fiber AS resin plate	Do not have	49.1	Exposed fiber
Embodiment 4	Contain the aramid fiber epoxy resin board	(sheet material 1) is arranged	49.1	Exposed fiber
					Example 1 in the past	Foaming polyurethane resin plate (double-decker)	Have	67.2	There is not exposed fiber
Comparative example 3	The AS resin plate	Do not have	94.5	There is not exposed fiber
					Reference example 1	Contain the aramid fiber epoxy resin board	Do not have	3.6	Exposed fiber

Adopt to be installed to each embodiment of lapping device, the grinding pad and the CMP lapping liquid of example, reference example and comparative example in the past as mentioned above,, estimate its characteristic according to following viewpoint as the grinding of following enforcement silicon wafer (dielectric film cover wafers and TEG wafer).These evaluation results are shown in table 4.

Grind the evaluation of damage quantity

On φ 200mm silicon wafer, adopt the TEOS-plasma CVD method to form the silicon oxide film of 1 μ m, this cover wafers is installed on the lapping device.At this moment, wafer is maintained at head, and the silica face is contacted with grinding pad on the platform.The grinding pressure that is applied to wafer surface in the process of lapping is set at 21kPa (3PSI), mix with cerium oxide lapping liquid (Hitachi changes into industry (strain) system HS-8005) quantity delivered 40mL/min and additive (Hitachi changes into industry (strain) system HS-8102GP) quantity delivered 160mL/min, the limit drops onto on the platform, the limit make platform with 100rpm, make head with 90rpm rotation, grind 1 minute silicon oxide film on the wafer.Fully clean silicon wafer after the grinding with pure water, dry then, it is all to observe wafer surface with microscope in dark field, and counting grinds damage.

The evaluation of grinding rate

Finish the silicon oxide film thickness that grinding damages each cover wafers of quantitative assessment with light interference type determining film thickness device mensuration, from obtaining average grinding rate with the difference of grinding the preceding silicon oxide film thickness of measuring.

Inhomogeneity evaluation

Identical with the mensuration of grinding rate, for 45 points on from end 5mm to 8mm on the diameter of the craspedodrome in each cover wafers face, measure the grinding rate of silicon oxide film everywhere, obtain the unevenness (1 δ/average grinding rate * 100) of grinding rate from standard deviation (1 δ).

Could terminal point the evaluation of management

On φ 200mm silicon wafer, make width and the patterns such as line that are spaced apart 25～2000 μ m with the silicon nitride film of thickness 100nm, then with the Si exposed division with the 350nm deep etching, on this wafer, form silicon oxide film 600nm, be produced on the surface and have the concavo-convex TEG wafer of 450nm with the TEOS-plasma CVD method.When using this wafer the condition identical to grind with foregoing cover wafers, employed lapping device during in-service evaluation (Applied Material Technology corporate system MIRRA) subsidiary, according to the ISRM terminal point management system of laser, judgement could detect the situation of exposing of silicon nitride film.

The evaluation of flatness

Detect the situation of exposing of silicon nitride film by the management of above-mentioned terminal point, measure the silicon nitride film line (width 100 μ m) that finishes the TEG wafer that grinds with contact pin type section difference meter Dektak3030 (SLOAN corporate system) poor with the surface section of adjacent silicon oxide film line (width 300 μ m).

Table 4

	Grinding rate (nm/min)	Uniformity (%)	Grind damage (individual/wafer)	Could manage terminal point	Flatness (nm)
						Embodiment 3	280	3	3	Can	20
Embodiment 4	290	5	5	Can	25
						Example 1 in the past	180	5	30	Can	20
Comparative example 3	210	12	55	Can	20
						Reference example 1	310	5	5	Cannot	-

Can know that from the embodiment 3 of table 4 and 4 result the grinding pad of the application of the invention can detect the management terminal point according to light, and, can suppress according to the effect of organic fiber to produce to grind to damage by relatively just knowing with example 1 and comparative example 3 in the past.And, also know grinding rate height this moment, uniformity is also abundant.In addition, the grinding pad of reference example 1 during employed TEG wafer, is not seen the variation that abundant significant reflection rate is arranged during by the rayed endpoint detection in grind estimating.The result that light transmittance is low in the grinding pad research in front of this and reference example 1 is corresponding.

The embodiment of relevant maximum exposed fiber length then, is described.

Embodiment 5

The unit mass that constitutes for the polyester fiber by fibre diameter 12.5 μ m, fibre length 5mm is 70g/m ²Nonwoven fabrics (Japanese バ イ リ one Application (strain) system " EPM-4070TE "), flood following varnish, 170 ℃ of dryings 5 minutes, make prepreg.

Varnish is, for 100 weight portion bisphenol A type epoxy resins, adds 20 weight portion curing agent dicyan diamides, 0.1 weight portion curing accelerator 2-ethyl-4 methylimidazole, is dissolved into 40 weight portion methyl ethyl ketones and makes.

20 above-mentioned prepregs of lamination disposing mould release film (polypropylene, thickness 50 μ m) up and down, are clamped with mirror board.Buffering paper across thickness 10mm carries out the heating and pressurizing shaping between the pressurization hot plate.Here, molding condition is, 175 ℃, 400kPa, 120 minutes.Its result has obtained the laminated board of thickness 1.5mm.The all fiber contents of laminated board are 50 weight %.Be cut into circle, the surface is cut with the ciamond grinder of #70 in the surface after, processing ditch, make grinding pad.Here, formed the clathrate ditch that is spaced apart 15mm, the width of ditch is that 2mm, the degree of depth are 0.6mm.

Embodiment 6

Except 10 of prepregs shown in the lamination embodiment 5 alternately with not 10 of the polyester non-woven fabrics of impregnating resin, carry out similarly to Example 5, obtain the laminated board of thickness 1.5mm.The all fiber contents of laminated board are 70 weight %.Then, cut in the same manner into the surface with embodiment 5, the processing ditch is made grinding pad.

Embodiment 7

Except employed fiber is that unit mass is 130g/m ³Polyester woven cloths (Asahi Chemical Industry's (strain) system " BKE Port プ リ Application ", fibre diameter: 9 μ m) in addition, carry out similarly to Example 5, make grinding pad.In the present embodiment, all fiber contents of laminated board are 50 weight %.

Embodiment 8

Organic fiber uses the polyester fiber (Japanese バ イ リ one Application (strain) system) of fibre diameter 12.5 μ m, fibre length 3mm, and matrix composition uses the ABS resin spherolite, uses the extrusion shaper melting mixing, makes tablet.Here, being adjusted to fiber content is 10 weight %.Tablet with large-sized drying machines 120 ℃ of dryings after 5 hours, with extrusion shaper and roll, making thickness 1.2mm and width is the sheet-like formed product of 1m.After forming the ditch of rectangular cross sectional shape of degree of depth 0.6mm, width 2.0mm with 15mm clathrate at interval in the above, be cut into circle.And then behind the bonding two-sided tape of opposition side of the face that has carried out ditch processing, the ciamond grinder of using #70 is made grinding pad with surface roughening.

Reference example 2

Mixing contraposition is aramid fiber mince (fibre diameter 12.5 μ m, fibre length 5mm, Supreme Being people's (strain) makes " テ Network ノ one ラ ") and a bit-by-bit be aramid fiber mince (fibre diameter 25 μ m, fibre length 6mm, Supreme Being people's (strain) makes " コ one ネ Star Network ス "), behind the 20 weight % aqueous solution to its spray water dissolubility epobond epoxyn (big Japanese ink chemical industry (strain) system, trade name " V コ one ト "), 150 ℃ of dryings 3 minutes, obtain 70g/m ²Nonwoven fabrics, and then, make between the hot-rolling of this nonwoven fabrics by 300 ℃ of temperature, linear pressure 196kN/m, add hot compression and obtain nonwoven fabrics.Except using this nonwoven fabrics, carry out similarly to Example 5, make grinding pad.In addition, the surface be with the ciamond grinder of #150 cut into.In this reference example, all fiber contents of laminated board are 50 weight %.

Comparative example 4

The ABS of used thickness 1.5mm (acrylonitrile-butadiene rubber-styrol copolymer) plate is cut into circle, is spaced apart the clathrate ditch of 15mm in Surface Machining, and the width of ditch is that 2mm, the degree of depth are 0.6mm.Then, the ciamond grinder of using #70 is made grinding pad with surface roughening.

Reference example 3

Except cut the surface with the ciamond grinder of #70, carry out similarly to Example 8, make grinding pad.

Observe the surface

With 100 times and 200 times of any 5 places of observing the pad surface, measure the maximum length of institute's exposed fiber with SEM (scanning electron microscopy).

Lapping liquid

As lapping liquid, prepare the CMP slurries in accordance with the following methods.

2kg cerous carbonate hydrate is put into the platinum container made, and sintering is 2 hours in 800 ℃ of air, to resultant ceria oxide powder 1kg, uses injector-type mill to carry out dry type and pulverizes.The polypropylene acid ammonium salt aqueous solution (40 weight %) 23g and deionized water 8977g applies 10 minutes ultrasonic waves while stirring and disperses therein.The slurries that obtain are filtered with 1 micron filter, and then the adding deionized water obtains the 5wt% slurries.Slurries pH is 8.3.In order to measure the particle of slurries with the laser diffraction granularity distribution instrument, be diluted to debita spissitudo and the result that measures, the D99% of particle diameter is 0.99 μ m.

The evaluation of Ginding process and abrasive characteristic

Preparation adopts the TEOS-plasma CVD method to form the cover wafers of the silicon oxide film of 2 μ m on the Si of φ 127mm substrate, and is provided with on the Si of φ 200mm substrate and disposes the groove of square protuberance, adopt the TEOS-plasma CVD method to form the Si of 600 μ m thereon ₃N ₄The testing wafer of film and silicon oxide film.It is that 0.35 μ m, density are that protuberance 60%, groove width are the part of 500 μ m that groove is to use the degree of depth.

The support that is stained with absorption layer that is used to install wafer substrate at lapping device, above-mentioned wafer is installed, on the platform that has adhered to as the φ 380mm of the grinding pad of above-mentioned making, make the dielectric film ground placing rack that faces down, and then to set the processing loading be 29kPa (300gf/cm ²).On one side the speed with 150cc/ minute drips above-mentioned cerium oxide abrasive liquid on platform, on one side with two minutes platforms of 38rpm rotation and wafer, grinds dielectric film.Fully clean wafer after the grinding with pure water, dry then.Thickness before and after measure grinding with light interference type determining film thickness device poor obtained grinding rate.About grinding damage, observe wafer surface after grinding with microscope in dark field, the damage that causes by grinding that the counting wafer surface exists.

In addition, about the evaluation of flatness, the section that reams the protuberance of TEG wafer and recess differs from 1 μ m, and it is poor to measure the terminal section of protuberance Si3N4 film before exposing.In addition, to the above-mentioned groove of TEG wafer, cave in surely with contact pin type section difference instrumentation.

Abrasive characteristic at table 5 expression embodiment, reference example and comparative example.The embodiment 5,6,7 and 8 that contains polyester fiber of the present invention compares with the reference example 2 that contains high rigidity fiber aramid fiber, reduces exposed fiber length easily, and the flatness excellence is not also ground damage.In addition, with embodiment 5,6,7 and 8 and the comparative example 4 that do not contain fiber just can know clearly that relatively grinding rate improves, and grind and damage.

Table 5

	Maximum exposed fiber length (μ m)	Grinding rate (nm/min)	Grind damage (individual/wafer)	Flatness	Depression (nm)
						Embodiment 5	10	210	0	20	25
Embodiment 6	10	240	0	20	28
						Embodiment 7	10	240	0	20	29
Embodiment 8	10	220	10	30	25
						Reference example 2	50	190	40	20	40
Comparative example 4	0	10	250	Can't measure	Can't measure
						Reference example 3	150	350	0	50	50

Can know from table 5, if use the grinding pad of maximum exposed fiber length smaller or equal to 0.1mm, just can not grind the anti-pitting of damage ground raising flatness, groove, can effectively carry out the planarization with interlayer dielectric, bpsg film, the semiconductor formation technology that forms representative of shallow-trench isolation.

The possibility of utilizing on the industry

If the grinding pad that uses grinding pad of the present invention or made by manufacture method of the present invention carries out CMP, can by the organic fiber that exposes at the grinding charge side surface of grinding pad, suppress grinding charge and produce tiny grinding damage. Thus, can under low loading condition, carry out smooth grinding. In addition, also can adopt the system that detects the grinding state of grinding charge with optical means, the grinding endpoint of management grinding charge under the condition of not grinding damage. Therefore, can improve productivity ratio and the yield rate of grinding charge.

Therefore, in the manufacturing process of for example semiconductor device, can carry out the little and also grinding of excellence of flatness of load to interlayer dielectric, easily implement follow-on dual-inlaid method.

Claims (24)

1. a grinding pad is characterized in that, is made of fiber that contains organic fiber and the matrix resin that keeps this fiber, and exposes organic fiber at the grinding charge side surface at least.

2. a grinding pad is characterized in that, be made of fiber that contains organic fiber and the matrix resin that keeps this fiber, and the grinding charge side surface after finishing is handled exposes organic fiber at least.

3. grinding pad according to claim 1 and 2 is characterized in that described matrix resin contains a kind of thermoplastic resin at least.

4. according to each the described grinding pad in the claim 1～3, it is characterized in that described matrix resin is made of the hemicrystalline thermoplastic resin.

5. according to each the described grinding pad in the claim 1～4, it is characterized in that, be dispersed with elastomer in the described matrix resin.

6. grinding pad according to claim 5 is characterized in that, described elastomeric vitrifying transition temperature is below 0 ℃ or 0 ℃.

7. according to each the described grinding pad in the claim 1～6, it is characterized in that fiber is to be made of aromatic polyamide.

8. according to each the described grinding pad in the claim 1～7, it is characterized in that, contain the organic fiber of 1～50 weight %.

9. according to each the described grinding pad in the claim 1～8, it is characterized in that the diameter of organic fiber is 1mm or below the 1mm.

10. according to each the described grinding pad in the claim 1～9, it is characterized in that the length of organic fiber is 1cm or below the 1cm.

11. each the described grinding pad according in the claim 1～10 is characterized in that, keeps polishing particles by the organic fiber that exposes at the grinding charge side surface.

12. each the described grinding pad according in the claim 1～11 is characterized in that, the maximum exposed division length of the described organic fiber that exposes is 0.1mm or below the 0.1mm.

13. grinding pad according to claim 12 is characterized in that, the described organic fiber that exposes is made of polyester.

14. according to claim 12 or 13 described grinding pads, it is characterized in that, in matrix resin, be dispersed with the polyester fiber of chunky shape.

15., it is characterized in that lamination has polyester non-woven fabric in matrix resin according to claim 12 or 13 described grinding pads.

16. according to each the described grinding pad in the claim 1,2～4,7,9～11, it is characterized in that, it is to be applicable to the grinding pad that detects grinding endpoint at the grinding charge surface with optical mode in process of lapping, constitute by the matrix resin that does not foam in fact that contains 1～20 weight % organic fiber, have the function of conveying and maintenance grinding milk particle, and can see through the light of 190～3500nm range of wavelength.

17. according to each the described grinding pad in the claim 1,2～4,7,9～11, it is characterized in that, it is to be applicable to the grinding pad that detects grinding endpoint at the grinding charge surface with optical mode in process of lapping, comprise the part that can see through the light of 190～3500nm range of wavelength, this part is made of the matrix resin that does not foam in fact that contains 1～20 weight % organic fiber, and has the function of conveying and maintenance grinding milk particle.

18., it is characterized in that described organic fiber is an aramid fiber according to claim 16 or 17 described grinding pads.

19. the manufacture method of a grinding pad; it is characterized in that; it is to adhere on the platform and use; carrying out by the manufacture method of the grinding pad of the planarization of abradant surface, comprise mix the fiber that contains organic fiber and contain the matrix composition of thermoplastic resin and obtain mixture step, this mixture is made the step of spherolite or tablet and the step that this spherolite or tablet is processed into tabular or sheet by extrusion molding or injection molded.

20. the manufacture method of a grinding pad, it is characterized in that, it is to adhere on the platform and use, carrying out, comprise that step, the lamination of the fiber base material impregnation matrix resin combination that contains organic fiber being made resin impregnation sheet-like fiber base material contain the sheet-like fiber base material of this resin impregnation sheet-like fiber base material and implement the step that heating and pressurizing is shaped by the manufacture method of the grinding pad of the planarization of abradant surface.

21. the manufacture method according to claim 19 or 20 described grinding pads is characterized in that, further comprises the step that makes surperficial exposed fiber.

22. Ginding process, it is characterized in that, the organic fiber that is pressed into each the described grinding pad in the claim 1～18 by abradant surface of grinding charge is exposed on the face, between by abradant surface and grinding pad, supply with lapping liquid on one side, grinding charge and pad are relatively slided, to grind by abradant surface.

23. Ginding process according to claim 22 is characterized in that, described is by having covered conductor layer at the dielectric constant that is formed with distribution or groove on smaller or equal to 2.7 insulating barrier, having also had the laminate of copper layer to constitute by abradant surface.

24. a Ginding process is characterized in that, uses each the described grinding pad in the claim 16～18, detects grinding endpoint with optical mode.