KR20100017564A - Stacked polishing pad for high temperature applications - Google Patents

Abstract

The invention provides a polishing pad for chemical-mechanical polishing comprising a polishing layer, a bottom layer, and a hot-melt adhesive, the hot-melt adhesive joining together the polishing layer and the bottom layer. The hot-melt adhesive comprises between 2 and 18 wt.% EVA and is substantially resistant to delamination when the polishing layer attains a temperature of 40°C. The invention also provides a method of polishing a substrate with the aforementioned polishing pad, as well as a method of preparing such a polishing pad.

Description

Stacked Polishing Pads for High Temperature Applications {STACKED POLISHING PAD FOR HIGH TEMPERATURE APPLICATI0NS}

Chemical-mechanical polishing (“CMP”) processes are used in the manufacture of microelectronic devices to form flat surfaces on semiconductor wafers, field emission displays, and many other microelectronic workpieces. For example, fabrication of semiconductor devices generally involves the formation of various processing layers for forming semiconductor wafers, selective removal or patterning of some of these layers, and deposition of additional processing layers on the surface of the semiconductor workpiece. . The processing layer may include, for example, an insulating layer, a gate oxide layer, a conductive layer, a metal layer, a glass layer, or the like. In general, it is preferred that the top surface of the processing layer is flat, ie flat, for the deposition of the next layer at a particular stage of wafer processing. CMP is used to planarize the processed layer, where the wafer is planarized by polishing the deposited material, such as a conductive or insulating material, for the next process step.

In a typical CMP process, the wafer is mounted face down on the carrier of the CMP equipment. Force is applied downward to the carrier and wafer so that the carrier and wafer face toward the polishing pad. The carrier and wafer are rotated on a rotating polishing pad on a polishing table of the CMP apparatus. Generally, a polishing composition (also referred to as polishing slurry) is introduced between the rotating wafer and the rotating polishing pad during the polishing process. Typically the polishing composition comprises chemicals that interact with or dissolve some of the top wafer layer (s) and grinding materials that physically remove some of the layer (s). The wafer and the polishing pad can be rotated in the same direction or in the opposite direction as desired to perform a particular polishing process. The carrier can also vibrate across the polishing pad on the polishing table. This process removes the desired amount of material from the wafer to ideally achieve a planar surface.

CMP polishing pads often include two or more layers, such as a polishing layer and an underlying layer (eg, a subpad layer). Multilayer polishing pads are typically formed by stacking two or more layers made of different materials. For example, conventional two-layer polishing pads include both a hard polishing layer and a more compressible soft subpad layer to improve the flatness and uniformity of the polishing wafer. Bonding between the polishing pad layers can be accomplished by laminating the layers using an adhesive. Such multilayer polishing pads are disclosed, for example, in US Pat. No. 5,257,478.

Typically, multiple layers of polishing pads are bonded to each other by pressure sensitive adhesive (PSA) or hot-melt adhesive (HMA). Pressure sensitive adhesives are relatively poor in chemical resistance and can easily be weakened by high pH slurries during polishing. During polishing, breakage of the adhesive may cause the layers of the polishing pad to separate, ie, to be laminated, which renders the polishing pad unusable for polishing. While hot-melt adhesives typically have better chemical resistance, hot-melt adhesives often have lower thermal resistance, resulting in delamination at high polishing temperatures. Since high temperatures of around 70 ° C. are used in many CMP polishing applications, it is important that the adhesive used in the polishing pad have a relatively high thermal resistance.

Hot-melt adhesive materials typically include thermoplastic or thermoset materials selected from the group consisting of polyolefins, ethylene vinyl acetate, polyamides, polyesters, polyurethanes, and polyvinyl chlorides (see, eg, US Pat. Nos. 6,422,921 and 6,905,402).

The bonding force of the hot-melt adhesive can be represented by the "T-peel" force (see, eg, US Pat. No. 4,788,798). The T-peel test can be performed according to ASTM D1876 (2001), a test presented by the American Society for Testing and Materials (ASTM). This test measures the peel adhesion of the adhesive. Peel adhesion is the force per unit width required to remove a test sample from a standard test panel at a given angle and speed. Interfacial destruction is a process of irreversible entropy generation that requires significant energy dissipation. In a standard T-peel test, the force applied to the sample is increased at a constant rate until the sample is removed from the test panel to determine the force required to peel the sample.

Rohm & Haas Electronic Materials CMP Holdings, Inc., Wilmington, Delaware, U.S. Pat. Claims are made for polishing pads using any of several known hot-melt adhesives that are at least 40 Newtons (N) above per minute (column 6, lines 1-3). The '275 patent claims that the disclosed polishing pads are "more resilient than the pads of prior art" due to the nature of the hot-melt adhesives, but the hot-melt adhesives cited in the 275 patents are generally the same as those used in the prior art. Since it is a family, it does not have an advantage over the hot-melt adhesives used in the prior art and thus does not provide a polishing pad with improved resistance to delamination. For example, US Pat. No. 6,422,921 (hereinafter referred to as the '921 patent) describes the same general series of hot-melt adhesives suitable for use in polishing pads (Patent' 921, column 3, lines 22-24). '275 patent, column 3, lines 33-36). When applied to a polishing pad and tested according to the disclosure of the '275 patent, this hot-melt adhesive exhibits an average T-peel force far above the minimum T-peel force mentioned in the' 275 patent, but especially hot polishing. In an application, the polishing pad using this adhesive during use may be delaminated.

Several variables contribute to pad deposition during polishing applications. For example, the force required to break the adhesive bond depends on the type of adhesive, the process conditions of the polishing procedure and the temperature at which the polishing procedure is performed. Specifically, shear and frictional stresses are both caused by the pressure exerted on the polishing wafer during polishing, and also by the chemicals used during polishing. Shear stress can negatively affect the performance of hot-melt adhesives, and shear deformation occurs during polishing in many polishing pads using such adhesives. Since the T-peel test is not for shear stress measurements, it may not always provide an accurate set of bond strengths of the hot-melt adhesive.

Summary of the invention

The present invention relates to a polishing layer comprising: (a) an abrasive layer, (b) an underlayer coextensive in substantially the same space as the abrasive layer, and (c) an abrasive layer and an underlayer, wherein 2-18% by weight of ethylene vinyl acetate or ethyl A polishing pad for chemical-mechanical polishing comprising vinyl acrylate (collectively "EVA") and comprising a hot-melt adhesive that is substantially resistant to delamination when the polishing layer reaches a temperature of 40 ° C. To provide.

The present invention also provides

(i) the (a) abrasive layer, (b) an underlayer extending in substantially the same space as the abrasive layer, and (c) the abrasive layer and the underlayer are combined and comprise from 2 to 18% by weight of EVA, wherein the abrasive layer is Providing a polishing pad for chemical-mechanical polishing, comprising a hot-melt adhesive that is substantially resistant to delamination when a temperature of 40 ° C. is reached,

(ii) contacting the substrate with the polishing pad and the polishing composition, and

(iii) moving the polishing pad and the polishing composition relative to the substrate to polish at least a portion of the surface of the substrate with the polishing pad to polish the substrate.

The present invention additionally

providing a polishing pad for chemical-mechanical polishing, comprising: (i) an abrasive layer, and (b) an underlying layer spreading in substantially the same space as the abrasive layer, and

(ii) combining the abrasive layer with the underlying layer, comprising from 2 to 18% by weight of EVA, using a hot-melt adhesive that is substantially resistant to delamination when the abrasive layer reaches a temperature of 40 ° C. and A method of making a polishing pad for chemical-mechanical polishing, comprising laminating at least one of the underlying layers.

1 is a graph of EVA content percentages for the melting point and Vicat softening point of an EVA-based hot-melt adhesive.

FIG. 2 is a graph showing the time to delamination measured by a holding force test performed on a comparative hot-melt adhesive and a hot-melt adhesive according to the present invention. Pad lamination was performed at approximately 165 ° C., two adhesives were applied to the EPIC ™ D100 pad (Cabot Microelectronics, Aurora, Ill.) And the retention test was performed at 80 ° C.

3 is a graph of approximate lamination temperature versus time until delamination measured by a holding force test performed on a hot-melt adhesive according to the present invention. Hot-melt adhesive was applied to the EPIC ™ D100 pads and the retention test was performed at 80 ° C. Delamination was not observed at a lamination temperature of approximately 175 ° C., even when the test was stopped after 960 minutes.

The present invention provides a chemical-mechanical polishing pad for polishing a substrate. The polishing pad includes a polishing layer, an underlayer spreading in substantially the same space as the polishing layer, and a hot-melt adhesive. The hot-melt adhesive bonds the abrasive layer and the underlying layer. The hot-melt adhesive comprises 2 to 18% by weight of ethylene vinyl acetate or ethyl vinyl acrylate (collectively "EVA") and is substantially resistant to delamination when the abrasive layer reaches a temperature of 40 ° C. have.

The polishing layer of the polishing pad can be any suitable polishing layer. Preferably, the abrasive layer is spread in substantially the same space as the underlying layer. The polishing layer of the polishing pad optionally includes grooves, channels and / or perforations. This feature facilitates lateral transport of the polishing composition across the surface of the polishing layer. The grooves, channels and / or perforations can have any suitable pattern and can have any suitable depth and width. The abrasive layer can have a combination of two or more different groove patterns, for example, large grooves and small grooves as described in US Pat. No. 5,489,233. The grooves may be in the form of linear grooves, inclined grooves, concentric grooves, helical or circular grooves or X-Y reticulated patterns, and the connections may be continuous or discontinuous.

The underlayer of the polishing pad, ie the subpad, can be any suitable underlayer. Preferably, the underlayer spreads in substantially the same space as the polishing layer.

The polishing pad optionally further includes one or more intermediate layers disposed between the polishing layer and the underlying layer. Optionally, the polishing pad includes three or more (eg, four or more, six or more or eight or more) layers between the polishing layer and the underlying layer. Typically, the polishing pad includes up to 10 (up to 8 or up to 6) layers between the polishing layer and the underlying layer.

The interlayer or interlayers of the polishing pad can be any layer or layers. Preferably, each intermediate layer or intermediate layers extend in substantially the same space as the polishing layer and the underlying layer. The abrasive layer, the bottom layer and the intermediate or intermediate layer are each joined together preferably by a hot-melt adhesive.

The advantage of such multilayer polishing pads is that each layer can have different physical or chemical properties. For example, in some applications each layer has the same chemical composition but different physical properties such as hardness, density, porosity, compressibility, stiffness, tensile modulus, bulk modulus, rheology, creep, glass transition temperature, melting point, It may be desirable to have a viscosity or transparency. In other applications, although the polishing pad layer has similar physical properties, it may be desirable to have different chemical properties (eg, different chemical compositions). Naturally, the polishing pad layers may have different chemical properties while having different physical properties.

The layer of polishing pad can be any suitable layer. Each layer of the polishing pad can be hydrophilic, hydrophobic or a combination thereof. Each layer of the polishing pad optionally contains particles, for example particles introduced into the layer.

The particles can be grinding particles, polymer particles, composite particles (eg encapsulated particles), organic particles, inorganic particles, clarifying particles, water soluble particles, and mixtures thereof. Suitable particles are described, for example, in US Pat. Nos. 6,884,156 and 7,059,936.

Each layer of the polishing pad can have any suitable hardness (eg, 30-50 Shore A or 25-80 Shore D). Similarly, each layer can have any suitable density and / or porosity. For example, each layer can be non-porous (eg, full), nearly full (eg, less than 10% void volume), or porous and / or have a density of 0.3 g / cm ³ or greater (eg, 0.5). at least g / cm ³ , or at least 0.7 g / cm ³ ) or even at least 0.9 g / cm ³ (eg, at least 1.1 g / cm ³ , or up to 99% of the theoretical density of the material). In some applications, one or more layers of polishing pad material (eg, polishing layer) are hard and / or dense and / or have low porosity, and one or more of the other layers are soft and / or highly porous. It may be desirable to have a low density.

Each layer of the polishing pad can have any suitable thickness. Preferably, each layer has a thickness of at least 10% (eg, at least 20% or at least 30%) of the total thickness of the polishing pad. The thickness of each layer will depend to some extent on the total number of polishing pad layers. In addition, two or more (eg, all) polishing pad layers may have the same thickness or the layers may each have a different thickness.

Each layer of polishing pad optionally further includes an optical endpoint detection port. Preferably, each layer of the multilayer polishing pad includes an optical endpoint detection port, with the optical endpoint detection port substantially aligned. The optical endpoint sensing port may be one or more openings, transparent areas or translucent areas, for example windows as described in US Pat. No. 5,893,796. When used in connection with an in situ CMP process monitoring technique, it is desirable to include such openings or translucent regions, ie optically transmissive regions. Techniques for inspecting and monitoring the polishing process by analyzing light or other radiation reflected from the surface of the workpiece are known in the art. Such methods are described, for example, in US Pat. Nos. 5,196,353, 5,433,651, 5,609,511, 5,643,046, 5,658,183, 5,730,642, 5,838,447, 5,893,796, 5,949,927 and 5,964,643. Preferably, inspecting or monitoring the progress of the polishing process for the workpiece being polished, it is possible to determine when polishing is to end, i.e. when to terminate the polishing process with respect to that particular workpiece.

The openings can have any suitable shape and can be used in combination with drainage channels to minimize or eliminate excess polishing composition on the polishing surface. The optically transmissive region or window can be any suitable window, many of which are known in the art. For example, the optically transmissive region may comprise a glass or polymer-based plug inserted into the opening of the polishing pad, or may comprise the same polymeric material as used for the remainder of the polishing pad. Typically, the optically transmissive region is at least 10%, for example at least 20%, at one or more wavelengths of 190 nm to 10,000 nm, for example 190 nm to 3500 nm, 200 nm to 1000 nm, or 200 nm to 780 nm. Or 30% or more light transmittance.

The optically transmissive region can have any suitable structure, for example crystallinity, density and porosity. For example, the optically transmissive region can be either solid or porous, such as microporous or nanoporous. Preferably, the optically transmissive region is solid or is almost solid, for example with a volume of 3% or less of void space. The optically transmissive region optionally further comprises particles selected from polymer particles, inorganic particles and combinations thereof. The optically transmissive region optionally comprises voids.

The optically transmissive region additionally optionally includes a dye in which the polishing pad substrate material can selectively transmit light of a particular wavelength (s). The dye serves to filter out light of an undesired wavelength, for example background light, thus improving the signal to noise ratio of the detection. The optically transmissive region may comprise any suitable dye or may comprise a combination of dyes. Suitable dyes include polymethine dyes, di- and tri-arylmethine dyes, aza analogs of diarylmethine dyes, aza (18) anurene dyes, natural dyes, nitro dyes, nitroso dyes, azo dyes, anthraquinone dyes, sulfides Dyes and the like. Preferably, the transmission spectrum of the dye coincides or overlaps with the wavelength of light used for in situ endpoint detection. For example, when the light source for an end point detection (EPD) system is a HeNe laser that produces visible light with a wavelength of 633 nm, it is preferred that the dye is a red dye capable of transmitting light having a wavelength of 633 nm. .

The hot-melt adhesive can be any suitable hot-melt adhesive. Hot-melt adhesives comprise from 2 to 18 weight percent ethylene vinyl acetate or ethyl vinyl acrylate (collectively "EVA"). In particular, EVA is 18 wt% or less, for example 16 wt% or less, 15 wt% or less, 12 wt% or less, 11 wt% or less, 10 wt% or less, 8 wt% or less, 5 wt.% In the hot-melt adhesive. It may be present in an amount of up to 3 or up to 3 weight percent. Alternatively or additionally, EVA is at least 2 weight percent, for example at least 3 weight percent, at least 5 weight percent, at least 8 weight percent, at least 10 weight percent, at least 12 weight percent, or 15 in the hot-melt adhesive. It may be present in an amount of at least% by weight. For example, EVA may be present in the hot-melt adhesive in an amount of 3 to 15 weight percent, 5 to 11 weight percent, 8 to 10 weight percent, or 12 to 16 weight percent.

Unexpectedly, it has been found that hot-melt adhesives comprising from 2 to 18% by weight of EVA exhibit high chemical and thermal resistance during CMP and thus resistance to delamination. Preferably, the hot-melt adhesive layer has a polishing layer of 40 ° C, for example 45 ° C, 50 ° C, 55 ° C, 60 ° C, 65 ° C, 70 ° C, 75 ° C, 80 ° C, 85 ° C, 90 ° C. It is substantially resistant to delamination when a temperature of 95 ° C. or 100 ° C. is reached.

The thermal resistance of the hot-melt adhesive according to the invention can be measured by shear adhesion or retention test. Holding force provides an accurate prediction of adhesion force under elevated temperature and shear conditions. The holding force used here is the time required for the standard area of the sample to slide in a direction parallel to the surface on a standard flat surface under certain test conditions. Holding force is a constant load creep test that measures the millimeter (mm) at which a sample has moved after a predetermined time at a given load.

The relatively high holding force of the hot-melt adhesive used in the present invention demonstrates the thermal resistance of the adhesive at high polishing temperatures of 100 ° C. The hot-melt adhesive moves for example for up to 0.2 mm, for example up to 0.15 mm, up to 0.1 mm, up to 0.05 mm or 0 mm under stress at 40 ° C., 1 kg load. After 24 hours under the same temperature and the same stress, the hot-melt adhesive moves 0.5 mm or less, for example 0.4 mm or less, 0.3 mm or less, 0.2 mm or less, 0.1 mm or less or 0 mm. The hot-melt adhesive moves for example for up to 0.2 mm, for example up to 0.15 mm, up to 0.1 mm, up to 0.05 mm or 0 mm under a stress of 60 ° C., 1 kg load. After 24 hours under the same temperature and the same stress, the hot-melt adhesive moves 0.5 mm or less, for example 0.4 mm or less, 0.3 mm or less, 0.2 mm or less, 0.1 mm or less or 0 mm. The hot-melt adhesive, for example, moves at 0.5 mm or less, for example 0.4 mm or less, 0.3 mm or less, 0.2 mm or less, 0.1 mm or less or 0 mm, for one hour under a stress of 80 ° C., 1 kg load. After 24 hours under the same temperature and the same stress, the hot-melt adhesive moves below 1.0 mm, for example below 0.8 mm, below 0.5 mm, below 0.3 mm, below 0.1 mm or 0 mm. The hot-melt adhesive, for example, moves at 0.5 mm or less, for example 0.4 mm or less, 0.3 mm or less, 0.2 mm or less, 0.1 mm or less or 0 mm, for 1 hour under a stress of 100 ° C., 1 kg load. After 24 hours under the same temperature and the same stress, the hot-melt adhesive moves below 1.5 mm, for example below 1.2 mm, below 1.0 mm, below 0.8 mm, below 0.5 mm, below 0.3 mm, below 0.1 mm or 0 mm. .

The melt flow index of the hot-melt adhesive can be measured according to the test described in ASTM D1238 (2004). The melt flow index measures the rate of extrusion of the thermoplastic material through the orifice at a given temperature and load. This provides a method of measuring the flow of molten material that can be used to classify the materials. Specifically, with respect to polishing pad applications, the melt flow index describes the speed of the adhesive filling any divot or pinhole that may be present on the surface on the layer in contact with the adhesive.

The melt flow index of the hot-melt adhesive can be any suitable value. For example, the melt flow index may be 400 g / 10 minutes or less, for example 200 g / 10 minutes or less, 100 g / 10 minutes or less, 75 g / 10 minutes or less, 65 g / 10 minutes or less, 50 g / 10 minutes. Up to minutes, up to 35 g / 10 minutes, up to 25 g / 10 minutes, up to 15 g / 10 minutes, up to 10 g / 10 minutes, or up to 5 g / 10 minutes. Alternatively or additionally, the melt flow index is at least 4 g / 10 minutes, for example at least 10 g / 10 minutes, at least 25 g / 10 minutes, at least 50 g / 10 minutes, at least 75 g / 10 minutes. , At least 100 g / 10 minutes, at least 200 g / 10 minutes, or at least 300 g / 10 minutes. The melt flow index of the hot-melt adhesive is preferably from 4 g / 10 minutes to 400 g / 10 minutes.

The Vicat softening point of the hot-melt adhesive can be measured according to the test described in ASTM D1525 (2006). The Vicat softening point is a 1 mm ² flat end to 1 mm deep in the sample under the given load at the given heating rate. The temperature at which the needle penetrates. The Vicat softening point can be used to predict at what temperature the adhesive softens when applied to a polishing pad or when used for high temperature applications.

The invention also relates to (i) providing the polishing pad for chemical-mechanical polishing, (ii) contacting the substrate with the polishing pad and polishing composition, and (iii) moving the polishing pad and polishing composition relative to the substrate. A method of polishing a substrate, comprising polishing the substrate by grinding at least a portion of the surface of the substrate with a polishing pad.

In particular, the present invention

(i) the (a) abrasive layer, (b) an underlayer extending in substantially the same space as the abrasive layer, and (c) the abrasive layer and the underlayer are combined and comprise from 2 to 18% by weight of EVA, wherein the abrasive layer is Providing a polishing pad for chemical-mechanical polishing, comprising a hot-melt adhesive that is substantially resistant to delamination when a temperature of 40 ° C. is reached,

(ii) contacting the substrate with the polishing pad and the polishing composition, and

(iii) moving the polishing pad and the polishing composition relative to the substrate to polish at least a portion of the surface of the substrate with the polishing pad to polish the substrate.

The polishing composition can be any suitable polishing composition. The polishing composition typically comprises an aqueous carrier, a pH adjuster and optionally a soft erase. Depending on the type of workpiece being polished, the polishing composition may optionally further comprise an oxidizing agent, organic acid, complexing agent, pH buffer, surfactant, corrosion inhibitor, antifoaming agent, and the like.

The present invention provides a polishing pad for chemical-mechanical polishing, comprising (i) an abrasive layer, and (b) an underlying layer spreading in substantially the same space as the abrasive layer, and

(ii) combining the abrasive layer with the underlying layer, comprising from 2 to 18% by weight of EVA, using a hot-melt adhesive that is substantially resistant to delamination when the abrasive layer reaches a temperature of 40 ° C. and A method of making a polishing pad for chemical-mechanical polishing, comprising laminating at least one of the underlying layers.

Lamination can be accomplished by any suitable lamination method. Typically, lamination is accomplished by applying an adhesive to the layer (s) of the polishing pad using a standard laminator roll. In a polishing pad comprising an abrasive layer and an underlayer, for example, a hot-melt adhesive is applied to at least one of the abrasive layer and the underlayer, and the abrasive layer and the underlayer are in contact with each other. Optionally, a hot-melt adhesive is applied to both the abrasive layer and the underlayer, and the abrasive layer and the underlayer are in contact with each other. In a polishing pad comprising at least one intermediate layer disposed between the polishing layer and the underlying layer, the hot-melt adhesive is also applied to at least one of the intermediate layer additionally or alternatively to the polishing layer and / or the underlying layer, the polishing layer, The bottom layer and the middle layer can be contacted with each other simultaneously or separately. Preferably, the hot-melt adhesive bonds each layer and thus applies to at least one side of each pair of layers in contact with each other such that there is an adhesive between the pair of layers.

Lamination can be carried out at any suitable lamination temperature and pressure. Preferably, lamination is carried out at a temperature sufficient to heat the layer to a temperature above or above the activation temperature of the hot-melt adhesive. The layer laminated at the adhesive activation temperature or higher retains the holding force even at relatively high polishing temperatures and is resistant to delamination. The activation temperature of the EVA-based hot-melt adhesive is typically 80 ° C. to 120 ° C., for example 80 ° C. to 110 ° C., 80 ° C. to 100 ° C., 80 ° C. to 90 ° C., 90 ° C. to 120 ° C., 90 ° C. to 110 ° C, 90 ° C to 100 ° C, 100 ° C to 120 ° C, 100 ° C to 110 ° C or 110 ° C to 120 ° C. Preferably, lamination is carried out at a temperature sufficient to heat the layer to a temperature of 110 ° C to 120 ° C, for example 112 ° C, 115 ° C or 118 ° C.

In practice the temperature reached by the layer can be much lower than the lamination temperature set on a typical lamination device. Specifically, the temperature reached by the layer may be 50 ° C to 70 ° C lower than the set lamination temperature. The lamination temperature in the lamination apparatus may be set to any suitable temperature to achieve the temperature of the desired layer. For example, the lamination temperature is 150 ° C to 200 ° C, for example, 150 ° C to 190 ° C, 150 ° C to 180 ° C, 150 ° C to 170 ° C, 150 ° C to 160 ° C, 160 ° C to 200 ° C, 160 ° C to 190 ° C. ℃, 160 ℃ to 180 ℃, 160 ℃ to 170 ℃, 170 ℃ to 200 ℃, 170 ℃ to 190 ℃, 170 ℃ to 180 ℃, 180 ℃ to 200 ℃, 180 ℃ to 190 ℃ or 190 ℃ to 200 ℃ range It can be set to the temperature of. Typically, the lamination temperature is set at a temperature in the range of 170 ° C to 190 ° C, for example 175 ° C, 180 ° C or 185 ° C.

Lamination can be performed at any suitable rate. For example, the layer can pass through the laminator roll at any suitable rate and can be exposed to the laminator roll for any suitable residence time. Preferably, the laminator roll speed can be reduced in order to increase the residence time of the layer, and thus the surface temperature of the layer can be brought closer to the lamination temperature set in the lamination apparatus.

Unexpectedly, polishing pads laminated using a hot-melt adhesive at a temperature sufficient to heat the surface of the pad to or above the activation temperature of the hot-melt adhesive exhibited improved resistance to delamination in hot polishing applications. Found. Specifically, the polishing pad laminated in the range of 150 ° C. to 200 ° C. using a hot-melt adhesive comprising 2 to 18% by weight of EVA exhibits high chemical and thermal resistance during CMP, thus resisting delamination. Specifically, the polishing layer is 40 ° C or higher, for example, 40 ° C, 45 ° C, 50 ° C, 55 ° C, 60 ° C, 65 ° C, 70 ° C, 75 ° C, 80 ° C, 85 ° C, 90 ° C, 95 ° C or When reaching a temperature of 100 ° C., the hot-melt adhesive is substantially resistant to delamination.

The following examples further illustrate the invention but, of course, should not be construed as limiting the scope of the invention in any way.

Example 1

This example confirms the thermal stability and melt flow of EVA-based hot-melt adhesives as a function of EVA content.

The melting point, Vicat softening point, and melt flow index of 12 different hot-melt adhesives containing various amounts of EVA, namely adhesives 1A-1L, were measured. Melt flow index was measured according to ASTM D1238 (2004) to determine the flow of various hot-melt adhesives. The Vicat softening point was measured according to ASTM D1525 (2006) to determine the thermal stability of the hot-melt adhesive.

[Table 1] Characteristics of hot-melt adhesive according to EVA content

These results confirmed that the hot-melt adhesive comprising 2 to 18% by weight of EVA had a relatively low melt flow index as compared to the hot-melt adhesive containing different amounts of EVA or without EVA.

Example 2

This example confirms the holding force of the hot-melt adhesive according to the invention at high temperatures.

The holding forces of three different adhesives, adhesives 2A to 2C, were measured at various temperatures. Adhesive 2A (comparative) is a hot-melt adhesive. Adhesive 2B (Comparative Example) is a pressure sensitive adhesive. Adhesive 2C (invention) is an EVA-based hot-melt adhesive comprising from 2 to 18 weight percent EVA. Adhesives 2B and 2C were tested twice.

Laminated samples were prepared for testing. The length of the laminated sample was approximately 4 inches. Each laminated sample is one release layer, one adhesive layer (mainly used to secure the pad assembly to the platen for polishing), one subpad, one adhesive to secure the subpad to the top pad and one top pad It included. The release liner was removed from the sample and the sample was fixed to an aluminum plate approximately 10.16 cm (4 inches) long, 2.54 cm (1 inch) wide, and 0.64 cm (0.25 inch) thick. The laminated sample was left on the aluminum plate for 15-30 minutes to fully adhere.

Each aluminum plate had a hole approximately 0.24 cm (0.25 inches) in diameter, allowing each aluminum plate to be hooked into the oven. In addition, one hole was drilled in each stacked sample to allow a 1 kg weight to be added to the sample. Holding force tests were performed in temperature-controlled ovens heated to different temperatures (approximately 40 ° C., 60 ° C., 80 ° C. and 100 ° C.). An aluminum plate containing laminated samples and weighing was placed in a heated oven. The timer was started after the sample and oven temperature had stabilized. The degree of delamination between the adhesive and the pad layer was recorded after 1 hour and after 24 hours. "Falling" indicates that the sample was completely delaminated, ie the adhesive was completely debonded from the pad layer. The results are summarized in Table 2.

[Table 2] Adhesive Retention with Time and Temperature

These results confirmed that not only the specific chemical composition of the adhesive, ie the weight percent of EVA, but also the type of adhesive used, ie the pressure sensitive adhesive or the hot-melt adhesive, had a great influence on the holding strength of the adhesive at various temperatures. The hot-melt adhesives according to the invention exhibited greater holding forces, i.e., less delamination, even at high temperatures of 80 ° C or 100 ° C.

Example 3

This example confirms the effect of lamination temperature on the holding force of the hot-melt adhesive according to the invention.

27 polishing pads, namely polishing pads 3AA to 3BA, were laminated at various lamination temperatures using the EVA-based hot-melt adhesive according to the invention. Samples of laminated pads were prepared according to Example 2, and retention tests were performed at 70 ° C and 80 ° C. The polishing pad was observed up to 16 hours (960 minutes) and the time until any delamination was observed. The results are summarized in Table 3.

[Table 3] Delamination of hot-melt adhesive according to lamination temperature

These results confirmed that the polishing pad laminated using the hot-melt adhesive according to the present invention at or above the activation temperature of the hot-melt adhesive has increased holding force and resistance to delamination at high temperatures.

Example 4

In this embodiment, the characteristics of the polishing pad prepared using the hot-melt adhesive according to the present invention and the hot-melt adhesive described in US Pat. No. 6,422,921 and the same series of hot-melt adhesive cited in US Pat. No. 7,101,275 were prepared. The characteristics of the polishing pads were compared.

UAF-420 hot-melt adhesive was obtained from Adhesive Films, Pine Brook, NJ. Four EPIC ™ D100 pads (Cabot Microelectronics, Aurora, Illinois, USA), i.e. polishing pads 4A-4D, were fabricated using a UAF-420 hot-melt adhesive with a residence time of 1 minute at a lamination temperature of 90 ° C to 95 ° C. Laminated. The laminator roll pressure was set to 8.6 kPa (1.25 psi) and the actual pressure applied to the pad was 550 kPa (80 psi). T-peel force of each laminated pad was measured at a speed of 305 mm / min.

This test parameter is in accordance with US Pat. No. 7,101,275. Specifically, the '275 patent has a lamination temperature of 50 ° C. to 150 ° C. (column 5, lines 4-5), and the T-peel force at a rate of 305 mm / min (eg, third column, 62). -63 line). The '275 patent states that polyurethane hot-melt adhesives are included in "the invention" (column 3, lines 33-36), and U.S. Patent 6,422,921 describes UAF-420 as such polyurethane hot-melt adhesives. (Column 3, lines 25-27). The T-peel results of the UAF-420 hot-melt adhesive are summarized in Table 4A.

TABLE 4A T-peelability of hot-melt adhesives of the prior art

These results further confirmed that polishing pads prepared using the general series of hot-melt adhesives described in the prior art have similar T-peel strength as the polishing pads subsequently claimed in the '275 patent.

Five additional EPIC ™ D100 pads, ie, polishing pads 4E-4I, were laminated using a UAF-420 hot-melt adhesive at a lamination temperature of 170 ° C. The laminator roll pressure was set to 8.6 kPa (1.25 psi) and the actual pressure applied to the pad was 550 kPa (80 psi). Samples of the laminated pad were prepared according to Example 2, and a holding test was performed at 80 ° C. The polishing pad was observed and the time until any delamination was observed. Each delamination was either a complete delamination or “falled off,” ie, the adhesive was completely debonded from the pad layer. The results are summarized in Table 4B.

TABLE 4B Holding Force of Prior Art Hot-melt Adhesives

As a result, the UAF-420 prior art hot-melt adhesive had a sufficient T-peel to satisfy the claims of US Pat. No. 7,101,275, but the T- with the EVA-based hot-melt adhesive used in the present invention at high temperatures. It was confirmed that the holding force is comparable to the peeling force. In particular, when the polishing pad was laminated using the EVA-based hot-melt adhesive according to the invention at approximately 170 ° C. and a holding force test was performed at an oven temperature of 80 ° C., no delamination was observed even after 960 minutes. (See Example 3, Laminated Polishing Pads 3AW, 3AX, 3AY, 3AZ, and 3BA). In contrast, after 12.4 minutes on average, under the same test conditions, complete delamination of the UAF-420 adhesive was observed.

These results further confirmed that the T-peel test was insufficient as an indicator of adhesion under elevated temperature and shear conditions. The UAF-420 prior art hot-melt adhesive had sufficient T-peel force to satisfy the claims of US Pat. No. 7,101,275, but the results of the retention test confirmed that the shear force could not withstand shear forces at elevated temperatures. The T-peel force of the adhesive alone is not an indicator of whether or not the polishing pad laminated with the adhesive is resistant to delamination in hot polishing applications. The holding force test described herein more accurately represents the adhesion under elevated temperature and shear conditions.

Claims (43)

Polishing Layer, An underlayer coextensive in substantially the same space as the abrasive layer, and Combining the abrasive layer with the underlying layer, comprising 2-18% by weight of EVA, and comprising a hot-melt adhesive that is substantially resistant to delamination when the abrasive layer reaches a temperature of 40 ° C. For polishing pads. The polishing pad of claim 1, wherein the hot-melt adhesive is substantially resistant to delamination when the polishing layer reaches a temperature of 60 ° C. 3. 3. The polishing pad of claim 2 wherein the hot-melt adhesive is substantially resistant to delamination when the polishing layer reaches a temperature of 80 ° C. 4. The polishing pad of claim 3 wherein the hot-melt adhesive is substantially resistant to delamination when the polishing layer reaches a temperature of 100 ° C. The polishing pad of claim 1, wherein the hot-melt adhesive comprises 12 to 16 weight percent EVA. The polishing pad of claim 1, wherein the hot-melt adhesive comprises 5 to 11 weight percent EVA. The polishing pad of claim 1, wherein each polishing layer and underlying layer comprises an optical endpoint detection port, wherein the optical endpoint detection port is substantially aligned. 10. The method of claim 1, further comprising at least one intermediate layer disposed between the abrasive layer and the underlying layer, wherein each abrasive layer, bottom layer and intermediate layer or intermediate layers are spread out in substantially the same space and joined together by a hot-melt adhesive. Polishing pads. The polishing pad of claim 8, wherein each layer of the polishing pad includes an optical endpoint detection port, the optical endpoint detection port being substantially aligned. The polishing pad of claim 1, wherein the hot-melt adhesive has a holding force that moves below 0.2 mm after 1 hour at 40 ° C. under a stress of 1 kg load. The polishing pad of claim 10, wherein the hot-melt adhesive has a holding force that moves below 0.5 mm after 24 hours at 40 ° C. under a stress of 1 kg load. 12. The polishing pad of claim 11 wherein the hot-melt adhesive has a holding force that moves below 0.3 mm after 24 hours at 40 [deg.] C. under a stress of 1 kg load. The polishing pad of claim 1, wherein the hot-melt adhesive has a holding force that moves to 0.2 mm or less after 1 hour at 60 ° C. under a stress of 1 kg load. The polishing pad of claim 13, wherein the hot-melt adhesive has a holding force that moves below 0.5 mm after 24 hours at 60 ° C. under a stress of 1 kg load. The polishing pad of claim 1, wherein the hot-melt adhesive has a holding force that moves up to 0.5 mm after one hour at 80 ° C. under a stress of 1 kg load. The polishing pad of claim 15, wherein the hot-melt adhesive has a holding force that moves below 1 mm after 24 hours at 80 ° C. under a stress of 1 kg load. The polishing pad of claim 16, wherein the hot-melt adhesive has a holding force that moves below 0.8 mm after 24 hours at 80 ° C. under a stress of 1 kg load. The polishing pad of claim 1, wherein the hot-melt adhesive has a holding force that moves up to 0.5 mm after 1 hour at 100 ° C. under a stress of 1 kg load. 19. The polishing pad of claim 18 wherein the hot-melt adhesive has a holding force that moves below 1.5 mm after 24 hours at 100 ° C under a stress of 1 kg load. The polishing pad of claim 19, wherein the hot-melt adhesive has a holding force that moves below 1.2 mm after 24 hours at 100 ° C. under a stress of 1 kg load. The polishing pad of claim 1, wherein the hot-melt adhesive has a melt index of 4 g / 10 minutes to 400 g / 10 minutes. (i) an abrasive layer, An underlayer extending in substantially the same space as the abrasive layer, and Combining the abrasive layer with the underlying layer, comprising 2-18% by weight of EVA, and comprising a hot-melt adhesive that is substantially resistant to delamination when the abrasive layer reaches a temperature of 40 ° C. Providing a polishing pad for (ii) contacting the substrate with the polishing pad and the polishing composition, and (iii) polishing the substrate by moving the polishing pad and the polishing composition relative to the substrate to grind the substrate by grinding at least a portion of the surface of the substrate with the polishing pad. 23. The method of claim 22, wherein the polishing layer of the polishing pad is performed at a temperature sufficient to heat the temperature to 40 to 100 ° C. The method of claim 22, wherein the hot-melt adhesive has a holding force that moves below 0.2 mm after 1 hour at 40 ° C. under a stress of 1 kg load. The method of claim 24, wherein the hot-melt adhesive has a holding force that moves below 0.5 mm after 24 hours at 40 ° C. under a stress of 1 kg load. 23. The method of claim 22, wherein the hot-melt adhesive has a holding force that moves up to 0.5 mm after one hour at 80 ° C. under a stress of 1 kg load. The method of claim 26, wherein the hot-melt adhesive has a holding force that moves below 1 mm after 24 hours at 80 ° C. under a stress of 1 kg load. The method of claim 22 wherein the hot-melt adhesive has a melt index of 4 g / 10 minutes to 400 g / 10 minutes. 23. The polishing pad of claim 22 wherein each polishing layer and underlying layer comprises an optical endpoint sensing port, wherein the optical endpoint sensing port is substantially aligned and remains substantially aligned while the substrate and polishing pad are in contact. situ) further comprising detecting a polishing endpoint. 30. The method of claim 29, wherein the polishing layer of the polishing pad is performed at a temperature sufficient to heat the temperature to 40 to 100 ° C. 23. The polishing pad of claim 22 wherein the polishing pad further comprises at least one intermediate layer disposed between the polishing layer and the underlying layer, wherein each polishing layer, the lower layer and the intermediate or intermediate layers are laid out in substantially the same space and are covered by a hot-melt adhesive. Coupled to each other, each layer of the polishing pad includes an optical endpoint detection port, wherein the optical endpoint detection port is substantially aligned and remains substantially aligned while the substrate and the polishing pad are in contact with each other. And further comprising detecting. 32. The method of claim 31, wherein the polishing layer of the polishing pad is performed at a temperature sufficient to heat the temperature to 40 to 100 ° C. (i) an abrasive layer, and Providing a polishing pad for chemical-mechanical polishing, comprising a lower layer extending in substantially the same space as the polishing layer, and (ii) combining the abrasive layer with the underlying layer, comprising from 2 to 18% by weight of EVA, using a hot-melt adhesive that is substantially resistant to delamination when the abrasive layer reaches a temperature of 40 ° C. and Laminating at least one of the underlayers. 34. The method of claim 33, wherein laminating is performed at a temperature sufficient to heat each laminated layer to a temperature above or above the activation temperature of the hot-melt adhesive. 35. The method of claim 34, wherein lamination is performed at a temperature in the range of 150 ° C to 200 ° C. 36. The method of claim 35, wherein lamination is performed at a temperature in the range of 170 ° C to 190 ° C. The method of claim 34, wherein during the lamination each laminated layer reaches a temperature in the range of 80 ° C. to 120 ° C. 35. The method of claim 37, wherein each laminated layer reaches a temperature in the range of 110 ° C. to 120 ° C. during lamination. 34. The method of claim 33, wherein the hot-melt adhesive is substantially resistant to delamination when the abrasive layer reaches a temperature of 60 ° C. 34. The method of claim 33, wherein the hot-melt adhesive is substantially resistant to delamination when the abrasive layer reaches a temperature of 80 ° C. The method of claim 33, wherein the hot-melt adhesive is substantially resistant to delamination when the abrasive layer reaches a temperature of 100 ° C. 35. 34. The method of claim 33, wherein each polishing layer and underlying layer comprises an optical endpoint detection port, wherein the optical endpoint detection port is substantially aligned. 34. The polishing pad of claim 33 wherein the polishing pad further comprises at least one intermediate layer disposed between the polishing layer and the underlying layer, wherein each polishing layer, the lower layer and the intermediate or intermediate layers are laid out in substantially the same space and are covered by a hot-melt adhesive. Coupled to each other, wherein each layer of the polishing pad includes an optical endpoint detection port, wherein the optical endpoint detection port is substantially aligned.

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