JP2012039093A - Chemical mechanical polishing pad, method for manufacturing the same, and chemical mechanical polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical mechanical polishing pad having excellent storage stability, a method for manufacturing the same, and a chemical mechanical polishing method using the chemical mechanical polishing pad.SOLUTION: The chemical mechanical polishing pad according to the present invention is a chemical mechanical polishing pad comprising a polishing layer, whose surface subjected to polishing has a silicon atom concentration or fluorine atom concentration of 0.5 to 10 atom% calculated by elemental analysis using x-ray photoelectron spectroscopy (XPS).

Description

  The present invention relates to a chemical mechanical polishing pad, a method for producing the same, and a chemical mechanical polishing method using the chemical mechanical polishing pad.

  In the manufacture of semiconductor devices, chemical mechanical polishing (hereinafter, also referred to as “CMP”) has attracted attention as a method for forming a flat surface. In CMP, the wafer surface (surface to be polished) on which elements and wiring are fabricated is slid against the surface of the chemical mechanical polishing pad while being slid against each other while being pressed against the polishing layer of the chemical mechanical polishing pad. This is a mechanical polishing technique. In this chemical mechanical polishing, it is known that the polishing rate, the scratch on the surface to be polished, the in-plane uniformity of the surface to be polished, etc. vary greatly depending on the properties and characteristics of the chemical mechanical polishing pad.

  As the chemical mechanical polishing pad, for example, a chemical mechanical polishing pad made of a foamed resin such as polyurethane foam (for example, see Patent Document 1), or a chemical mechanical polishing pad in which water-soluble particles are dispersed in a non-foamed matrix (for example, Patent Document 2) is used.

JP-A-11-70463 JP 2000-34416 A

  However, such a chemical mechanical polishing pad may cause a reduction in polishing performance when stored for a long period of time. For example, a chemical mechanical polishing pad made of a foamed resin such as polyurethane foam has a large surface area of the polishing layer, so that it tends to adsorb moisture and organic components in the storage atmosphere as the storage period until use becomes longer. . As a result, not only the surface layer portion of the polishing layer but also the deep layer portion may be altered, and it has been difficult to maintain good polishing characteristics. On the other hand, in a chemical mechanical polishing pad in which water-soluble particles are dispersed in a non-foamed matrix, since the water-soluble particles have deliquescence, it is necessary to strictly control the amount of water in the storage atmosphere. For example, if the water-soluble particles are altered by adsorbing moisture during storage, it may be difficult to maintain good polishing characteristics.

  Accordingly, some aspects of the present invention provide a chemical mechanical polishing pad excellent in storage stability, a method for manufacturing the chemical mechanical polishing pad, and a chemical mechanical polishing method using the chemical mechanical polishing pad by solving the above-described problems. To do.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
One aspect of the chemical mechanical polishing pad according to the present invention is:
A chemical mechanical polishing pad with a polishing layer,
A silicon atom concentration or a fluorine atom concentration calculated by elemental analysis of the surface of the polishing layer subjected to polishing by X-ray photoelectron spectroscopy (XPS) is 0.5 atom% or more and 10 atom% or less. And

[Application Example 2]
In the chemical mechanical polishing pad of Application Example 1,
Under the condition that the silicon oxide film is etched by 50 nm, a surface to be etched is prepared by performing argon ion etching on the surface used for polishing the polishing layer,
The silicon atom concentration and the fluorine atom concentration calculated by elemental analysis of the surface to be etched by X-ray photoelectron spectroscopy (XPS) can be 0 atom% or more and 0.1 atom% or less.

[Application Example 3]
In the chemical mechanical polishing pad of Application Example 1 or Application Example 2,
A chemical mechanical polishing pad provided with a plurality of recesses on the surface used for polishing the polishing layer,
The silicon atom concentration or fluorine atom concentration calculated by elemental analysis of the inner surface of the concave portion by X-ray photoelectron spectroscopy (XPS) may be 0.5 atom% or more and 10 atom% or less.

[Application Example 4]
One aspect of the chemical mechanical polishing method according to the present invention is:
Chemical mechanical polishing is performed using the chemical mechanical polishing pad described in any one of Application Examples 1 to 3.

[Application Example 5]
One aspect of a method for producing a chemical mechanical polishing pad according to the present invention is as follows.
Including molding a polyurethane-containing composition using a mold,
The mold is coated with a material containing at least one element selected from silicon and fluorine.

[Application Example 6]
In the method for producing the chemical mechanical polishing pad of Application Example 5,
The surface of the mold may be provided with a concave pattern.

  The chemical mechanical polishing pad according to the present invention is excellent in storage stability by having a surface layer portion having a predetermined silicon atom concentration or fluorine atom concentration in the polishing layer, and is good even when stored for a long period of time. The polishing performance can be exhibited. In addition, since the chemical mechanical polishing method according to the present invention uses the chemical mechanical polishing pad described above, it can always exhibit a certain polishing performance even when stored for a long period of time.

It is sectional drawing which shows typically the chemical mechanical polishing pad which concerns on this Embodiment. It is an enlarged view of the area | region I in FIG. It is a top view which shows typically the chemical mechanical polishing pad which concerns on this Embodiment. It is a top view which shows typically the chemical mechanical polishing pad which concerns on a 1st modification. It is a top view which shows typically the chemical mechanical polishing pad which concerns on a 2nd modification.

  Hereinafter, preferred embodiments of the present invention will be described in detail. In addition, this invention is not limited to the following embodiment, Various modifications implemented in the range which does not change the summary of this invention are also included.

1. Chemical mechanical polishing pad The structure of the chemical mechanical polishing pad according to the present embodiment is not particularly limited as long as it has a polishing layer on at least one surface. The polishing layer has a surface layer portion and a deep layer portion. Hereinafter, an example of the chemical mechanical polishing pad according to the present embodiment will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing an example of a chemical mechanical polishing pad according to the present embodiment. As shown in FIG. 1, the chemical mechanical polishing pad 100 includes a polishing layer 10 and a support layer 12 formed on the surface side of the polishing layer 10 that comes into contact with the polishing apparatus surface plate 14.

1.1. Polishing Layer The polishing layer 10 is composed of a surface layer portion 10a and a deep layer portion 10b. The surface layer portion 10 a is located in the vicinity of the surface used for polishing the polishing layer 10. The deep layer portion 10b is located inside the polishing layer 10a. The planar shape of the polishing layer 10 is not particularly limited, but may be, for example, a circular shape. When the planar shape of the polishing layer 10 is circular, the size is preferably 150 mm to 1200 mm in diameter, and more preferably 500 mm to 1000 mm in diameter. The thickness of the polishing layer 10 is preferably 0.5 mm to 5.0 mm, more preferably 1.0 mm to 4.0 mm, and particularly preferably 1.5 mm to 3.5 mm.

  In this specification, the “surface layer portion” means photoelectrons generated by irradiating the surface to be polished of the polishing layer with X-rays in elemental analysis by X-ray photoelectron spectroscopy (hereinafter also referred to as “XPS”). The region to be analyzed when measuring at a photoelectron take-off angle of 90 ° with respect to the surface subjected to polishing of the polishing layer, that is, the region within several nm from the surface subjected to polishing of the polishing layer. Say.

  In this specification, the “deep layer portion” refers to a region other than the surface layer portion of the polishing layer. For example, the surface layer portion of the polishing layer can be reliably removed by performing argon ion etching on the surface used for polishing the polishing layer under the condition of etching the silicon oxide film by 50 nm. It can be said that the surface is a deep layer.

  In the chemical mechanical polishing pad according to the present embodiment, in the elemental analysis by X-ray photoelectron spectroscopy (XPS), photoelectrons generated by irradiating the surface used for polishing the polishing layer with X-rays are polished by the polishing layer. The silicon atom concentration or the fluorine atom concentration, which is calculated by measuring at a photoelectron take-off angle of 90 ° with respect to the surface to be provided, is 0.5 atom% or more and 10 atom% or less. That is, in the chemical mechanical polishing pad 100 shown in FIG. 1, it can be said that the silicon atom concentration or the fluorine atom concentration in the surface layer portion 10a is 0.5 atom% or more and 10 atom% or less.

  The silicon atom concentration in the surface layer portion 10a is preferably 1 atom% or more and 9 atom% or less, and more preferably 1.5 atom% or more and 7 atom% or less. Further, the fluorine atom concentration in the surface layer portion 10a is preferably 1 atom% or more and 9 atom% or less, and more preferably 1.5 atom% or more and 7 atom% or less. When the silicon atom concentration or the fluorine atom concentration in the surface layer portion 10a is in the above range, the balance between hydrophobicity and hydrophilicity in the surface layer portion 10a becomes good, and the deep layer portion 10b can be effectively protected even during long-term storage. It is considered possible.

  The total of the silicon atom concentration and the fluorine atom concentration in the surface layer portion 10a is preferably 0.6 atom% or more and 10 atom% or less, and more preferably 1 atom% or more and 9 atom% or less. When the sum of the silicon atom concentration and the fluorine atom concentration in the surface layer portion 10a is within the above range, the surface layer portion 10a is considered to be moderately hydrophobic and can suppress moisture adsorption from the atmosphere in which the chemical mechanical polishing pad 100 is stored. It is done. As a result, the deep layer 10b can be effectively protected even during long-term storage.

  In the present specification, the silicon atom concentration and the fluorine atom concentration are silicon or fluorine atoms when the total of all atom number quantification values having an atomic number equal to or greater than the atomic number of the carbon atom measured by XPS is 100 atom%. It represents the ratio of the number of atoms. The silicon atom concentration and the fluorine atom concentration existing in the surface layer portion 10a of the polishing layer 10 are measured by using XPS, and the principle of XPS is generally as follows.

  XPS is a spectroscopic method that measures the energy of photoelectrons emitted from a sample by X-ray irradiation. Since photoelectrons collide with molecules and are scattered immediately in the atmosphere, it is necessary to keep the apparatus in a vacuum. Also, photoelectrons emitted deep inside the solid sample are scattered within the sample and cannot escape from the surface. Therefore, XPS is effective as a surface analysis method because it measures photoelectrons only from the sample surface.

The observed kinetic energy E of the photoelectron is a value obtained by subtracting the energy φ for transferring the electron out of the sample surface from hν-E _K , that is,
E = hν−E _K −φ (1)
It can be expressed as. Where h: Planck's constant, ν: frequency, E _K : electron binding energy. From the above equation (1), it can be seen that the value of E varies depending on the energy of the X-rays of the excitation source. The method for measuring the electron energy is not particularly limited, but a representative one is an electrostatic field type in which electrons are introduced into an electrostatic field and only a fixed orbit is detected.

By XPS, it is possible to measure the binding energy _{E K} electrons. Since such binding energy is basically a value inherent to the element, the type of element can be specified. Each element can also be quantified from the intensity of the photoelectron spectrum.

  By the way, incident X-rays enter from the surface of the sample to the inside, but since the mean free path of excited photoelectrons is as small as 0.1 nm to several nm, the photoelectrons are emitted only from the vicinity of the surface of the sample. Become. Thereby, analysis in the vicinity of the surface of the sample becomes possible. However, when there are several layers formed in the vicinity of the surface of the sample, it may not be detected accurately even if an attempt is made to observe a trace composition of the layer. This is because XPS observes the relative amount of a composition that averages several tens of kilometers from the surface. Thus, when observing the composition of several layers from the surface, the angular dependence of the escape depth of photoelectrons can be utilized. That is, the photoelectrons are isotropically emitted from the surface of the sample, but the escape depth of the photoelectrons from the solid surface varies depending on the photoelectron extraction angle. By utilizing this phenomenon, the escape depth is maximized by setting the photoelectron extraction angle to 90 ° with respect to the sample surface, and information on a deeper portion on the surface of the sample can be obtained. The “photoelectron take-off angle” means an angle formed between the sample surface and the detector.

  The apparatus used for XPS is not particularly limited as long as it can analyze the qualitative, quantitative, and chemical state of the elements present on the surface of the sample.

  FIG. 2 is an enlarged view of the region I in FIG. 1, and is a cross-sectional view schematically showing the detailed shape of the polishing layer 10. As shown in FIG. 2, a plurality of recesses 16 may be formed on a surface 20 (hereinafter referred to as “polishing surface”) 20 used for polishing the polishing layer 10. The recess 16 holds slurry supplied during chemical mechanical polishing, distributes it evenly on the polishing surface, and temporarily retains waste such as polishing debris and used slurry and discharges it to the outside. It has a function as a route for

  Although the cross-sectional shape of the recess 16 is not particularly limited, it can be, for example, a polygonal shape such as a rectangle as shown in FIG. 2, a U shape, a V shape, or the like. The depth a of the recess 16 is preferably 0.1 mm or more, more preferably 0.1 mm to 2.5 mm, and particularly preferably 0.2 mm to 2.0 mm. The width b of the recess 16 is preferably 0.1 mm or more, more preferably 0.1 mm to 5.0 mm, and particularly preferably 0.2 mm to 3.0 mm. In the polishing surface 20, the interval c between the adjacent recesses 16 is preferably 0.05 mm or more, more preferably 0.05 mm to 100 mm, and particularly preferably 0.1 mm to 10 mm. The pitch d, which is the sum of the width of the recess and the distance between adjacent recesses, is preferably 0.15 mm or more, more preferably 0.15 mm to 105 mm, and particularly preferably 0.6 mm to 13 mm. it can. The concave portion 16 can be formed with a certain interval within the above range. By forming the concave portion 16 having a shape in the above range, a chemical mechanical polishing pad having an excellent effect of reducing scratches on the surface to be polished and having a long life can be easily manufactured.

  Each preferred range can be a combination of each. That is, for example, it is preferable that the depth a is 0.1 mm or more, the width b is 0.1 mm or more, the interval c is 0.05 mm or more, the depth a is 0.1 mm to 2.5 mm, and the width b is 0. More preferably, the thickness c is 0.05 mm to 100 mm, the depth a is 0.2 mm to 2.0 mm, the width b is 0.2 mm to 3.0 mm, and the distance c is 0.00 mm. 1 mm to 10 mm is particularly preferable.

  FIG. 3 is a plan view of the chemical mechanical polishing pad 100 according to the present embodiment. As shown in FIG. 3, the recess 16 can be formed in a plurality of concentric circles whose diameter gradually increases from the center of the polishing surface 20 toward the outer edge.

  FIG. 4 is a plan view of the chemical mechanical polishing pad 200 according to the first modification, and corresponds to FIG. The chemical mechanical polishing pad 200 according to the first modification further includes a plurality of recesses 17 and recesses 18 extending radially from the center of the polishing surface 20 toward the outer edge in addition to the plurality of recesses 16 provided in an annular shape. It differs from the chemical mechanical polishing pad 100 in that it includes. Here, the center portion refers to a region surrounded by a circle having a radius of 50 mm with the center of gravity of the polishing layer as the center. The concave portion 17 and the concave portion 18 need only extend from an arbitrary position in the “center portion” in the outer edge direction, and the shape thereof may be, for example, a linear shape, an arc shape, or a combination thereof. The cross-sectional shapes of the recess 17 and the recess 18 can be the same as the recess 16 described above. The other configuration of the chemical mechanical polishing pad 200 according to the first modification is the same as the configuration of the polishing layer 10 described with reference to FIGS.

  FIG. 5 is a plan view of a chemical mechanical polishing pad 300 according to the second modification, and corresponds to FIG. The chemical mechanical polishing pad 300 according to the second modified example further includes a plurality of recesses 19 extending radially from the center of the polishing surface 20 toward the outer edge in addition to the plurality of recesses 16 provided in an annular shape. It differs from the chemical mechanical polishing pad 100 described above. The cross-sectional shape of the recess 19 can be the same as the recess 16 described above. The other configuration of the chemical mechanical polishing pad 300 according to the second modification is the same as the configuration of the polishing layer 10 described with reference to FIGS.

  When a plurality of recesses 16 are formed on the polishing surface 20 of the polishing layer 10, it is preferable that the inner surface of the recess 16 also includes a surface layer portion 10 a having a silicon atom concentration or a fluorine atom concentration of 0.5 atom% or more and 10 atom% or less. . In the present specification, the “inner surface of the recess” means an inner surface of the recess such as a side surface and a bottom surface.

  When the inner surface of the recess 16 is provided with the surface layer portion 10a as described above, even if the polishing surface 20 is worn in the polishing step, the surface layer portion 10a existing on the inner surface is not lost due to wear. Therefore, the surface layer portion 10a existing in the recess 16 can prevent the slurry from penetrating from the inner surface of the recess 16 to the deep layer portion 10b in the polishing process. As a result, it is possible to effectively suppress deformation of the recess 16 due to the deep layer portion 10b absorbing water and swelling, and it is preferable that the polishing characteristics are not deteriorated even in a polishing process over a long period of time.

  In addition, the silicon atom concentration and the fluorine atom concentration in the deep layer portion 10b of the polishing layer 10 are preferably 0 atom% or more and 0.1 atom% or less from the viewpoint of suppressing contamination of the object to be polished in the polishing process. In addition, it is more preferable that the deep layer part 10b does not contain silicon and fluorine from the above viewpoint.

  The silicon atom concentration and the fluorine atom concentration in the deep layer portion 10b of the polishing layer 10 can be calculated as follows, for example. First, when argon ion etching is performed on the surface used for polishing the polishing layer 10 under the condition that the silicon oxide film is etched by 50 nm, the surface layer portion 10a of the polishing layer 10 is completely removed. The etched surface thus obtained is the deep layer portion 10 b of the polishing layer 10. Next, the surface to be etched is irradiated with X-rays using XPS, and the generated photoelectrons are measured at a photoelectron extraction angle of 90 ° with respect to the surface to be etched, whereby silicon atoms in the deep layer portion 10b of the polishing layer 10 are measured. Concentration and fluorine atom concentration can be calculated.

  The deep layer portion 10b may be made of any material as long as the object of the present invention can be achieved. One of the functions of the deep layer portion 10b is to hold a slurry during chemical mechanical polishing. Therefore, it is preferable that pores are formed in the deep layer portion 10b during chemical mechanical polishing. For this reason, the deep layer portion 10b is preferably made of a material made of a water-insoluble matrix in which water-soluble particles are dispersed or a material made of a water-insoluble matrix in which pores are dispersed, for example, a foam.

1.2. Support Layer The support layer 12 is used in the chemical mechanical polishing pad 100 to support the polishing layer 10 on the polishing apparatus surface plate 14. The support layer 12 may be an adhesive layer or a cushion layer having the adhesive layer on both sides.

  The adhesive layer can be made of, for example, an adhesive sheet. The thickness of the pressure-sensitive adhesive sheet is preferably 50 μm to 250 μm. By having a thickness of 50 μm or more, the pressure from the polishing surface 20 side of the polishing layer 10 can be sufficiently relaxed, and by having a thickness of 250 μm or less, the influence of unevenness on the polishing performance is not affected. A chemical mechanical polishing pad 100 having a uniform thickness is obtained.

  The material of the pressure-sensitive adhesive sheet is not particularly limited as long as the polishing layer 10 can be fixed to the polishing apparatus surface plate 14, but is preferably an acrylic or rubber-based material having a lower elastic modulus than the polishing layer 10.

  The adhesive strength of the pressure-sensitive adhesive sheet is not particularly limited as long as the chemical mechanical polishing pad can be fixed to the polishing apparatus surface plate 14, but when the adhesive strength of the pressure-sensitive adhesive sheet is measured according to the standard of “JIS Z0237”, the adhesive strength is Preferably it is 3N / 25mm or more, More preferably, it is 4N / 25mm or more, Most preferably, it is 10N / 25mm or more.

  As long as the cushion layer is made of a material whose hardness is lower than that of the polishing layer 10, the material is not particularly limited, and may be a porous body (foam) or a non-porous body. As a cushion layer, the layer which shape | molded foamed polyurethane etc. is mentioned, for example. The thickness of the cushion layer is preferably 0.1 mm to 5.0 mm, more preferably 0.5 mm to 2.0 mm.

2. Method for Producing Chemical Mechanical Polishing Pad The chemical mechanical polishing pad according to the present embodiment can be produced, for example, by coating the surface used for polishing the polishing layer with a specific material as described later. Hereinafter, an example of a method for manufacturing a chemical mechanical polishing pad will be described.

  First, a foamed resin block such as polyurethane foam is prepared and then sliced. Next, after forming a recess on the surface of the foamed resin block by means of cutting or the like, a material containing at least one element selected from silicon and fluorine is further applied to the surface. According to this manufacturing method, the above-mentioned chemical mechanical polishing pad can be manufactured by applying the material to the surface to be subjected to polishing of the polishing layer.

  Further, the chemical mechanical polishing pad according to the present embodiment can be manufactured by a method including a step of preparing a composition containing at least polyurethane and a step of molding the composition using a mold. it can. Here, the mold is preferably coated with a material containing at least one element selected from silicon and fluorine. According to this manufacturing method, the above-described chemical mechanical polishing pad can be efficiently manufactured by using a mold. Hereinafter, an example of a method for producing a chemical mechanical polishing pad using a mold will be described.

  First, a mold for molding the polishing layer is prepared. The material of the mold is not particularly limited, and examples thereof include aluminum, carbon steel, tool steel, and ceramic. The surface shape of the mold to be used may be flat, but it is preferable to have a recess pattern for molding a known recess shape as described in the section “1. Chemical mechanical polishing pad”. By providing the mold with the concave pattern, the concave pattern can be efficiently transferred to the molded polishing layer.

  The shape of the concave pattern is not particularly limited, and may be, for example, a spiral shape, an annular shape, a lattice shape, or the like in plan view. When the planar shape of the concave pattern is annular, the diameter of the ring is preferably 1 mm to 1100 mm, more preferably 1 mm to 1000 mm, and particularly preferably 2 mm to 850 mm. Moreover, when the planar shape of the said recessed part pattern is a spiral, cyclic | annular form, or a grid | lattice form, it is preferable that the width | variety of a recessed part is 0.1 mm-5.0 mm, and it is 0.2 mm-3.0 mm. More preferred. Regardless of the shape of the recess pattern, the depth of the recess is preferably 0.1 mm to 2.5 mm, more preferably 0.2 mm to 2.0 mm, and 0.2 mm to 1.5 mm. It is particularly preferred. These recess patterns may be formed by a single line or only one, or may be formed by two or more lines or two or more.

  Further, the arithmetic surface roughness (Ra) of the mold surface is preferably 20 μm or less, and more preferably 15 μm or less, from the viewpoint of improving the peelability of the polishing layer from the mold. The arithmetic surface roughness of the mold surface can be measured by using, for example, an optical surface roughness measuring device, a contact surface roughness measuring device, or the like. Examples of the optical surface roughness measuring device include a three-dimensional surface structure analysis microscope, a scanning laser microscope, and an electron beam surface morphology analyzer. Examples of the contact type surface roughness measuring device include a stylus type surface roughness meter.

  Next, a composition containing at least polyurethane is prepared. Although it does not specifically limit as a polyurethane, It is preferable to use a thermoplastic polyurethane. If necessary, additives such as water-soluble particles, a crosslinking agent, a crosslinking aid, an organic filler, and an inorganic filler may be added to such a composition.

  Next, the mold is filled with the composition, and a polishing layer is molded by means such as compression molding or extrusion molding. When a crosslinking agent is added to the composition, preferably the mold is preheated to a temperature of 160 ° C. to 220 ° C., more preferably 170 ° C. to 210 ° C., and then crosslinked and molded. Good. On the other hand, when no cross-linking agent is added to the composition, the plasticized composition is molded by a press machine or an injection molding machine and solidified by cooling, or plasticized using an extruder equipped with a T die. -Molding may be performed by using a sheeting method.

  Finally, a material containing at least one element selected from silicon and fluorine is applied to at least a surface of the obtained polishing layer to be subjected to polishing. Examples of the material containing at least one element selected from silicon and fluorine include silicon, silicone, silicon dioxide, silicon nitride, silicic acid, silicon carbide, silicate, silicon resin, organosilane, siloxide, and silyl. Examples thereof include a composition containing at least one selected from hydride, silene, polytetrafluoroethylene, polyvinylidene fluoride, fluororesin, metal fluoride, and nonmetal fluoride.

  In the case of using a mold, a material containing at least one element selected from silicon and fluorine is applied to the mold surface in advance, and the surface layer portion and the deep layer portion are formed simultaneously with the molding of the polishing layer. The manufacturing method is efficient and preferable.

  Moreover, the surface treatment other than apply | coating the material containing the at least 1 sort (s) of element selected from silicon and a fluorine can be arbitrarily performed to the metal mold | die used. Optional surface treatments include, for example, electroplating, hot dipping, diffusion plating, vapor deposition plating, electroless plating, thermal spraying, chemical conversion treatment, flame quenching, induction quenching, carburization, nitriding, electron beam quenching, laser firing. And shot peening.

3. Chemical mechanical polishing method using chemical mechanical polishing pad The chemical mechanical polishing method according to the present embodiment is characterized in that chemical mechanical polishing is performed using the chemical mechanical polishing pad described above. The above-mentioned chemical mechanical polishing pad is provided with a surface layer portion having a predetermined silicon atom concentration or fluorine atom concentration in the polishing layer. Therefore, the chemical mechanical polishing pad is particularly excellent in storage stability in the deep layer portion and is stored for a long period of time. Can also exhibit good polishing performance. Since the chemical mechanical polishing method according to the present embodiment uses such a chemical mechanical polishing pad, a constant polishing performance can always be exhibited even when stored for a long period of time.

  In the chemical mechanical polishing method according to the present embodiment, a commercially available chemical mechanical polishing apparatus can be used. Examples of commercially available chemical mechanical polishing apparatuses include, for example, model “EPO-112”, model “EPO-222” (manufactured by Ebara Corporation); model “LGP-510”, model “LGP-552” (and above, Wrap master SFT); model “Mirra” (Applied Materials) and the like.

  Further, as the slurry, an optimal one can be appropriately selected according to the object to be polished (copper film, insulating film, low dielectric constant insulating film, etc.).

4). Example 4.1. Example 1
40 parts by mass of thermoplastic polyurethane (BASF, trade name “Elastolan 1174D”), 40 parts by weight of thermoplastic polyurethane (trade name “Elastolan NY97A”), β-cyclodextrin (brine) as water-soluble particles A thermoplastic polyurethane composition was obtained by kneading 20 parts by mass of Minato Seika Co., Ltd., trade name “Dexy Pearl β-100”) with a rudder heated to 180 ° C. Next, a mold of a material S55C having a concentric rib having a width of 0.5 mm, a height of 1.4 mm, and a pitch of 1.5 mm and having a surface with a silicon resin coating of about 1 μm was prepared. The composition obtained in this mold is filled, and compression molding is performed at 180 ° C., thereby having a recess having a width of 0.5 mm, a depth of 1.4 mm, and a pitch of 1.5 mm, a diameter of 845 mm, and a thickness of 3. A 1 mm disc-shaped chemical mechanical polishing pad was obtained. No chipping was observed on the surface of the obtained chemical mechanical polishing pad, and the moldability was good.

  It was calculated by measuring using an X-ray photoelectron spectrometer (model “Quantum 2000” manufactured by ULVAC-PHI) at any three points on the surface to be used for polishing the polishing layer of the chemical mechanical polishing pad. Table 1 shows the average values of the silicon atom concentration and the fluorine atom concentration.

  Further, in the X-ray photoelectron spectrometer, argon ion etching was performed for 5 minutes under the condition of an acceleration voltage of 5 kV on the surface of the chemical mechanical polishing pad used for polishing the polishing layer. Table 1 shows the average values of silicon atom concentration and fluorine atom concentration calculated by measurement using an X-ray photoelectron spectrometer at three arbitrary points on the surface to be etched.

  Two chemical mechanical polishing pads were produced by the above production method. One sheet was left in the atmosphere for 1 day after molding and then subjected to a polishing test. The other sheet was molded and then wrapped with a polyethylene film, left in this state in the atmosphere for 500 days, and then subjected to a polishing test.

  The polishing test was carried out under the following conditions by mounting these chemical mechanical polishing pads on a chemical mechanical polishing apparatus (Applied Reflexion LK, manufactured by Applied Materials).

<Initial dressing>
・ Surface plate speed: 120rpm
・ Deionized water supply amount: 100 mL / min ・ Polishing time: 600 seconds

<Polishing rate evaluation>
Chemical mechanical polishing was performed under the following conditions using a 12-inch PETEOS film-coated wafer as an object to be polished. Note that the PETEOS film is a silicon oxide film formed by a chemical vapor deposition method using tetraethyl silicate (TEOS) as a raw material and using plasma as an acceleration condition.
・ Surface plate speed: 120rpm
-Polishing head rotation speed: 36 rpm
Polishing head pressing pressure: 240 hPa
・ Slurry supply amount: 300 mL / min ・ Polishing time: 60 seconds ・ Slurry: CMS1101 (manufactured by JSR Corporation)

The thickness of the PETEOS film before and after chemical mechanical polishing was measured at 33 points, which were equally taken except for a range of 5 mm from both ends in the diameter direction, on the wafer with 12 inch PETEOS film as the object to be polished. From this measurement result, the polishing rate was calculated by the following formulas (2) and (3).
Polishing amount (nm) = film thickness before polishing (nm) −film thickness after polishing (nm) (2)
Polishing rate (nm / min) = average value of polishing amount at 33 points (nm) / polishing time (min) (3)
The evaluation results of the polishing rate are also shown in Table 1. In addition, when the polishing rate was 200 nm / min or more, it was judged that the polishing characteristics were good, and indicated as “◯”. When the polishing rate was less than 200 nm / min, it was judged that the polishing characteristics were poor, and “x” was written.

4.2. Example 2
A mold having the same shape as the mold used in Example 1 and a non-surface-treated mold was prepared, and a spray-type mold release agent containing a silicon compound (product name “Permallyse 10”, manufactured by Silund Seilach) Was applied to the surface. A chemical mechanical polishing pad was produced in the same manner as in Example 1 except that this mold was used. Table 1 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.3. Example 3
A mold having a flat surface without ribs was prepared. This mold was filled with the thermoplastic polyurethane composition obtained in Example 1, and compression molded at 180 ° C. to obtain a base of a chemical mechanical polishing pad. A disk having a diameter of 845 mm and a thickness of 3.1 mm having recesses having a width of 0.5 mm, a depth of 1.4 mm, and a pitch of 1.5 mm is formed by subjecting the obtained base to a sanding process and then forming recesses by cutting. A shaped chemical mechanical polishing pad was obtained. Furthermore, 2 g of a spray containing a silicon compound (trade name “Permallyse 10”, manufactured by Silund Seilach) was sprayed on the surface of the resulting chemical mechanical polishing pad to be polished. In this way, the intended chemical mechanical polishing pad was produced. Table 1 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.4. Example 4
A chemical mechanical polishing pad was obtained in the same manner as in Example 3 except that 3 g of a spray containing a silicon compound (trade name “Permallyse 10”, manufactured by Silund Seirach) was sprayed. Table 1 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.5. Example 5
A chemical mechanical polishing pad was produced in the same manner as in Example 1 except that a mold made of material S55C coated with a fluorine-based resin coating having a surface of about 5 μm was used. Table 1 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.6. Example 6
A chemical mechanical polishing pad was obtained in the same manner as in Example 3 except that 2 g of a spray containing a fluorine-based compound (trade name “Flease 20” manufactured by Neos Co., Ltd.) was sprayed. Table 1 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.7. Example 7
A chemical mechanical polishing pad was obtained in the same manner as in Example 3, except that 2 g of a spray containing a silicon compound and a fluorine compound (trade name “Flease 11F” manufactured by Neos Co., Ltd.) was sprayed. Table 1 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.8. Comparative Example 1
A mold having the same shape as that of the mold used in Example 1 and a non-surface-treated mold was prepared, and a spray-type mold release agent containing a silicon compound (manufactured by Silund Seilach, trade name “Permally 90”) A chemical mechanical polishing pad was produced in the same manner as in Example 1 except that 5 g of was applied to the surface. Table 2 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.9. Comparative Example 2
A chemical mechanical polishing pad was obtained in the same manner as in Example 3 except that 10 g of a spray containing a silicon compound (trade name “Permallyse 10”, manufactured by Silund Seirach) was sprayed. Table 2 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.10. Comparative Example 3
Prepare a mold with the same shape and no surface treatment as the mold used in Example 1, and apply a spray-type mold release agent (trade name “Flease 20”, manufactured by Neos Co., Ltd.) containing a fluorine compound on its surface. A chemical mechanical polishing pad was produced in the same manner as in Example 1 except that 5 g was applied. Table 2 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.11. Comparative Example 4
A chemical mechanical polishing pad was obtained in the same manner as in Example 3 except that 10 g of a spray containing a fluorine compound (trade name “Flease 20” manufactured by Neos Co., Ltd.) was sprayed. Table 2 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.12. Comparative Example 5
A mold having the same shape as the mold used in Example 1 and having no surface treatment was prepared, and a spray-type mold release agent containing a silicon compound and a fluorine compound (trade name “Flease 11F” manufactured by Neos Co., Ltd.) was used. 5 g was applied to the surface. A chemical mechanical polishing pad was produced in the same manner as in Example 1 except that this mold was used. Table 2 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.13. Comparative Example 6
A chemical mechanical polishing pad was obtained in the same manner as in Example 3 except that the spray containing a silicon compound (trade name “Permallyse 10”) was not sprayed. Table 2 shows the evaluation results of the silicon atom concentration, fluorine atom concentration, and polishing rate of the obtained chemical mechanical polishing pad.

4.14. Evaluation Results According to the chemical mechanical polishing pads prepared in Examples 1 to 7, after the silicon layer concentration or fluorine atom concentration in the surface layer portion is 0.5 atom% or more and 10 atom% or less, after storage for 500 days The polishing characteristics using the chemical mechanical polishing pad were good.

  On the other hand, according to the chemical mechanical polishing pads produced in Comparative Example 1, Comparative Example 3, Comparative Example 5 and Comparative Example 6, the silicon atom concentration or fluorine atom concentration in the surface layer portion is less than 0.5 atom%, Polishing characteristics using the chemical mechanical polishing pad after storage for 500 days were poor.

  According to the chemical mechanical polishing pads produced in Comparative Example 2 and Comparative Example 4, the chemical mechanical polishing after storage for 1 day and 500 days due to the silicon atom concentration or fluorine atom concentration in the surface layer portion being 10 atom% or more. The polishing characteristics using the pad were all poor.

  From the above results, it was found that a chemical mechanical polishing pad having a silicon atom concentration or a fluorine atom concentration in the surface layer portion of 0.5 atom% or more and 10 atom% or less can improve storage stability.

  The present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the present invention includes substantially the same configuration (for example, a configuration having the same function, method, and result, or a configuration having the same purpose and effect) as the configuration described in the embodiment. In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that achieves the same effect as the configuration described in the embodiment or a configuration that can achieve the same object. In addition, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 10 ... Polishing layer, 10a ... Surface layer part, 10b ... Deep layer part, 12 ... Support layer, 14 ... Surface plate for polishing apparatus, 16, 17, 18, 19 ... Recessed part, 20 ... Polishing surface, 100, 200, 300 ... Chemical Mechanical polishing pad

Claims (6)

A chemical mechanical polishing pad with a polishing layer,
A silicon atom concentration or a fluorine atom concentration calculated by elemental analysis of the surface of the polishing layer subjected to polishing by X-ray photoelectron spectroscopy (XPS) is 0.5 atom% or more and 10 atom% or less. And chemical mechanical polishing pad. Under the condition that the silicon oxide film is etched by 50 nm, a surface to be etched is prepared by performing argon ion etching on the surface used for polishing the polishing layer,
2. The silicon atom concentration and fluorine atom concentration calculated by elemental analysis of the surface to be etched by X-ray photoelectron spectroscopy (XPS) are 0 atom% or more and 0.1 atom% or less. The chemical mechanical polishing pad described in 1. A chemical mechanical polishing pad provided with a plurality of recesses on the surface used for polishing the polishing layer,
2. The silicon atom concentration or fluorine atom concentration calculated by elemental analysis of the inner surface of the recess by X-ray photoelectron spectroscopy (XPS) is 0.5 atom% or more and 10 atom% or less. Or the chemical mechanical polishing pad of Claim 2.   A chemical mechanical polishing method comprising performing chemical mechanical polishing using the chemical mechanical polishing pad according to any one of claims 1 to 3. In a method for producing a chemical mechanical polishing pad comprising a step of molding a composition containing polyurethane using a mold,
The method of manufacturing a chemical mechanical polishing pad, wherein the mold is coated with a material containing at least one element selected from silicon and fluorine.   The method of manufacturing a chemical mechanical polishing pad according to claim 5, wherein a surface of the mold has a concave pattern.

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