JP2009135386A - Cmp abrasive for semiconductor insulating film and substrate polishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CMP abrasive for a semiconductor insulating film and a substrate polishing method, polishing a semiconductor insulating film at a high speed without a polishing damage and suppressing dishing. <P>SOLUTION: The CMP abrasive for a semiconductor insulating film contains cerium oxide particles, a high-density polyethylene resin, a dispersant, and water. Then, the particle diameter of D50 volume% of the cerium oxide particle is set to 50 to 300 nm and the particle diameter of D99 volume% is set to 200 to 1,000 nm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a CMP polishing agent for a semiconductor insulating film used in a planarization process of a substrate surface, which is a semiconductor element manufacturing technique, and a substrate polishing method.

  In the present ultra-large scale integrated circuit, various fine processing techniques have been researched and developed in order to increase the mounting density. The design rules are already in the order of sub-half microns. One of the techniques that have been developed in order to satisfy such demands for strict miniaturization is a CMP (chemical mechanical polishing) technique.

  The CMP technique can completely planarize the layer to be exposed in the manufacturing process of the semiconductor device, reduce the burden of the exposure technique, and stabilize the yield. For example, planarization of an interlayer insulating film, BPSG film, shallow This technique is essential when performing trench isolation and the like.

  CMP polishing agent for planarizing an inorganic insulating film layer such as a silicon oxide insulating film formed by a method such as plasma-CVD (Chemical Vapor Deposition) or low-pressure CVD in a manufacturing process of a semiconductor device Application of a cerium oxide-based abrasive is being studied. Cerium oxide particles have a lower hardness than silica particles and alumina particles, and are therefore useful for finishing mirror polishing because they do not easily scratch the polished surface.

  Moreover, cerium oxide has a chemically active property as known as a strong oxidizing agent. Taking advantage of this advantage, it is useful to apply it to a chemical mechanical polishing agent for an insulating film capable of high speed polishing. However, currently used cerium oxide-based abrasives can perform high-speed polishing, but have a problem that many polishing scratches are attached to the surface of the insulating film.

  On the other hand, the CMP technique sometimes polishes copper, which is a wiring material used in a damascene process, and metals such as Ta, TaN, W, and Ru, which are used for preventing diffusion of copper. In that case, the composition of the abrasive is appropriately selected depending on the metal to be polished, but the abrasive grains used are mainly silica particles such as colloidal silica and are used for forming the interlayer insulating film and STI. Its composition is significantly different from that of abrasives.

  An example of application of a thermoplastic polymer to a CMP abrasive is disclosed in Patent Document 1, in which a polishing composition containing a polyvinyl alcohol copolymer and a thermoplastic polymer is used as an abrasive for selectively polishing a barrier layer. It is described that lower surface roughness and less scratching properties can be obtained with respect to the surface to be polished of the semiconductor substrate than when a polishing composition containing no plastic polymer is used. The polishing target of such an abrasive is a barrier layer, and there is no description about using it for polishing an insulating film.

  Examples of CMP abrasives using resin as abrasive grains include, as disclosed in Patent Document 2, a methacrylic resin, polystyrene resin, urea having a functional group and a primary particle diameter of 0.05 μm or more and 5 μm or less. A CMP abrasive containing resin particles selected from a resin, a melamine resin, a polyacetal resin and a polycarbonate resin is shown, but the abrasive is for polishing a resin called a resist film and is used for polishing an interlayer insulating film. Application is not shown.

Further, as a method for reducing polishing scratches, Patent Document 3 discloses a defect suppression method by pH adjustment. Patent Document 4 states that defects such as scratches can be reduced by polishing at a high temperature. Further, in Patent Document 5, the density of defects such as scratches is reduced by controlling the slurry flow rate.
JP 2006-186356 A JP 2004-363191 A Japanese Patent Laid-Open No. 10-321588 JP 2004-128319 A JP 2002-367938

  An object of the present invention is to provide a CMP polishing agent for a semiconductor insulating film and a method for polishing a substrate, which can polish a semiconductor insulating film at high speed without scratching and suppress dishing.

  That is, the present invention relates to (1) a CMP abrasive for a semiconductor insulating film comprising cerium oxide particles, a high-density polyethylene resin, a dispersant, and water.

  The present invention also relates to (2) a CMP abrasive for a semiconductor insulating film comprising cerium oxide particles, an ultrahigh molecular weight polyethylene resin, a dispersant and water.

  The present invention is also characterized in that (3) the particle diameter of D50 volume% of the cerium oxide particles is 50 to 300 nm, and the particle diameter of D99 volume% is 200 to 1000 nm, (1) or (2) The present invention relates to the CMP polishing agent for a semiconductor insulating film.

  The present invention also relates to (4) the CMP polishing slurry for semiconductor insulating films according to (1) or (3), wherein the high-density polyethylene resin has a maximum particle size of 1 μm or less.

  The present invention also relates to (5) the CMP polishing slurry for semiconductor insulating films according to (1) or (3), wherein the high-density polyethylene resin has a maximum particle size of 500 nm or less.

  The present invention also relates to (6) the CMP polishing agent for a semiconductor insulating film according to (2) or (3), wherein the ultra high molecular weight polyethylene resin has a maximum particle size of 1 μm or less.

  The present invention also relates to (7) the CMP polishing slurry for a semiconductor insulating film according to (2) or (3), wherein the ultra high molecular weight polyethylene resin has a maximum particle size of 500 nm or less.

  In the present invention, (8) CMP for a semiconductor insulating film according to any one of (1) to (7), wherein the substrate on which a film to be polished is formed is pressed against a polishing cloth on a polishing platen and pressed. The present invention relates to a method for polishing a substrate, wherein the film is polished by relatively moving a substrate and a polishing surface plate while supplying an abrasive between the film and a polishing cloth.

  According to the present invention, it is possible to provide a CMP polishing agent for a semiconductor insulating film and a method for polishing a substrate capable of polishing a semiconductor insulating film at high speed without polishing scratches and suppressing dishing.

  The CMP abrasive | polishing agent for semiconductor insulating films of this invention is an abrasive | polishing agent formed by containing a cerium oxide particle, a high density polyethylene resin, a dispersing agent, and water.

  Moreover, the CMP abrasive | polishing agent for semiconductor insulating films of this invention is an abrasive | polishing agent formed by containing a cerium oxide particle, ultra high molecular weight polyethylene resin, a dispersing agent, and water.

(Cerium oxide particles)
The production method of the cerium oxide particles used in the present invention is not limited, but can be obtained, for example, by firing a cerium compound of carbonate, nitrate, sulfate, or oxalate. The firing temperature is preferably 400 ° C. or higher and 900 ° C. or lower, and more preferably 700 ° C. or higher and 900 ° C. or lower in order to reduce the particle size of cerium oxide.

  Since the cerium oxide particles obtained by oxidation are usually agglomerated, it is preferably mechanically pulverized. Examples of the pulverization method include a dry pulverization method such as a jet mill and a ball mill, and a wet pulverization method such as a bead mill and a ball mill. The jet mill is described, for example, in Chemical Industrial Papers Vol. 6 No. 5 (1980) pp. 527-532. The cerium oxide particles can be classified with a filter or the like as necessary.

  The particle diameter of D50 volume% of the cerium oxide particles dispersed in the CMP polishing agent for semiconductor insulating film is preferably 50 to 300 nm, more preferably 100 to 200 nm. If the particle diameter of D50 volume% of the cerium oxide particles is less than 50 nm, the semiconductor insulating film tends to be difficult to polish at high speed, and if it exceeds 300 nm, polishing scratches are likely to occur on the surface to be polished.

  Moreover, the particle diameter of D99 volume% of the cerium oxide particle disperse | distributed in CMP abrasive | polishing agent for semiconductor insulating films becomes like this. Preferably it is 200-1000 nm, More preferably, it is 250-500 nm. If the particle diameter of D99 volume% of the cerium oxide particles is less than 200 nm, the semiconductor insulating film tends to be difficult to polish at high speed, and if it exceeds 1000 nm, polishing scratches are likely to occur on the surface to be polished.

  In the CMP polishing slurry for semiconductor insulation film of the present invention, since the cerium oxide particles dispersed in the polishing slurry form secondary particles, the particle diameter of D50 volume% and the particle diameter of D99 volume% are It is a particle diameter regarding secondary particles.

  The D50 volume% and D99 volume% of the cerium oxide particles in the CMP polishing agent for semiconductor insulating film are measured using a laser diffraction method, for example, a laser diffraction particle size distribution meter (refractive index: 1.93, absorption 0). be able to. As the laser diffraction particle size distribution analyzer, for example, Malvern Instruments, Mastersizer, Horiba, Ltd., LA series can be used.

  Further, the particle diameter of D50 volume% is the median value of the volume particle diameter distribution, and means the particle diameter when the volume ratio of the particles is accumulated from the fine particle diameter to 50%. That is, when particles having an amount of volume ratio Vi% exist in a range of particle diameters in a certain section Δ, assuming that the average particle diameter in the section Δ is di, particles having a particle diameter di exist in Vi volume%. The particle abundance ratio VI (volume%) is accumulated from the smaller particle diameter di, and di when Vi = 50% is taken as the particle diameter of D50 volume%. Further, di when Vi = 99% is set to a particle size of D99 volume%.

(High density polyethylene resin)
The high-density polyethylene resin used in the present invention is obtained by homopolymerizing or copolymerizing ethylene alone or ethylene and an α-olefin having 3 to 12 carbon atoms in the presence of a so-called Phillips catalyst or Ziegler catalyst. In general, it is produced at a pressure of normal pressure to about 100 kg / cm ² . The α-olefin preferably has 3 to 8 carbon atoms, and examples thereof include propylene, butene-1, hexene-1, 4-methylpentene-1, and octene-1. Since the density decreases as the proportion of copolymerization with α-olefin increases, it is preferably at most about 6.0% by weight. Further, since the density decreases as the number of branches in the copolymer with α-olefin increases, it is preferably about 1 to 5 with respect to the ethylene monomer 1000.

The density of the high-density polyethylene resin used in the present invention is preferably 0.942 (g / cm ³ ) or more, more preferably 0.942 to 0.970 (g / cm ³ ), and It is especially preferable that it is 950-0.970 (g / cm < ³ >). If the density exceeds 0.970 (g / cm ³ ), it becomes brittle, and if it is less than 0.942 (g / cm ³ ), the dishing suppression effect may not be obtained. In the present invention, the ethylene chain may have a branched structure derived from an α-olefin as long as the density of the high-density polyethylene resin does not fall below 0.942 (g / cm ³ ). Here, the density is a value measured by a density gradient tube method (23 ° C.) based on JIS K 7112 (1999) and JIS K6922-1 (1999).
The melt flow index (MFR) of the high-density polyethylene resin used in the present invention is preferably 40 g / 10 minutes or less, and more preferably 10 g / 10 minutes or less. When the melt flow index exceeds 40 g / 10 min, the average molecular weight tends to be low. The melt flow index represents the average molecular weight. If the melt flow index is low, the average molecular weight is generally high. Here, the melt flow index is a value measured according to JIS K 7210 (1999) and JIS K6922-1 (1999).
When the melt flow index cannot be measured due to the large molecular weight, the molecular weight can be calculated by obtaining the intrinsic viscosity in accordance with JIS K7367-3.

  In the present invention, the high-density polyethylene resin can be used alone or in combination of two or more.

  Examples of commercially available high-density polyethylene resins that can be used in the present invention include Novatec (registered trademark) HD manufactured by Nippon Polyethylene Co., Ltd. and Hi-Zex (registered trademark) manufactured by Prime Polymer Co., Ltd.

  The maximum particle size of the high-density polyethylene resin dispersed in the CMP polishing agent for semiconductor insulating film is preferably 1 μm or less, more preferably 500 nm or less. When the maximum particle size of the high-density polyethylene resin exceeds 1 μm, polishing scratches or the like are likely to occur, and it tends to be recognized as a foreign substance in a defect inspection or the like.

  In addition, the maximum particle size of the high-density polyethylene resin dispersed in the CMP abrasive for the semiconductor insulating film is preferably smaller than the particle size of D99 volume% of the cerium oxide particles from the viewpoint of preventing the occurrence of polishing flaws. More preferably, it is 500 nm or less.

The high-density polyethylene resin used in the present invention is preferably a solid and has good wear and sliding properties. A high-density polyethylene resin is a crystalline polymer, but is considered to be relatively easily pulverized compared to inorganic substances such as cerium oxide. When pulverizing the cerium oxide particles, if the high-density polyethylene resin is pulverized together in the same system, a high-density polyethylene resin having a particle size equal to or smaller than the particle size of the cerium oxide particles can be easily obtained. The pulverization method is not particularly limited, but a wet pulverization method that easily generates finer particles is preferable. As a method for adjusting the maximum particle size of the high-density polyethylene resin to a desired value, for example, a method of classification using a filter can be mentioned.
When high-density polyethylene resin is pulverized together in the same system as cerium oxide particles, the maximum particle diameter of high-density polyethylene resin can be confirmed by using a cerium oxide-dispersed aqueous solution containing high-density polyethylene resin pulverized by wet pulverization. A flocculant such as ammonium polyacrylate is mixed and allowed to stand for 30 to 90 days, after which the supernatant is removed and the sedimented layer is allowed to stand. The black-colored material that appears on the surface of the sedimentation layer is a precipitate of high-density polyethylene resin and aggregates of high-density polyethylene resin and ammonium polyacrylate. Therefore, the black-colored material is collected and suction filtered using a membrane filter. The maximum particle size of the high density polyethylene resin can be confirmed by confirming the residue on the filter. For example, when the collected black substance is suction filtered with a 0.5 μm membrane filter and the filter is observed with an optical microscope, if there is no precipitate, the maximum particle size of the black substance may be 0.5 μm or less. I can confirm.

  The concentration of the high-density polyethylene resin in the present invention is preferably 0.001 ppm to 100 ppm, more preferably 0.01 ppm to 10 ppm with respect to the weight of the cerium oxide particles in the CMP abrasive for semiconductor insulating films. If the concentration of the high-density polyethylene resin exceeds 100 ppm, the high-density polyethylene resin itself may agglomerate and cause factors such as polishing scratches. It becomes difficult to obtain the effect of polishing scratches. In the present invention, since a high-density polyethylene resin is present in a small amount in the CMP polishing agent for a semiconductor insulating film, it acts on an additive such as a dispersant and a polishing pad to cause polishing scratches on the insulating film of the cerium oxide particles. It is thought that it has the effect | action which buffers production | generation.

  The ultra high molecular weight polyethylene resin used in the present invention is polyethylene having an average molecular weight of 1,000,000 or more, preferably 1,000,000 to 7,000,000, as determined by the viscosity method. Those having an average molecular weight of less than 1 million are generally not called ultrahigh molecular weight polyethylene resins. The ultrahigh molecular weight polyethylene resin can be increased in molecular weight by using a low-pressure suspension polymerization method and extending the reaction time. Here, the average molecular weight is a value determined according to ASTM D2857 or JIS K7367-3.

  In the present invention, the ultrahigh molecular weight polyethylene resin can be used alone or in combination of two or more.

  Examples of commercially available ultra-high molecular weight polyethylene resins that can be used in the present invention include Saxin Newlite (registered trademark) manufactured by Sakushin Kogyo Co., Ltd., Hi-X Million (registered trademark) manufactured by Mitsui Chemicals, Inc., Asahi Kasei Chemicals Corporation Examples thereof include Sun Fine (registered trademark) UH manufactured by Sumitomo Bakelite Co., Ltd., Sun Moller (registered trademark), and Sun Flick (registered trademark).

  Further, the maximum particle size of the ultrahigh molecular weight polyethylene resin dispersed in the CMP polishing agent for semiconductor insulating film is preferably 1 μm or less, more preferably 500 nm or less. When the maximum particle size of the ultrahigh molecular weight polyethylene resin exceeds 1 μm, polishing scratches or the like are likely to occur, and it tends to be recognized as a foreign substance in a defect inspection or the like.

  In addition, the maximum particle size of the ultrahigh molecular weight polyethylene resin dispersed in the CMP polishing agent for semiconductor insulating film is smaller than the particle size of D99 volume% of the cerium oxide particles from the viewpoint of preventing the occurrence of polishing flaws. Preferably, it is 500 nm or less.

The ultra high molecular weight polyethylene resin used in the present invention is preferably a solid, and has good wear and slidability. The ultrahigh molecular weight polyethylene resin is a crystalline polymer, but is considered to be relatively easily pulverized compared to inorganic cerium oxide. When pulverizing cerium oxide particles, if ultra high molecular weight polyethylene resin is pulverized together in the same system, it is possible to easily obtain ultra high molecular weight polyethylene resin having a particle size equal to or smaller than that of cerium oxide particles. Become. The pulverization method is not particularly limited, but a wet pulverization method that easily generates finer particles is preferable. Examples of a method for adjusting the maximum particle size of the ultrahigh molecular weight polyethylene resin to a desired value include a method of classifying using a filter.
When ultra high molecular weight polyethylene resin is pulverized together in the same system as cerium oxide particles, the maximum particle size of ultra high molecular weight polyethylene resin is confirmed by cerium oxide containing ultra high molecular weight polyethylene resin pulverized by wet pulverization. A flocculant such as ammonium polyacrylate is mixed with the aqueous dispersion, and after standing for 30 to 90 days, the supernatant is removed and the sedimented layer is allowed to stand. The black material that appears on the surface of the sedimentation layer is a precipitate of ultra high molecular weight polyethylene resin and an aggregate of ultra high molecular weight polyethylene resin and ammonium polyacrylate, so collect the black material and use a membrane filter. By performing suction filtration and confirming the residue on the filter, the maximum particle size of the ultra-high molecular weight polyethylene resin can be confirmed. For example, when the collected black substance is suction filtered with a 0.5 μm membrane filter and the filter is observed with an optical microscope, if there is no precipitate, the maximum particle size of the black substance may be 0.5 μm or less. I can confirm.

  The concentration of the ultrahigh molecular weight polyethylene resin in the present invention is preferably 0.001 ppm to 100 ppm, more preferably 0.01 ppm to 10 ppm, based on the weight of the cerium oxide particles in the CMP abrasive for semiconductor insulating films. When the concentration of the ultra high molecular weight polyethylene resin exceeds 100 ppm, the ultra high molecular weight polyethylene resin itself may aggregate and cause a factor such as polishing scratches, and if it is less than 0.001 ppm, flatness when used for polishing. And the effect of low polishing scratches is difficult to obtain. In the present invention, since the ultra high molecular weight polyethylene resin is present in a small amount in the CMP polishing slurry for semiconductor insulating film, it acts on additives such as a dispersant and polishing pad to cause polishing scratches on the insulating film of cerium oxide particles. It is considered that there is an action to buffer the production of.

  Ultra-high molecular weight polyethylene resin and high-density polyethylene resin are high-strength and highly-slidable plastics, and are used for pulverizing equipment such as high-pressure homogenizers and parts of sliding parts such as agitation equipment for dispersing slurry. Even if the ultrahigh molecular weight polyethylene resin or high density polyethylene resin used in these is mixed unintentionally, the same effect as the present invention can be obtained.

  In the present invention, the high-density polyethylene resin and the ultra-high molecular weight polyethylene resin may be used in combination, and in that case, the concentration of the high-density polyethylene resin and the ultra-high-molecular weight polyethylene resin in the CMP polishing slurry for semiconductor insulating film Preferably it is 0.001 ppm to 100 ppm, more preferably 0.01 ppm to 10 ppm, based on the weight of the cerium oxide particles. If the concentration of the high-density polyethylene resin and the ultra-high-molecular-weight polyethylene resin exceeds 100 ppm, the high-density polyethylene resin and the ultra-high-molecular-weight polyethylene resin may agglomerate and cause factors such as polishing scratches, and less than 0.001 ppm. When it exists, it becomes difficult to obtain the effect of flatness and low polishing scratches when used for polishing.

(Dispersant)
As the dispersant used in the present invention, the content of alkali metals such as sodium ions and potassium ions, and halogens and sulfur is preferably 10 ppm or less, for example, water-soluble organic polymers such as acrylic acid polymers and polyvinyl alcohol. Water-soluble anionic surfactants such as ammonium lauryl sulfate, polyoxyethylene lauryl ether ammonium sulfate, polyoxyethylene lauryl ether ammonium sulfate, and water-soluble nonionic surfactants such as polyoxyethylene lauryl ether and polyethylene glycol monostearate And water-soluble amines such as monoethanolamine and diethanolamine. Examples of acrylic polymers include acrylic acid polymers and ammonium salts thereof, methacrylic acid polymers and ammonium salts thereof, and copolymers of ammonium acrylate salts with alkyl acrylates (methyl, ethyl or propyl). Can be mentioned. Of these, polyacrylic acid ammonium salt or a copolymer of ammonium acrylate salt and methyl acrylate is preferred. When the latter is used, the molar ratio of ammonium acrylate salt to methyl acrylate is preferably 10/90 to 90/10 for ammonium acrylate salt / methyl acrylate. When the ammonium acrylate salt is less than 10 or more than 90 in the molar ratio of the ammonium acrylate salt to methyl acrylate, the dispersibility tends not to be maintained.

  Moreover, it is preferable that the weight average molecular weights of an acrylic acid polymer are 1000-20000. If the weight average molecular weight of the acrylic polymer exceeds 20000, the particle size distribution tends to change over time due to reaggregation of the cerium oxide particles, and if it is less than 1000, the dispersibility of the cerium oxide particles and the effect of preventing sedimentation are not sufficient. There is a case.

  Further, the blending amount of the dispersant is preferably in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the cerium oxide particles from the viewpoint of dispersibility of the cerium oxide particles in the abrasive and anti-settling property. . When the blending amount of the dispersant is less than 0.01 parts by weight, the cerium oxide particles tend to settle, and when it exceeds 5 parts by weight, the particle size distribution tends to change with time due to reaggregation of the cerium oxide particles.

  In order to enhance the dispersion effect of the dispersant on the cerium oxide particles, it is preferable to place the dispersant in the disperser at the same time as the cerium oxide particles.

  The CMP polishing slurry for a semiconductor insulating film of the present invention is a slurry in which cerium oxide particles, high-density polyethylene resin and / or ultrahigh molecular weight polyethylene resin, and a dispersant are dispersed in water. In addition to the dispersion treatment using a stirrer, a homogenizer, an ultrasonic disperser, a ball mill, or the like can be used. In order to disperse the sub-μm order cerium oxide particles, it is preferable to use a wet disperser such as a ball mill, a vibration ball mill, a planetary ball mill, a medium stirring mill or the like. Further, the cerium oxide particles may be classified prior to the dispersing operation as necessary, and examples of the classification method include a normal natural sedimentation method, a hydrocyclone method, and a centrifugal sedimentation method.

  Although there is no restriction | limiting in the density | concentration of the cerium oxide particle in CMP abrasive | polishing agent for semiconductor insulating films, The range of 0.5 to 10 weight% is preferable from the ease of handling of abrasive | polishing agent.

  The pH of the CMP abrasive for semiconductor insulating film of the present invention is preferably 4.5-10. If the pH is less than 4.5, particles tend to aggregate, and if it exceeds 10, the polishing rate stability tends to deteriorate. Examples of a method for adjusting the pH of the CMP polishing agent for semiconductor insulating film include a method of adding an alkaline substance not containing metal ions such as aqueous ammonia during or after the dispersion treatment.

  In addition, the CMP polishing slurry for semiconductor insulating film of the present invention includes water-soluble amines such as N, N-diethylethanolamine, N, N-dimethylethanolamine, and aminoethylethanolamine; ammonium lauryl sulfate, ammonium polyoxyethylene lauryl ether sulfate, and the like. An anionic surfactant; additives such as water-soluble organic polymers such as polyvinyl alcohol and polyvinylpyrrolidone can be appropriately added depending on the form of use.

In the substrate polishing method of the present invention, the substrate on which the film to be polished is formed is pressed against the polishing cloth of the polishing surface plate, and the CMP abrasive for semiconductor insulating film of the present invention is supplied between the film and the polishing cloth. However, the film is polished by relatively moving the substrate and the polishing surface plate. The film to be polished is a semiconductor insulating film, and is preferably an inorganic insulating film such as a silicon oxide insulating film or a silicon nitride insulating film. For example, SiH ₄ or tetraethoxysilane is used as a Si source, and oxygen or ozone is used. Examples thereof include a SiO ₂ film formed by a CVD method using an oxygen source. As the substrate, a substrate in which a SiO ₂ insulating film layer is formed on a semiconductor substrate such as a semiconductor substrate in which a circuit element and an aluminum wiring are formed, a semiconductor substrate in a stage in which a circuit element is formed, and the like can be used. A substrate containing a SiO ₂ insulating film formed for the purpose of semiconductor isolation (shallow trench isolation) can also be used.

By polishing the SiO ₂ insulating film layer formed on such a substrate with the CMP polishing agent for semiconductor insulating film of the present invention, unevenness on the surface of the SiO ₂ insulating film layer is eliminated, and the entire surface of the semiconductor substrate is removed. Make the surface smooth. Here, as an apparatus for polishing, a general polishing having a surface plate with a holder for holding a substrate having a film to be polished and a polishing cloth (pad) attached (a motor etc. capable of changing the number of rotations is attached). The device can be used.

  Although there is no restriction | limiting in particular as abrasive cloth, It is preferable to use a general nonwoven fabric, a polyurethane foam, a porous fluororesin, etc. Further, it is preferable that the polishing cloth is subjected to groove processing so that an abrasive is collected.

The polishing conditions are not limited, but the rotation speed of the surface plate is preferably low rotation of 100 min ⁻¹ or less so that the substrate does not jump out, and the pressure applied to the substrate is 1 kg / cm so that polishing scratches do not occur after polishing. ² or less is preferable.

In order to move the polishing cloth and the film to be polished relatively with the polishing film on the substrate pressed against the polishing cloth, specifically, at least one of the substrate and the polishing surface plate may be moved. In addition to rotating the polishing surface plate, polishing may be performed by rotating or swinging the holder. Further, a polishing method in which a polishing surface plate is rotated on a planetary surface, a polishing method in which a belt-like polishing cloth is moved linearly in one direction in the longitudinal direction, and the like can be mentioned. The holder may be in any state of being fixed, rotating and swinging. These polishing methods can be appropriately selected depending on the surface to be polished and the polishing apparatus as long as the polishing cloth and the film to be polished are moved relatively. During polishing, the slurry-like CMP abrasive for semiconductor insulating film of the present invention is continuously supplied to the polishing cloth by a pump or the like. Although there is no restriction | limiting in this supply amount, it is preferable that the surface of polishing cloth is always covered with the abrasive | polishing agent. Specifically, it is preferable to supply 0.02 to 0.25 ml per 1 cm ^{2 of} the polishing pad area.

The semiconductor substrate after polishing is preferably washed in running water and then dried after removing water droplets adhering to the semiconductor substrate using a spin dryer or the like. A second-layer metal wiring is formed on the thus planarized SiO ₂ insulating film layer, and after the SiO ₂ insulating film is formed again between the wirings and on the wiring by the above method, the semiconductor insulating film is formed. By polishing using a CMP polishing agent for a film, unevenness on the surface of the insulating film is eliminated, and a smooth surface is obtained over the entire surface of the semiconductor substrate. By repeating this process a predetermined number of times, a desired number of semiconductor layers are manufactured.

The CMP abrasive for a semiconductor insulating film according to the present invention is not limited to an SiO ₂ insulating film formed on a semiconductor substrate, but also an inorganic insulating material such as SiO ₂ insulating film formed on a wiring board having predetermined wiring, glass, silicon nitride, etc. Optical glass such as films, photomasks, lenses, and prisms, inorganic conductive films such as ITO (Indium Tin Oxide), glass and crystalline materials, optical integrated circuits, optical switching elements, optical waveguides, optical fiber end faces, scintillators It is used for polishing optical single crystals such as, solid laser single crystals, LED sapphire substrates for blue lasers, semiconductor single crystals such as SiC, GaP, and GaAs, glass substrates for magnetic disks, magnetic heads and the like.

The predetermined substrate in the present invention, a semiconductor substrate which SiO ₂ insulating film is formed, SiO ₂ insulating film is formed wiring board, glass, inorganic insulating films such as silicon nitride, optical such as a photo mask lenses and prisms Optical integrated circuits, optical switching elements and optical waveguides composed of inorganic conductive films such as glass and ITO, glass and crystalline materials, optical fiber end faces, optical single crystals such as scintillators, solid state laser single crystals, blue laser LEDs Including sapphire substrates, semiconductor single crystals such as SiC, GaP, and GaAs, glass substrates for magnetic disks, magnetic heads, and the like.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1
(1-1) Preparation of cerium oxide particles 4 kg of cerium carbonate hydrate was placed in a platinum container and calcined in the air at 800 ° C. for 2 hours to obtain 2 kg of yellowish white powder. When this powder was phase-identified by X-ray diffraction, it was confirmed to be cerium oxide.

  The fired powder particle size was 30 to 100 μm.

High density polyethylene resin (trade name: Novatec HD, product number: HJ560, JISK6922-1, 2 measured according to JISK6922-1, 2 was added to 2 kg of the cerium oxide powder obtained as described above, and density: 0.964 (g / cm ³ )) After 0.02 g was mixed, wet grinding was performed using a high-pressure homogenizer under conditions of a grinding pressure of 100 MPa and a circulation time of 520 minutes required for grinding. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution analyzer (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 155 nm, and the particle size of D99 volume% was 450 nm.

(1-2) Preparation of CMP Polishing Agent for Semiconductor Insulating Film 1 kg of mixture of cerium oxide particles and high-density polyethylene resin obtained in (1-1) above, aqueous solution of ammonium polyacrylate having a weight average molecular weight of 5000 (40 wt. %) 23 g and deionized water 8977 g were mixed and subjected to ultrasonic dispersion for 10 minutes while stirring. The obtained slurry was filtered with a 3 micron filter, then with a 0.5 micron filter, and diluted with deionized water so that the solid content concentration was 1% by weight to obtain a CMP abrasive for a semiconductor insulating film. . The pH of the CMP polishing agent for semiconductor insulating film was 8.3. When measuring the CMP abrasive for semiconductor insulating film using a laser diffraction particle size distribution analyzer (LA-920, manufactured by HORIBA), the particle diameter of D50 volume% of cerium oxide particles (secondary particles) is 155 nm, D99 volume. % Particle size was 350 nm.

(1-3) Polishing of insulating film (1-3-1)
The Si wafer on which the SiO ₂ insulating film was formed was adsorbed and fixed to the adsorption pad for substrate attachment affixed to the holder by the TEOS-plasma CVD method. Place this holder on the surface plate with a diameter of 600 mm with a porous urethane resin polishing pad affixed with the insulating film face down while holding the Si wafer. Was set to 30 kPa. While the CMP polishing slurry for semiconductor insulating film (solid content: 1% by weight) prepared in (1-2) above was dropped on the surface plate at a rate of 100 ml / min, the surface plate and the wafer were respectively 75 min ⁻¹ and 76 min. ^The SiO ₂ insulating film was polished by rotating for 1 minute under the condition of ^-1 .

The polished wafer was thoroughly washed with pure water and then dried. The polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing using an interference-type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and found to be 610 nm / min.

Further, when the polished SiO ₂ insulating film surface was observed using an optical microscope, no clear scratch was found.

(1-3-2)
100 g of CMP slurry (manufactured by Hitachi Chemical Co., Ltd., trade name: HS-7303GP) as an additive and 700 g of ultrapure water are mixed with the CMP abrasive for semiconductor insulating film produced in (1-2) above, and the solid content concentration is mixed. 1% by weight of a CMP abrasive for a semiconductor insulating film was obtained. Using this, a product name pattern wafer S754 manufactured by SEMATECH was polished for 70 seconds by the same method as in (1-3-1) above.

  At this time, the remaining film thickness of the active region of 100 μm / 100 μm and the trench portion was measured using an interference film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 17 nm. Moreover, when the remaining film thickness of the 500 μm / 500 μm active region and the trench portion was measured in the same manner and the dishing amount was evaluated, it was 20 nm, and a good result was obtained.

Example 2
(2-1) Preparation of cerium oxide particles The same procedure as in (1-1) of Example 1 was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 μm.

Ultrahigh molecular weight polyethylene resin (made by Sakushin Kogyo Co., Ltd., trade name: Saxin New Light, product number: NL-AS, ASTM D1505) density measured to 2 kg of the cerium oxide powder obtained as described above: 950 (kg / cm ³ ), molecular weight measured according to viscosity method ASTM D2857: 5.5 million) After mixing 0.02 g, wet grinding is performed using a high-pressure homogenizer at a grinding pressure of 100 MPa and a circulation time of 520 minutes required for grinding. went. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution analyzer (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 160 nm, and the particle size of D99 volume% was 450 nm.

(2-2) Preparation of CMP Abrasive for Semiconductor Insulating Film Instead of the mixture of cerium oxide particles and high density polyethylene resin, the mixture of cerium oxide particles and ultrahigh molecular weight polyethylene resin obtained in (2-1) above is used. Except for this, the same operation as in (1-2) of Example 1 was carried out to obtain a CMP abrasive for semiconductor insulating film having a pH of 8.3 and a solid content concentration of 1% by weight. When the particle diameter of the cerium oxide particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 155 nm, and the particle diameter of D99 volume% was 350 nm.

(2-3) Polishing of insulating film (2-3-1)
The SiO ₂ insulating film is operated in the same manner as (1-3-1) in Example 1 except that the CMP polishing agent for semiconductor insulating film prepared in (2-2) above is used as the CMP polishing agent for semiconductor insulating film. The polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing, and it was 620 nm / min.

Further, when the polished SiO ₂ insulating film surface was observed using an optical microscope, no clear scratch was found.

(2-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film prepared in (2-2) above was used as the CMP abrasive for semiconductor insulating film. The remaining film thickness of the active region of 100 μm / 100 μm and the trench portion was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 14 nm. Further, the remaining film thicknesses of the active region and the trench portion of 500 μm / 500 μm were measured in the same manner, and the dishing amount was evaluated. As a result, the result was 18 nm.

Example 3
(3-1) Preparation of cerium oxide particles The same procedure as in (1-1) of Example 1 was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 µm.

2 kg of the cerium oxide powder obtained above was added to a high density polyethylene tree (manufactured by Prime Polymer Co., Ltd., trade name: Hi-Zex, product number: 2100JH, density measured according to JISK7112: 952 (kg / cm ³ )) After mixing 01 g, wet grinding was performed using a high-pressure homogenizer under conditions of a grinding pressure of 100 MPa and a circulation time of 500 minutes required for grinding. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 160 nm, and the particle size of D99 volume% was 450 nm.

(3-2) Preparation of polishing agent Example 1 except that the mixture of cerium oxide particles and high density polyethylene resin obtained in (3-1) above was used as a mixture of cerium oxide particles and high density polyethylene resin. The same operation as in (1-2) was performed to obtain a CMP abrasive for a semiconductor insulating film having a pH of 8.4 and a solid concentration of 1% by weight. When the particle diameter of the cerium oxide particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 155 nm, and the particle diameter of D99 volume% was 350 nm.

(3-3) Polishing of insulating film (3-3-1)
The SiO ₂ insulation is operated in the same manner as (1-3-1) in Example 1 except that the CMP abrasive for semiconductor insulating film prepared in (3-2) above is used as the CMP abrasive for semiconductor insulating film. The film was polished, the difference in thickness of the SiO ₂ insulating film before and after polishing was measured to calculate the polishing rate, and it was 640 nm / min.

Further, observation of the SiO ₂ insulating film surface after polishing using an optical microscope, clear scratches were observed.

(3-3-2)
CMP slurry for semiconductor insulating film produced in (3-2) above was mixed with 150 g of CMP slurry (manufactured by Hitachi Chemical Co., Ltd., trade name: HS-7303GP) and 650 g of ultrapure water as additives, and the solid content concentration was mixed. 1% by weight of a CMP abrasive for a semiconductor insulating film was obtained. Using this, a product name: pattern wafer S754 manufactured by SEMATECH was polished for 70 seconds in the same manner as in (1-3-2) of Example 1. The remaining film thickness of the active region of 100 μm / 100 μm and the trench portion was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 11 nm. Further, the remaining film thicknesses of the active region and the trench portion of 500 μm / 500 μm were measured in the same manner, and the dishing amount was evaluated. As a result, the result was 19 nm.

Example 4
(4-1) Preparation of cerium oxide particles The same procedure as in Example 1-1 (1-1) was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 µm.

High-density polyethylene resin obtained cerium oxide powder 2kg by the (Prime Polymer Co., Ltd., Ltd., trade name: Hizex, No.: 2200J, density was measured according to ^{JIK7112: 964 (kg / cm 3} )) 0.02g After mixing, wet pulverization was performed using a high-pressure homogenizer under conditions of a pulverization pressure of 100 MPa and a circulation time of 520 minutes required for the pulverization. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 160 nm, and the particle size of D99 volume% was 450 nm.

(4-2) Preparation of polishing agent (Example 1) except that the mixture of cerium oxide particles and high-density polyethylene resin obtained in (4-1) above was used as a mixture of cerium oxide particles and high-density polyethylene resin. The same operation as in 1-2) was performed to obtain a CMP abrasive for a semiconductor insulating film having a pH of 8.4 and a solid concentration of 1% by weight. When the particle diameter of the cerium oxide polycrystalline primary particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 155 nm, and the particle diameter of D99 volume% was 350 nm. there were.

(4-3) Polishing of insulating film (4-3-1)
Example (1-3) of Example 1 except that the CMP polishing agent for semiconductor insulating film prepared in (4-2) above is used as the CMP polishing agent for semiconductor insulating film, and the dropping rate of the polishing agent is 200 ml / min. The SiO ₂ insulating film was polished in the same manner as in -1), the difference in thickness of the SiO ₂ insulating film before and after polishing was measured, and the polishing rate was calculated to be 600 nm / min.

Further, observation of the SiO ₂ insulating film surface after polishing using an optical microscope, clear scratches were observed.

(4-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film produced in (4-2) above was used as the CMP abrasive for semiconductor insulating film. The remaining film thickness of the active region and the trench portion of 100 μm / 100 μm was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 13 nm. Further, the remaining film thicknesses of the active region and the trench portion of 500 μm / 500 μm were measured in the same manner, and the dishing amount was evaluated. As a result, the result was 18 nm.

Example 5
(5-1) Preparation of cerium oxide particles The same procedure as in (1-1) of Example 1 was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 µm.

Ultrahigh molecular weight polyethylene resin (trade name: Sunfine, product number: UH-950, manufactured by Asahi Kasei Chemicals Co., Ltd., density: 940 (kg / cm ³ ) measured based on cerium oxide powder 2 kg obtained as described above. , Molecular weight measured according to viscosity method: 4.5 million)) After mixing 0.01 g, wet grinding was performed using a high-pressure homogenizer at a grinding pressure of 100 MPa and a circulation time of 520 minutes required for grinding. . The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 150 nm, and the particle diameter of D99 volume% was 450 nm.

(5-2) Preparation of abrasives Examples except that the mixture of cerium oxide particles and ultrahigh molecular weight polyethylene resin obtained in (5-1) above was used instead of the mixture of cerium oxide particles and high-density polyethylene resin. The same operation as (1-2) in No. 1 was performed to obtain a CMP abrasive for a semiconductor insulating film having a pH of 8.4 and a solid concentration of 1% by weight. When the particle diameter of the cerium oxide polycrystalline primary particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 155 nm, and the particle diameter of D99 volume% was 350 nm. there were.

(5-3) Polishing of insulating film (5-3-1)
The SiO ₂ insulating film is operated in the same manner as in (1-3-1) of Example 1 except that the CMP polishing agent for semiconductor insulating film produced in (5-2) above is used as the CMP polishing agent for semiconductor insulating film. The polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing and found to be 590 nm / min.

Further, observation of the SiO ₂ insulating film surface after polishing using an optical microscope, clear scratches were observed.

(5-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film produced in (5-2) above was used as the CMP abrasive for semiconductor insulating film. The remaining film thickness of the active region and the trench portion of 100 μm / 100 μm was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 13 nm. Further, the remaining film thicknesses of the active region and the trench portion of 500 μm / 500 μm were measured in the same manner, and the dishing amount was evaluated.

Comparative Example 1
(6-1) Preparation of cerium oxide particles The same procedure as in Example 1-1 (1-1) was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 µm. The density of the low-density polyethylene resin (trade name: Novatec LD, model number LJ803, JISK6922-1, 2 measured according to JISK6922-1 and 2) was added to 2 kg of the cerium oxide powder obtained above. After mixing 0.02 g of ³ )), wet pulverization was performed using a high-pressure homogenizer at a pulverization pressure of 100 MPa and a circulation time of 520 minutes required for the pulverization.

  The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 160 nm, and the particle size of D99 volume% was 450 nm.

(6-2) Preparation of CMP Abrasive for Semiconductor Insulating Film 1 kg of mixture of cerium oxide particles and low-density polyethylene resin obtained in (6-1) above, aqueous solution of ammonium polyacrylate having a weight average molecular weight of 5000 (40 wt. %) 23 g and deionized water 8977 g were mixed and subjected to ultrasonic dispersion for 10 minutes while stirring. The obtained slurry was filtered with a 3 micron filter, then with a 0.5 micron filter, and diluted with deionized water so that the solid content concentration was 1% by weight to obtain a CMP abrasive for a semiconductor insulating film. . The pH of the CMP polishing agent for semiconductor insulating film was 8.3. When the particle size of the CMP abrasive for semiconductor insulating film was measured in the same manner as in Example 1-2 (1-2), the particle size of D50 volume% of cerium oxide particles (secondary particles) was 155 nm and D 99 volume%. The particle size was 350 nm.

(6-3) Polishing of insulating film (6-3-1)
The SiO ₂ insulating film was operated in the same manner as (1-3-1) in Example 1 except that the CMP polishing agent for semiconductor insulating film prepared in (6-2) above was used as the CMP polishing agent for semiconductor insulating film. The polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing and found to be 600 nm / min.

Further, when the polished SiO ₂ insulating film surface was observed using an optical microscope, 66 polishing scratches having a size of 0.2 μm or more were observed on the film surface.

(6-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film produced in (6-2) above was used as the CMP abrasive for semiconductor insulating film. The remaining film thickness of the active region of 100 μm / 100 μm and the trench portion was measured using an interference-type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 37 nm. Further, the residual film thickness of the 500 μm / 500 μm active region and the trench portion was measured in the same manner, and the dishing amount was evaluated to be 59 nm.

Comparative Example 2
(7-1) Preparation of cerium oxide particles The same procedure as in Example 1-1 (1-1) was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 μm. After mixing 0.02 g of acrylic resin (trade name: Acrylite L, specific gravity measured according to JISK7112: 1.19) with 2 kg of the cerium oxide powder obtained as described above, a high-pressure homogenizer was used. The wet pulverization was performed using the pulverization pressure of 100 MPa and the circulation time of 520 minutes required for the pulverization. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 150 nm, and the particle diameter of D99 volume% was 450 nm.

(7-2) Preparation of CMP abrasive for semiconductor insulating film Except for using the mixture of cerium oxide particles and acrylic resin obtained in (7-1) above instead of the mixture of cerium oxide particles and high-density polyethylene resin. The same operation as in (1-2) of Example 1 was performed to obtain a CMP abrasive for a semiconductor insulating film having a pH of 8.3 and a solid concentration of 1% by weight. When the particle diameter of the cerium oxide particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 150 nm, and the particle diameter of D99 volume% was 350 nm.

(7-3) Polishing of insulating film (7-3-1)
Except for using the CMP polishing agent for semiconductor insulating film produced in the above (7-2) as the CMP polishing agent for semiconductor insulating film and setting the dropping rate of the polishing agent to 200 ml / min, (1- The SiO ₂ insulating film was polished in the same manner as in 3-1), and the polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing, and was 600 nm / min.

Further, when the polished SiO ₂ insulating film surface was observed using an optical microscope, 104 polishing scratches having a size of 0.2 μm or more per 8 inch wafer were observed.

(7-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film prepared in (7-2) above was used as the CMP abrasive for semiconductor insulating film. The remaining film thickness of the active region of 100 μm / 100 μm and the trench portion was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 31 nm. Further, the remaining film thickness of the 500 μm / 500 μm active region and the trench portion was measured in the same manner, and the dishing amount was evaluated to be 53 nm.

Comparative Example 3
(8-1) Preparation of cerium oxide particles The same procedure as in (1-1) of Example 1 was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 µm. After mixing 0.02 g of ethylene-vinyl copolymer resin (trade name: Novatec EVA, product number: LV151) manufactured by Nippon Polyethylene Co., Ltd. with 2 kg of the cerium oxide powder obtained as described above, using a high-pressure homogenizer, the pulverization pressure is 100 MPa, Wet pulverization was performed under conditions of a circulation time of 520 minutes required for pulverization. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 160 nm, and the particle size of D99 volume% was 450 nm.

(8-2) Preparation of CMP abrasive for semiconductor insulating film Instead of a mixture of cerium oxide particles and high-density polyethylene resin, use a mixture of cerium oxide particles and ethylene-vinyl copolymer resin obtained in (8-1) above. Except for the above, the same operation as in Example 1-2 (1-2) was carried out to obtain a CMP abrasive for a semiconductor insulating film having a pH of 8.3 and a solid concentration of 1% by weight. When the particle diameter of the cerium oxide particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 150 nm, and the particle diameter of D99 volume% was 350 nm.

(8-3) Polishing of insulating film (8-3-1)
The SiO ₂ insulating film was operated in the same manner as in (1-3-1) of Example 1 except that the CMP abrasive for semiconductor insulating film prepared in (8-2) above was used as the CMP abrasive for semiconductor insulating film. The polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing and found to be 600 nm / min.

Further, when the polished SiO ₂ insulating film surface was observed using an optical microscope, 143 polishing scratches having a size of 0.2 μm or more per 8 inch wafer were observed.

(8-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film prepared in (8-2) above was used as the CMP abrasive for semiconductor insulating film. The remaining film thickness of the active region of 100 μm / 100 μm and the trench portion was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 29 nm. Further, the residual film thickness of the 500 μm / 500 μm active region and the trench portion was measured in the same manner, and the dishing amount was evaluated to be 47 nm.

Comparative Example 4
(9-1) Preparation of cerium oxide particles The same procedure as in (1-1) of Example 1 was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 µm.

  After mixing 0.02 g of a polyester resin (trade name: Mylar, product number: A, specific gravity: 1.4) manufactured by Teijin DuPont Films Ltd. with 2 kg of the cerium oxide powder obtained as described above, the mixture was pulverized using a high-pressure homogenizer. Wet pulverization was performed under the conditions of a pressure of 100 MPa and a circulation time of 520 minutes required for the pulverization. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 150 nm, and the particle diameter of D99 volume% was 450 nm.

(9-2) Preparation of CMP abrasive for semiconductor insulating film Except for using the mixture of cerium oxide particles and polyester resin obtained in (9-1) above instead of the mixture of cerium oxide particles and high-density polyethylene resin. Then, the same operation as in Example 1-2 (1-2) was carried out to obtain a CMP abrasive for a semiconductor insulating film having a pH of 8.3 and a solid concentration of 1% by weight. When the particle diameter of the cerium oxide particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 150 nm, and the particle diameter of D99 volume% was 350 nm.

(9-3) Polishing of insulating film (9-3-1)
The SiO ₂ insulating film is operated in the same manner as in (1-3-1) of Example 1 except that the CMP abrasive for semiconductor insulating film prepared in (9-2) above is used as the CMP abrasive for semiconductor insulating film. The polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing, and found to be 570 nm / min.

Further, when the polished SiO ₂ insulating film surface was observed using an optical microscope, 191 polishing scratches having a size of 0.2 μm or more per 8 inch wafer were observed.

(9-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film prepared in (9-2) above was used as the CMP abrasive for semiconductor insulating film. The residual film thickness of the active region of 100 μm / 100 μm and the trench portion was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 27 nm. Further, the remaining film thickness of the 500 μm / 500 μm active region and the trench portion was measured in the same manner, and the dishing amount was evaluated to be 44 nm.

Comparative Example 5
(10-1) Preparation of cerium oxide particles The same procedure as in (1-1) of Example 1 was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 µm.

  After mixing 0.02 g of polycarbonate resin (trade name: Carbograss, specific gravity: 1.2) manufactured by Asahi Glass Co., Ltd. with 2 kg of the cerium oxide powder obtained as described above, using a high-pressure homogenizer, the pulverization pressure is 100 MPa and pulverization. Wet pulverization was performed under the conditions of a circulation time of 520 minutes required for the above. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 150 nm, and the particle diameter of D99 volume% was 450 nm.

(10-2) Preparation of CMP abrasive for semiconductor insulating film Except for using a mixture of cerium oxide particles and polycarbonate resin obtained in (10-1) above instead of a mixture of cerium oxide particles and high-density polyethylene resin. Then, the same operation as in Example 1-2 (1-2) was carried out to obtain a CMP abrasive for a semiconductor insulating film having a pH of 8.3 and a solid concentration of 1% by weight. When the particle diameter of the cerium oxide particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 150 nm, and the particle diameter of D99 volume% was 350 nm.

(10-3) Polishing of insulating film (10-3-1)
The SiO ₂ insulating film is operated in the same manner as in (1-3-1) of Example 1 except that the CMP abrasive for semiconductor insulating film prepared in (10-2) above is used as the CMP abrasive for semiconductor insulating film. The polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing, and found to be 580 nm / min.

Further, when the surface of the SiO ₂ insulating film after polishing was observed using an optical microscope, 113 polishing scratches having a size of 0.2 μm or more per 8 inch wafer were observed.

(10-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film produced in (10-2) above was used as the CMP abrasive for semiconductor insulating film. The remaining film thickness in the active region of 100 μm / 100 μm and the trench portion was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 33 nm. Further, the remaining film thickness of the 500 μm / 500 μm active region and the trench portion was measured in the same manner, and the dishing amount was evaluated to be 49 nm.

Comparative Example 6
(11-1) Preparation of cerium oxide particles The same procedure as in Example 1-1 (1-1) was performed to obtain cerium oxide having a calcined powder particle size of 30 to 100 µm.

  After mixing 0.02 g of low molecular weight polyethylene resin (trade name: High Wax 720P, molecular weight: about 7200) made by 2 kg of the cerium oxide powder obtained as described above, the pulverization pressure was adjusted using a high pressure homogenizer. Wet pulverization was performed under conditions of 100 MPa and a circulation time of 520 minutes required for pulverization. The particle diameter of the obtained cerium oxide particles was measured using a laser diffraction particle size distribution meter (manufactured by Malvern Instruments, Mastersizer) under the conditions of a refractive index of 1.93 and zero absorption. The diameter was 150 nm, and the particle diameter of D99 volume% was 450 nm.

(11-2) Preparation of CMP abrasive for semiconductor insulating film Instead of the mixture of cerium oxide particles and high density polyethylene resin, the mixture of cerium oxide particles and low molecular weight polyethylene resin obtained in (11-1) above is used. Except for the above, the same operation as in (1-2) of Example 1 was performed to obtain a CMP abrasive for a semiconductor insulating film having a pH of 8.3 and a solid content concentration of 1% by weight. When the particle diameter of the cerium oxide particles (secondary particles) was measured in the same manner as in (1-2) above, the particle diameter of D50 volume% was 150 nm, and the particle diameter of D99 volume% was 350 nm.

(11-3) Polishing of insulating film (11-3-1)
The SiO ₂ insulating film is operated in the same manner as in (1-3-1) of Example 1 except that the CMP abrasive for semiconductor insulating film prepared in (11-2) above is used as the CMP abrasive for semiconductor insulating film. The polishing rate was calculated by measuring the difference in thickness of the SiO ₂ insulating film before and after polishing and found to be 550 nm / min.

Further, when the polished SiO ₂ insulating film surface was observed using an optical microscope, 233 polishing scratches having a size of 0.2 μm or more per 8 inch wafer were observed.

(11-3-2)
The same operation as in (1-3-2) of Example 1 was performed except that the CMP abrasive for semiconductor insulating film produced in (11-2) above was used as the CMP abrasive for semiconductor insulating film. The remaining film thickness in the active region of 100 μm / 100 μm and the trench portion was measured using an interference type film thickness device Nanospec / AFT5100 manufactured by Nanometrics, and the dishing amount was evaluated to be 46 nm. Further, the remaining film thickness of the 500 μm / 500 μm active region and the trench portion was measured in the same manner, and the dishing amount was evaluated to be 54 nm.

Claims (8)

  A CMP abrasive for a semiconductor insulating film, comprising cerium oxide particles, a high-density polyethylene resin, a dispersant, and water.   A CMP abrasive for a semiconductor insulating film, comprising cerium oxide particles, an ultrahigh molecular weight polyethylene resin, a dispersant and water.   The CMP abrasive | polishing agent for semiconductor insulation films of Claim 1 or 2 whose particle diameter of D50 volume% of the said cerium oxide particle is 50-300 nm, and the particle diameter of D99 volume% is 200-1000 nm.   4. The CMP abrasive for a semiconductor insulating film according to claim 1, wherein the maximum particle size of the high-density polyethylene resin is 1 [mu] m or less.   4. The CMP abrasive for a semiconductor insulating film according to claim 1, wherein the maximum particle size of the high-density polyethylene resin is 500 nm or less.   4. The CMP polishing agent for a semiconductor insulating film according to claim 2, wherein the ultra-high molecular weight polyethylene resin has a maximum particle size of 1 [mu] m or less.   4. The CMP abrasive for a semiconductor insulating film according to claim 2, wherein the ultra high molecular weight polyethylene resin has a maximum particle size of 500 nm or less.   The substrate on which the film to be polished is formed is pressed against the polishing cloth of the polishing surface plate and pressurized, and the CMP abrasive for semiconductor insulating film according to any one of claims 1 to 7 is supplied between the film and the polishing cloth. A method for polishing a substrate, wherein the film is polished by relatively moving the substrate and a polishing surface plate.