Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
  • H01L21/3105—After-treatment
  • H01L21/31051—Planarisation of the insulating layers
  • H01L21/31053—Planarisation of the insulating layers involving a dielectric removal step
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09G—POLISHING COMPOSITIONS; SKI WAXES
  • C09G1/00—Polishing compositions
  • C09G1/02—Polishing compositions containing abrasives or grinding agents
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
  • C09K3/1409—Abrasive particles per se
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/14—Anti-slip materials; Abrasives
  • C09K3/1454—Abrasive powders, suspensions and pastes for polishing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
  • H01L21/304—Mechanical treatment, e.g. grinding, polishing, cutting
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
  • H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
  • H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
  • H01L21/30625—With simultaneous mechanical treatment, e.g. mechanico-chemical polishing

Definitions

• the present invention relates to a polishing liquid and a polishing method using the polishing liquid.
• CMP Chemical Mechanical Polishing
• the CMP technique is a technique for forming a material to be polished on a substrate by chemical vapor deposition (CVD) or the like to obtain a substrate, and then flattening the surface of the substrate. If the surface of the substrate after flattening is uneven, inconveniences such as inability to focus in the exposure process and inability to sufficiently form a fine wiring structure occur.
• CMP technology is a process of forming an element separation region by polishing plasma oxides (BPSG, HDP-SiO 2 , p-TEOS, etc.), a process of forming an interlayer insulating material, and a metal wiring of silicon oxide in the device manufacturing process. It is also applied to the process of flattening a plug (for example, Al / Cu plug) after embedding in.
• silicon oxide is formed by CVD or the like so as to fill the groove provided in advance on the surface of the substrate.
• the element separation region is formed by flattening the surface of silicon oxide by CMP.
• silicon oxide is formed on a substrate provided with irregularities on the surface for obtaining an element separation region, irregularities corresponding to the irregularities of the substrate are also generated on the surface of the silicon oxide.
• the convex portions are preferentially removed, while the concave portions are slowly removed to flatten the surface.
• STI shallow trench isolation
• One aspect of the present invention is to solve the above-mentioned problems, and when polishing a surface to be polished having irregularities, a polishing liquid capable of obtaining a high polishing rate without depending on the state of irregularities can be obtained. provide. Another aspect of the present invention provides a polishing method using the polishing liquid.
• One aspect of the present invention is an abrasive grain containing a metal oxide, at least one hydroxy acid compound selected from the group consisting of a hydroxy acid having a structure represented by the following general formula (A1) and a salt thereof, and water.
• a polishing solution containing is provided.
• R 11 represents a hydrogen atom or a hydroxy group
• R 12 represents a hydrogen atom, an alkyl group or an aryl group
• n 11 represents an integer of 0 or more
• n 12 represents an integer of 0 or more.
• Another aspect of the present invention provides a polishing method comprising a step of polishing the material to be polished using the above-mentioned polishing liquid.
• polishing liquid and polishing method when polishing a surface to be polished having irregularities, a high polishing rate can be obtained without depending on the state of irregularities.
• polishing liquid capable of obtaining a high polishing rate without depending on the state of irregularities.
• polishing method using the polishing liquid.
• polishing liquids and polishing methods can be used to polish an insulating material (for example, silicon oxide) provided on the surface of a substrate (for example, a semiconductor wafer).
• the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively.
• the upper limit value or the lower limit value of the numerical range of one step can be arbitrarily combined with the upper limit value or the lower limit value of the numerical range of another step.
• the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
• “A or B” may include either A or B, or both.
• the materials exemplified in the present specification may be used alone or in combination of two or more.
• the amount of each component used in the composition is the total amount of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition.
• the term “membrane” includes not only a structure having a shape formed on the entire surface but also a structure having a shape partially formed when observed as a plan view.
• the term "process” is included in this term not only as an independent process but also as long as the desired action of the process is achieved even if it cannot be clearly distinguished from other processes. ..
• the polishing liquid according to the present embodiment contains abrasive grains containing a metal oxide, at least one hydroxy acid compound selected from the group consisting of a hydroxy acid having a structure represented by the following general formula (A1) and a salt thereof. Contains water.
• the polishing liquid according to this embodiment can be used as a CMP polishing liquid (polishing liquid for CMP).
• CMP polishing liquid polishing liquid for CMP.
• the polishing liquid according to the present embodiment when polishing a surface to be polished having irregularities, it is possible to obtain a high polishing rate without depending on the state of the irregularities, for example, due to the wiring width.
• a high polishing rate can be obtained regardless of the width of the irregularities.
• Such a polishing liquid is highly versatile and can be used for polishing various substrates having different surface conditions.
• the above-mentioned hydroxy acid compound is likely to be strongly adsorbed on the surface of abrasive grains containing a metal oxide, and by improving the activity of the surface of the abrasive grains, a high polishing rate can be obtained regardless of the state of unevenness. It is presumed that it can be done.
• the factors for obtaining the above effects are not limited to the contents.
• polishing liquid according to the present embodiment when polishing the surface to be polished of silicon oxide having no unevenness, it is 3000 ⁇ / min or more (preferably 5000 ⁇ / min or more, more preferably 8000 ⁇ / min or more). Polishing speed can be obtained. According to the polishing liquid according to the present embodiment, it is possible to obtain a high polishing rate in both the case of polishing the surface to be polished having unevenness and the case of polishing the surface to be polished having no unevenness. A high polishing rate can be obtained regardless of the surface condition of the surface to be polished (presence or absence of unevenness, density, etc.). The mechanism by which silicon oxide is polished by CMP has not been clarified in many parts, and the cause of such a phenomenon is not clear.
• the polishing process of the insulating material may be divided into two stages, and different types of polishing solutions may be used in each step to improve the production efficiency.
• the first step roughing step
• most of the insulating material is removed by using a polishing liquid having a high polishing rate of the insulating material.
• the second step finishing step
• the insulating material is slowly removed to finish the surface to be polished so that it is sufficiently flat.
• the CMP for the insulating material When the CMP for the insulating material is divided into two or more stages, a decrease in the polishing rate can lead to a decrease in productivity because a higher polishing rate is prioritized over flatness in the first step.
• the polishing liquid according to the present embodiment since it is possible to obtain a high polishing rate regardless of the state of unevenness, the CMP for the insulating material (for example, silicon oxide) is divided into two or more stages. Even so, the decrease in productivity can be suppressed.
• Abrasive grains contain metal oxides.
• the metal oxide can include cerium oxide (ceria), alumina, silica, titania, zirconia, magnesia, mullite and the like.
• cerium oxide ceria
• alumina silica
• titania titania
• zirconia zirconia
• magnesia mullite
• mullite alumina
• the abrasive grains preferably contain cerium oxide from the viewpoint that a high polishing rate can be easily obtained regardless of the state of the unevenness when polishing the surface to be polished having the unevenness.
• the polishing liquid using abrasive grains containing cerium oxide has a feature that there are relatively few polishing scratches on the surface to be polished.
• a polishing liquid containing silica particles has been widely used as abrasive grains from the viewpoint of easily achieving a high polishing rate of a material to be polished (for example, an insulating material such as silicon oxide).
• a polishing liquid using silica particles generally has a problem that polishing scratches are likely to occur on the surface to be polished. In a device having a fine pattern with a wiring width of 45 nm or later, even fine scratches that have not been a problem in the past may affect the reliability of the device.
• the abrasive grains preferably contain polycrystalline cerium oxide having crystal grain boundaries (for example, polycrystalline cerium oxide having a plurality of crystallites surrounded by crystal grain boundaries).
• the polycrystalline cerium oxide particles having such a structure are different from simple aggregates in which single crystal particles are agglomerated, and at the same time, the active surface (the surface that is not exposed to the outside before becoming fine) becomes finer due to stress during polishing. Since it appears one after another, it is considered that the high polishing rate of the material to be polished (for example, an insulating material such as silicon oxide) can be maintained at a high level.
• Such polycrystalline cerium oxide particles are described in detail in, for example, WO99 / 31195.
• the method for producing abrasive grains containing cerium oxide is not particularly limited, and examples thereof include liquid phase synthesis; firing, and a method of oxidizing with hydrogen peroxide or the like.
• a method of firing a cerium source such as cerium carbonate is preferable.
• the temperature at the time of firing is preferably 350 to 900 ° C.
• the pulverization method is not particularly limited, but for example, dry pulverization by a jet mill or the like; wet pulverization by a planetary bead mill or the like is preferable. Jet mills are described, for example, in "Chemical Engineering Proceedings," Vol. 6, No. 5, (1980), pp. 527-532.
• Abrasive grains may contain constituent components other than metal oxides.
• the constituent components other than the metal oxide include cerium compounds (excluding cerium oxide), silicon nitride, ⁇ -sialon, aluminum nitride, titanium nitride, silicon carbide, and boron carbide.
• the cerium-based compound include cerium hydroxide, ammonium cerium nitrate, cerium acetate, cerium sulfate hydrate, cerium bromide, cerium bromide, cerium chloride, cerium oxalate, cerium nitrate, cerium carbonate and the like.
• the lower limit of the content of metal oxide (for example, cerium oxide) in the abrasive grains is based on the total mass of the abrasive grains (total mass of the abrasive grains contained in the polishing liquid) from the viewpoint that a high polishing rate of silicon oxide can be easily obtained.
• metal oxide for example, cerium oxide
• the lower limit of the content of metal oxide (for example, cerium oxide) in the abrasive grains is based on the total mass of the abrasive grains (total mass of the abrasive grains contained in the polishing liquid) from the viewpoint that a high polishing rate of silicon oxide can be easily obtained.
• 50% by mass or more is preferable, 70% by mass or more is more preferable, 90% by mass or more is further preferable, 95% by mass or more is particularly preferable, 97% by mass or more is extremely preferable, and 99% by mass or more is very preferable.
• the abrasive grains containing the metal oxide may be in a mode in which the abrasive grains are substantially made of the metal oxide (a mode in which 100% by mass of the abrasive grains is substantially the metal oxide).
• the abrasive grains may be in a mode that does not contain zirconia.
• the lower limit of the average particle size of the abrasive grains is preferably 50 nm or more, more preferably 70 nm or more, still more preferably 80 nm or more, from the viewpoint that a high polishing rate of the material to be polished (for example, an insulating material such as silicon oxide) can be easily obtained. , 90 nm or more is particularly preferable.
• the upper limit of the average particle size of the abrasive grains is preferably 500 nm or less, more preferably 300 nm or less, further preferably 280 nm or less, particularly preferably 250 nm or less, extremely preferably 200 nm or less, and 180 nm or less from the viewpoint of easily suppressing polishing scratches.
• the average particle size of the abrasive grains is preferably 50 to 500 nm.
• a conventionally known method can be used.
• examples of the method for controlling the average particle size of the abrasive grains include the above-mentioned control of firing temperature, firing time, crushing conditions, etc .; application of filtration, classification, etc.
• an arithmetic mean diameter measured by a laser diffraction / scattering type particle size distribution meter for a polishing liquid sample in which abrasive grains are dispersed can be used.
• the average particle size of the abrasive grains is a value measured using, for example, LA-920 (trade name) manufactured by HORIBA, Ltd.
• the zeta potential (surface potential) of the abrasive grains in the polishing liquid is positive from the viewpoint that a high polishing speed can be easily obtained regardless of the state of the unevenness when polishing the surface to be polished having unevenness (zeta potential).
• the lower limit of the zeta potential of the abrasive grains is preferably 10 mV or more, more preferably 20 mV or more, and more preferably 30 mV, from the viewpoint that a high polishing rate can be easily obtained regardless of the state of the unevenness when polishing the surface to be polished having unevenness.
• the above is more preferable, 40 mV or more is particularly preferable, 50 mV or more is extremely preferable, and 60 mV or more is very preferable.
• the upper limit of the zeta potential of the abrasive grains is preferably 200 mV or less, more preferably 150 mV or less, further preferably 100 mV or less, particularly preferably 80 mV or less, and extremely preferably 70 mV or less. From these viewpoints, the zeta potential of the abrasive grains is preferably more than 0 mV and 200 mV or less, more preferably 10 to 200 mV, and even more preferably 30 to 70 mV.
• the zeta potential of the abrasive grains can be measured using, for example, a dynamic light scattering type zeta potential measuring device (for example, manufactured by Beckman Coulter Co., Ltd., trade name: DelsaNano C).
• a dynamic light scattering type zeta potential measuring device for example, manufactured by Beckman Coulter Co., Ltd., trade name: DelsaNano C.
• the content of abrasive grains is preferably in the following range based on the total mass of the polishing liquid.
• the lower limit of the content of abrasive grains is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.10% by mass or more, and 0.00% by mass or more, from the viewpoint that a high polishing rate can be easily achieved. It is particularly preferably more than 10% by mass, extremely preferably 0.15% by mass or more, very preferably 0.18% by mass or more, even more preferably more than 0.18% by mass, and 0.20% by mass or more.
• the upper limit of the content of abrasive grains is preferably 10% by mass or less, more preferably 5.0% by mass or less, from the viewpoint of easily suppressing aggregation of abrasive grains and easily achieving a high polishing rate.
• the content of abrasive grains is preferably 0.01 to 10% by mass, more preferably 0.10 to 10% by mass, and even more preferably 0.10 to 3.0% by mass.
• the polishing liquid according to the present embodiment is referred to as at least one hydroxy acid compound selected from the group consisting of a hydroxy acid having a structure represented by the following general formula (A1) and a salt thereof (hereinafter, referred to as "specific hydroxy acid compound”. ) Is contained.
• a hydroxy acid is a carboxylic acid having a hydroxy group.
• R 11 represents a hydrogen atom or a hydroxy group
• R 12 represents a hydrogen atom, an alkyl group or an aryl group
• n 11 represents an integer of 0 or more
• n 12 represents an integer of 0 or more.
• Examples of the salt of the hydroxy acid having the structure represented by the general formula (A1) include a salt in which the hydrogen atom of the carboxyl group is replaced with an alkali metal (for example, a sodium atom).
• the polishing liquid according to the present embodiment may or may not contain a hydroxy acid compound other than the specific hydroxy acid compound.
• the specific hydroxy acid compound preferably satisfies at least one of the following characteristics from the viewpoint of easily obtaining a high polishing rate without depending on the state of the unevenness when polishing the surface to be polished having the unevenness.
• the carbon number of the alkyl group of R 12 is preferably 0-3, 0-2 and more preferably, 1 or 2 being more preferred.
• the aryl group of R 12 is preferably a phenyl group.
• n11 is preferably 0 to 3, more preferably 0 to 2, and even more preferably 0 or 1.
• n12 is preferably 0 to 3, more preferably 0 to 2, further preferably 0 or 1, and particularly preferably 1.
• the specific hydroxy acid compound preferably has a branched carbon chain.
• the specific hydroxy acid compound preferably does not have a polyoxyalkylene group (for example, a polyoxyethylene group).
• the specific hydroxy acid compound is preferably at least one selected from the group consisting of hydroxy acids having a molecular weight of 90 to 200 and salts thereof.
• the lower limit of the molecular weight is preferably 95 or more, more preferably 100 or more, further preferably more than 100, particularly preferably 102 or more, and extremely preferably 104 or more.
• the upper limit of the molecular weight is preferably 180 or less, more preferably 170 or less, further preferably 160 or less, and particularly preferably 150 or less.
• the specific hydroxy acid compound has a structure represented by the following general formula (A2) from the viewpoint that a high polishing rate can be easily obtained regardless of the state of the unevenness when polishing the surface to be polished having the unevenness.
• a salt thereof and at least one selected from the group consisting of a hydroxy acid having a structure represented by the following general formula (A3) and a salt thereof.
• R 21 and R 22 each independently represent a hydrogen atom, an alkyl group or an aryl group, and the total number of carbon atoms of R 21 and R 22 is 2 or more.
• R 3 represents a hydrogen atom, an alkyl group or an aryl group
• n31 represents an integer of 0 to 2
• n 32 represents an integer of 0 or more.
• the structure represented by the general formula (A2) satisfies at least one of the following features from the viewpoint of easily obtaining a high polishing rate regardless of the state of the unevenness when polishing the surface to be polished having the unevenness.
• the alkyl group of R 21 preferably has 0 to 3 carbon atoms, more preferably 0 to 2 carbon atoms, and even more preferably 1 or 2 carbon atoms.
• the aryl group of R 21 is preferably a phenyl group.
• the total number of carbon atoms of R 21 and R 22 is preferably 2 to 9, more preferably 2 to 6, and even more preferably 2 to 4.
• R 3 is preferably a hydrogen atom or an alkyl group.
• the alkyl group of R 3 preferably has 0 to 3 carbon atoms, more preferably 0 to 2 carbon atoms, and even more preferably 1 or 2 carbon atoms.
• n31 is preferably 0 or 1.
• n32 is preferably 0 to 3, more preferably 0 to 2, further preferably 0 or 1, and particularly preferably 1.
• the specific hydroxy acid compound is oxidized when polishing a surface to be polished having irregularities, from the viewpoint that a high polishing rate can be easily obtained regardless of the state of irregularities, and when polishing a surface to be polished having no irregularities.
• a high polishing rate of silicon from the group consisting of glyceric acid, mandelic acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxymethyl) butyric acid, and hydroxyisobutyric acid. It is preferable to contain at least one selected, and at least one selected from the group consisting of glyceric acid, 2,2-bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxymethyl) butyric acid, and hydroxyisobutyric acid.
• hydroxyisobutyric acid examples include 2-hydroxyisobutyric acid (also known as 2-methyllactate) and 3-hydroxyisobutyric acid.
• the lower limit of the content of the specific hydroxy acid compound is from the viewpoint that when polishing the surface to be polished having irregularities, it is easy to obtain a high polishing rate regardless of the state of the irregularities, and the surface to be polished having no irregularities. From the viewpoint of easily achieving a high polishing rate of silicon oxide in the case of polishing, 50% by mass or more is preferable based on the total mass of the hydroxy acid compound (hydroxy acid compound contained in the polishing liquid according to the present embodiment). 70% by mass or more is more preferable, 90% by mass or more is further preferable, 95% by mass or more is particularly preferable, 97% by mass or more is extremely preferable, and 99% by mass or more is very preferable.
• the hydroxy acid compound contained in the polishing solution according to the present embodiment is substantially composed of a specific hydroxy acid compound (substantially, 100% by mass of the hydroxy acid compound contained in the polishing solution according to the present embodiment). It may be an embodiment of a specific hydroxy acid compound).
• the content of the specific hydroxy acid compound is from the viewpoint that when polishing the surface to be polished having irregularities, it is easy to obtain a high polishing speed without depending on the state of the irregularities, and the surface to be polished having no irregularities is polished. In some cases, the following range is preferable based on the total mass of the acid component (acid component contained in the polishing liquid according to the present embodiment) from the viewpoint of easily achieving a high polishing rate of silicon oxide.
• the lower limit of the content of the specific hydroxy acid compound is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably more than 10% by mass, particularly preferably 15% by mass or more, and more than 15% by mass. Is extremely preferable, and 20% by mass or more is very preferable.
• the upper limit of the content of the specific hydroxy acid compound is preferably 90% by mass or less, more preferably 85% by mass or less, further preferably 80% by mass or less, particularly preferably 75% by mass or less, and extremely preferably 70% by mass or less. From these viewpoints, the content of the specific hydroxy acid compound is preferably 5 to 90% by mass.
• the lower limit of the content of the specific hydroxy acid compound is based on the total mass of the acid component from the viewpoint that a particularly high polishing rate can be easily obtained without depending on the state of the unevenness when polishing the surface to be polished having the unevenness. It is preferably more than 20% by mass, more preferably 30% by mass or more, further preferably 30% by mass or more, particularly preferably 40% by mass or more, and extremely preferably 50% by mass or more.
• the content of the specific hydroxy acid compound is from the viewpoint that a high polishing rate can be easily obtained regardless of the state of the unevenness when polishing the surface to be polished having unevenness, and the surface to be polished having no unevenness is polished. In some cases, the following range is preferable based on the total mass of the polishing liquid from the viewpoint of easily achieving a high polishing rate of silicon oxide.
• the lower limit of the content of the specific hydroxy acid compound is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, further preferably 0.05% by mass or more, and particularly preferably 0.06% by mass or more. 0.07% by mass or more is extremely preferable, and 0.075% by mass or more is very preferable.
• the upper limit of the content of the specific hydroxy acid compound is preferably 10% by mass or less, more preferably 5.0% by mass or less, further preferably 3.0% by mass or less, particularly preferably 1.0% by mass or less, and 0. 80% by mass or less is extremely preferable, 0.70% by mass or less is very preferable, 0.60% by mass or less is further preferable, 0.50% by mass or less is further preferable, 0.40% by mass or less is particularly preferable. Less than 0.40% by mass is extremely preferable, and 0.30% by mass or less is very preferable. From these viewpoints, the content of the specific hydroxy acid compound is preferably 0.01 to 10% by mass, more preferably 0.01 to 1.0% by mass.
• the lower limit of the content of the specific hydroxy acid compound is based on the total mass of the polishing liquid from the viewpoint that it is easy to obtain a particularly high polishing rate without depending on the state of the unevenness when polishing the surface to be polished having the unevenness. 0.08% by mass or more is preferable, 0.10% by mass or more is more preferable, 0.10% by mass or more is further preferable, 0.15% by mass or more is particularly preferable, and 0.20% by mass or more is extremely preferable. , 0.25% by mass or more is very preferable, and 0.30% by mass or more is even more preferable.
• the upper limit of the content of the specific hydroxy acid compound is 0.25 based on the total mass of the polishing liquid from the viewpoint of easily achieving a particularly high polishing rate of silicon oxide when polishing a surface to be polished having no unevenness. It is preferably 0% by mass or less, more preferably 0.20% by mass or less, further preferably 0.15% by mass or less, particularly preferably 0.10% by mass or less, extremely preferably less than 0.10% by mass, and 0.08% by mass. % Or less is very preferable, and 0.075% by mass or less is even more preferable.
• Ratio A1 content of hydroxy acid compound / content of abrasive grains of the content of the hydroxy acid compound to the content of the abrasive grains (total amount of the hydroxy acid compounds contained in the polishing liquid according to the present embodiment), and / Alternatively, the ratio of the content of the specific hydroxy acid compound to the content of the abrasive grains A2 (content of the specific hydroxy acid compound / content of the abrasive grains) is the unevenness when polishing the surface to be polished.
• Ratio A1 and ratio A2 are referred to as "ratio A").
• the lower limit of the ratio A is preferably 0.01 or more, more preferably 0.03 or more, further preferably 0.05 or more, particularly preferably 0.06 or more, extremely preferably 0.07 or more, and 0.075 or more. Very preferred.
• the upper limit of the ratio A is preferably 10 or less, more preferably 5.0 or less, further preferably 3.0 or less, particularly preferably 1.0 or less, extremely preferably 0.80 or less, and very preferably 0.70 or less.
• 0.60 or less is even more preferable, 0.50 or less is further preferable, 0.40 or less is particularly preferable, less than 0.40 is extremely preferable, and 0.30 or less is very preferable. From these viewpoints, the ratio A is preferably 0.01 to 10.
• the lower limit of the ratio A is preferably 0.08 or more, more preferably 0.10 or more, from the viewpoint of easily obtaining a particularly high polishing speed regardless of the state of the unevenness when polishing the surface to be polished having unevenness. , 0.10 or more, particularly preferably 0.15 or more, extremely preferably 0.20 or more, very preferably 0.25 or more, and even more preferably 0.30 or more.
• the upper limit of the ratio A is preferably 0.25 or less, more preferably 0.20 or less, and more preferably 0.20 or less, from the viewpoint of easily achieving a particularly high polishing rate of silicon oxide when polishing a surface to be polished having no unevenness. 15 or less is further preferable, 0.10 or less is particularly preferable, less than 0.10 is extremely preferable, 0.08 or less is very preferable, and 0.075 or less is even more preferable.
• the polishing liquid according to the present embodiment may further contain other additives (excluding abrasive grains and hydroxy acid compounds).
• the additive include an acid component other than the hydroxy acid compound; an alkaline component; a water-soluble polymer, and a nonionic surfactant.
• the acid component and the alkaline component can be used as a pH adjuster for adjusting the pH.
• the polishing liquid according to this embodiment may contain a buffering agent in order to stabilize the pH.
• a buffer may be added as a buffer (a solution containing a buffer). Examples of the buffer solution include acetate buffer solution and phthalate buffer solution.
• the polishing liquid according to the present embodiment may contain at least one amino acid component selected from the group consisting of amino acids and amino acid derivatives as an acid component other than the hydroxy acid compound.
• amino acid derivatives include amino acid esters, amino acid salts, peptides and the like.
• Amino acids are compounds that have both functional groups of amino and carboxyl groups.
• Amino acid components include glycine, ⁇ -alanine, ⁇ -alanine (also known as 3-aminopropanoic acid), 2-aminobutyric acid, norvaline, valine, leucine, norleucine, isoleucine, aloisoleucine, phenylalanine, proline, sarcosin, ornitine, Glycine, serine, threonine, isoleucine, homoserine, tyrosine, 3,5-diiodo-tyrosine, ⁇ - (3,4-dihydroxyphenyl) -alanine, tyrosin, 4-hydroxy-proline, cysteine, methionine, etionine, lanthionin, Sistathionine, cystine, tyrosine, aspartic acid, glutamic acid, S- (carboxymethyl) -cysteine, 4-aminobutyric acid, asparagine, glutamine, aza
• the amino acid component preferably contains a low molecular weight amino acid from the viewpoint of easily suppressing the aggregation of abrasive grains (cerium oxide particles, etc.).
• the molecular weight of the amino acid component is preferably 300 or less, more preferably 250 or less, and even more preferably 200 or less.
• Examples of such amino acids include glycine (molecular weight 75), ⁇ -alanine (molecular weight 89), ⁇ -alanine (molecular weight 89), serine (molecular weight 105), histidine (molecular weight 155), glycylglycine (molecular weight 132), and glycine. Examples thereof include ruglycylglycine (molecular weight 189).
• the amino acid component of silicon oxide is used from the viewpoint that a high polishing rate can be easily obtained regardless of the state of unevenness when polishing the surface to be polished having unevenness, and when polishing the surface to be polished having no unevenness. It is preferable to contain glycine from the viewpoint of easily achieving a high polishing rate.
• the content of acid components (for example, amino acid components) other than the hydroxy acid compound is preferably in the following range based on the total mass of the polishing liquid.
• the lower limit of the content of the acid component other than the hydroxy acid compound is preferably 0.005% by mass or more, more preferably 0.01% by mass or more, and 0.05% by mass or more, from the viewpoint of easily achieving a sufficiently high polishing rate of silicon oxide.
• 02% by mass or more is further preferable, 0.03% by mass or more is particularly preferable, 0.05% by mass or more is extremely preferable, 0.10% by mass or more is very preferable, and 0.20% by mass or more is even more preferable.
• the upper limit of the content of the acid component other than the hydroxy acid compound is preferably 10% by mass or less, more preferably 5.0% by mass or less, and more preferably 3.0% by mass from the viewpoint of easily achieving a sufficiently high polishing rate of silicon oxide. % Or less is more preferable, 1.0% by mass or less is particularly preferable, 0.50% by mass or less is extremely preferable, and 0.40% by mass or less is very preferable. From these viewpoints, the content of the acid component other than the hydroxy acid compound is preferably 0.005 to 10% by mass.
• Ratio of content of amino acid component to content of hydroxy acid compound (total amount of hydroxy acid compound contained in the polishing solution according to this embodiment) B1 (content of amino acid component / content of hydroxy acid compound), and / Or, the ratio of the content of the amino acid component to the content of the specific hydroxy acid compound B2 (content of the amino acid component / content of the specific hydroxy acid compound) is uneven when polishing the surface to be polished.
• the following ranges are preferable from the viewpoint that a high polishing rate can be easily obtained regardless of the state and that a high polishing rate of silicon oxide can be easily achieved when polishing a surface to be polished having no unevenness (hereinafter, the following range is preferable.
• Ratio B1 and ratio B2 are referred to as "ratio B").
• the lower limit of the ratio B is preferably 0.01 or more, more preferably 0.05 or more, further preferably 0.10 or more, particularly preferably 0.30 or more, and extremely preferably 0.50 or more.
• the upper limit of the ratio B is preferably 10 or less, more preferably 8.0 or less, further preferably 5.0 or less, and particularly preferably 4.0 or less. From these viewpoints, the ratio B is preferably 0.01 to 10.
• the upper limit of the ratio B is preferably 3.0 or less, more preferably 2.0 or less, from the viewpoint that a particularly high polishing rate can be easily obtained regardless of the state of the unevenness when polishing the surface to be polished having unevenness. , 1.5 or less is more preferable, and 1.0 or less is particularly preferable.
• alkaline component examples include heterocyclic amines, alkanolamines, ammonia, sodium hydroxide, tetramethylammonium hydroxide (TMAH) and the like.
• the polishing liquid according to this embodiment does not have to contain an alkaline component.
• the heterocyclic amine is an amine having at least one heterocycle.
• the heterocyclic amine include pyrrolidine, pyrrole, imidazole, pyrazole, oxazole, thiazole, pyridine, pyrazine, pyrimidine, pyridazine, triazine, tetrazine, and derivatives thereof (compounds having the structure of these compounds as a skeleton). Can be mentioned.
• As the derivative aminothiazole, dialkylpyrazole (for example, dimethylpyrazole such as 3,5-dialkylpyrazole) and the like can be used.
• the heterocyclic amine is oxidized when polishing a surface to be polished having irregularities, from the viewpoint that a high polishing rate can be easily obtained without depending on the state of irregularities, and when polishing a surface to be polished having no irregularities.
• the content of the heterocyclic amine is preferably in the following range based on the total mass of the polishing liquid.
• the lower limit of the content of the heterocyclic amine is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and 0.01% by mass from the viewpoint of easily achieving a sufficiently high polishing rate of silicon oxide.
• the above is more preferable.
• the upper limit of the content of the heterocyclic amine is preferably 10% by mass or less, more preferably 5.0% by mass or less, and 3.0% by mass or less from the viewpoint of easily achieving a sufficiently high polishing rate of silicon oxide. More preferably, 1.0% by mass or less is particularly preferable, 0.50% by mass or less is extremely preferable, and 0.30% by mass or less is very preferable. From these viewpoints, the content of the heterocyclic amine is preferably 0.001 to 10% by mass.
• Alkanolamine is a compound having a hydroxy group and an amino group bonded to an alkane skeleton.
• alkanolamines include methanolamine, ethanolamine, diethanolamine, triethanolamine, propanolamine, dimethylethanolamine, N-methylethanolamine, N-polyoxypropylene ethylenediamine, aminoethylethanolamine, heptaminol, isoethane, sphingosine and the like. Be done.
• the content of alkanolamine is preferably in the following range based on the total mass of the polishing liquid.
• the lower limit of the alkanolamine content is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and preferably 0.01% by mass or more from the viewpoint of easily achieving a sufficiently high polishing rate of silicon oxide. More preferred.
• the upper limit of the alkanolamine content is preferably 10% by mass or less, more preferably 5.0% by mass or less, still more preferably 3.0% by mass or less, from the viewpoint of easily achieving a sufficiently high polishing rate of silicon oxide. , 1.0% by mass or less is particularly preferable, 0.50% by mass or less is extremely preferable, and 0.30% by mass or less is very preferable. From these viewpoints, the content of alkanolamine is preferably 0.001 to 10% by mass.
• water-soluble polymer examples include polyacrylic acid-based polymers such as polyacrylic acid, polyacrylic acid copolymer, polyacrylic acid salt, and polyacrylic acid copolymer salt; and polymethacrylic acid such as polymethacrylic acid and polymethacrylate.
• Acid-based polymers Polyacrylamide; Polydimethylacrylamide; Arginic acid, pectinic acid, carboxymethyl cellulose, agar, polysaccharides such as curdran, dextrin, cyclodextrin, and purulan; vinyl-based polymers such as polyvinyl alcohol, polyvinylpyrrolidone, and polyacrolein; Glycerin-based polymers such as glycerin and polyglycerin derivatives; polyethylene glycol and the like can be mentioned.
• the polishing liquid according to this embodiment does not have to contain a water-soluble polymer.
• the polishing liquid according to this embodiment does not have to contain a water-soluble polymer.
• the polishing liquid according to the present embodiment does not have to contain at least one selected from the group consisting of polyvinyl alcohol, polyvinylpyrrolidone, polyglycerin and polyethylene glycol.
• nonionic surfactants polyoxypropylene polyoxyethylene alkyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene polyoxypropylene ether derivative, polyoxypropylene glyceryl ether, polyethylene glycol oxyethylene Ether-type surfactants such as adducts, oxyethylene adducts of methoxypolyethylene glycol, and oxyethylene adducts of acetylene-based diols; ester-type surfactants such as sorbitan fatty acid esters and glycerol volate fatty acid esters; polyoxyethylene alkylamines Amino ether type surfactants such as; ether ester type surfactants such as polyoxyethylene sorbitan fatty acid ester, polyoxyethylene glycerol volate fatty acid ester, polyoxyethylene alkyl ester; fatty acid alkanolamide, polyoxyethylene fatty acid alkanolamide, etc.
• Alkanolamide-type surfactant oxyethylene adduct of acetylene-based diol; polyvinylpyrrolidone; polyacrylamide; polydimethylacrylamide; polyvinyl alcohol and the like.
• the polishing liquid according to this embodiment does not have to contain a nonionic surfactant.
• the upper limit of the content of the polymer compound having a hydroxy group may be less than 0.01% by mass and 0.005% by mass or less based on the total mass of the polishing liquid. It may be 0.001% by mass or less, 0.0001% by mass or less, and less than 0.0001% by mass.
• the polishing liquid according to this embodiment does not have to contain a polymer compound having a hydroxy group.
• the upper limit of the content of the polymer compound having an amide group may be less than 0.01% by mass and 0.005% by mass or less based on the total mass of the polishing liquid. It may be 0.001% by mass or less, 0.0001% by mass or less, and less than 0.0001% by mass.
• the polishing liquid according to this embodiment does not have to contain a polymer compound having an amide group.
• the polishing liquid according to this embodiment does not have to contain poly-N-vinylacetamide.
• the upper limit of the content of the compound having a cyclic structure is less than 0.01% by mass based on the total mass of the polishing liquid. It may be 0.005% by mass or less, 0.001% by mass or less, less than 0.001% by mass, 0.0001% by mass or less, 0.0001. It may be less than% by mass.
• the polishing liquid according to the present embodiment does not have to contain a compound having a cyclic structure (for example, a compound having two or more cyclic structures).
• the upper limit of the content of the compound having a polyalkylene chain may be less than 0.01% by mass and 0.005% by mass or less based on the total mass of the polishing liquid. It may be 0.001% by mass or less, 0.0001% by mass or less, and less than 0.0001% by mass.
• the polishing liquid according to this embodiment does not have to contain a compound having a polyalkylene chain.
• the upper limit of the content of the water-soluble polyamide may be less than 0.0001% by mass based on the total mass of the polishing liquid.
• the polishing liquid according to this embodiment does not have to contain a water-soluble polyamide.
• the upper limit of the content of the azo compound may be less than 0.025% by mass and 0.02% by mass or less based on the total mass of the polishing liquid. It may be 0.01% by mass or less, 0.005% by mass or less, 0.001% by mass or less, 0.0001% by mass or less, 0.0001. It may be less than% by mass.
• the polishing liquid according to this embodiment does not have to contain an azo compound (for example, an azo derivative).
• the upper limit of the content of the oxidizing agent may be less than 0.003 mol / L and may be 0.001 mol / L or less based on the entire polishing liquid.
• the polishing liquid according to this embodiment does not have to contain an oxidizing agent.
• the polishing liquid according to this embodiment contains water.
• water examples include deionized water and ultrapure water.
• the content of water is not particularly limited, and may be the balance of the polishing liquid excluding the content of other constituent components.
• the total amount of abrasive grains and water is from the viewpoint that when polishing an uneven surface to be polished, it is easy to obtain a high polishing speed without depending on the state of the unevenness, and the surface to be polished having no unevenness is polished. In some cases, the following range is preferable based on the total mass of the polishing liquid from the viewpoint of easily achieving a high polishing rate of silicon oxide.
• the lower limit of the total amount of abrasive grains and water is preferably 95% by mass or more, more preferably 96% by mass or more, further preferably 97% by mass or more, particularly preferably 98% by mass or more, and extremely preferably 99% by mass or more.
• the upper limit of the total amount of abrasive grains and water is preferably less than 100% by mass, more preferably 99.9% by mass or less, and further preferably 99.8% by mass or less. From these viewpoints, the total amount of abrasive grains and water is preferably 95% by mass or more and less than 100% by mass.
• the total amount of abrasive grains and water preferably exceeds 99.4% by mass, preferably 99.5% by mass, from the viewpoint of easily achieving a particularly high polishing rate of silicon oxide when polishing a surface to be polished having no unevenness. More preferably, it is 99.6% by mass or more, and further preferably 99.6% by mass or more.
• the total amount of the hydroxy acid compound and water is from the viewpoint that when polishing the surface to be polished having irregularities, it is easy to obtain a high polishing rate without depending on the state of the irregularities, and the surface to be polished having no irregularities is polished. From the viewpoint of easily achieving a high polishing rate of silicon oxide, the following range is preferable with reference to the total mass of the polishing liquid.
• the lower limit of the total amount of the hydroxy acid compound and water is preferably 95% by mass or more, more preferably 96% by mass or more, further preferably 97% by mass or more, particularly preferably 98% by mass or more, and 98.2% by mass or more.
• the upper limit of the total amount of the hydroxy acid compound and water is preferably less than 100% by mass, more preferably 99.8% by mass or less, further preferably 99.5% by mass or less, particularly preferably 99.2% by mass or less, and 99. It is extremely preferably mass% or less, and very preferably less than 99 mass%. From these viewpoints, the total amount of the hydroxy acid compound and water is preferably 95% by mass or more and less than 100% by mass.
• the lower limit of the total amount of abrasive grains, hydroxyic acid compound, and water is from the viewpoint that when polishing a surface to be polished having irregularities, it is easy to obtain a high polishing speed regardless of the state of the irregularities, and there is no irregularities. From the viewpoint of easily achieving a high polishing rate of silicon oxide when polishing the surface to be polished, 95% by mass or more is preferable, 96% by mass or more is more preferable, and 97% by mass or more is used as a reference based on the total mass of the polishing liquid.
• the total amount of abrasive grains, hydroxy acid compound and water may be 100% by mass or less.
• the lower limit of the pH of the polishing liquid according to the present embodiment is preferably 1.0 or more, more preferably 1.5 or more, still more preferably 2.0 or more, from the viewpoint of easily achieving a sufficiently high polishing rate of silicon oxide.
• 2.2 or more is particularly preferable, 2.4 or more is extremely preferable, 2.5 or more is very preferable, 3.0 or more is even more preferable, 3.2 or more is further preferable, and 3.4 or more is particularly preferable. It is extremely preferable that it exceeds 3.4.
• the upper limit of pH is preferably 7.0 or less, more preferably 6.5 or less, further preferably 6.0 or less, and particularly preferably 5.5 or less, from the viewpoint of easily achieving a sufficiently high polishing rate of silicon oxide.
• the pH of the polishing liquid is preferably 1.0 to 7.0, more preferably 3.0 to 7.0, further preferably 3.0 to 6.0, and 3.0 to 5.0. Is particularly preferable, and 3.5 to 5.0 is extremely preferable.
• the pH of the polishing liquid is defined as the pH at a liquid temperature of 25 ° C.
• the pH of the polishing liquid according to this embodiment can be measured with a pH meter (for example, manufactured by Electrochemical Instruments Co., Ltd., model number PHL-40). For example, using a standard buffer (phthalate pH buffer, pH: 4.01; neutral phosphate pH buffer, pH: 6.86; borate pH buffer, pH: 9.18). After calibrating at three points, the electrode is placed in a polishing solution, and after a lapse of 3 minutes or more and stable, the pH is measured by the measuring device.
• the temperature of both the standard buffer solution and the polishing solution shall be 25 ° C.
• the polishing liquid according to the present embodiment may be stored as a one-component polishing liquid containing at least abrasive grains and a hydroxy acid compound, and a slurry (first liquid) and an additive liquid (second liquid) may be stored.
• the constituent components of the polishing liquid may be stored as a set of a plurality of liquid type (for example, a two-component type) polishing liquid in which the constituent components of the polishing liquid are divided into a slurry and an additive liquid so as to be mixed to obtain the polishing liquid.
• the slurry contains, for example, abrasive grains and at least water.
• the additive liquid contains, for example, at least a hydroxy acid compound and water.
• the slurry and the additive liquid are mixed immediately before or during polishing to prepare a polishing liquid.
• the one-component polishing liquid may be stored as a storage liquid for a polishing liquid in which the content of the liquid medium is reduced, and may be diluted with a liquid medium at the time of polishing.
• the multi-component polishing liquid set may be stored as a storage liquid for slurry and a storage liquid for additive liquid in which the content of the liquid medium is reduced, and may be diluted with a liquid medium at the time of polishing.
• the polishing method according to the present embodiment includes a polishing step of polishing the material to be polished using the polishing liquid according to the present embodiment.
• the polishing step is, for example, a step of polishing the insulating material of a substrate having an insulating material (for example, an insulating material such as silicon oxide) on the surface by using the polishing liquid according to the present embodiment.
• the polishing step is, for example, a step of polishing the material to be polished by the polishing member while supplying the polishing liquid according to the present embodiment between the material to be polished (for example, an insulating material) and a member for polishing (polishing pad or the like). is there.
• the material to be polished may include an insulating material, may include an inorganic insulating material, and may contain silicon oxide.
• the polishing step is, for example, a step of flattening a substrate having an insulating material (for example, an insulating material such as silicon oxide) on the surface by CMP technology using a polishing liquid in which the content of each component, pH, etc. are adjusted. is there.
• the material to be polished may be in the form of a film (film to be polished), or may be an insulating film such as a silicon oxide film.
• the polishing step involves a substrate having an uneven surface, a stopper provided on the substrate along the surface shape of the substrate, and an insulating material (for example, silicon oxide) provided on the stopper along the shape of the stopper. It may be a step of polishing a substrate comprising.
• the polishing step is a first step (roughing step) of polishing and removing the insulating material until the portion of the stopper located on the convex portion of the substrate surface is exposed, and after the first step, the stopper and the insulating material are removed. It may have a second step (finishing step) of polishing and removing.
• the polishing liquid and polishing method according to the present embodiment can be used in at least one selected from the group consisting of the first step and the second step.
• the stopper may include silicon nitride.
• the stopper may be in the form of a film (stopper film) or may be a silicon nitride film.
• the polishing method according to the present embodiment is suitable for polishing a substrate having a material to be polished (for example, an insulating material such as silicon oxide) on the surface in the following device manufacturing process.
• Devices include individual semiconductors such as diodes, transistors, compound semiconductors, thermistas, varistor, and thyristors; DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), EPROM (Erasable Programmable Read).
• Storage elements such as (only memory), mask ROM (mask read only memory), EPROM (electrically erasable programmable read only memory), flash memory; theoretical circuits such as microprocessors, DSPs, ASICs, etc.
• Elements Integrated circuit elements such as compound semiconductors typified by MMIC (Monolithic Microwave Integrated Circuit); photoelectric conversion elements such as hybrid integrated circuits (hybrid ICs), light emitting diodes, and charge coupling elements.
• the polishing method according to the present embodiment is particularly suitable for flattening the surface of a substrate having a step (unevenness) on the surface.
• the substrate include semiconductor devices for logic.
• the material to be polished may have a portion in which a concave portion or a convex portion is provided in a T-shape or a lattice shape when viewed from above.
• the object to be polished having the material to be polished may be a semiconductor substrate having a memory cell.
• an insulating material for example, an insulating material such as silicon oxide
• DRAM semiconductor device
• flash memory etc.
• the polishing rate is high while ensuring high flatness. Can be polished.
• the polishing method can polish a material to be polished having a pattern in which the ratio of the line width to the total of the line width (L: Line) and the space width (S: Space) is in the following range.
• the ratio of the line width may be 10% or more, 20% or more, 30% or more, 40% or more, or 50% or more.
• the ratio of the line width may be 60% or less, 50% or less, 40% or less, 30% or less, or 20% or less.
• the total of the line width and the space width may be 50 ⁇ m or more, 80 ⁇ m or more, or 100 ⁇ m or more.
• the total of the line width and the space width may be 200 ⁇ m or less, 150 ⁇ m or less, 120 ⁇ m or less, or 100 ⁇ m or less.
• the polishing liquid according to the present embodiment can be used for polishing a material to be polished having a pattern in which the ratio of the line width is in these ranges.
• the polishing liquid may be selected based on the polishing rate of 190,000 ⁇ / min or more when the material to be polished (for example, silicon oxide) is polished.
• the object to be polished is not limited to a substrate having silicon oxide that covers the entire surface, but may be a substrate that further has silicon nitride, polycrystalline silicon, or the like in addition to silicon oxide on the surface.
• the objects to be polished include insulating materials (for example, inorganic insulating materials such as silicon oxide, glass, and silicon nitride), polysilicon, Al, Cu, Ti, TiN, W, Ta, and TaN on a wiring plate having a predetermined wiring. It may be a formed substrate.
• polishing device for example, a device provided with a holder for holding a substrate, a polishing surface plate to which a polishing pad is attached, and a means for supplying a polishing liquid on the polishing pad is suitable.
• polishing equipment polishing equipment manufactured by Ebara Seisakusho Co., Ltd. (model number: EPO-111, EPO-222, FREX200, FREX300, etc.), polishing equipment manufactured by Applied Materials (trade name: Mira3400, Reflection polishing machine, etc.) Can be mentioned.
• polishing pad a general non-woven fabric, foam, non-foam, etc.
• material of the polishing pad polyurethane, acrylic resin, polyester, acrylic-ester copolymer, polytetrafluoroethylene, polypropylene, polyethylene, poly4-methylpentene, cellulose, cellulose ester, polyamide (for example, nylon (trade name)) And aramid), polyimide, polyimideamide, polysiloxane copolymer, oxylan compound, phenol resin, polystyrene, polycarbonate, epoxy resin and other resins can be used.
• the material of the polishing pad at least one selected from the group consisting of foamed polyurethane and non-foamed polyurethane is preferable from the viewpoint of easily obtaining excellent polishing speed and flatness.
• the polishing pad is preferably grooved so that the polishing liquid collects.
• the polishing conditions are not particularly limited, but from the viewpoint of preventing the substrate from popping out, the rotation speed of the polishing surface plate is preferably 200 rpm (min -1 ) or less, and the pressure (working load) applied to the substrate is to be polished. From the viewpoint of easily suppressing surface scratches, 100 kPa or less is preferable.
• the polishing liquid it is preferable to continuously supply the polishing liquid to the polishing pad by a pump or the like. Although the supply amount is not limited, it is preferable that the surface of the polishing pad is always covered with the polishing liquid.
• polishing After the polishing is completed, it is preferable to thoroughly wash the substrate in running water, and further remove the water droplets adhering to the substrate with a spin dryer or the like before drying.
• the substrate thus obtained can be used as various electronic parts and mechanical parts.
• semiconductor devices include semiconductor devices; optical glass such as photomasks, lenses, and prisms; inorganic conductive films such as ITO; optical integrated circuits, optical switching elements, and optical waveguides composed of glass and crystalline materials; end faces of optical fibers.
• Optical single crystals such as scintillators; solid-state laser single crystals; sapphire substrates for blue laser LEDs; semiconductor single crystals such as SiC, GaP, and GaAs; glass substrates for magnetic disks; magnetic heads and the like.
• the type and mixing ratio of the material of the polishing liquid may be a type and ratio other than the type and ratio described in this example, and the composition and structure to be polished are also other than the composition and structure described in this example.
• the composition and structure of the above may be used.
• a CMP polishing liquid containing 1.0% by mass of the above-mentioned abrasive grains, the acid components (hydroxy acid compounds and other acid components) shown in Tables 1 to 3, and deionized water (remaining portion) was obtained.
• the average particle size of the abrasive grains in the polishing liquid was measured using a laser diffraction / scattering type particle size distribution meter (manufactured by HORIBA, Ltd., trade name: LA-920), the average particle size was 90 nm in each case. ..
• the pH of the CMP polishing liquid was measured under the following conditions.
• the pH of Examples and Comparative Examples other than Comparative Example 1 was 3.5, and the pH of Comparative Example 1 was 5.0.
• the blanket wafer is a wafer having a silicon oxide film having a film thickness of 1000 nm arranged on a silicon substrate having a diameter of 200 mm.
• a pattern wafer having an uneven silicon oxide film as a film to be polished was polished under the following polishing conditions to determine the polishing rate.
• a silicon nitride film is formed as a stopper film on a part of a silicon substrate having a diameter of 200 mm, and then the silicon substrate in the portion without the silicon nitride film is etched by 350 nm to form a recess, and then a recess is formed by a plasma CVD method. It was obtained by forming a silicon oxide film of 600 nm on the stopper film and in the recess.
• Polishing device CMP polishing machine Mira3400 (manufactured by APPLIED MATERIALS) Polishing pad: Porous urethane pad IC-1010 (manufactured by Rohm and Haas Japan) Polishing pressure: 3.0 psi (20.7 kPa) Surface plate rotation speed: 126 rpm Head rotation speed: 125 rpm Supply amount of CMP polishing liquid: 200 mL / min Polishing time: 30 seconds
• polishing speed (Calculation of blanket wafer polishing speed) The film thickness of the silicon oxide film before and after polishing was measured using an optical interference type film thickness measuring device (device name: F80) manufactured by Filmometrics. The film thicknesses of 79 points located at equal intervals on the line (diameter) passing through the center of the wafer were measured, and the average value was obtained as the film thickness.
• polishing speed (Film thickness before polishing [ ⁇ ] -Film thickness after polishing [ ⁇ ]) / Polishing time [min]

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