Polishing composition

Abstract

Provided is a novel polishing composition capable of suppressing depression while reducing the residue of an object to be polished such as polycrystalline silicon. The polishing composition includes: colloidal silica; an alkali metal salt; a polyalkylene glycol; at least one of a cellulose derivative and a polymer compound X; and water; the pH of the polishing composition is 9.0-11.5, and the specific definition of the polymer compound X is as defined in the description: (i) the polishing composition is used in a step for exposing a first layer by polishing a second layer in an object to be polished having the first layer provided with a recess and the second layer formed so as to fill the recess, and (i) the polishing composition is used in a step for exposing the first layer by polishing the second layer in the object to be polished having the first layer provided with the recess and the second layer formed so as to fill the recess; the first layer is selected from one having an oxygen-silicon bond or a nitrogen-silicon bond, and the second layer has a silicon-silicon bond; and / or (ii) the number of silanol groups in the colloidal silica is from 6 / nm2 to 22 / nm2 (inclusive).

Description

TECHNICAL FIELD

[0001] The present application relates to a polishing composition. BACKGROUND

[0002] In the field of CMP, sometimes a silicon dioxide film provided with a recess and a polysilicon film formed so as to fill the recess are configured, and the silicon dioxide film is polished as a barrier layer.

[0003] As an index indicating how easily the polysilicon film is polished relative to the silicon dioxide film, the selectivity ratio of the speed at which the polysilicon film is polished to the speed at which the silicon dioxide film is polished is used. This is obtained by dividing the speed at which the polysilicon film is polished by the speed at which the silicon dioxide film is polished. In order for the silicon dioxide film to function as a barrier layer, it is preferable that the selectivity ratio be large. For example, in Patent Literature 1, as a problem to be solved, a polishing composition capable of obtaining a large selectivity ratio and having a small number of surface defects is provided, and a polishing composition including a polishing material such as silicon dioxide and water, and optionally an alkaline organic compound such as tetramethylammonium hydroxide is provided.

[0004] In addition, silicon nitride is sometimes used as a barrier film, and in this case, it is also preferable that the ratio of the polishing speed of a material other than silicon nitride to the polishing speed of silicon nitride be large. As an example in which silicon nitride is used as a barrier film, in Patent Literature 2, a chemical mechanical polishing composition is disclosed, which is formed of silicon dioxide, amino phosphonic acid, polysaccharide, a tetraalkylammonium salt, a hydrogen carbonate salt, a compound including an azole ring, potassium hydroxide belonging to any of the components, and water, and the pH of the polishing composition is 7 to 11.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: Japanese Patent Application Laid-Open No. 10-321569

[0008] Patent Literature 2: Japanese Patent Application Laid-Open No. 2014-505358 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The present inventors and others have found, in the course of developing a new polishing composition, that in the prior art, even if the selectivity ratio is controlled, the polishing target such as polysilicon that should be polished remains after polishing, or a recess is generated.

[0011] Therefore, the present application aims to provide a new polishing composition that reduces the remaining of the polishing target such as polysilicon while also suppressing the generation of a recess.

[0012] SOLUTION TO THE PROBLEM

[0013] One embodiment of the present application is a polishing composition,

[0014] which contains: colloidal silica; an alkali metal salt; a polyalkylene glycol; at least one of a cellulose derivative and a high-molecular compound X; and water; the pH of the polishing composition is 9.0 to 11.5,

[0015] The aforementioned high-molecular compound X contains a repeating unit represented by the following formula (1):

[0016]

[0017] In the aforementioned formula (1), A is a group selected from at least one of the following,

[0018]

[0019] m is an integer of 1 to 5, R 1 ~R 4 are each independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, wherein R 1 and R 2 optionally form a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally form a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, in formula 1-1, the ring optionally contains at least one oxygen atom,

[0020] The aforementioned high-molecular compound X optionally further contains a repeating unit represented by the following formula (2):

[0021]

[0022] In the aforementioned formula (2), A is a hydroxyl group,

[0023] (i) A polishing composition is used in a process of polishing a second layer of a polishing object having a first layer provided with a recess and the second layer formed so as to fill the recess, to expose the first layer, the first layer being selected from those having an oxygen-silicon bond or those having a nitrogen-silicon bond, the second layer having a silicon-silicon bond;

[0024]

[0025] (ii) The number of silanol groups of the aforementioned colloidal silica is 6 / nm 2 or more and 22 / nm 2 or less.

[0026] Effects of the Invention

[0027] ​According to the present invention, a novel polishing composition can be provided that reduces the residue of polishing objects such as polycrystalline silicon while suppressing depressions. Attached Figure Description

[0028] Figure 1 It is a simplified cross-sectional view of the object to be ground before grinding.

[0029] Figure 2 It is a simplified cross-sectional view of the object after ideal grinding.

[0030] Figure 3 It is a simplified cross-sectional view of the polished object, which has been polished but not ideally polished, resulting in a depression.

[0031] Figure 4 It is a simplified cross-sectional view of the polished object after polishing, showing that the polished object was not polished ideally and has defects remaining as such.

[0032] Figure 5 It means that they are produced simultaneously. Figure 3 and Figure 4 A simplified cross-sectional view of the object after grinding to remove defects.

[0033] Explanation of reference numerals in the attached figures

[0034] 1st floor

[0035] 2nd floor

[0036] 2a depression,

[0037] 2b represents the residue of the second layer that should be ground.

[0038] 10. Grinding objects

[0039] The object to be ground after 10' grinding. Detailed Implementation

[0040] In the present specification, "X to Y" is used as a meaning that includes the numerical values (X and Y) recited before and after it as lower limit value and upper limit value, and means "X or more and Y or less". In the case where a plurality of "X to Y" is recited, for example, in the case where it is recited as "X1 to Y1 or X2 to Y2", the disclosure of each numerical value as upper limit, the disclosure of each numerical value as lower limit, and the combination of these upper limit and lower limit are all disclosed (i.e., become a legal basis for modification). Specifically, X1 or more modification, Y2 or less modification, X1 or less modification, Y2 or more modification, X1 to X2 modification, X1 to Y2 modification, and the like should be considered to be all legal. Note that the recitation of "X or more" means X or more than X, and thus includes the meaning of "more than X". Similarly, the recitation of "Y or less" means Y or less than Y, and thus includes the meaning of "less than Y". In addition, unless specifically recited, the measurement of operation and physical properties and the like is measured under the condition of room temperature (20 to 25°C) / relative humidity 40 to 50% RH. Note that the concentration recited in the present specification can be the concentration at the point of use (POU), or can be the concentration before dilution to the concentration at the POU. The dilution ratio can be 2 to 10 times. In addition, it must be understood that the combination of all the embodiments and explanations disclosed in the present specification is disclosed in the present application. That is, it must be understood that it can be a legal basis for modification. In addition, when the content or concentration of each component is explained, it can be the total amount when there are two or more.

[0041] <Polishing composition>

[0042] One embodiment of the present application is a polishing composition comprising: colloidal silica; an alkali metal salt; a polyalkylene glycol; at least one of a cellulose derivative and a high molecular compound X; and water; the pH of the polishing composition is 9.0 to 11.5, and the high molecular compound X contains a repeating unit represented by the following formula (1):

[0043]

[0044] In the above formula (1), A is a group selected from at least one of

[0045]

[0046] m is an integer of 1 to 5, R 1 ~ R 4 are each independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, and here, R 1 and R 2 optionally form a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, and R 3 and R 4Optionally forms a ring, in the case of ring formation, the ring optionally contains at least one oxygen atom, in formula 1-1, the ring optionally contains at least one oxygen atom, the high molecular compound X optionally further comprises the repeating unit represented by the following formula (2):

[0047]

[0048] In the above formula (2), A is a hydroxyl group,

[0049] (i) the polishing composition is used in a step of polishing the second layer of a polishing target having a first layer provided with a recess and a second layer formed so as to fill the recess, to expose the first layer, the first layer is selected from a group consisting of a member having an oxygen-silicon bond or a member having a nitrogen-silicon bond, and the second layer has a silicon-silicon bond; and / or (ii) the colloidal silica has a silanol group number of 6 / nm 2 above and 22 / nm 2 below. According to the above-described mode, it is possible to provide a novel polishing composition which can reduce the residue of a polishing target such as polysilicon to be polished while also inhibiting dishing.

[0050] The mechanism of embodying such technical effects is considered as follows. In an alkaline pH region, the polishing composition becomes a state of being rich in hydroxide ions (OH - ) and the surface of the polishing target such as polysilicon having a silicon-silicon bond becomes a silanol group (SiOH). At the time of polishing, the polishing target which has become a silanol group (SiOH) is promoted to react with the colloidal silica having a silanol group number in the above-described range through a hydrogen bond, and the residue on the pattern wafer is reduced. In addition, it is presumed that by using an alkali metal salt, the excessive etching of the polishing target having a silicon-silicon bond is inhibited, and as a result, the inhibition of dishing is effective. In addition to this, it is considered that the cellulose derivative and / or the high molecular compound X in the polishing composition protect the polysilicon surface by being adsorbed to the polysilicon surface, and the generation of dishing is further inhibited. On the other hand, it is considered that by the cellulose derivative and / or the high molecular compound X, the removal of silicon and the like which is locally left on the pattern wafer is hindered, and there is a concern that the residue of silicon and the like will increase, but by the presence of the polyalkylene glycol which has a low adsorption force to silicon and the like, the above-described situation is inhibited. That is, it is considered that the polishing composition of the present application can give a high level of balance between the reduction of the residue of the polishing target such as polysilicon to be polished and the inhibition of dishing by the above-described multiple mechanisms in cooperation. However, the above-described mechanism is only a presumption, and the scope of the protection of the present application is not limited by the above-described mechanism.

[0051] [abrasive particles]

[0052] The polishing composition of one embodiment of the present application contains colloidal silica as abrasive grains. The abrasive grains have a function of mechanically polishing a polishing target. The colloidal silica can be produced by a sol-gel method. For example, it can be obtained by performing a hydrolysis-condensation reaction using a hydrolyzable silicon compound (for example, an alkoxysilane or a derivative thereof) as a raw material.

[0053] According to one embodiment of the present application, the number of silanol groups of the colloidal silica is 6 / nm 2 or more than 22 / nm 2 The following. Although the detailed mechanism is not clear, by using the colloidal silica whose number of silanol groups is 6 / nm 2 or more than 22 / nm 2 The following, surprisingly, the residue of the polishing target to be polished such as polysilicon is reduced, and the dishing is further suppressed. In other words, if the number of silanol groups of the colloidal silica is less than 6 / nm 2 or more than 22 / nm 2 there is a concern that the residue of the polishing target to be polished such as polysilicon is increased, or the dishing is promoted. As a method of controlling the number of silanol groups of the colloidal silica to be 6 / nm 2 or more than 22 / nm 2 The following, for example, there are: hydrothermal treatment of a dispersion liquid containing colloidal silica. As a condition of the hydrothermal treatment, the dispersion liquid containing colloidal silica is heated at a temperature of, for example, 100°C to 200°C for 30 to 60 minutes.

[0054] According to one embodiment of the present application, the number of silanol groups of the colloidal silica is 6.1 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2 or more than 22 / nm 2above, 7.7 per nm 2 above, 7.8 per nm 2 above, 9 per nm 2 above, 10 per nm 2 above, 12 per nm 2 above, 14 per nm 2 above, or 16 per nm 2 above.

[0055] According to an embodiment of the present application, the colloidal silica has a silanol group number of 21 per nm 2 below, 20 per nm 2 below, 19 per nm 2 below, 18 per nm 2 below, less than 17.5 per nm 2 , 17 per nm 2 below, 16 per nm 2 below, 15 per nm 2 below, 14 per nm 2 below, 13 per nm 2 below, 12 per nm 2 below, 11 per nm 2 below, 10 per nm 2 below, 9 per nm 2 below, 8 per nm 2 below, or 7 per nm 2 below. The method for measuring the number of silanol groups is based on the method described in the examples.

[0056] According to an embodiment of the present application, the colloidal silica has a pulse NMR specific surface area of 40 m 2 / g or less. According to an embodiment of the present application, the colloidal silica has a pulse NMR specific surface area of 39 m 2 / g or less, 38 m 2 / g or less, 37 m 2 / g or less, 36 m 2 / g or less, 35 m 2 / g or less, 34 m 2 / g or less, 33 m 2 / g or less, 32 m 2 / g or less, 31 m 2 / g or less, 30 m 2 / g or less, 29 m 2 / g or less, 28 m 2 / g or less, 27 m 2 / g or less, 26 m 2 / g or less, 25 m 2 / g or more than 24 m 2 / g or more than 24 m 2 / g or more than 24 m 2 / g or more than 24 m 2 / g or more than 24 m The measurement method of the specific surface area of the abrasive grains (particularly, colloidal silica) by pulsed NMR is based on the method described in the examples. For the specific surface area of the colloidal silica by pulsed NMR, since the relaxation speed of the proton resonance varies depending on the amount of molecules adsorbed to the surface of the solid and the like, it is possible to control according to the increase or decrease of the number of protons of the functional groups on the surface of the colloidal silica.

[0057] According to an embodiment of the present application, the lower limit of the average primary particle diameter of the abrasive grains (particularly, colloidal silica) is 60 nm or more, 70 nm or more, more than 70 nm, 71 nm or more, 72 nm or more, 73 nm or more, 74 nm or more, 75 nm or more, 76 nm or more, 77 nm or more, 78 nm or more, 79 nm or more, 80 nm or more, 81 nm or more, 82 nm or more, 83 nm or more, 84 nm or more, 85 nm or more, 86 nm or more, 87 nm or more, 88 nm or more, 89 nm or more, or 95 nm or more.

[0058] According to an embodiment of the present application, the upper limit of the average primary particle diameter of the abrasive grains (particularly, colloidal silica) is 110 nm or less, less than 100 nm, 99 nm or less, 98 nm or less, 97 nm or less, 96 nm or less, 95 nm or less, 94 nm or less, 93 nm or less, 92 nm or less, or 91 nm or less. According to an embodiment of the present application, the average primary particle diameter of the colloidal silica is more than 70 nm and less than 100 nm. The measurement method of the average primary particle diameter is based on the method described in the examples.

[0059] According to an embodiment of the present application, the lower limit of the average secondary particle diameter of the abrasive grains (particularly, colloidal silica) is 110 nm or more, 120 nm or more, 130 nm or more, 140 nm or more, 150 nm or more, 160 nm or more, 170 nm or more, 180 nm or more, 190 nm or more, 200 nm or more, 210 nm or more, or 215 nm or more.

[0060] According to one embodiment of the present application, the upper limit of the average secondary particle diameter of the abrasive grains (particularly, colloidal silica) is 350 nm or less, 340 nm or less, 330 nm or less, 320 nm or less, 310 nm or less, 300 nm or less, 290 nm or less, 280 nm or less, 270 nm or less, 260 nm or less, 250 nm or less, 240 nm or less, 230 nm or less, or 225 nm or less. The measurement method of the average secondary particle diameter is based on the method described in the Examples.

[0061] According to one embodiment of the present application, the average association degree (average secondary particle diameter / average primary particle diameter) of the abrasive grains (particularly, colloidal silica) is 1.6 or more, 1.7 or more, 1.8 or more, 1.9 or more, 2.0 or more, 2.1 or more, 2.2 or more, 2.3 or more, or 2.4 or more.

[0062] According to one embodiment of the present application, the average association degree (average secondary particle diameter / average primary particle diameter) of the abrasive grains (particularly, colloidal silica) is 4.6 or less, 4.4 or less, 4.2 or less, 4.0 or less, 3.8 or less, 3.6 or less, 3.4 or less, 3.2 or less, 3.0 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, or 2.5 or less.

[0063] According to one embodiment of the present application, the content ratio of the abrasive grains (particularly, colloidal silica) in the polishing composition is 0.01 mass% or more, 0.05 mass% or more, 0.1 mass% or more, 0.5 mass% or more, 0.6 mass% or more, 0.7 mass% or more, 0.8 mass% or more, 0.9 mass% or more, 1.0 mass% or more, 1.1 mass% or more, 1.2 mass% or more, 1.3 mass% or more, or 1.4 mass% or more.

[0064] According to one embodiment of the present application, the content ratio of the abrasive grains (particularly, colloidal silica) in the polishing composition is 10 mass% or less, 5 mass% or less, 3 mass% or less, or 2 mass% or less.

[0065] According to one embodiment of the present application, the content of colloidal silica in the abrasive grains contained in the polishing composition is 90 mass% or more, 95 mass% or more, 98 mass% or more, 99 mass% or more, 99.5 mass% or more, or 99.9 mass% or more (the upper limit is 100 mass%).

[0066] According to one embodiment of the present application, the surface of the abrasive grains (particularly, colloidal silica) contained in the polishing composition is not subjected to a treatment of chemically bonding a treating agent such as an organic acid (for example, sulfonic acid, carboxylic acid), and the like.

[0067] [Alkali Metal Salts]

[0068] The polishing composition according to an embodiment of the present application contains a basic metal salt. If the polishing composition does not contain a basic metal salt, there is a concern that the polishing object to be polished, such as polysilicon, cannot be reduced in residue or that dishing is promoted.

[0069] According to an embodiment of the present application, at least one of a hydroxide containing a basic metal and a carbonate containing a basic metal is contained as the basic metal salt. According to an embodiment of the present application, a hydroxide containing a basic metal is contained as the basic metal salt. According to an embodiment of the present application, potassium hydroxide is contained as the hydroxide containing a basic metal. Of the basic metal salts, from the viewpoint of reducing the residue metal, the hydroxide containing a basic metal is preferable compared to the carbonate containing a basic metal. As the basic metal, potassium, sodium, lithium, and the like can be given, of which, from the viewpoint of reducing the residue metal, potassium is particularly preferable.

[0070] The basic metal salt also functions as a pH adjuster for adjusting the pH of the polishing composition. According to an embodiment of the present application, the content of the pH adjuster (particularly, the basic metal salt) contained in the polishing composition is an appropriate amount for adjusting the polishing composition to a prescribed pH (particularly, pH 9.0 to 11.5).

[0071] According to an embodiment of the present application, the basic metal salt (particularly, potassium hydroxide) is 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, 99.5% by mass or more, or 99.9% by mass or more (upper limit: 100% by mass) of the pH adjuster contained in the polishing composition. According to an embodiment of the present application, the potassium hydroxide is 90% by mass or more, 95% by mass or more, 98% by mass or more, 99% by mass or more, 99.5% by mass or more, or 99.9% by mass or more (upper limit: 100% by mass) of the pH adjuster contained in the polishing composition. Note that the abrasive grains (particularly, colloidal silica), the polyalkylene glycol, the cellulose derivative, the high-molecular compound X, and the optional preservative have a low ability to change the pH of the polishing composition even if they have some function to change the pH, and therefore, they are not included in the category of the pH adjuster in the present application.

[0072] [Polyalkylene glycol]

[0073] The polishing composition according to an embodiment of the present application contains a polyalkylene glycol. If the polishing composition does not contain a polyalkylene glycol, there is a concern that the polishing object to be polished, such as polysilicon, increases in residue. Note that the polyalkylene glycol can be used alone or in combination of two or more. In addition, a commercially available product or a synthetic product can be used as the polyalkylene glycol.

[0074] As the kind of the polyalkylene glycol, there is no particular limitation, and for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol-polypropylene glycol random copolymer, polyethylene glycol-polytetramethylene glycol random copolymer, polypropylene glycol-polytetramethylene glycol random copolymer, polyethylene glycol-polypropylene glycol-polytetramethylene glycol random copolymer, polyethylene glycol-polypropylene glycol block copolymer, polypropylene glycol-polyethylene glycol-polypropylene glycol triblock copolymer, polyethylene glycol-polypropylene glycol-polyethylene glycol triblock copolymer, and the like can be given. Among these, from the viewpoint of more effectively reducing the residue of the polishing object to be polished such as polysilicon, polyethylene glycol, polypropylene glycol, and more preferably polyethylene glycol are preferred.

[0075] In one embodiment of the present application, the weight average molecular weight (Mw) of the polyalkylene glycol is 50 or more, 70 or more, 90 or more, 100 or more, 120 or more, 150 or more, 160 or more, 170 or more, 180 or more, or 190 or more. In one embodiment of the present application, the weight average molecular weight (Mw) of the polyalkylene glycol is 2000 or less, 1500 or less, 1000 or less, 800 or less, 700 or less, 600 or less, 500 or less, 400 or less, 300 or less, or 250 or less. In one embodiment of the present application, the weight average molecular weight of the polyalkylene glycol is, for example, 100 or more and 1000 or less, 100 or more and 500 or less, or 150 or more and 300 or less. If it is in the above range, the effect of reducing the residue of the polishing object to be polished such as polysilicon while controlling the selection ratio becomes more apparent.

[0076] Note that in the present specification, the weight average molecular weight of the polyalkylene glycol can be measured by gel permeation chromatography (GPC) using polyethylene glycol as a standard substance. The detailed measurement method is as described in the examples.

[0077] In one embodiment of the present application, the mass concentration of the polyalkylene glycol in the polishing composition is 1 mass ppm or more, 2 mass ppm or more, 4 mass ppm or more, 6 mass ppm or more, 8 mass ppm or more, 10 mass ppm or more, more than 10 mass ppm, 15 mass ppm or more, 20 mass ppm or more, 25 mass ppm or more, 30 mass ppm or more, 35 mass ppm or more, 40 mass ppm or more, more than 40 mass ppm, 60 mass ppm or more, or 80 mass ppm or more. In one embodiment of the present application, the mass concentration of the polyalkylene glycol in the polishing composition is 1000 mass ppm or less, 800 mass ppm or less, 600 mass ppm or less, 400 mass ppm or less, 200 mass ppm or less, 150 mass ppm or less, 100 mass ppm or less, less than 100 mass ppm, 80 mass ppm or less, 60 mass ppm or less, 50 mass ppm or less, 40 mass ppm or less, 30 mass ppm or less, 20 mass ppm or less, or 15 mass ppm or less. In one embodiment of the present application, the mass concentration of the polyalkylene glycol in the polishing composition is, for example, 1 mass ppm or more and 1000 mass ppm or less, 4 mass ppm or more and 600 mass ppm or less, 8 mass ppm or more and 400 mass ppm or less, or 10 mass ppm or more and 200 mass ppm or less. If it is within the above range, the effect of reducing the residue of the polishing object to be polished such as polysilicon becomes more apparent.

[0078] [Cellulose derivative and high-molecular compound X]

[0079] The polishing composition of one embodiment of the present application contains at least one of a cellulose derivative and a high-molecular compound X. If the polishing composition does not contain at least one of a cellulose derivative and a high-molecular compound X, there is a concern that dishing is promoted. Note that the cellulose derivative and the high-molecular compound X can be used alone or in combination with two or more kinds. In addition, the cellulose derivative and the high-molecular compound X can be a commercially available product or a synthetic product.

[0080] (Cellulose derivative)

[0081] In one embodiment of the present application, the "cellulose derivative" refers to a substance in which part of the hydroxyl groups of cellulose is substituted with another different substituent. The cellulose derivative can be used alone or in combination with two or more kinds. As the cellulose derivative, for example, a cellulose derivative such as hydroxyethyl cellulose (HEC), hydroxypropyl cellulose, hydroxyethyl methyl cellulose, hydroxypropyl methyl cellulose, methyl cellulose, ethyl cellulose, ethyl hydroxyethyl cellulose, carboxymethyl cellulose, and the like, and a pullulan, and the like can be given.

[0082] (High molecular compound X)

[0083] The high molecular compound X contains a repeating unit represented by the following formula (1):

[0084]

[0085] In the above formula (1), A is a group selected from at least one of

[0086]

[0087] m is an integer of 1 to 5, R 1 ~R 4 each is independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, and here, R 1 and R 2 optionally form a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally form a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, and in formula 1-1, the ring optionally contains at least one oxygen atom. Here, * indicates a bonding site. The number of oxygen atoms contained in the ring is, for example, 1 or 2. In addition, the high molecular compound X optionally contains a repeating unit represented by the following formula (2):

[0088]

[0089] In the above formula (2), A is a hydroxyl group.

[0090] In one embodiment of the present application, R 1 and R 2 each is independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4. In one embodiment of the present application, R 3 and R 4 each is independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4.

[0091] In one embodiment of the present application, m is 1, 2, 3, or 4.

[0092] In one embodiment of the present application, R 1 ~R 4 the alkyl group has a carbon number of 1 to 3 or 1 or 2. In one embodiment of the present application, the alkyl group having a carbon number of 1 to 4 is, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, or a tert-butyl group.

[0093] In one embodiment of the present application, at least one of R 1 and R 2 is a hydrogen atom.

[0094] In one embodiment of the present application, R 3and R 4 one of R and R is a hydrogen atom, and the other is an alkyl group having 1 to 4 carbon atoms.

[0095] In the high molecular compound X in one embodiment of the present application, in the case where the repeating unit in which A in Formula (1) is represented by at least one of Formula (1-1), Formula (1-2), and Formula (1-3) is contained, the total of these repeating units is 90 mol% or more or 95 mol% or more (the upper limit is 100 mol%) in the high molecular compound X. In one embodiment of the present application, in the case where the high molecular compound X contains the repeating unit in which A in Formula (1) is Formula (1-1), the total of these repeating units is 90 mol% or more or 95 mol% or more (the upper limit is 100 mol%) in the high molecular compound X.

[0096] In the high molecular compound X in one embodiment of the present application, in the case where the repeating unit in which A in Formula (1) is at least one of Formula (1-1), Formula (1-2), and Formula (1-3) and the repeating unit in which A in Formula (2) is a hydroxyl group is contained, the total of these repeating units is 90 mol% or more or 95 mol% or more (the upper limit is 100 mol%) in the high molecular compound X. In one embodiment of the present application, in the case where the high molecular compound X contains the repeating unit in which A in Formula (1) is Formula (1-1) and the repeating unit in which A in Formula (2) is a hydroxyl group, the total of these repeating units is 90 mol% or more or 95 mol% or more (the upper limit is 100 mol%) in the high molecular compound X.

[0097] In one embodiment of the present application, as a specific example of the repeating unit in which A is Formula (1-1) (an N-vinyl lactam type repeating unit), N-vinyl pyrrolidone (VP), N-vinyl piperidone, N-vinyl caprolactam (VC), and the like can be given. In one embodiment of the present application, as a suitable example of a polymer containing an N-vinyl lactam type repeating unit, a vinyl pyrrolidone-based polymer can be given.

[0098] Here, the vinyl pyrrolidone-based polymer refers to a homopolymer of VP or a copolymer of VP (e.g., a copolymer in which the copolymerization ratio of VP is more than 20 mol%). Here, as a copolymer of VP, a copolymer of VP and VA (vinyl alcohol) (PVA-PVP) can be given. In the vinyl pyrrolidone-based polymer, the ratio of the number of moles of VP units to the number of moles of all repeating units is usually 20 mol% or more, and can be 25 mol% or more, 30 mol% or more, 50 mol% or more, 80 mol% or more, 90 mol% or more, 95 mol% or more (the upper limit is 100 mol%).

[0099] In one embodiment of the present application, as a specific example of the repeating unit of A being formula (1-2) (a repeating unit derived from a monomer of the α,β-unsaturated amide type), acryloylmorpholine, acrylamide, dimethyl acrylamide, N-isopropyl acrylamide, and the like can be given. The above R 3 and R 4 One example of forming a ring and containing at least one oxygen atom in the ring is acryloylmorpholine. In one embodiment of the present application, as a suitable example of a polymer derived from a monomer of the α,β-unsaturated amide type, an acrylamide-based polymer can be given. Here, the acrylamide-based polymer refers to a homopolymer of acrylamide or a copolymer of acrylamide (for example, a copolymer in which the copolymerization ratio of acrylamide is more than 50 mol%). In the acrylamide-based polymer, the ratio of the number of moles of acrylamide units to the number of moles of all repeating units is usually 50 mol% or more, and is suitably 80 mol% or more (for example, 90 mol% or more, typically 95 mol% or more) (the upper limit is 100 mol%).

[0100] In one embodiment of the present application, as a specific example of the repeating unit of A being formula (1-3) (a repeating unit of the N-vinyl chain amide type), N-vinyl acetamide, N-vinyl propionamide, N-vinyl butyramide, and the like can be given. In one embodiment of the present application, as a suitable example of a polymer containing a repeating unit of the N-vinyl chain amide type, a vinyl acetamide-based polymer can be given. Here, the vinyl acetamide-based polymer refers to a homopolymer of vinyl acetamide or a copolymer of vinyl acetamide (for example, a copolymer in which the copolymerization ratio of vinyl acetamide is more than 50 mol%). In the vinyl acetamide-based polymer, the ratio of the number of moles of vinyl acetamide units to the number of moles of all repeating units is usually 50 mol% or more, and is suitably 80 mol% or more (for example, 90 mol% or more, typically 95 mol% or more) (the upper limit is 100 mol%).

[0101] In one embodiment of the present application, the high-molecular compound X can be polyvinylpyrrolidone, polyacrylamide, poly-N-vinyl acetamide, or a copolymer of vinyl pyrrolidone and vinyl alcohol (PVP-PVA). Among these, from the viewpoint of reducing the residue of the polishing object to be polished such as polysilicon while also inhibiting dishing, polyvinylpyrrolidone or a copolymer of vinyl pyrrolidone and vinyl alcohol (PVP-PVA) is suitable, and polyvinylpyrrolidone is more suitable.

[0102] In one embodiment of the present application, the weight average molecular weight of the cellulose derivative and the high molecular compound X is each independently 1000 or more, 2000 or more, 4000 or more, 6000 or more, 8000 or more, more than 8000, 10000 or more, 20000 or more, 40000 or more, 43000 or more, 47000 or more, 60000 or more, 90000 or more, 120000 or more, 160000 or more, 200000 or more, 500000 or more, or 1000000 or more. In one embodiment of the present application, the weight average molecular weight of the cellulose derivative and the high molecular compound X is each independently 2000000 or less, 1500000 or less, 1000000 or less, 500000 or less, 400000 or less, 300000 or less, less than 250000, 250000 or less, 100000 or less, 90000 or less, 80000 or less, 70000 or less, 60000 or less, 50000 or less, 40000 or less, 30000 or less, 20000 or less, or 10000 or less. In one embodiment of the present application, the weight average molecular weight of the cellulose derivative and the high molecular compound X is each independently 1000 or more and 2000000 or less. In addition, in one embodiment of the present application, the weight average molecular weight of the cellulose derivative can be 500000 or more and 2000000 or less, or 1000000 or more and 1500000 or less. In addition, in one embodiment of the present application, the weight average molecular weight of the high molecular compound X can be 1000 or more and 250000 or less, 10000 or more and 100000 or less, or 20000 or more and 90000 or less. If the above range is satisfied, the effect of reducing the residue of the polishing object to be polished such as polysilicon while suppressing the effect of the dishing becomes more apparent.

[0103] In one embodiment of the present application, the mass concentration of the cellulose derivative and the high-molecular compound X in the polishing composition is each independently 1 mass ppm or more, 2 mass ppm or more, 4 mass ppm or more, 6 mass ppm or more, 8 mass ppm or more, 10 mass ppm or more, more than 10 mass ppm, 15 mass ppm or more, 20 mass ppm or more, 25 mass ppm or more, 30 mass ppm or more, 35 mass ppm or more, or 40 mass ppm or more. In one embodiment of the present application, the mass concentration of the cellulose derivative and the high-molecular compound X in the polishing composition is each independently 1000 mass ppm or less, 800 mass ppm or less, 600 mass ppm or less, 400 mass ppm or less, 200 mass ppm or less, 100 mass ppm or less, less than 100 mass ppm, 80 mass ppm or less, 60 mass ppm or less, 50 mass ppm or less, or 40 mass ppm or less. In one embodiment of the present application, the mass concentration of the cellulose derivative and the high-molecular compound X in the polishing composition is each independently more than 10 mass ppm and less than 100 mass ppm. If it is in the above range, the effect of reducing the residue of the polishing target such as polysilicon to be polished while suppressing dishing becomes apparent. Here, in the case where the polishing composition contains two or more kinds of high-molecular compound X, the mass concentration of the high-molecular compound X in the polishing composition means the total of the mass concentrations of the two or more kinds of high-molecular compound X in the polishing composition. In addition, in the case where the polishing composition contains one kind of high-molecular compound X, the mass concentration of the high-molecular compound X in the polishing composition means the mass concentration of the one kind of high-molecular compound X in the polishing composition.

[0104] [pH]

[0105] The pH of the polishing composition of one embodiment of the present application is 9.0 to 11.5. If the pH of the polishing composition is lower than 9.0 or more than 11.5, there is a concern that the effect of reducing the residue of the polishing target such as polysilicon to be polished while suppressing dishing is not obtained.

[0106] According to one embodiment of the present application, the pH of the polishing composition is 9.1 or more, 9.2 or more, 9.3 or more, 9.4 or more, 9.5 or more, more than 9.5, 9.6 or more, 9.7 or more, 9.8 or more, 9.9 or more, or 10.5 or more. According to one embodiment of the present application, the pH of the polishing composition is 11.5 or less, 11.4 or less, 11.3 or less, 11.2 or less, less than 11.2, 11.1 or less, 11 or less, less than 11, 10.9 or less, 10.8 or less, 10.7 or less, 10.6 or less, 10.5 or less, 10.4 or less, 10.3 or less, 10.2 or less, 10.1 or less, or 9.8 or less.

[0107] According to an embodiment of the present application, the pH of the polishing composition is more than 10.0 and less than 11.2. If it is in the above range, the effect of reducing the residue of the polishing object such as polysilicon to be polished and suppressing the recess becomes more obvious.

[0108] According to an embodiment of the present application, the pH of the polishing composition is not 9.1, 9.2, 9.3, 9.4, 9.6, 9.7, 9.8, 9.9, 10.1, 10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.9, 11.1, 11.3, 11.4 or 11.5. The measuring method of the pH of the polishing composition is based on the method described in the Examples.

[0109] [Polishing Object]

[0110] According to an embodiment of the present application, the polishing composition of the present application is used in a step of polishing the second layer of a polishing object having a first layer provided with a recess and a second layer formed so as to fill the recess, to expose the first layer. Figure 1 is a schematic cross-sectional view of the (pre-polishing) polishing object. As shown in Figure 1 the upper drawing of FIG. 1, a first layer 1 (a film having an oxygen-silicon bond or a film having a nitrogen-silicon bond) is formed on an arbitrary film (for example, a Si substrate) so as to provide a recess. Then, as shown in Figure 1 the lower drawing of FIG. 1, a second layer 2 (a film having a silicon-silicon bond) is formed so as to fill the recess, thereby forming a polishing object 10 including the first layer and the second layer.

[0111] According to an embodiment of the present application, when the polishing composition of the present application is applied, as shown in Figure 2 , the polished polishing object 10' as a post-polishing polishing object can become a desired polished surface in which the residue of the polishing object to be polished (the film having a silicon-silicon bond) is reduced (no residue) and / or the recess is suppressed (not generated). In addition, by applying the polishing composition of the present application, the number of metal atoms that can remain after polishing can also be reduced. According to an embodiment of the present application, the number of metal atoms remaining per 1 cm 2 of the polished polishing object (unit: x 10 10 atoms / cm 2 ) is less than 40, less than 38, less than 35, less than 30, less than 25, less than 24, less than 20, less than 19 or less than 17. According to an embodiment of the present application, the number of metal atoms remaining per 1 cm 2 of the polished polishing object (unit: x 10 10 atoms / cm 2for example, 0, 0.01 or more, 0.5 or more, 1 or more, 5 or more, or 10 or more. Note that, Figure 3 is a schematic cross-sectional view of the generation of a recess 2a. Figure 4 is a schematic cross-sectional view of the generation of a residue 2b of a polishing target (a film having a silicon-silicon bond) to be polished. Figure 5 is a schematic cross-sectional view of the simultaneous generation of a recess 2a and a residue 2b of a polishing target (a film having a silicon-silicon bond) to be polished.

[0112] In one embodiment of the present application, as the polishing target having an oxygen-silicon bond, TEOS-type silicon oxide (hereinafter, also referred to as "TEOS") generated using tetraethyl orthosilicate as a precursor, HDP (High Density Plasma), USG (Undoped Silicate Glass), PSG (Phosphorus Silicate Glass), BPSG (Boron-Phospho Silicate Glass), or RTO (Rapid Thermal Oxidation), and the like can be given. A TEOS film can be formed by plasma CVD.

[0113] In one embodiment of the present application, as the polishing target having a nitrogen-silicon bond, a silicon nitride film or SiCN (silicon carbonitride), and the like can be given. As a raw material of a barrier film, it is suitable to contain a polishing target having a nitrogen-silicon bond in the first layer. In one embodiment of the present application, as the polishing target having a silicon-silicon bond, polysilicon, amorphous silicon, single crystal silicon, n-type doped single crystal silicon, p-type doped single crystal silicon, SiGe, and the like can be given. Among them, the second layer is preferably polysilicon (polycrystalline silicon).

[0114] [Polishing rate]

[0115] According to one embodiment of the present application, the polishing composition has a polishing rate of the second layer of 0.1 μm / min or more, 0.5 μm / min or more, 1 μm / min or more, 5 μm / min or more, or 10 μm / min or more. / minute or more, / minute or more, / minute or more, / minute or more, or / minute or more. According to one embodiment of the present application, the polishing composition has a polishing rate of the second layer of 0.1 μm / min or more, 0.5 μm / min or more, 1 μm / min or more, 5 μm / min or more, or 10 μm / min or more. / minute or less, / minute or less, / minute or less, or / minute or less.

[0116] According to one embodiment of the present application, in the case where the first layer has an oxygen-silicon bond, the polishing composition has a polishing rate of the first layer of / minute or more, / minute or more, / minute or more, / minute or more, / minute or more, or / minute or more. According to one embodiment of the present application, in the case where the first layer has an oxygen-silicon bond, the polishing composition has a polishing rate of the first layer of / minute or less, / minute or less, / minute or less, / minute or less, / minute or less, or / minute or less.

[0117] According to one embodiment of the present application, in the case where the first layer has a nitrogen-silicon bond, the polishing composition has a polishing rate of the first layer of / minute or more, / minute or more, / minute or more, / minute or more, / minute or more, / minute or more, / minute or more, / minute or more, or / minute or more. According to one embodiment of the present application, in the case where the first layer has a nitrogen-silicon bond, the polishing composition has a polishing rate of the first layer of / minute or less, / minute or less, / minute or less, / minute or less, or / minute or less.

[0118] [Selection Ratio]

[0119] According to one embodiment of the present application, in the case where the first layer has an oxygen-silicon bond, the polishing composition has a polishing rate of the second layer relative to the polishing rate of the first layer (selection ratio) of 17 to 40 or 20 to 40.

[0120] According to one embodiment of the present application, in the case where the first layer has a nitrogen-silicon bond, the polishing composition has a polishing rate of the second layer relative to the polishing rate of the first layer (selection ratio) of more than 40 and 100 or less, 45 to 95, 50 to 90, 55 to 85, or 60 to 80.

[0121] According to one embodiment of the present application, in the case where the first layer has an oxygen-silicon bond, the polishing composition has a property in which the selectivity ratio becomes 17 or more, 18 or more, 19 or more, 20 or more, 21 or more, 22 or more, 23 or more, 24 or more, 25 or more, 26 or more, 27 or more, 28 or more, 29 or more, 30 or more, 31 or more, 32 or more, 33 or more, 34 or more, or 35 or more. According to one embodiment of the present application, in the case where the first layer has an oxygen-silicon bond, the polishing composition has a property in which the selectivity ratio becomes 39 or less, 37 or less, 35 or less, 33 or less, 31 or less, or 29 or less.

[0122] According to one embodiment of the present application, in the case where the first layer has a nitrogen-silicon bond, the polishing composition has a property in which the selectivity ratio becomes more than 40, 45 or more, 50 or more, 55 or more, 60 or more, 65 or more, or 70 or more. According to one embodiment of the present application, in the case where the first layer has a nitrogen-silicon bond, the polishing composition has a property in which the selectivity ratio becomes 95 or less, 90 or less, 85 or less, 80 or less, 75 or less, or 70 or less.

[0123] [Transmittance]

[0124] According to one embodiment of the present application, in the case where the concentration of the abrasive grains (particularly, colloidal silica) contained in the polishing composition is 1.5 mass%, the transmittance when light having a wavelength of 450 nm is transmitted through the polishing composition is more than 0.1% and less than 1%. According to the polishing composition of the above-described embodiment, it is possible to suppress the residual of polysilicon. As a method of adjusting the transmittance to the above-described range, for example, a method of adjusting the particle diameter of colloidal silica; and, a method of adjusting the electric conductivity can be mentioned.

[0125] According to one embodiment of the present application, the transmittance is 0.13% or more, 0.15% or more, 0.2% or more, or 0.5% or more. According to one embodiment of the present application, the transmittance is 0.9% or less, 0.7% or less, 0.5% or less, or 0.3% or less.

[0126] Here, in the case where the abrasive grain concentration of the polishing composition is not 1.5 mass%, the abrasive grain concentration can be adjusted to 1.5 mass% as follows. That is, in the case where the abrasive grain concentration of the polishing composition exceeds 1.5 mass%, an appropriate amount of water can be added to make the abrasive grain concentration 1.5 mass%. In the case where the abrasive grain concentration of the polishing composition is less than 1.5 mass%, the polishing composition can be stored at an environment of 25 to 40°C until the abrasive grain concentration becomes 1.5 mass% or a treatment such as ultrafiltration can be performed until the abrasive grain concentration becomes 1.5 mass%.

[0127] [Water]

[0128] The polishing composition according to one embodiment of the present application contains water as an aqueous carrier. According to one embodiment of the present application, the aqueous carrier is not limited to containing methanol, ethanol, ethylene glycol, or the like alcohol; acetone or the like ketone; or the like, but water is 90 mass% or more, 95 mass% or more, 98 mass% or more, 99 mass% or more, 99.5 mass% or more, or 99.9 mass% or more (upper limit: 100 mass%) in the aqueous carrier.

[0129] [Preservative]

[0130] According to one embodiment of the present application, the polishing composition contains a preservative. The polishing composition can be a liquid that is aqueous, and thus, microorganisms (bacteria, mold) easily proliferate, and there is a possibility that stability is impaired during long-term storage or use. Therefore, a preservative can be added, and a preservative having a function of inhibiting the proliferation of microorganisms (bacteria, mold) can be contained. As the preservative, for example, 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 1,2-benzisothiazolin-3(2H)-one (BIT), or the like isothiazolinone-based preservative, methyl parahydroxybenzoate, ethyl parahydroxybenzoate, or the like parahydroxybenzoic acid ester-based preservative, phenoxyethanol, or the like can be given. These preservatives can be used alone or in combination of two or more.

[0131] According to one embodiment of the present application, the polishing composition can contain 0.001 to 1 mass%, 0.005 to 0.5 mass%, or 0.01 to 0.1 mass% of a preservative.

[0132] According to one embodiment of the present application, a polishing composition is provided, which substantially contains only a silanol group number of 6 / nm 2 22 / nm 2at least one of the following: colloidal silica; alkali metal salt; polyalkylene glycol; cellulose derivative and high molecular compound X; preservative; and water, the high molecular compound X containing a repeating unit represented by the following formula (1):

[0133]

[0134] In the above formula (1), A is a group selected from at least one of the following:

[0135]

[0136] m is an integer of 1 to 5, R 1 ~R 4 each independently is selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, and here, R 1 and R 2 optionally forms a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally forms a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, and in formula 1-1, the ring optionally contains at least one oxygen atom, and the high molecular compound X optionally further contains a repeating unit represented by the following formula (2):

[0137]

[0138] In the above formula (2), A is a hydroxyl group, and the pH of the polishing composition is 9.0 to 11.5. The above description regarding the colloidal silica, the alkali metal salt, the polyalkylene glycol, the cellulose derivative, and the at least one of the high molecular compound X, the water, the pH, and the preservative is applicable. The description regarding "substantially contains" is described later.

[0139] [Other Components]

[0140] According to an embodiment of the present application, the polishing composition substantially does not contain at least any of a surfactant, an oxidizing agent, and a compound having a nitrogen atom (excluding the cellulose derivative and the high molecular compound X). "Substantially does not contain" herein means that the content of the component in the polishing composition is 0.1% by mass or less, 0.01% by mass or less, 0.001% by mass or less, or less than 0.0001% by mass, unless otherwise explicitly described.

[0141] The surfactant is a substance having a hydrophilic group and a hydrophobic group. As the surfactant, for example, an alkyl ether type such as polyoxyethylene lauryl ether, polyoxyethylene oleyl ether, and the like; an alkyl phenyl ether type such as polyoxyethylene octyl phenyl ether, and the like; an alkyl ester type such as polyoxyethylene lauryl ester, and the like; an alkyl amine type such as polyoxyethylene lauryl amino ether, and the like; an alkyl amide type such as polyoxyethylene lauryl amide, and the like; a polypropylene glycol ether type such as polyoxyethylene polyoxypropylene ether, and the like; an alkanol amide type such as oleic acid diethanol amide, and the like; an allyl phenyl ether type such as polyoxyalkylene allyl phenyl ether, and the like, and the like can be given. Further, a nonionic surfactant such as propylene glycol, diethylene glycol, monoethanol amine, alcohol ethoxylate, alkyl phenol ethoxylate, a tertiary acetylene glycol, an alkanol amide, and the like; a carboxylic acid type such as sodium myristate, sodium palmitate, sodium stearate, sodium laurate, potassium laurate, and the like; a sulfate type such as sodium octyl sulfate, and the like; a phosphate type such as lauryl phosphate, sodium lauryl phosphate, and the like; a sulfonic acid type such as sodium dioctyl sulfosuccinate, sodium dodecyl benzene sulfonate, and the like; an anionic surfactant such as the above; an amine type such as lauryl amine hydrochloride, and the like; a cationic surfactant such as lecithin, an alkyl amine oxide, an N-alkyl-N,N-dimethyl ammonium betaine, a sulfobetaine, and the like; and the like can be given. According to an embodiment of the present application, the polishing composition substantially does not contain at least one of these. One described in this item is sometimes referred to as one under the meaning of "genus" called "surfactant", and is sometimes referred to as one under the meaning of "species" called "polyoxyethylene lauryl ether", for example. The description regarding the at least one above can also be applied to the description below.

[0142] The oxidizing agent can be a substance having a higher redox potential than that of the substrate material (particularly, polysilicon) at the pH at which the polishing is performed. Here, the pH at which the polishing is performed is generally the same as the pH of the polishing composition. Note that the redox potential of the substrate material can be a value obtained by dispersing a powder of the material (particularly, polysilicon) in water to form a slurry, adjusting the slurry to the same pH as the polishing composition, and measuring the redox potential (the redox potential with respect to a standard hydrogen electrode at a liquid temperature of 25°C) of the slurry using a commercially available redox potential meter. As the oxidizing agent, for example, hydrogen peroxide, a metal oxide, a peroxide, a nitrate, an iodate, a periodate, a hypochlorite, a chlorite, a chlorate, a persulfate, a dichromate, a permanganate, an organic oxidizing agent, ozonated water, a silver (II) salt, an iron (III) salt, and the like can be given. According to an embodiment of the present application, the polishing composition substantially does not contain at least one of these.

[0143] As a compound having a nitrogen atom, for example, hydroxides or salts such as chlorides, carbonates, sulfates, phosphates, and the like of tetramethylammonium, tetraethylammonium, tetrabutylammonium, and the like can be given. As specific examples, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, and the like quaternary ammonium compounds such as tetraalkylammonium hydroxides, tetramethylammonium carbonate, tetramethylammonium chloride, and the like, amines such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, monoethanolamine, N-(β-aminoethyl)ethanolamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, anhydrous piperazine, piperazine hexahydrate, 1-(2-aminoethyl)piperazine, N-methylpiperazine, guanidine, and the like, or ammonia can be given. According to one embodiment of the present application, the polishing composition is substantially free of at least one of these. According to one embodiment of the present application, the content of the tetraalkylammonium salt in the polishing composition is less than 0.05 mass%.

[0144] According to one embodiment of the present application, the polishing composition is substantially free of abrasive particles other than colloidal silica.

[0145] According to one embodiment of the present application, the polishing composition is substantially free of silica having an acidic group (e.g., a sulfo group, a carboxyl group, a phosphoric acid group, or the like) derived from an organic acid fixed on the surface.

[0146] According to one embodiment of the present application, the polishing composition is substantially free of silica having an amino group fixed on the surface.

[0147] According to one embodiment of the present application, the polishing composition is substantially free of an organic acid.

[0148] According to one embodiment of the present application, the polishing composition is free of R 1 R 2 R 3 R 4 N + X - , R 1 R 2 R 3 R 4 P + X - , R 1 R 2 R 3 S + X - , any one of imidazolium salts and pyridinium salts, where R 1 , R 2 , R 3 and R 4 are each independently a C1to C6alkyl group, a C7to C 12 arylalkyl group, or a C6to C 10 aryl group, X -is an anion. The reason for this is that, when this cationic agent having a hydrophobic portion is adsorbed to the surface of colloidal silica, the surface of the colloidal silica becomes hydrophobic, the colloidal silica becomes less likely to be detached from the polishing object (particularly, polysilicon) having high water repellency, and the colloidal silica becomes likely to remain as a residue.

[0149] According to an embodiment of the present application, the polishing composition does not contain carrageenan and xanthan gum.

[0150] According to an embodiment of the present application, the polishing composition substantially does not contain a phosphate ester. In the present specification, "substantially does not contain a phosphate ester" means that the polishing composition can contain less than 0.001 mass% of a phosphate ester, in addition to meaning that the polishing composition does not contain a phosphate ester at all (below the detection limit).

[0151] In an embodiment of the present application, there is provided a polishing composition which is substantially composed of only colloidal silica; an alkali metal salt; a polyalkylene glycol; at least one of a cellulose derivative and a high molecular compound X; and water, the high molecular compound X containing a repeating unit represented by the following formula (1): 2 In an embodiment of the present application, there is provided a polishing composition which is substantially composed of only colloidal silica; an alkali metal salt; a polyalkylene glycol; at least one of a cellulose derivative and a high molecular compound X; and water, the high molecular compound X containing a repeating unit represented by the following formula (1): 2 the following colloidal silica; an alkali metal salt; a polyalkylene glycol; at least one of a cellulose derivative and a high molecular compound X; and water, the high molecular compound X containing a repeating unit represented by the following formula (1):

[0152]

[0153] In the above formula (1), A is a group selected from at least one of the following,

[0154]

[0155] m is an integer of 1 to 5, R 1 ~R 4 each is independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, and here, R 1 and R 2 optionally forms a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally forms a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, and in formula 1-1, the ring optionally contains at least one oxygen atom, and the high molecular compound X optionally further contains a repeating unit represented by the following formula (2):

[0156]

[0157] In the above formula (2), A is a hydroxyl group, and the pH of the polishing composition is 9.0 to 11.5. The descriptions of the colloidal silica, the alkali metal salt, the polyalkylene glycol, the cellulose derivative, and at least one of the high-molecular compounds X, the water, and the pH can be applied to the above descriptions. "Substantially consists of" means that, in the case where the polishing composition contains components other than the colloidal silica, the alkali metal salt (particularly, potassium hydroxide), the polyalkylene glycol, the cellulose derivative, and at least one of the high-molecular compounds X, the water, and the optional preservative, the ratio (total) thereof in the polishing composition is 0.1% by mass or less, 0.01% by mass or less, 0.001% by mass or less, or less than 0.0001% by mass.

[0158] In one embodiment of the present application, the polishing composition can be of a single component type, or of a multi-component type typified by a two-component type. In addition, the polishing composition of one aspect of the present application can be used, for example, after being diluted (typically, by water) to form a polishing liquid, or can be used directly as a polishing liquid. That is, the concept of the polishing composition in the present application includes both a polishing composition (working slurry) that is supplied to a polishing target and used for polishing of the polishing target, and a concentrated liquid (stock solution of the working slurry) that is diluted and used for polishing. The concentration ratio of the above concentrated liquid can be, for example, about 2 to 100 times or so on a volume basis.

[0159] <Method for producing a polishing composition>

[0160] In one embodiment of the present application, the method for producing a polishing composition includes a step of adjusting the pH to 9.0 to 11.5 by mixing the colloidal silica, the alkali metal salt (particularly, potassium hydroxide), the polyalkylene glycol (particularly, PEG), the cellulose derivative, and at least one of the high-molecular compounds X (particularly, PVP), the water, and the optional preservative. The descriptions of the colloidal silica, the alkali metal salt (particularly, potassium hydroxide), the cellulose derivative, and at least one of the high-molecular compounds X (particularly, PVP), the water, the pH, and the preservative can be applied to the above descriptions. The temperature at the time of mixing the components is not particularly limited, but is preferably 10°C or higher and 40°C or lower, and heating can be performed in order to improve the dissolution rate. In addition, the mixing time is not particularly limited as long as uniform mixing can be performed.

[0161] <Method for polishing a polishing target>

[0162] In one embodiment of the present application, the method for polishing a polishing target includes a step of polishing the polishing target by supplying the polishing composition to the polishing target, and a step of adjusting the pH of the polishing composition to 9.0 to 11.5. Figure 1In the polishing object 10 shown in which the first layer 1 (a layer having an oxygen-silicon bond or a layer having a nitrogen-silicon bond) provided with a recess and the second layer 2 (a layer having a silicon-silicon bond) formed so as to fill the recess are formed on an arbitrary film (for example, a Si substrate), the second layer 2 is polished to expose the first layer 1. In one embodiment of the present application, a process of further polishing the first layer after the first layer is exposed is included. By further including the above process, a technical effect of completely removing the remaining of the polishing object such as polysilicon which should be polished is obtained.

[0163] In one embodiment of the present application, as shown in Figure 1 the first layer 1 (a layer having an oxygen-silicon bond or a layer having a nitrogen-silicon bond) is formed on an arbitrary film (for example, a Si substrate) so as to be provided with a recess. Then, the second layer 2 (a layer having a silicon-silicon bond) is formed so as to fill the recess, and the second layer 2 is formed by laminating an excess amount so as to overflow from the recess of the first layer 1, thereby forming a polishing object 10 including the first layer 1 and the second layer 2. Such a polishing object 10 is polished by a polishing device capable of supplying the polishing composition of the present application.

[0164] In one embodiment of the present application, as a polishing device, a general polishing device in which a holder for holding a substrate or the like having a polishing object and a motor or the like capable of changing a rotation speed are installed, and a polishing flat capable of adhering a polishing pad (polishing cloth) is included can be used.

[0165] In one embodiment of the present application, as a polishing pad, a general nonwoven fabric, polyurethane, porous fluororesin, or the like can be used without particular limitation. It is preferable that the polishing pad is subjected to groove processing such that a polishing liquid is stored.

[0166] In one embodiment of the present application, with respect to the polishing conditions, for example, the rotation speeds of the polishing flat, the carrier are each independently preferably 10 to 500 rpm. The pressure applied to the substrate having a polishing object (polishing pressure) is preferably 0.5 to 10 psi. The method of supplying the polishing composition to the polishing pad is also not particularly limited, and for example, a method of continuously supplying by a pump or the like can be employed. The amount of supply is not limited, but it is preferable that the surface of the polishing pad is always covered with the polishing composition of the present application.

[0167] In one embodiment of the present application, by applying the polishing composition of the present application, as shown in Figure 2 the polished polishing object 10' after polishing can have a desired polishing surface in which the remaining of the polishing object which should be polished is reduced (no remaining) and / or the recess is also suppressed (not generated).

[0168] The present application includes the following modes and aspects.

[0169] 1. A polishing composition comprising: colloidal silica; an alkali metal salt; at least one of a polyalkylene glycol; a cellulose derivative and a high molecular compound X; and water; the polishing composition having a pH of 9.0 to 11.5,

[0170] The aforementioned high molecular compound X comprises a repeating unit represented by the following formula (1):

[0171]

[0172] In the aforementioned formula (1), A is a group selected from at least one of

[0173]

[0174] m is an integer of 1 to 5, R 1 ~ R 4 are each independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, where R 1 and R 2 optionally form a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally form a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, and in formula 1-1, the ring optionally contains at least one oxygen atom,

[0175] The aforementioned high molecular compound X optionally further comprises a repeating unit represented by the following formula (2):

[0176]

[0177] In the aforementioned formula (2), A is a hydroxyl group,

[0178] (i) The aforementioned polishing composition is used in a step of polishing the aforementioned second layer of a polishing object having a first layer provided with a recess and a second layer formed so as to fill the recess, to expose the aforementioned first layer, the aforementioned first layer being selected from those having an oxygen-silicon bond or those having a nitrogen-silicon bond, and the aforementioned second layer having a silicon-silicon bond;

[0179] and / or

[0180] (ii) The aforementioned colloidal silica has a silanol group number of 6 to 22 per nm 2 above and 22 per nm 2 below.

[0181] 2. The polishing composition according to the aforementioned 1, wherein, in the case where the aforementioned first layer has an oxygen-silicon bond, the polishing rate of the aforementioned second layer is 20 to 40 relative to the polishing rate of the aforementioned first layer.

[0182] 3. The polishing composition according to any one of the above 1. or 2., wherein, in the case where the aforementioned first layer has a nitrogen-silicon bond, the polishing rate of the aforementioned second layer is more than 40 and 100 or less relative to the polishing rate of the aforementioned first layer.

[0183] 4. The polishing composition according to any one of the above 1. to 3., wherein the aforementioned colloidal silica has a pulse NMR specific surface area of 40 m 2 / g or less.

[0184] 5. The polishing composition according to any one of the above 1. to 4., wherein the aforementioned colloidal silica has an average primary particle diameter of more than 70 nm and less than 100 nm.

[0185] 6. The polishing composition according to any one of the above 1. to 5., wherein the aforementioned alkali metal salt is a hydroxide of an alkali metal.

[0186] 7. The polishing composition according to the above 6., wherein the aforementioned hydroxide of an alkali metal is potassium hydroxide.

[0187] 8. The polishing composition according to any one of the above 1. to 7., wherein, in the case where the aforementioned colloidal silica has a concentration of 1.5 mass%, the transmittance when light having a wavelength of 450 nm is transmitted is more than 0.1% and less than 1%.

[0188] 9. A polishing composition consisting essentially of at least one of colloidal silica having a silanol group number of 6 / nm 2 or more and 22 / nm 2 or less; an alkali metal salt; a polyalkylene glycol; a cellulose derivative and a high molecular compound X; and water,

[0189] the aforementioned high molecular compound X contains a repeating unit represented by the following formula (1):

[0190]

[0191] in the aforementioned formula (1), A is a group selected from at least one of

[0192]

[0193] m is an integer of 1 to 5, R 1 to R 4 are each independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, and here, R 1 and R 2 optionally form a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, R 3 and R 4optionally forms a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, in Formula 1-1, the ring optionally contains at least one oxygen atom,

[0194] The aforementioned high molecular compound X optionally further contains a repeating unit represented by the following Formula (2):

[0195]

[0196] In the aforementioned Formula (2), A is a hydroxyl group, and the pH of the polishing composition is 9.0 to 11.5.

[0197] 10. A polishing composition consisting essentially of at least one of colloidal silica; an alkali metal salt; a polyalkylene glycol; a cellulose derivative and a high molecular compound X; a preservative; and water, wherein the number of silanol groups per nm 2 The above and 22 per nm 2 The following colloidal silica; an alkali metal salt; a polyalkylene glycol; a cellulose derivative and a high molecular compound X; a preservative; and water,

[0198] The aforementioned high molecular compound X contains a repeating unit represented by the following Formula (1):

[0199]

[0200] In the aforementioned Formula (1), A is a group selected from at least one of

[0201]

[0202] m is an integer of 1 to 5, R 1 ~ R 4 are each independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, and here, R 1 and R 2 optionally forms a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally forms a ring, and in the case of forming a ring, the ring optionally contains at least one oxygen atom, in Formula 1-1, the ring optionally contains at least one oxygen atom,

[0203] The aforementioned high molecular compound X optionally further contains a repeating unit represented by the following Formula (2):

[0204]

[0205] In the aforementioned Formula (2), A is a hydroxyl group, and the pH of the polishing composition is 9.0 to 11.5.

[0206] Example

[0207] The present application is further explained in detail by the following examples and comparative examples. However, the scope of the present application should not be limited to the following examples. In addition, in the following description, the operations are performed at room temperature (25°C) / relative humidity 40 to 50% RH, unless otherwise specifically noted.

[0208] <Manufacture of polishing composition>

[0209] The abrasive grains; the alkali metal salt; the polyalkylene glycol; one of the cellulose derivative and the high-molecular compound X (in Table 1, noted as additive); and the water were mixed in such a manner as to become the composition shown in Table 1, thereby preparing the polishing composition. For example, the polishing composition of Example 1 was prepared in such a composition as to contain colloidal silica 1.5 mass% having a pulse NMR specific surface area of 23.8 m2 / g, a silanol group number of 7.9 per nm2, and an average primary particle diameter of 90 nm and an average secondary particle diameter of 220 nm; potassium hydroxide; polyvinylpyrrolidone (PVP) (weight average molecular weight 45,000) 40 mass ppm; polyethylene glycol (PEG) (weight average molecular weight 200) 10 mass ppm; and water, with a pH of 10.8. 2 2

[0210] [Weight average molecular weight]

[0211] In the present specification, the "weight average molecular weight" can use the value of the weight average molecular weight (polyethylene glycol conversion) measured by gel permeation chromatography (GPC). The weight average molecular weight is measured by the following device and conditions:

[0212] GPC device: manufactured by Shimadzu Corporation

[0213] Model: Prominence + ELSD detector (ELSD-LTII)

[0214] Column: VP-ODS (manufactured by Shimadzu Corporation)

[0215] Mobile phase A: MeOH

[0216] B: 1% acetic acid aqueous solution

[0217] Flow rate: 1 mL / min

[0218] Detector: ELSD temp. 40°C, Gain 8, N2 GAS 350 kPa

[0219] Column oven temperature: 40°C

[0220] Injection amount: 40 μL.

[0221] <Method for calculating particle diameter> ​​

[0222] The average primary particle diameter of the abrasive grains was calculated from the specific surface area of the abrasive grains based on the BET method measured with "Macsorb HM model-1210" manufactured by MOUNTECH Co., Ltd. and the density of the abrasive grains.

[0223] The average secondary particle diameter of the abrasive grains was measured with a dynamic light scattering particle size / particle size distribution device UPA-UT151 manufactured by NIKKISO CO., LTD.

[0224] Measurement method of specific surface area by pulsed NMR

[0225] A dispersion liquid in which each abrasive grain (colloidal silica) was dispersed in water at a concentration of 20 mass% was prepared as a sample. The measuring device was a pulsed NMR particle interface property evaluation device (manufactured by Xigo nanotools), and the results obtained by measuring the specific surface area under the following measurement conditions are shown in Table 1.

[0226] Measurement conditions

[0227] Bulk relaxation time: 2409 ms

[0228] Specific surface relaxivity: 0.00026

[0229] Volume ratio of particle to liquid: 0.1136.

[0230] Calculation method of silanol group number

[0231] The silanol group number per unit surface area of the abrasive grains (unit: number / nm 2 ) was calculated as follows: after each parameter was measured or calculated according to the following measurement method or calculation method, it was calculated according to the following method.

[0232] More specifically, C in the following formula is the total mass of the abrasive grains, and S in the following formula is the BET specific surface area of the abrasive grains. Further specifically, first, 1.50 g of the abrasive grains as a solid component was collected in a 200-ml beaker, 100 ml of pure water was added to form a slurry, and then 30 g of sodium chloride was added and dissolved. Next, 1N hydrochloric acid was added, the pH of the slurry was adjusted to 3.0 to 3.5, and then pure water was added until the slurry became 150 ml.

[0233] For the slurry, using an automatic titration device (COM-1700 manufactured by Hiranuma Industry Co., Ltd.), 0.1 N sodium hydroxide was used to adjust the pH to 4.0 at 25°C, and then, by pH titration, the volume V [L] of 0.1 N sodium hydroxide solution required to raise the pH from 4.0 to 9.0 was measured. The average silanol group density (silanol group number) can be calculated according to the following formula.

[0234] ρ = (c x V x N A ) / (C x S)

[0235] In the above formula,

[0236] ρ represents the average silanol group density (silanol group number) (number / nm 2 );

[0237] c represents the concentration of the sodium hydroxide solution used in the titration (mol / L);

[0238] V represents the volume of the sodium hydroxide solution required to raise the pH from 4.0 to 9.0 (L);

[0239] N A represents Avogadro's number (number / mol);

[0240] C represents the total mass of the abrasive grains (solid content) (g);

[0241] S represents the weighted average value of the BET specific surface area of the abrasive grains (nm 2 / g). The BET specific surface area is the value of the specific surface area of the abrasive grains based on the BET method, measured using "Macsorb HM model-1210" manufactured by MOUNTECH Co., Ltd.

[0242] Measurement of the pH of the polishing composition

[0243] Using a glass electrode type hydrogen ion concentration indicator (Model F-23 manufactured by HORIBA, Ltd.), after 3-point calibration with standard buffers (phthalate pH buffer pH: 4.01 (25°C), neutral phosphate pH buffer pH: 6.86 (25°C), carbonate pH buffer pH: 10.01 (25°C)), the glass electrode was placed in the polishing composition, and the value after stabilization for 2 minutes or more was measured as the pH of the polishing composition.

[0244] Measurement of the transmittance of the polishing composition

[0245] The transmittance of the polishing composition was measured by irradiating the polishing composition with light of wavelength 450 nm using a UV-visible spectrophotometer (UV-2450 manufactured by Shimadzu Corporation). The results are shown in Table 1.

[0246] Measurement of Polishing Rate

[0247] The surface of the polishing object was polished under the following polishing conditions using the polishing composition. Note that, as the polishing object, a silicon wafer (300 mm, blank wafer) on the surface of which a polysilicon (Poly-Si) film having a thickness of 1000 nm was formed, a silicon wafer (300 mm, blank wafer) on the surface of which a P-TEOS film (a TEOS film (silicon dioxide film) formed by plasma CVD) having a thickness of 1000 nm was formed, and a silicon wafer (300 mm, blank wafer) on the surface of which a silicon nitride (SiN) film having a thickness of 1000 nm was formed were used, respectively.

[0248] (Polishing Conditions)

[0249] Polishing device: CMP single-side polishing device Reflexion LK for 300 mm (manufactured by Applied Materials, Inc.) Pad: hard polyurethane pad IC1010 (manufactured by Nitta Haas Incorporated.)

[0250] Polishing pressure: 1.5 psi (1 psi = 6894.76 Pa, the same applies hereinafter)

[0251] Polishing platen rotation speed: 70 rpm

[0252] Carrier rotation speed: 70 rpm

[0253] Supply of polishing composition: flow-through

[0254] Amount of supply of polishing composition: 200 ml / minute

[0255] Polishing time: 60 seconds.

[0256] The polishing rate was determined as follows: the thickness was found using an optical film thickness meter (RE-3500 (manufactured by SCREEN), and (thickness before polishing) - (thickness after polishing) was divided by the polishing time, whereby the polishing rate was determined. In addition, the ratio of the polishing rate of the polysilicon film (nm / minute) to the polishing rate of the P-TEOS film (nm / minute) was calculated as the selectivity. In addition, the ratio of the polishing rate of the polysilicon film (nm / minute) to the polishing rate of the SiN film (nm / minute) was calculated as the selectivity. The results are shown in Table 2.

[0257] Evaluation of Dishing of Polysilicon ​​​​​​​

[0258] The polishing of the pattern wafer with the polysilicon film was carried out according to the following [Condition 1] using the polishing composition described in Table 1. The pattern wafer was one in which a P-TEOS film or a silicon nitride film (SiN film) was laminated on a Si substrate, a groove of a depth of 1,000 nm was dug to make a recess, and then the recess was filled with a polysilicon film. Figure 1

[0259] The polishing of the pattern wafer with the polysilicon film was carried out as follows: after the end point signal was detected, further polishing was continued for only a time corresponding to 40% of the polishing time until the end point signal was detected, and then the polishing was ended. Thus, a process of further polishing the first layer (P-TEOS film) after the first layer (P-TEOS film or silicon nitride film (SiN film)) was exposed was realized.

[0260] The amount of recess of the isolated wiring portion of 10 μm in width on the surface of the pattern wafer was measured with an atomic force microscope (trade name: InSight CAP, manufactured by Bruker Corporation). The amount of recess thus obtained was evaluated according to the following judgment criteria.

[0261] [Condition 1]

[0262] Polishing device: CMP single-side polishing device Reflexion LK for 300 mm, manufactured by Applied Materials, Inc.

[0263] Pad: hard polyurethane pad IC1010, manufactured by Nitta Haas Incorporated.

[0264] Polishing pressure: 1.5 psi (1 psi = 6894.76 Pa, the same hereinafter)

[0265] Polishing platen rotation speed: 70 rpm

[0266] Carrier rotation speed: 70 rpm

[0267] Supply of polishing composition: overflow

[0268] Amount of supply of polishing composition: 200 ml / minute

[0269] Polishing time: 1 minute

[0270] [Amount of recess]

[0271] The recess was judged according to the following 4-stage judgment criteria. Δχ is a case that cannot be allowed in practice. The results are shown in Table 2.

[0272] ◎: less than 50 nm ​​​​

[0273] O: 50 nm or more and less than 75 nm

[0274] Δ: 75 nm or more and less than 100 nm

[0275] X: 100 nm or more.

[0276] <Residual Polysilicon (polishing residual)>

[0277] The film thickness of the residual polysilicon on the P-TEOS film after polishing was measured with an optical film thickness meter (ASET-f5x: manufactured by KLA-Tencor Corp.). The film thickness at this time was taken as the polishing residual, and was judged according to the 4-stage judgment criteria described below. ΔX is a situation that cannot be allowed in practice. The results are shown in Table 2.

[0278] ◎: less than

[0279] O: 50 nm or more and less than

[0280] Δ: 75 nm or more and less than

[0281] X: 100 nm or more.

[0282] [Measurement of metal impurities (atomic number after cleaning)]

[0283] For the silicon wafer with the P-TEOS film after polishing, the cleaning section was cleaned with a PVA brush while flowing deionized water (DIW) for 60 seconds. After that, it was dried in a spin dryer for 30 seconds. The concentration of Na, K, and Li on the surface of the wafer after cleaning was measured with a total reflection fluorescence X-ray device (device name: TREX-610T) manufactured by Tecnos Co., Ltd. The results are shown in Table 2.

[0284] [Table 1]

[0285]

[0286] [Table 2]

[0287]

[0288] <Investigation>

[0289] The polishing composition of the example reduced the residual polysilicon that should be polished while also suppressing dishing. In contrast, the polishing composition of the comparative example produced a residual polysilicon that should be polished, or promoted dishing, as shown in Table 2. Figures 3-5 ​

[0290] Here, when Comparative Examples 1 to 3 are compared, it is found that, from the viewpoint of suppressing the remaining of polysilicon, the mass concentration of polyalkylene glycol in the polishing composition is preferably 40 ppm or more. Further, when Comparative Example 2 and Example 4 are compared, it is found that, among polyalkylene glycols, PEG is preferable from the viewpoint of suppressing the remaining of polysilicon. Further, when Comparative Example 2 and Example 5 are compared, it is found that, from the viewpoint of suppressing the remaining of polysilicon and suppressing the generation of recesses, PVP is more preferable than HEC. Further, when Comparative Example 2 and Example 6 are compared, it is found that, among high molecular compounds X, PVP is also preferable from the viewpoint of suppressing the generation of recesses. Further, when Comparative Example 2 and Examples 7 and 8 are compared, it is found that, from the viewpoint of suppressing the remaining of polysilicon and suppressing the generation of recesses, the number of silanol groups of colloidal silica is preferably more than 6.6 / nm 2 and less than 17.5 / nm 2 Further, when Comparative Example 2 and Examples 9 and 10 are compared, it is found that, from the viewpoint of suppressing the remaining of polysilicon, the pH of the polishing composition is preferably more than 10.0. Further, when Comparative Example 2 and Examples 11 to 13 are compared, it is found that, from the viewpoint of reducing the remaining metal, as an alkali metal salt, the hydroxide of an alkali metal is more preferable than the carbonate of an alkali metal. It is also found that, as an alkali metal, potassium is particularly preferable from the viewpoint of reducing the remaining metal. Further, when Comparative Example 2 and Example 14 are compared, it is found that, from the viewpoint of suppressing the generation of recesses, the pH of the polishing composition is preferably less than 11.2.

[0291] On the other hand, in the polishing composition of the comparative examples, none of them is a composition that takes into account both the reduction of the remaining of polysilicon to be polished and the suppression of recesses. More specifically, it is found from the results of Comparative Example 1 that, when none of the cellulose derivative and the high molecular compound X (additives) and the polyalkylene glycol is contained, the generation of recesses increases. Further, it is found from the results of Comparative Examples 2 to 4 that, when the polyalkylene glycol is not contained, the remaining of polysilicon increases. Further, it is found from the results of Comparative Example 5 that, when none of the cellulose derivative and the high molecular compound X is contained, the generation of recesses increases. Further, it is found from the results of Comparative Examples 6 to 12 and 14 that, when the number of silanol groups of colloidal silica is less than 6 / nm 2 , the remaining of polysilicon increases. Further, it is found from the results of Comparative Example 13 that, when the number of silanol groups of colloidal silica is more than 22 / nm 2 , the generation of recesses increases. Further, it is found from the results of Comparative Example 15 that, when the pH of the polishing composition is less than 9.0, the remaining of polysilicon increases.

[0292] This application is based on Japanese Patent Application No. 2024-081896 filed on May 20, 2024, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A polishing composition comprising: colloidal silica; an alkali metal salt; a polyalkylene glycol; at least one of a cellulose derivative and a high molecular compound X; and water; the pH of the polishing composition being 9.0 to 11.5, the high molecular compound X comprising a repeating unit represented by the following formula (1): in the formula (1), A is a group selected from at least one of m is an integer of 1 to 5, R 1 ~R 4 each independently is selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, wherein, R 1 and R 2 optionally form a ring, and in the case of ring formation, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally form a ring, and in the case of ring formation, the ring optionally contains at least one oxygen atom, in Formula 1-1, the ring optionally contains at least one oxygen atom, the high molecular compound X optionally further comprising a repeating unit represented by the following formula (2): in the formula (2), A is a hydroxyl group, (i) the polishing composition is used in a process in which the polishing composition polishes a second layer of a polishing object having a first layer provided with a recess and the second layer formed so as to fill the recess, the first layer being selected from those having an oxygen-silicon bond or a nitrogen-silicon bond, and the second layer having a silicon-silicon bond, to expose the first layer; and / or (ii) the colloidal silica has a silanol group number of 6 / nm 2 above and 22 / nm 2 below.

2. The polishing composition according to claim 1, wherein, in the case where the first layer has an oxygen-silicon bond, the polishing rate of the second layer relative to the polishing rate of the first layer is 20 to 40.

3. The polishing composition according to claim 1, wherein, in the case where the first layer has a nitrogen-silicon bond, the polishing rate of the second layer relative to the polishing rate of the first layer exceeds 40 and is 100 or less.

4. The polishing composition according to claim 1, wherein, The colloidal silicon dioxide has a pulse NMR specific surface area of 40 m 2 / g or less.

5. The polishing composition according to claim 1, wherein, the average primary particle diameter of the colloidal silica exceeds 70 nm and is less than 100 nm.

6. The polishing composition according to claim 1, wherein, the alkali metal salt is a hydroxide of an alkali metal.

7. The polishing composition according to claim 6, wherein, the hydroxide of the alkali metal is potassium hydroxide.

8. The polishing composition according to claim 1, wherein, in the case where the concentration of the colloidal silica is 1.5% by mass, the transmittance when light having a wavelength of 450 nm is transmitted exceeds 0.1% and is less than 1%.

9. A polishing composition consisting essentially of at least one of colloidal silica; an alkali metal salt; a polyalkylene glycol; a cellulose derivative and a high molecular compound X; and water, wherein the number of silanol groups is 6 / nm 2 above and 22 / nm 2 the following colloidal silica; an alkali metal salt; a polyalkylene glycol; a cellulose derivative and a high molecular compound X; and water, the high molecular compound X comprises a repeating unit represented by the following formula (1): in the formula (1), A is a group selected from at least one of m is an integer of 1 to 5, R 1 ~R 4 each independently is selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, wherein, R 1 and R 2 optionally form a ring, and in the case of ring formation, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally form a ring, and in the case of ring formation, the ring optionally contains at least one oxygen atom, in Formula 1-1, the ring optionally contains at least one oxygen atom, the high molecular compound X optionally further comprising a repeating unit represented by the following formula (2): in the formula (2), A is a hydroxyl group, the pH of the polishing composition is 9.0 to 11.

5.

10. A polishing composition consisting essentially of only silanol groups of 6 / nm 2 the above and 22 / nm 2 at least one of the following: colloidal silica; alkali metal salt; polyalkylene glycol; cellulose derivative and high molecular compound X; preservative; and water, the high molecular compound X comprises a repeating unit represented by the following formula (1): in the formula (1), A is a group selected from at least one of m is an integer of 1 to 5, R 1 ~R 4 each independently selected from a hydrogen atom and an alkyl group having a carbon number of 1 to 4, R 1 and R 2 optionally form a ring, and in the case of ring formation, the ring optionally contains at least one oxygen atom, R 3 and R 4 optionally form a ring, and in the case of ring formation, the ring optionally contains at least one oxygen atom, in Formula 1-1, the ring optionally contains at least one oxygen atom, the high molecular compound X optionally further comprising a repeating unit represented by the following formula (2): in the formula (2), A is a hydroxyl group, the pH of the polishing composition is 9.0 to 11.5.

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