FIELD

The present invention relates to a chemical-mechanical polishing composition and a rinse composition, as well as a method of chemically-mechanically polishing a substrate and a method of rinsing a substrate in which these compositions are used.

BACKGROUND

The silicon wafers used in the production of semiconductor devices have strict surface quality requirements. In order to ensure such surface quality, conventionally, a chemical-mechanical polishing (CMP) technology has been used. In the CMP of silicon wafers, along with a recent increase in demand and the advancement of high performance and high integration of semiconductor devices, in addition to an improvement in productivity, an improvement in surface quality has been increasingly demanded. In particular, in order to realize high integration and high speed, such as in ultra-large-scale integrated circuits (ULSI) used for computers, refinement of design rules of semiconductor devices is progressing year by year. Additionally, the importance of managing nano-level surface defects, which has not been a problem in the past, is increasing.

Surface defect inspection devices are generally used to manage surface defects on silicon wafers. The defects detected by a surface defect inspection device include foreign matter and residue on a silicon wafer which could not be removed by a polishing process or rinsing process. As such a surface defect inspection device, devices which irradiate a surface of the silicon wafer with light, such as laser light, and then detect reflected light or scattered light generated at the surface of the silicon wafer to detect defects on the surface of the silicon wafer are generally known.

When the surface of a silicon wafer is irradiated with such strong light, clouding may be seen due to diffuse reflection as a result of the roughness of the silicon wafer surface. This clouding is referred to as haze, and since haze has a close relationship with the surface roughness of the silicon wafer, haze can be used as an indicator of surface roughness. In recent years, though surface defects can be observed on a nano-level due to the rapid progress of surface defect inspection devices, when haze is present on the silicon wafer surface, the diffusely reflected light caused by the haze becomes background noise, whereby defect detection by the surface defect inspection device may be hindered. Thus, as the size of surface defects to be managed decreases, the need to achieve lower surface roughness and reduce haze levels is increasing.

Patent Literature 1 describes a polishing slurry comprising a chain hydrocarbon polymer having a carbon long-chain structure and a hydroxy lower alkoxy group as a side chain in a polishing slurry comprising an alkali component and colloidal silica. Patent Literature 1 further describes that since the above polishing slurry is excellent in the improvement of swelling and haze and polishing speed can be maintained at practical levels, the polishing slurry is extremely useful particularly as a polishing slurry for secondary polishing.

Patent Literature 2 describes a polishing composition comprising (A) a block-type polyether represented by the general formula HO-(EO)a—(PO)b-(EO)c—H (where EO represents an oxyethylene group, PO represents an oxypropylene group, and a, b, and c are integers of 1 or more), (B) silicon dioxide, (C) a basic compound, (D) at least one selected from hydroxyethyl cellulose and polyvinyl alcohol, and (E) water. Patent Literature 2 further describes that according to such a polishing composition, silicon wafer polishing speed can be increased, and haze level and COP can be improved.

Patent Literature 3 describes a polishing composition comprising a nonionic surfactant having a molecular weight from 1,000 to less than 100,000 and an HLB value of 17 or more, a basic compound, and water. Patent Literature 3 further describes that according to the above polishing composition, in addition to enabling a reduction of semiconductor substrate surface haze after polishing, the adhesion of particles to the surface can be suppressed.

Patent Literature 4 describes a silicon wafer polishing composition comprising water, a basic compound, and a nonionic surfactant composed of a polyoxyethylene adduct, wherein the polyoxyethylene adduct has an HLB value of 8 to 15, the weight average molecular weight of the polyoxyethylene adduct is 1400 or less, the average addition mol numbers of oxyethylene of the polyoxyethylene adduct is 13 or less, and the content of the polyoxyethylene adduct in the polishing composition is 0.00001 to 0.10% by mass. Patent Literature 4 further describes that according to the above polishing composition, haze can be reduced by suppressing roughness of the silicon wafer surface caused by the polishing or rinsing of the silicon wafer, and as a result, evaluation of minute defects and product management based on thereon becomes easy.

CITATION LIST

Patent Literature

[PTL 1] Japanese Unexamined Patent Publication (Kokai) No. 11-140427[PTL 2] Japanese Unexamined Patent Publication (Kokai) No. 2005-85858[PTL 3] Japanese Unexamined Patent Publication (Kokai) No. 2011-181765[PTL 4] WO 2012/039390

SUMMARY

Technical Problem

In general, when carrying out a chemical-mechanical polishing operation, slurry used in the polishing, the abrasive included in the slurry, and the shavings produced by polishing adhere to or are deposited on the polishing pad. If this foreign matter and/or residue is allowed to remain on the polishing pad as-is, when a subsequent chemical-mechanical polishing operation is performed, there is a risk that they will generate defects on the substrate surface of the silicon wafer or the like. Thus, in general, prior to each polishing step, this foreign matter and/or residue is removed from the polishing pad by carrying out pad conditioning or the like.

However, for example, if the additive components contained in the polishing composition for reducing haze and/or for other purposes can easily adhere to the polishing pad, and if such components are adhered to the polishing pad during polishing, such adhered additive components may not be completely removed by the above pad conditioning in some cases. In such a case, as the polishing of substrates such as silicon wafers is repeatedly performed, such additive components gradually accumulate on the polishing pad. There is not only a risk of such accumulated additive components themselves causing defects on the substrate surface during polishing, but additionally there is a risk that the wettability of the substrate surface will be reduced. If the wettability of the substrate surface is reduced, shavings generated by the polishing and other foreign matter easily adhere to the substrate, and as a result, there is a risk that defects will be generated on the substrate surface. Thus, not only is it extremely important that the additive components included in a polishing composition used during the polishing process and a rinse composition used in a rinse process after the polishing process, be capable of reducing the haze of the substrate surface, but it is also extremely important that they not adversely impact the wettability of the substrate surface.

In PTLs 1 to 4, though additive components which can reduce the haze of a substrate surface are described, the effects of these additive components on the wettability of the substrate surface have not been sufficiently examined.

The present invention aims to provide a chemical-mechanical polishing composition and rinse composition which can reduce the haze of a substrate surface and which can maintain the wettability of the substrate surface, and a method of chemical-mechanical polishing a substrate and a method of rinsing a substrate using these compositions.

Solution to Problem

The present invention, which can achieve the aforementioned objects, is as described below.

(1) A chemical-mechanical polishing composition, comprising:

an abrasive,

a basic component,

a polyoxyalkylene alkyl ether represented by the formula (i) RO-(AO)n—H, wherein R is a linear or branched C1to C15alkyl group, A is an alkylene group selected from the group consisting of an ethylene group, a propylene group, and a combination thereof, n represents average addition mol numbers of AO and is 2 to 30, and an aqueous carrier.

(2) The chemical-mechanical polishing composition of (1), wherein R is a linear or branched C1to C13alkyl group.

(3) The chemical-mechanical polishing composition of (1), wherein R is a branched C11to C15alkyl group.

(4) The chemical-mechanical polishing composition of (1), wherein the polyoxyalkylene alkyl ether comprises at least one of polyoxyethylene oxypropylene 2-propylheptyl ether, and polyoxyethylene isotridecyl ether.

(5) The chemical-mechanical polishing composition of any one of (1) to (4), further comprising a water-soluble polymer different from the polyoxyalkylene alkyl ether.

(6) The chemical-mechanical polishing composition of (5), wherein the water-soluble polymer comprises at least one selected from the group consisting of a cellulose derivative, a polymer containing a polyvinyl alcohol structural unit, an alkylene polyalkylene oxide amine polymer containing at least two repeating structural units containing a tertiary amine having an alkylene group and a polyalkyleneoxide group bound to an N atom, and any combination thereof.

(7) The chemical-mechanical polishing composition of (6), wherein the water-soluble polymer comprises a cellulose derivative, a polymer containing a polyvinyl alcohol structural unit, and an alkylene polyalkylene oxide amine polymer containing at least two repeating structural units containing a tertiary amine having an alkylene group and a polyalkyleneoxide group bound to an N atom.

(8) The chemical-mechanical polishing composition of (6), wherein the water-soluble polymer is a polymer containing a polyvinyl alcohol structural unit.

(9) A rinse composition, comprising:

a polyoxyalkylene alkyl ether represented by the formula (i) RO-(AO)n—H, wherein R is a linear or branched C1to C15alkyl group, A is an alkylene group selected from the group consisting of an ethylene group, a propylene group, and a combination thereof, n represents average addition mol numbers of AO and is 2 to 30, and

an aqueous carrier.

(10) The rinse composition of (9), wherein R is a linear or branched C1to C13alkyl group.

(11) The rinse composition of (9), wherein R is a branched C11to C15alkyl group.

(12) The rinse composition of (9), wherein the polyoxyalkylene alkyl ether comprises at least one of polyoxyethylene oxypropylene 2-propylheptyl ether, and polyoxyethylene isotridecyl ether.

(13) The rinse composition of any one of (9) to (12), further comprising a water-soluble polymer different from the polyoxyalkylene alkyl ether.

(14) The rinse composition of (13), wherein the water-soluble polymer comprises at least one selected from the group consisting of a cellulose derivative, a polymer containing a polyvinyl alcohol structural unit, an alkylene polyalkylene oxide amine polymer containing at least two repeating structural units containing a tertiary amine having an alkylene group and a polyalkyleneoxide group bound to an N atom, and any combination thereof.

(15) The rinse composition of (14), wherein the water-soluble polymer comprises a cellulose derivative, a polymer containing a polyvinyl alcohol structural unit, and an alkylene polyalkylene oxide amine polymer containing at least two repeating structural units containing a tertiary amine having an alkylene group and a polyalkyleneoxide group bound to an N atom.

(16) The rinse composition of (14), wherein the water-soluble polymer is a polymer containing a polyvinyl alcohol structural unit.

(17) A method of chemically-mechanically polishing a substrate, comprising:

contacting a substrate with a polishing pad and a chemical-mechanical polishing composition of any one of (1) to (8),

moving the polishing pad relative to the substrate with the chemical-mechanical polishing composition therebetween, and

abrading at least a portion of the substrate to polish the substrate.

(18) A method of rinsing a substrate, comprising:

contacting a substrate after chemically-mechanically polishing with a polishing pad and a rinse composition of any one of (9) to (16), and

moving the polishing pad relative to the substrate with the rinse composition therebetween.

Advantageous Effects of Invention

According to the present invention, by using a polyoxyalkylene alkyl ether represented by the formula (i) RO-(AO)n—H, wherein R is a linear or branched C1to C15alkyl group, A is an alkylene group selected from the group consisting of an ethylene group, a propylene group, and a combination thereof, and n represents average addition mol numbers of AO and is 2 to 30, substrate surface haze can be reduced as compared to the case in which the polyoxyalkylene alkyl ether is not used, and further, even when a substrate polishing operation is performed for a long period of time using the chemical-mechanical polishing composition comprising the polyoxyalkylene alkyl ether, substrate surface wettability can be maintained at a high level which is equivalent to the case in which a chemical-mechanical polishing composition which does not comprise the polyoxyalkylene alkyl ether is used. Thus, according to the chemical-mechanical polishing composition of the present invention, which comprises such a polyoxyalkylene alkyl ether, by reducing the haze of the substrate surface, it is possible to reduce the background noise during defect detection by a surface defect inspection system, whereby detection and management of micro surface defects, for example, nano-level surface defects, can be facilitated using the surface defect inspection device. Additionally, according to the chemical-mechanical polishing composition of the present invention, the occurrence of surface defects caused by the reduction in the wettability of the substrate surface can be reliably eliminated, and the life of the polishing pad can be improved.

