Amine-based compound compositions for use in CMP with high polysilicon rates - Patent Application 20070122997

Abstract

The present invention provides a chemical-mechanical polishing composition comprising (a) a silica abrasive, (b) an amine-based compound comprising a carbon-to-nitrogen ratio of about 1:1 to about 3:1, (c) optionally a buffering agent, and (d) water, and having a pH of about 9 to about 12. The present invention also provides a method for chemical-mechanical polishing a substrate, particularly a substrate comprising polysilicon, using the polishing composition of the present invention.

Description

[Technical Field]

[0001]

[0001] In the fabrication of integrated circuits and other electronic devices (e.g., microelectromechanical systems (MEMS) fabrication), multiple layers of conducting, semiconducting, and dielectric materials are deposited on or removed from a substrate surface. As layers of material are sequentially deposited on and removed from the substrate, the top surface of the substrate may become uneven and require planarization. Planarizing a surface, or "polishing" a surface, is the process of removing material from the surface of a substrate to form a substantially uniform, planar surface. Planarization helps to remove undesirable surface topography and surface defects, such as rough surfaces, agglomerated material, crystal lattice damage, scratches, and contaminated layers or materials. Planarization also helps in forming features on a substrate by removing excess deposited material used to fill the features and creating a uniform surface for subsequent levels of metallization and processing. [Background technology]

[0002]

[0002] Compositions and methods for planarizing or polishing the surface of a substrate are well known in the art. Chemical mechanical planarization, or chemical mechanical polishing (CMP), is a common technique used to planarize substrates. CMP uses chemical compositions, called CMP compositions or more simply polishing compositions (also called polishing slurries), to selectively remove material from a substrate. The polishing composition is typically applied to a substrate by contacting a polishing pad (e.g., a polishing cloth or abrasive disc) impregnated with the polishing composition with the surface of the substrate. Polishing of the substrate is typically further aided by the chemical activity of the polishing composition and / or the mechanical activity of an abrasive suspended in the polishing composition or incorporated into the polishing pad (e.g., a fixed-abrasive polishing pad).

[0003]

[0003] As the size of integrated circuits shrinks and the number of integrated circuits on a chip increases, the components that make up the circuits must be placed closer together to fill the limited space available on a typical chip. Effective isolation between circuits is important to ensure optimal semiconductor performance. This is achieved by isolating the active areas of the integrated circuits by etching shallow trenches into the semiconductor substrate and filling them with an insulating material. Because the depth of the trenches formed in this manner varies, it is usually necessary to deposit excess dielectric material on the substrate to ensure complete filling of all trenches. The dielectric material conforms to the topography of the underlying substrate.

[0004]

[0004] In some applications, polycrystalline silicon (also referred to in the art as polysilicon, poly-Si, or poly) films can be used in the fabrication of integrated circuits and MEMS devices. For example, polysilicon can be used as the gate electrode material in metal-oxide-semiconductor (MOS) and metal-oxide-semiconductor field-effect transistors (MOSFETs). In addition, polysilicon is commonly used in various damascene / interconnect applications in IC devices, as well as structural components in MEMS devices.

[0005] In such applications, there is a critical need for polysilicon CMP compositions that provide high polysilicon removal rates and high polysilicon selectivity over silicon oxide and silicon nitride layers. While some commercially available CMP compositions provide adequate polysilicon removal rates, these previously used polysilicon CMP compositions (i) require hazardous materials such as tetramethylammonium hydroxide (TMAH) to enhance polysilicon removal rates, and / or (ii) suffer from high rates of surface defects and scratches.

[0006]

[0006] Therefore, there remains a need for polysilicon CMP compositions and chemical-mechanical polishing methods that exhibit high polysilicon removal rates, high selectivity to silicon oxide and silicon nitride layers, and limit the amount of surface defects and scratches.

[0007] The present invention provides such a polishing composition and method. These and other advantages of the present invention, as well as additional inventive features, will be apparent from the description of the invention provided herein. Summary of the Invention

[0008]

[0008] The present invention provides a chemical-mechanical polishing composition comprising (a) a silica abrasive, (b) an amine compound having a carbon to nitrogen ratio of about 1:1 to about 3:1, (c) optionally a buffer, and (d) water, and having a pH of about 9 to about 12.

[0009] The present invention further provides a method for polishing a substrate, the method comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing a chemical-mechanical polishing composition, the chemical-mechanical polishing composition comprising: (a) a silica abrasive; (b) an amine-based compound having a carbon to nitrogen ratio of about 1:1 to about 3:1; (c) optionally, a buffer; and (d) water, the chemical-mechanical polishing composition having a pH of about 9 to about 12; (iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to polish at least a portion of a surface of the substrate, thereby polishing the substrate. A method for chemically mechanically polishing a substrate is provided, comprising: [Brief explanation of the drawings]

[0010] [Figure 1]

[0010] This is a graph showing the effect of the molecular weight (MW) of the amine-based compound on the poly-Si removal rate (Å / min), TEOS removal rate (Å / min), and SiN removal rate for polishing compositions 5B to 5F described in Example 5. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0011] The present invention provides a chemical-mechanical polishing composition comprising, consisting essentially of, or consisting of (a) a silica abrasive, (b) an amine compound having a carbon-to-nitrogen ratio of about 1:1 to about 3:1, (c) optionally a buffer, and (d) water, wherein the chemical-mechanical polishing composition has a pH of about 9 to about 12.

[0012] The polishing composition includes a silica abrasive. As used herein, the terms "silica abrasive," "silica abrasive particles," "silica particles," and "abrasive particles" can be used interchangeably and can refer to any silica particles (e.g., colloidal silica particles). The silica can be in any suitable form, such as wet-process silica, fumed silica, or a combination thereof. For example, the silica can include wet-process silica particles (e.g., condensation-polymerized silica particles or precipitated silica particles).

[0013] Silica abrasives (e.g., colloidal silica particles) can be prepared by a variety of methods, some of which are commercially used and known. Useful silica abrasive particles include precipitated silica or condensation-polymerized silica, which can be prepared using known methods such as the so-called "sol-gel" method or the silicate ion-exchange method. Condensation-polymerized silica particles are often prepared by condensing Si(OH)4 to form substantially spherical (e.g., spherical, ovoid, or rectangular) particles. The precursor Si(OH)4 can be obtained, for example, by hydrolysis of high-purity alkoxysilanes or by acidification of aqueous silicate solutions. U.S. Pat. No. 5,230,833 describes a method for preparing colloidal silica particles in solution.

[0014] In some embodiments, the silica abrasive is a colloidal silica particle. As is well known to those skilled in the art, colloidal silica is a suspension of fine, amorphous, non-porous, typically spherical particles in a liquid phase. Colloidal silica can be in the form of condensation-polymerized silica particles or precipitated silica particles. In some embodiments, the silica is in the form of wet-process silica particles. The particles, e.g., colloidal silica, can have any suitable average size (i.e., mean particle diameter). If the average abrasive particle size is too small, the polishing composition may not provide sufficient removal rates. In contrast, if the average abrasive particle size is too large, the polishing composition may exhibit undesirable polishing performance, such as reduced substrate defectivity. Such colloidal silica particles may be agglomerated or non-agglomerated. Non-agglomerated particles are discrete particles that are spherical or near-spherical in shape, but can also have other shapes (usually elliptical, square, or rectangular in cross section). Agglomerated particles are particles in which multiple individual particles have joined together to form aggregates of generally irregular shapes.

[0015] In some embodiments, the silica abrasive is pyrogenic silica particles. Pyrogenic silica (also called fumed silica) is produced by a flame hydrolysis process in which suitable feedstock vapors (such as silicon tetrachloride) are burned in a hydrogen and oxygen flame. The combustion process forms roughly spherical molten particles, the diameter of which varies depending on the process parameters. These molten spheres, commonly referred to as primary particles, fuse together through collisions at contact points, forming branched, three-dimensional, chain-like aggregates. Fumed silica abrasives are commercially available from a number of sources, including Cabot Corporation, Evonic, and Wacker Chemie.

[0016]

[0016] Silica abrasives (e.g., colloidal silica particles) may be modified (e.g., surface-modified) or unmodified and may have a negative or positive intrinsic zeta potential. As used herein, the phrase "native zeta potential" refers to the zeta potential of the silica abrasive prior to its addition to the polishing composition. For example, the native zeta potential may refer to the zeta potential of the silica abrasive prior to its addition to the polishing composition, as measured in a neutral aqueous solution (i.e., having a pH of about 7).

[0017] A skilled artisan will be able to determine whether a silica abrasive has a negative or positive intrinsic zeta potential before adding it to a polishing composition. The charge of dispersed particles, such as silica abrasives (e.g., colloidal silica particles), is commonly referred to as the zeta potential (or electrokinetic potential). The zeta potential of a particle refers to the potential difference between the charge of the ions surrounding the particle and the charge of the bulk solution of the composition being measured (e.g., the liquid carrier and any other components dissolved therein). Zeta potential is typically dependent on the pH of the aqueous medium. For a particular polishing composition, the isoelectric point of the particle is defined as the pH at which the zeta potential is zero. As the pH increases or decreases from the isoelectric point, the surface charge (and therefore the zeta potential) decreases or increases accordingly (to negative or positive zeta potential values). The native zeta potential and zeta potential of a polishing composition can be obtained using a Model DT-1202 Acoustic and Electro-acoustic Spectrometer available from Dispersion Technologies, Inc. (Bedford Hills, NY). As used herein, the phrase "negative zeta potential" refers to a silica abrasive that exhibits a negative surface charge when measured in a polishing composition. As used herein, the term "positive zeta potential" refers to a silica abrasive that exhibits a positive surface charge when measured in a polishing composition.

[0018]

[0018] Silica abrasives (i.e., silica abrasive particles) can have any suitable particle size. Particle size of particles suspended in a liquid carrier is defined in the industry using various means. For example, particle size can be defined as the diameter of the smallest sphere enclosing the particle and can be measured using a number of commercially available instruments, including, for example, a CPS Disc Centrifuge, Model DC24000HR (available from CPS Instruments, Praireville, Louisiana), or a Zetasizer® available from Malvern Instruments®. Such instruments typically report the average particle size of the silica dispersion.

[0019]

[0019] Thus, the silica abrasive (e.g., silica particles or colloidal silica particles) can have an average particle size of about 10 nm or more, e.g., about 15 nm or more, about 20 nm or more, about 25 nm or more, about 30 nm or more, about 35 nm or more, about 40 nm or more, about 45 nm or more, about 50 nm or more, about 60 nm or more, about 70 nm or more, or about 80 nm or more. Alternatively or additionally, the silica abrasive can have an average particle size of about 200 nm or less, e.g., about 175 nm or less, about 150 nm or less, about 140 nm or less, about 130 nm or less, about 125 nm or less, about 120 nm or less, about 110 nm or less, about 100 nm or less, about 75 nm or less, about 50 nm or less, or about 40 nm or less. Thus, the silica abrasive can have an average particle size bounded by any two of the aforementioned endpoints.

[0020] For example, in some embodiments, the silica abrasive (e.g., silica particles or colloidal silica particles) has a particle size of about 10 nm to about 200 nm, e.g., about 10 nm to about 175 nm, about 10 nm to about 150 nm, about 10 nm to about 140 nm, about 10 nm to about 130 nm, about 10 nm to about 125 nm, about 10 nm to about 120 nm, about 10 nm to about 110 nm, about 10 nm to about 100 nm, about 10 nm to about 75 nm, about 10 nm to about 50 nm, about 10 nm to about 40 nm, about 20 nm to about 200 nm, about 20 nm to about 175 nm, about 20 nm to about 150 nm, Approximately 20nm to approximately 140nm, approximately 20nm to approximately 130nm, approximately 20nm to approximately 125nm, approximately 20nm to approximately 120nm, approximately 20nm to approximately 110 nm, about 20nm to about 100nm, about 20nm to about 75nm, about 20nm to about 50nm, about 20nm to about 40nm, about 30nm to about 200 nm, approximately 30 nm to approximately 175 nm, approximately 30 nm to approximately 150 nm, approximately 30 nm to approximately 140 nm, approximately 30 nm to approximately 130 nm, approximately 30 nm to approximately 125nm, about 30nm to about 120nm, about 30nm to about 110nm, about 30nm to about 100nm, about 30nm to about 75nm, about 30nm ~50nm, approx. 30nm ~ approx. 40nm, approx. 40nm ~ approx. 200nm, approx. 40nm ~ approx. 175nm, approx. 40nm ~ approx. 150nm, approx. 40n m ~ about 140nm, about 40nm - about 130nm, about 40nm - about 125nm, about 40nm - about 120nm, about 40nm - about 110nm, about 40nm to about 100nm, about 40nm to about 75nm, about 40nm to about 50nm, about 50nm to about 200nm, about 50nm to about 175nm, Approximately 50nm to approximately 150nm, approximately 50nm to approximately 140nm, approximately 50nm to approximately 130nm, approximately 50nm to approximately 125nm, approximately 50nm to approximately 120 nm, about 50nm to about 110nm, about 50nm to about 100nm, about 50nm to about 75nm, about 60nm to about 200nm, about 60nm to about 1 75nm, about 60nm to about 150nm, about 60nm to about 140nm, about 60nm to about 130nm, about 60nm to about 125nm, about 60nm ~about 120nm, about 60nm to about 110nm, about 60nm to about 100nm, about 60nm to about 75nm, about 70nm to about 200nm, about 70 nm ~ approx. 175 nm, approx. 70 nm ~ approx. 150 nm, approx. 70 nm ~ approx. 140 nm, approx. 70 nm ~ approx. 130 nm, approx. 70 nm ~ approx. 125 nm,The average particle size may be about 70 nm to about 120 nm, about 70 nm to about 110 nm, about 70 nm to about 100 nm, about 80 nm to about 200 nm, about 80 nm to about 175 nm, about 80 nm to about 150 nm, about 80 nm to about 140 nm, about 80 nm to about 130 nm, about 80 nm to about 125 nm, about 80 nm to about 120 nm, about 80 nm to about 110 nm, or about 80 nm to about 100 nm.

[0021]

[0021] Silica abrasives (e.g., silica particles or colloidal silica particles) are preferably colloidally stable in polishing compositions. The term colloid refers to a suspension of particles in a liquid carrier (e.g., water). Colloidal stability refers to the maintenance of that suspension over time. In the present invention, an abrasive is considered colloidally stable if, when the abrasive is placed in a 100 mL graduated cylinder and left unstirred for 2 hours, the difference between the particle concentration in the bottom 50 mL of the cylinder ([B] in g / mL) and the particle concentration in the top 50 mL of the cylinder ([T] in g / mL) divided by the initial particle concentration in the polishing composition ([C] in g / mL) is 0.5 or less (i.e., {[B] - [T]} / [C] ≦ 0.5). More preferably, the value of [B] - [T] / [C] is 0.3 or less, and most preferably 0.1 or less.

[0022]

[0022] The polishing composition can contain any suitable amount of silica abrasive. If the polishing composition of the present invention contains too little abrasive, it may not exhibit a sufficient polishing rate. In contrast, if the polishing composition contains too much abrasive, the polishing composition may exhibit undesirable polishing performance and / or may be less cost-effective and / or less stable. The polishing composition can contain about 10 wt% or less of silica abrasive, for example, about 9 wt% or less, about 8 wt% or less, about 7 wt% or less, about 6 wt% or less, about 5 wt% or less, about 4 wt% or less, about 3 wt% or less, about 2 wt% or less, about 1 wt% or less, about 0.9 wt% or less, about 0.8 wt% or less, about 0.7 wt% or less, about 0.6 wt% or less, or about 0.5 wt% or less of silica abrasive. Alternatively, or in addition, the polishing composition can comprise about 0.001 wt.% or more of the silica abrasive, e.g., about 0.005 wt.% or more, about 0.01 wt.% or more, about 0.05 wt.% or more, about 0.1 wt.% or more, about 0.2 wt.% or more, about 0.3 wt.% or more, about 0.4 wt.% or more, or about 0.5 wt.% or more. Thus, the polishing composition can optionally comprise an amount of silica abrasive bounded by any two of the foregoing endpoints.

[0023] For example, in some embodiments, the polishing composition comprises about 0.001 wt % to about 10 wt % silica abrasive, e.g., about 0.001 wt % to about 8 wt %, about 0.001 wt % to about 6 wt %, about 0.001 wt % to about 5 wt %, about 0.001 wt % to about 4 wt %, about 0.001 wt % to about 2 wt %, about 0.001 wt % to about 1 wt %, about 0.01 wt % to about 10 wt %, about 0.01 wt % to about 8 wt %, about 0.01 wt % to about 6 wt %, about 0.01 wt % to about 5 wt %, about 0.01 wt % to about 4 wt %, about 0.01 wt % to about 2 wt %, about 0.01 wt % to about 1 wt %, about 0.05 wt % to about 10 wt %, about 0.05% by weight to about 8% by weight, about 0.05% by weight to about 6% by weight, about 0.05% by weight to about 5% by weight, about 0.05% by weight to about 4% by weight, about 0.05% by weight to about 2% by weight, about 0.05% by weight to about 1% by weight, about 0.1% by weight to about 10% by weight, about 0.1% by weight to about 8% by weight, about 0.1% by weight to about 6% by weight, about 0.1% by weight to about 5% by weight, about 0.1% by weight to about 4% by weight, about 0.1% by weight to about 2% by weight, about 0.1% by weight to about 1% by weight, about 0.5% by weight to about 10% by weight, about 0.5% by weight to about 8% by weight, about 0.5% by weight to about 5% by weight, about 0.5% by weight to about 4% by weight, about 0.5% by weight to about 2% by weight, or about 0.5% by weight to about 1% by weight. In some embodiments, the polishing composition comprises from about 0.001% to about 8% by weight (e.g., from about 0.5% to about 8% by weight) of silica abrasive. In certain embodiments, the polishing composition comprises from about 0.001% to about 5% by weight (e.g., from about 0.5% to about 5% by weight) of silica abrasive. In other embodiments, the polishing composition comprises from about 0.001% to about 3% by weight (e.g., from about 0.5% to about 3% by weight) of silica abrasive.

[0024] The polishing composition contains an amine compound, and the amine compound has a carbon to nitrogen ratio of about 1:1 to about 3:1. For example, the amine compound may have a carbon to nitrogen ratio of about 1.1:1 to about 3:1, about 1.2:1 to about 3:1, about 1.3:1 to about 3:1, about 1.4:1 to about 3:1, about 1.5:1 to about 3:1, about 1.6:1 to about 3:1, about 1.7:1 to about 3:1, about 1.8:1 to about 3:1, about 1.9:1 to about 3:1, about 2:1 to about 3:1, or 2.1:1 to about 3:1. , about 2.2:1 to about 3:1, about 2.3:1 to about 3:1, about 2.4:1 to about 3:1, about 2.5:1 to about 3:1, about 2.6:1 to about 3:1, about 2.7:1 to about 3:1, about 2.8:1 to about 3:1, about 2.9:1 to about 3:1, about 1:1 to about 2.9:1, about 1:1 to about 2.8:1, about 1:1 to about 2.7:1, about 1:1 to about 2.6 :1, about 1:1 to about 2.5:1, about 1:1 to about 2.4:1, about 1:1 to about 2.3:1, about 1:1 to about 2.2:1, about 1:1 to about 2.1:1, about 1:1 to about 2:1, 1:1 to about 1.9:1, about 1:1 to about 1.8:1, about 1:1 to about 1.7:1, about 1:1 to about 1.6:1, about 1:1 to about 1.5:1, about 1:1 to about 1.4 The amine compound may have a carbon to nitrogen ratio of about 1:1 to about 1.3:1, about 1:1 to about 1.2:1, about 1:1 to about 1.1:1, about 1.2:1 to about 1.5:1, about 1.2:1 to about 1.8:1, about 1.5:1 to about 2.5:1, about 1.8:1 to about 2.2:1, 2.2:1 to about 2.5:1, or about 2.2:1 to about 2.8:1. In some embodiments, the amine compound comprises a carbon to nitrogen ratio of about 1:1 to about 2:1. In certain embodiments, the amine compound comprises a carbon to nitrogen ratio of about 1.2:1 to about 1.8:1. In other embodiments, the amine compound comprises a carbon to nitrogen ratio of about 2:1 to about 3:1.

[0025]

[0025] As used herein, the term "amine-based compound" refers to any compound containing a primary amine, a secondary amine, a tertiary amine, or a combination thereof, and the amine-based compound does not contain a higher functional group such as an aldehyde, a ketone, an imine, a carboxylic acid, an amide, a carbonate, a carbamate, or a urea. Although the amine-based compound may further contain a hydroxyl group or an ether group, in certain embodiments, the amine-based compound consists of carbon, nitrogen, and hydrogen atoms. In a preferred embodiment, the amine-based compound contains at least one primary amine, a secondary amine, or a combination thereof.

[0026] In some embodiments, the amine-based compound comprises at least one ethylenediamine subunit. In that regard, the amine-based compound can comprise one or more subunits of the following formula: Those skilled in the art will understand that the nitrogen atom of an ethylenediamine subunit can be shared by multiple ethylenediamine subunits. For example, piperazine and diethylenetriamine each have two ethylenediamine subunits, while tetraethylenepentamine has four ethylenediamine subunits. In certain embodiments, the amine-based compound contains at least two ethylenediamine subunits. In other embodiments, the amine-based compound contains at least three ethylenediamine subunits. Thus, the amine-based compound can contain one ethylenediamine subunit, two ethylenediamine subunits, three ethylenediamine subunits, four ethylenediamine subunits, five ethylenediamine subunits, six ethylenediamine subunits, seven ethylenediamine subunits, eight ethylenediamine subunits, nine ethylenediamine subunits, or more ethylenediamine subunits.

[0027]

[0027] For example, the amine compound can be selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctylamine, octaethylenenonylamine, tris(2-aminoethyl)amine, piperazine, homopiperazine, N,N-diethylethylenediamine, 1,3-diamino-2-propanol, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N'-dimethylethylenediamine, N,N-dimethylethylenediamine, 1-(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, aminoethylpiperazine, and combinations thereof. In some embodiments, the amine-based compound is a linear compound containing ethylenediamine subunits selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctylamine, and octaethylenenonylamine, hi other embodiments, the amine-based compound is tris(2-aminoethyl)amine.

[0028] The amine-based compound can have any suitable molecular weight (g / mol). The amine-based compound can have a molecular weight of about 1000 g / mol or less, for example, about 800 g / mol or less, about 600 g / mol or less, about 500 g / mol or less, about 450 g / mol or less, about 400 g / mol or less, about 350 g / mol or less, about 300 g / mol or less, about 250 g / mol or less, or about 200 g / mol or less. Alternatively, or in addition, the amine-based compound can include a molecular weight of about 60 g / mol or more, for example, about 80 g / mol or more, about 100 g / mol or more, about 120 g / mol or more, about 140 g / mol or more, about 160 g / mol or more, about 180 g / mol or more, or about 200 g / mol or more. Thus, the amine-based compound can have a molecular weight limited by any two of the aforementioned endpoints, as needed.

[0029] For example, in some embodiments, the amine compound has a concentration of about 60 g / mol to about 1000 g / mol, e.g., about 80 g / mol to about 1000 g / mol, about 100 g / mol to about 1000 g / mol, about 120 g / mol to about 1000 g / mol, about 140 g / mol to about 1000 g / mol, about 160 g / mol to about 1000 g / mol, about 180 g / mol to about 1000 g / mol, about 200 g / mol to about 1000 g / mol, about 60 g / mol to about 800 g / mol, about 80 g / mol to about 800 g / mol, about 100 g / mol to about 800 g / mol, about 120 g / mol to about 800 g / mol, or about 140 g / mol to about 1000 g / mol. g / mol, about 140 g / mol to about 800 g / mol, about 160 g / mol to about 800 g / mol, about 180 g / mol to about 800 g / mol, about 200 g / mol to about 800 g / mol, about 60 g / mol to about 600 g / mol, about 80 g / mol to about 600 g / mol, about 100 g / mol to about 600 g / mol, about 120 g / mol to about 600 g / mol, about 140 g / mol to about 600 g / mol, about 160 g / mol to about 600 g / mol, about 180 g / mol to about 600 g / mol, about 200 g / mol to about 600 g / mol, about 60 g / mol to about 500 g / mol, about 80 g / mol to about 500 g / mol mol, about 100 g / mol to about 500 g / mol, about 120 g / mol to about 500 g / mol, about 140 g / mol to about 500 g / mol, about 160 g / mol to about 500 g / mol, about 180 g / mol to about 500 g / mol, about 200 g / mol to about 500 g / mol, about 60 g / mol to about 450 g / mol, about 80 g / mol to about 450 g / mol, about 100 g / mol to about 450 g / mol, about 120 g / mol to about 450 g / mol, about 140 g / mol to about 450 g / mol, about 160 g / mol to about 450 g / mol, about 180 g / mol to about 450 g / mol, about 200 g / mol to about 450 g / mol mol, about 60 g / mol to about 400 g / mol, about 80 g / mol to about 400 g / mol, about 100 g / mol to about 400 g / mol, about 120 g / mol to about 400 g / mol, about 140 g / mol to about 400 g / mol, about 160 g / mol to about 400 g / mol, about 180 g / mol to about 400 g / mol, about 200 g / mol to about 400 g / mol, about 60 g / mol to about 350 g / mol, about 80 g / mol to about 350 g / mol, about 100 g / mol to about 350 g / mol, about 120 g / mol to about 350 g / mol, about 140 g / mol to about 350 g / mol, about 160 g / mol to about 350 g / mol,About 180 g / mol to about 350 g / mol, about 200 g / mol to about 350 g / mol, about 60 g / mol to about 300 g / mol, about 80 g / mol to about 300 g / mol, about 100 g / mol to about 300 g / mol, about 120 g / mol to about 300 g / mol, about 140 g / mol to about 300 g / mol, about 160 g / mol to about 300 g / mol, about 180 g / mol to about 300 g / mol, about 200 g / mol to about 300 g / mol, about 60 g / mol to about 250 g / mol, about 80 g / mol to about 250 g / mol, about 100 g / mol to about 12 The amine compound may have a molecular weight of 0 g / mol to about 250 g / mol, about 140 g / mol to about 250 g / mol, about 160 g / mol to about 250 g / mol, about 180 g / mol to about 250 g / mol, about 200 g / mol to about 250 g / mol, about 60 g / mol to about 200 g / mol, about 80 g / mol to about 200 g / mol, about 100 g / mol to about 200 g / mol, about 120 g / mol to about 200 g / mol, about 140 g / mol to about 200 g / mol, about 160 g / mol to about 200 g / mol, or about 180 g / mol to about 200 g / mol. In some embodiments, the amine compound has a molecular weight of about 80 g / mol to about 400 g / mol. In certain embodiments, the amine compound has a molecular weight of about 100 g / mol to about 300 g / mol. In another embodiment, the amine-based compound has a molecular weight of about 120 g / mol to about 250 g / mol.

[0030] The amine-based compound can be present in the polishing composition in any suitable amount. The polishing composition can contain about 5000 ppm or less of the amine-based compound, for example, about 4000 ppm or less, about 3000 ppm or less, about 2000 ppm or less, about 1000 ppm or less, or about 500 ppm or less. Alternatively, or in addition, the polishing composition can contain about 50 ppm or more of the amine-based compound, for example, about 100 ppm or more, about 200 ppm or more, about 300 ppm or more, about 400 ppm or more, or about 500 ppm or more. Thus, the polishing composition can optionally contain an amount of the amine-based compound bounded by any two of the aforementioned endpoints.

[0031] For example, in some embodiments, the amine compound is present in an amount of about 50 ppm to about 5000 ppm, e.g., about 50 ppm to about 4000 ppm, about 50 ppm to about 3000 ppm, about 50 ppm to about 2000 ppm, about 50 ppm to about 1000 ppm, about 50 ppm to about 500 ppm, about 100 ppm to about 5000 ppm, or about 100 ppm to about 4000 ppm. ppm, about 100ppm to about 3000ppm, about 100ppm to about 2000ppm, about 100ppm to about 1000ppm, about 100ppm to about 500ppm, about 200ppm to about 5000ppm, about 200ppm to about 4000ppm, about 200ppm to about 3000ppm, about 200ppm to about 2000ppm, about 200ppm to about 1000ppm, about 200 ppm~about 500ppm, about 300ppm~about 5000ppm, about 300ppm~about 4000ppm, about 300ppm~about 3000ppm, about 300ppm~about 2000ppm, Approximately 300ppm to approximately 1000ppm, approximately 300ppm to approximately 500ppm, approximately 400ppm to approximately 5000ppm, approximately 400ppm to approximately 4000ppm, approximately 400ppm to approximately 3000 The amine-based compound may be present in the polishing composition in an amount of about 100 ppm to about 5000 ppm, about 400 ppm to about 1000 ppm, about 400 ppm to about 500 ppm, about 500 ppm to about 5000 ppm, about 500 ppm to about 4000 ppm, about 500 ppm to about 3000 ppm, about 500 ppm to about 2000 ppm, or about 500 ppm to about 1000 ppm. In some embodiments, the polishing composition contains about 100 ppm to about 5000 ppm of the amine-based compound. In certain embodiments, the polishing composition contains about 100 ppm to about 3000 ppm of the amine-based compound. In a preferred embodiment, the polishing composition contains about 100 ppm to about 2000 ppm of the amine-based compound.

[0032] The polishing composition optionally includes a buffering agent. In some embodiments, the polishing composition includes a buffering agent. In other embodiments, the polishing composition does not include a buffering agent. When a buffering agent is present, any suitable compound capable of adjusting and buffering the pH of the polishing composition can be used. In some embodiments, the buffering agent is selected from the group consisting of alkylamines, ammonium salts, alkali metal salts, carboxylic acids, alkali metal nitrates, alkali metal carbonates, alkali metal bicarbonates, borates, and mixtures thereof. In certain embodiments, the buffering agent is an alkali metal salt (e.g., a potassium salt). For example, the buffering agent can be an alkali metal (e.g., lithium, sodium, potassium, rubidium, or cesium) carbonate, acetate, cyanide, sulfide, bicarbonate, metasilicate, or the like. In a preferred embodiment, the buffering agent is a potassium salt, such as potassium carbonate, potassium bicarbonate, or a combination thereof.

[0033]

[0033] The buffering agent can be present in the polishing composition in any suitable amount. The polishing composition can contain about 5000 ppm or less of the buffering agent, for example, about 4000 ppm or less, about 3000 ppm or less, about 2000 ppm or less, about 1000 ppm or less, or about 500 ppm or less. Alternatively, or in addition, the polishing composition can contain about 0 ppm or more of the buffering agent, for example, about 50 ppm or more, about 100 ppm or more, about 200 ppm or more, about 300 ppm or more, about 400 ppm or more, or about 500 ppm or more. Thus, the polishing composition can optionally contain an amount of the buffering agent bounded by any two of the aforementioned endpoints.

[0034] For example, in some embodiments, the buffering agent may be present in a concentration of from about 0 ppm to about 5000 ppm, e.g., from about 0 ppm to about 4000 ppm, from about 0 ppm to about 3000 ppm, from about 0 ppm to about 2000 ppm, from about 0 ppm to about 1000 ppm, from about 0 ppm to about 500 ppm, from about 50 ppm to about 5000 ppm, from about 50 ppm to about 4000 ppm, from about 50 ppm to about 3000 ppm, from about 50 ppm to about 2 000ppm, about 50ppm to about 1000ppm, about 50ppm to about 5000ppm, about 100ppm to about 4000ppm, about 100ppm to about 3000ppm, about 100ppm to about 2000ppm , about 100ppm to about 1000ppm, about 100ppm to about 500ppm, about 200ppm to about 5000ppm, about 200ppm to about 4000ppm, about 200ppm to about 3000ppm, about 200 ppm~about 2000ppm, about 200ppm~about 1000ppm, about 200ppm~about 500ppm, about 300ppm~about 5000ppm, about 300ppm~about 4000ppm, about 300ppm~about 3000ppm, about 300ppm to about 2000ppm, about 300ppm to about 1000ppm, about 300ppm to about 500ppm, about 400ppm to about 5000ppm, about 400ppm to about 4000p The buffering agent may be present in the polishing composition in an amount of about 50 ppm to about 5000 ppm, about 400 ppm to about 2000 ppm, about 400 ppm to about 1000 ppm, about 400 ppm to about 500 ppm, about 500 ppm to about 5000 ppm, about 500 ppm to about 4000 ppm, about 500 ppm to about 3000 ppm, about 500 ppm to about 2000 ppm, or about 500 ppm to about 1000 ppm. In some embodiments, the polishing composition comprises a buffering agent at a concentration of about 50 ppm to about 5000 ppm. In certain embodiments, the polishing composition comprises a buffering agent at a concentration of about 100 ppm to about 3000 ppm.

[0035] In certain embodiments, the polishing composition contains about 100 ppm to about 3000 ppm of a buffering agent. In certain embodiments, the polishing composition contains about 100 ppm to about 3000 ppm of a buffering agent. Examples of usable organic solvents include alcohols such as propylene alcohol, isopropyl alcohol, ethanol, 1-propanol, methanol, and 1-hexanol; aldehydes such as acetylaldehyde; ketones such as acetone, diacetone alcohol, and methyl ethyl ketone; esters such as ethyl formate, propyl formate, ethyl acetate, methyl acetate, methyl lactate, butyl lactate, and ethyl lactate; ethers containing sulfoxides such as dimethyl sulfoxide (DMSO), tetrahydrofuran, dioxane, and diglyme; amides such as N,N-dimethylformamide, dimethylimidazolidinone, and N-methylpyrrolidone; polyhydric alcohols and derivatives thereof such as ethylene glycol, glycerol, diethylene glycol, and diethylene glycol monomethyl ether; and nitrogen-containing organic compounds such as acetonitrile, amylamine, isopropylamine, imidazole, and dimethylamine. Preferably, the aqueous carrier is water only, ie, there are no organic solvents present.

[0036] In addition to a buffering agent, the polishing composition can include one or more compounds capable of adjusting (i.e., adjusting) the pH of the polishing composition (i.e., pH-adjusting compounds). For example, the pH of the polishing composition can be adjusted with a compound capable of adjusting the pH and then buffered with a buffering agent. In some embodiments, the buffering agent and the pH-adjusting compound are the same. In other embodiments, the pH-adjusting compound and the buffering agent are different. The pH of the polishing composition can be adjusted using any suitable compound capable of adjusting the pH of the polishing composition (e.g., by including an alkali metal hydroxide such as potassium hydroxide). It is desirable that the pH-adjusting compound be water-soluble and compatible with the other components of the polishing composition.

[0037]

[0037] Typically, the chemical-mechanical polishing composition has a pH of about 9 to about 12 at the point of use (e.g., about 9.5 to about 12, about 10 to about 12, about 10.5 to about 12, about 11 to about 12, about 9.5 to about 11.5, about 10 to about 11.5, about 10.5 to about 11.5, about 9.5 to about 11, about 10 to about 11, about 10.5 to about 11.5, or about 11 to about 12). In some embodiments, the polishing composition has a pH of about 9 to about 12 at the point of use. In some embodiments, the polishing composition has a pH of about 10 to about 12 at the point of use. Preferably, the polishing composition has a pH of about 10 to about 11 at the point of use.

[0038] In some embodiments, the polishing composition further comprises a complexing agent (i.e., a chelating agent). For example, the polishing composition can further comprise a silica chelating agent, such as an aminophosphonic acid. Without being bound by theory, it is believed that the aminophosphonic acid acts as a silica chelating agent, thereby increasing the polysilicon polishing rate in certain compositions. The silica chelating agent can include any suitable aminophosphonic acid, such as, for example, ethylenediaminetetra(methylenephosphonic acid), aminotri(methylenephosphonic acid), diethylenetriaminepenta(methylenephosphonic acid), salts thereof, and combinations thereof. In certain embodiments, the aminophosphonic acid is aminotri(methylenephosphonic acid). For example, the aminophosphonic acid can be DEQUEST™ 2000, commercially available from ThermPhos International.

[0039] The complexing agent can be present in the polishing composition in any suitable amount. The polishing composition can contain about 5000 ppm or less of the complexing agent, for example, about 4000 ppm or less, about 3000 ppm or less, about 2000 ppm or less, about 1000 ppm or less, or about 500 ppm or less. Alternatively, or in addition, the polishing composition can contain about 10 ppm or more of the complexing agent, for example, about 50 ppm or more, about 100 ppm or more, about 200 ppm or more, about 300 ppm or more, about 400 ppm or more, or about 500 ppm or more. Thus, the polishing composition can optionally contain an amount of the complexing agent bounded by any two of the aforementioned endpoints.

[0040] For example, in some embodiments, the complexing agent is present in an amount of from about 10 ppm to about 5000 ppm, e.g., from about 10 ppm to about 4000 ppm, from about 10 ppm to about 3000 ppm, from about 10 ppm to about 2000 ppm, from about 10 ppm to about 1000 ppm, from about 10 ppm to about 500 ppm, from about 50 ppm to about 5000 ppm, from about 50 ppm to about 4000 ppm, from about 50 ppm to about 3000 ppm, or from about 50 ppm to about 5000 ppm. m ~ about 2000ppm, about 50ppm - about 1000ppm, about 50ppm - about 5000ppm, about 100ppm - about 4000ppm, about 100ppm - about 3000ppm, about 100ppm - about 200 0ppm, about 100ppm to about 1000ppm, about 100ppm to about 500ppm, about 200ppm to about 5000ppm, about 200ppm to about 4000ppm, about 200ppm to about 3000ppm, about 200ppm to about 2000ppm, about 200ppm to about 1000ppm, about 200ppm to about 500ppm, about 300ppm to about 5000ppm, about 300ppm to about 4000ppm, about 300ppm m ~ about 3000ppm, about 300ppm - about 2000ppm, about 300ppm - about 1000ppm, about 300ppm - about 500ppm, about 400ppm - about 5000ppm, about 400ppm - about 400 The complexing agent may be present in the polishing composition in an amount of about 0 ppm, about 400 ppm to about 3000 ppm, about 400 ppm to about 2000 ppm, about 400 ppm to about 1000 ppm, about 400 ppm to about 500 ppm, about 500 ppm to about 5000 ppm, about 500 ppm to about 4000 ppm, about 500 ppm to about 3000 ppm, about 500 ppm to about 2000 ppm, or about 500 ppm to about 1000 ppm. In some embodiments, the polishing composition comprises about 50 ppm to about 1000 ppm of complexing agent.

[0041]

[0041] The chemical-mechanical polishing composition optionally further comprises one or more additives, examples of which include modifiers, acids (such as sulfonic acids), biocides, scale inhibitors, and dispersants.

[0042]

[0042] When present, the biocide can be any suitable biocide and can be present in the polishing composition in any suitable amount. Suitable biocides are isothiazolinone (e.g., methylisothiazolinone or benzoisothiazolinone) biocides. The biocide can be present in the polishing composition at a concentration of about 1 ppm to about 750 ppm, preferably about 20 ppm to about 200 ppm.

[0043]

[0043] The polishing composition can be manufactured by any suitable technique, many of which are known to those skilled in the art. The polishing composition can be prepared in a batch or continuous manner. Generally, the polishing composition is prepared by combining the components of the polishing composition. As used herein, the term "component" includes not only individual components (e.g., silica abrasive, amine-based compound, optional buffering agent, and / or any other optional additives) but also any combination of components (e.g., silica abrasive, amine-based compound, optional buffering agent, and / or any other optional additives).

[0044]

[0044] For example, the polishing composition can be prepared by (i) providing all or part of a liquid carrier, (ii) dispersing a silica abrasive, an amine-based compound, an optional buffer, and / or any other optional additives using any suitable means for preparing such a dispersion, (iii) adjusting the pH of the dispersion appropriately (e.g., by including an alkali metal hydroxide such as potassium hydroxide), and (iv) adding appropriate amounts of any other optional components and / or additives to the mixture, if desired.

[0045]

[0045] The polishing composition can be supplied as a one-package system containing a silica abrasive, an amine-based compound, an optional buffer, and / or any other optional additives, and water. Alternatively, the polishing composition of the present invention can be supplied as a two-package system containing an abrasive slurry in a first package and an additive solution in a second package, where the abrasive slurry consists essentially of or consists of abrasive particles and water, and the additive solution consists essentially of or consists of an amine-based compound, an optional buffer, and / or any other optional additives. The two-package system allows the properties of the polishing composition to be adjusted by changing the mixing ratio of the two packages, the abrasive slurry and the additive solution.

[0046]

[0046] Various methods can be adopted to utilize such a two-package polishing system. For example, the polishing slurry and the additive solution can be supplied to the polishing table through different pipes that are joined and connected at the outlet of the supply pipe. The polishing slurry and the additive solution can be mixed immediately before or just before polishing, or can be supplied simultaneously onto the polishing table. Furthermore, when the two packages are mixed, deionized water can be added as needed to adjust the polishing composition and the resulting substrate polishing characteristics.

[0047]

[0047] Similarly, in connection with the present invention, three, four, or more packaging systems can be utilized, with each of the multiple containers containing different components of the chemical mechanical polishing composition of the present invention, one or more optional components, and / or different concentrations of one or more of the same components.

[0048]

[0048] To mix components contained in two or more storage devices to produce a polishing composition at or near the point of use, the storage devices are typically provided with one or more flow lines leading from each storage device to the point of use of the polishing composition (e.g., a platen, a polishing pad, or a substrate surface). As used herein, the term "point of use" refers to the point at which the polishing composition is applied to the substrate surface (e.g., a polishing pad or the substrate surface itself). The term "flow line" refers to the flow path from an individual storage container to the point of use of the components stored therein. Each flow line can lead directly to the point of use, or two or more flow lines can be joined at any point to form a single flow line leading to the point of use. Furthermore, any of the flow lines (e.g., individual flow lines or combined flow lines) may first lead to one or more other devices (e.g., pumping devices, metering devices, mixing devices, etc.) before reaching the point of use of the component.

[0049] The components of the polishing composition can be delivered independently to the point of use (e.g., delivered to the substrate surface where they are mixed during the polishing process), or one or more of the components can be combined before being delivered to the point of use, e.g., immediately before or immediately before being delivered to the point of use. Components are mixed "immediately before delivery to the point of use" if they are mixed within about 5 minutes, e.g., within about 4 minutes, within about 3 minutes, within about 2 minutes, within about 1 minute, within about 45 seconds, within about 30 seconds, within about 10 seconds of being added to the platen in a mixed state, or simultaneously with delivery of the components at the point of use (e.g., the components are mixed in a dispenser). Components are also combined "immediately before delivery to the point of use" if they are combined within 5 m of the location of use, e.g., within 1 m of the point of use, or within 10 cm of the point of use (e.g., within 1 cm of the point of use).

[0050]

[0050] When two or more components of the polishing composition are mixed before reaching the point of use, the components can be mixed in a flow line and delivered to the point of use without using a mixing device. Alternatively, one or more flow lines can lead to a mixing device to facilitate mixing of the two or more components. Any suitable mixing device can be used. For example, the mixing device can be a nozzle or jet (e.g., a high-pressure nozzle or jet) through which two or more components flow. Alternatively, the mixing device can be a vessel-type mixing device having one or more inlets through which two or more components of the polishing slurry are introduced into the mixer and at least one outlet through which the mixed components exit the mixer and are delivered to the point of use directly or via other elements of the device (e.g., via one or more flow lines). Furthermore, the mixing device can have one or more chambers, each chamber having at least one inlet and at least one outlet, and two or more components are mixed within each chamber. When a vessel-type mixing device is used, the mixing device preferably has a mixing mechanism to further facilitate mixing of the components. Mixing mechanisms are commonly known in the art and include stirrers, blenders, agitators, paddle baffles, gas sparger systems, vibrators, and the like.

[0051]

[0051] The polishing composition can also be provided as a concentrate intended to be diluted with an appropriate amount of water before use. In such embodiments, the polishing composition concentrate contains the components of the polishing composition in amounts such that, upon dilution of the concentrate with an appropriate amount of water, each component of the polishing composition is present in the polishing composition in an amount within the appropriate range described above for each component. For example, the silica abrasive, the amine-based compound, the optional buffer, and / or any other optional additives can each be present in the concentrate in an amount that is about twice (e.g., about three, about four, or about five times) greater than the concentration described above for each component, such that, when the concentrate is diluted with an equal amount of water (e.g., 2 equivalents, 3 equivalents, or 4 equivalents, respectively), each component will be present in the polishing composition in an amount within the range described above for each component. Furthermore, as will be understood by those skilled in the art, the concentrate can include an appropriate proportion of the water that will be present in the final polishing composition to ensure that the silica abrasive, the amine-based compound, the optional buffer, and / or any other optional additives are at least partially or completely dissolved in the concentrate.

[0052]

[0052] The present invention further provides a method for polishing a substrate, the method comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing a chemical-mechanical polishing composition, the chemical-mechanical polishing composition comprising: (a) a silica abrasive; (b) an amine-based compound having a carbon to nitrogen ratio of about 1:1 to about 3:1; (c) optionally, a buffer; and (d) water, the chemical-mechanical polishing composition having a pH of about 9 to about 12; (iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to polish at least a portion of a surface of the substrate, thereby polishing the substrate. The present invention provides a method for chemically mechanically polishing a substrate comprising, consisting essentially of, or consisting of:

[0053] The chemical-mechanical polishing composition can be used to polish any suitable substrate, and is particularly useful for polishing substrates that include at least one layer (usually a surface layer) of a low-dielectric material. Suitable substrates include wafers used in the semiconductor industry. Wafers typically include or consist of, for example, metals, metal oxides, metal nitrides, metal composites, metal alloys, or combinations thereof. The method of the present invention is particularly useful for polishing substrates that include, for example, polysilicon, including any one or all of the foregoing materials. In some embodiments, the substrate includes polysilicon on a surface of the substrate, and at least a portion of the polysilicon on the surface of the substrate is polished to polish the substrate.

[0054] In some embodiments, the substrate comprises silicon oxide, silicon nitride, polysilicon, or a combination thereof. The polysilicon can be any suitable polysilicon, many of which are known in the art. The polysilicon can have any suitable phase, and can be amorphous, crystalline, or a combination thereof. The silicon nitride can be any suitable silicon nitride, many of which are known in the art. The silicon nitride can have any suitable phase, and can be amorphous, crystalline, or a combination thereof. The silicon oxide can likewise be any suitable silicon oxide, many of which are known in the art. Suitable types of silicon oxide include, but are not limited to, borophosphosilicate glass (BPSG), high-density plasma (HDP) oxide and / or plasma-enhanced tetraethylorthosilicate (PETEOS) and / or tetraethylorthosilicate (TEOS), thermal oxide, and undoped silicate glass. In certain embodiments, the substrate comprises polysilicon and silicon oxide and / or silicon nitride.

[0055] The chemical mechanical polishing composition of the present invention can be tailored to selectively provide effective polishing of a specific thin-layer material in a desired polishing range while minimizing surface defects, imperfections, corrosion, erosion, and removal of stop layers. Selectivity can be controlled to some extent by varying the relative concentrations of the components of the polishing composition. As used herein, the term "selectivity" refers to the removal rate ratio of two different target materials. For example, selectivity refers to the removal rate ratio of two different materials or the removal rate ratio of two different topographies (e.g., blanket removal vs. active removal).

[0056] In some embodiments, the substrate comprises polysilicon on the surface of the substrate, and at least a portion of the polysilicon on the surface of the substrate is polished at a polysilicon removal rate to polish the substrate; the substrate further comprises silicon oxide on the surface of the substrate, and at least a portion of the silicon oxide on the surface of the substrate is polished at a silicon oxide removal rate to polish the substrate. Generally, chemical-mechanical polishing compositions provide a polysilicon removal rate that is significantly higher than the silicon oxide removal rate. Thus, in some embodiments, a chemical-mechanical polishing composition comprising (a) a silica abrasive, (b) an amine-based compound, the amine-based compound having a carbon to nitrogen ratio of about 1:1 to about 3:1, (c) optionally a buffer, and (d) water provides a polysilicon removal rate that is about 25 times (e.g., at least 50 times, at least 75 times, or at least 100 times) higher than the silicon oxide removal rate. In some embodiments, the polysilicon removal rate is at least about 50 times the silicon oxide removal rate. In certain embodiments, the removal rate of polysilicon is at least about 75 times the removal rate of silicon oxide. In preferred embodiments, the removal rate of polysilicon is at least about 100 times the removal rate of silicon oxide.

[0057] In some embodiments, the substrate comprises polysilicon on the surface of the substrate, and at least a portion of the polysilicon on the surface of the substrate is polished at a polysilicon removal rate to polish the substrate; the substrate further comprises silicon nitride on the surface of the substrate, and at least a portion of the silicon nitride on the surface of the substrate is polished at a silicon nitride removal rate to polish the substrate. Generally, chemical-mechanical polishing compositions provide a polysilicon removal rate that is significantly higher than the silicon nitride removal rate. Thus, in some embodiments, a chemical-mechanical polishing composition comprising (a) a silica abrasive, (b) an amine-based compound, the amine-based compound having a carbon to nitrogen ratio of about 1:1 to about 3:1, (c) optionally a buffer, and (d) water provides a polysilicon removal rate that is about 25 times (e.g., at least 50 times, at least 75 times, or at least 100 times) higher than the silicon nitride removal rate. In some embodiments, the polysilicon removal rate is at least about 50 times the silicon nitride removal rate. In certain embodiments, the removal rate of polysilicon is at least about 75 times the removal rate of silicon nitride. In preferred embodiments, the removal rate of polysilicon is at least about 100 times the removal rate of silicon nitride.

[0058] In some embodiments, the substrate comprises polysilicon on the surface of the substrate, and at least a portion of the polysilicon on the surface of the substrate is polished at a removal rate of the polysilicon to polish the substrate; the substrate further comprises silicon oxide and silicon nitride on the surface of the substrate, and at least a portion of the silicon oxide on the surface of the substrate is polished at a removal rate of the silicon oxide, and at least a portion of the silicon nitride on the surface of the substrate is polished at a removal rate of the silicon nitride to polish the substrate. Generally, chemical mechanical polishing compositions provide a removal rate of polysilicon that is significantly higher than the removal rates of silicon oxide and silicon nitride. Thus, in some embodiments, a chemical mechanical polishing composition comprising (a) a silica abrasive, (b) an amine-based compound, the amine-based compound having a carbon to nitrogen ratio of about 1:1 to about 3:1, (c) optionally a buffer, and (d) water provides a removal rate of polysilicon that is about 25 times (e.g., at least 50 times, at least 75 times, or at least 100 times) higher than the removal rate of silicon oxide and silicon nitride. In certain embodiments, the removal rate of polysilicon is at least about 50 times the removal rate of silicon oxide and silicon nitride. In certain embodiments, the removal rate of polysilicon is at least about 75 times the removal rate of silicon oxide and silicon nitride.

[0059]

[0059] The polishing composition of the present invention desirably produces few particle defects when polishing a substrate, as determined by an appropriate technique. Particle defects on a substrate polished with the polishing composition of the present invention can be determined by any appropriate technique. For example, laser light scattering techniques such as dark-field normal beam composite (DCN) and dark-field oblique beam composite (DCO), or scanning electron microscope (SEM) analysis can be used to determine particle defects on the polished substrate. Suitable metrology instruments for evaluating particle defects are available, for example, from KLA-Tencor (e.g., SURFSCAN™ SPI metrology instruments operating at a 120 nm threshold or a 160 nm threshold).

[0060] Substrates (e.g., silicon oxide, silicon nitride, polysilicon, or combinations thereof) polished with the polishing composition of the present invention, particularly silicon containing polysilicon and silicon oxide and / or silicon nitride, desirably have a DCN value of about 20,000 counts or less, e.g., about 17,500 counts or less, about 15,000 counts or less, about 12,500 counts or less, about 3500 counts or less, about 3000 counts or less, about 2500 counts or less, about 2000 counts or less, about 1500 counts or less, or about 1000 counts or less. Preferably, substrates polished according to one embodiment of the present invention have a DCN value of about 750 counts or less, e.g., about 500 counts or less, about 250 counts or less, about 125 counts or less, or about 100 counts or less.

[0061] Alternatively, or in addition, substrates polished with the chemical-mechanical polishing composition of the present invention desirably exhibit low scratches as determined by a suitable technique. For example, silicon wafers polished according to one embodiment of the present invention desirably have about 250 or fewer scratches, about 125 or fewer scratches, about 100 or fewer scratches, about 75 or fewer scratches, about 50 or fewer scratches, or about 25 or fewer scratches, as measured by any suitable method known in the art, such as laser light scattering or scanning electron microscope (SEM) analysis of the film.

[0062] In some embodiments, rate control agents may be added to reduce defects due to particle and / or scratch counts. For example, the addition of rate control agents such as quaternary amines, such as tetraethylammonium hydroxide, benzyltrimethylammonium hydroxide (BTMAH), tetrabutylammonium hydroxide (TBAH), or polypropylene glycol (PPG), polyethylene glycol (PEG), and copolymers of PEG (e.g., Pluronic surfactants), can reduce particle defect and scratch counts. Generally, rate control agents slightly reduce the removal rate of polysilicon but do not affect the removal rates of silicon oxide or silicon nitride. Therefore, the use of rate control agents to reduce defects may also slightly reduce the selectivity of polysilicon to silicon oxide and silicon nitride.

[0063] The chemical mechanical polishing compositions and methods of the present invention are particularly suitable for use in combination with a chemical mechanical polishing apparatus. Typically, the apparatus includes a platen that is in motion during use and has a velocity resulting from orbital, linear, or circular motion; a polishing pad that contacts the platen and moves with the platen when in motion; and a carrier that holds a substrate to be polished by contacting and moving the substrate against the surface of the polishing pad. Polishing of the substrate is accomplished by contacting the substrate with the polishing pad and the polishing composition of the present invention, and then moving the polishing pad relative to the substrate to polish at least a portion of the substrate.

[0064]

[0064] The substrate can be polished with the chemical-mechanical polishing composition using any suitable polishing pad (e.g., polishing surface). Suitable polishing pads include, for example, woven and nonwoven polishing pads. Furthermore, suitable polishing pads can include any suitable polymer having various densities, hardnesses, thicknesses, compressibility, rebound ability upon compression, and compressive moduli. Suitable polymers include, for example, polyvinyl chloride, polyvinyl fluoride, nylon, fluorocarbon, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, co-molded versions thereof, and mixtures thereof. Soft polyurethane polishing pads are particularly useful in combination with the polishing method of the present invention. Common pads include SURFIN™ 000, SURFIN™ SSW1, SPM3100 (Emininess Technologies), POLITEX™ available from Dow Chemical Company (Newark, Delaware), POLYPAS™ 27 available from Fujibo (Osaka, Japan), EPIC™ D100 pad or NEXPLANAR™ E6088 available from Cabot Microelectronics (Aurora, Illinois). A preferred polishing pad is a hard, microporous polyurethane pad (IC1010™) available from Dow Chemical.

[0065]

[0065] Desirably, the chemical-mechanical polishing apparatus further includes an in situ polishing endpoint detection system, many of which are known in the art. Techniques for inspecting and monitoring the polishing process by analyzing light or other radiation reflected from the surface of the substrate being polished are known in the art. Such methods are described, for example, in U.S. Pat. Nos. 5,196,353, 5,433,651, 5,609,511, 5,643,046, 5,658,183, 5,730,642, 5,838,447, 5,872,633, 5,893,796, 5,949,927, and 5,964,643. Desirably, inspecting or monitoring the progress of the polishing process with respect to the substrate being polished allows for the determination of the polishing endpoint, i.e., when to terminate the polishing process with respect to a particular substrate.

[0066] Embodiment (1) In embodiment (1), (a) silica abrasive, (b) an amine-based compound containing a carbon to nitrogen ratio of about 1:1 to about 3:1; (c) optionally a buffering agent, and (d) water Including, A chemical-mechanical polishing composition having a pH of about 9 to about 12 is provided.

[0067] (2) In embodiment (2), the polishing composition of embodiment (1) is provided, wherein the polishing composition contains about 0.001 wt % to about 10 wt % of a silica abrasive.

[0068] (3) In embodiment (3), the polishing composition of embodiment (2) is provided, wherein the polishing composition contains about 0.1 wt % to about 5 wt % of a silica abrasive.

[0069] (4) In embodiment (4), the polishing composition according to any one of embodiments (1) to (3) is provided, wherein the polishing composition has a pH of about 10 to about 12.

[0070] (5) In embodiment (5), the polishing composition of embodiment (4) is provided, wherein the polishing composition has a pH of about 10 to about 11.

[0071] (6) In embodiment (6), there is provided the polishing composition according to any one of embodiments (1) to (5), wherein the polishing composition contains a buffer at a concentration of about 50 ppm to about 5000 ppm.

[0072] (7) In embodiment (7), the polishing composition of embodiment (6) is provided, wherein the polishing composition contains about 100 ppm to about 3000 ppm of a buffering agent.

[0073] (8) In embodiment (8), there is provided the polishing composition according to any one of embodiments (1) to (7), wherein the polishing composition further contains a complexing agent.

[0074] (9) In embodiment (9), the polishing composition of embodiment (8) is provided, wherein the polishing composition contains about 50 ppm to about 1000 ppm of a complexing agent.

[0075]

[0075] (10) In embodiment (10), the polishing composition according to any one of embodiments (1) to (9) is provided, wherein the amine compound contains a carbon to nitrogen ratio of about 1:1 to about 2:1.

[0076] (11) In embodiment (11), the polishing composition of embodiment (10) is provided, wherein the amine-based compound comprises a carbon to nitrogen ratio of about 1.2:1 to about 1.8:1.

[0077]

[0077] (12) In embodiment (12), the polishing composition according to any one of embodiments (1) to (9) is provided, wherein the amine compound contains a carbon to nitrogen ratio of about 2:1 to about 3:1.

[0078]

[0078] (13) In embodiment (13), there is provided the polishing composition according to any one of embodiments (1) to (12), wherein the amine compound has a molecular weight of about 80 g / mol to about 400 g / mol.

[0079] (14) In embodiment (14), the polishing composition of embodiment (13) is provided, wherein the amine compound has a molecular weight of about 100 g / mol to about 300 g / mol.

[0080] (15) In embodiment (15), the polishing composition of embodiment (14) is provided, wherein the amine compound has a molecular weight of about 120 g / mol to about 250 g / mol.

[0081] (16) In embodiment (16), there is provided the polishing composition according to any one of embodiments (1) to (15), wherein the amine compound contains at least one ethylenediamine subunit.

[0082] (17) In embodiment (17), the polishing composition of embodiment (16) is provided, wherein the amine-based compound includes at least two ethylenediamine subunits.

[0083] (18) In embodiment (18), the polishing composition of embodiment (17) is provided, wherein the amine-based compound includes at least three ethylenediamine subunits.

[0084] (19) In embodiment (19), there is provided the polishing composition according to any one of embodiments (1) to (18), wherein the amine compound consists of carbon, nitrogen, and hydrogen atoms.

[0085]

[0085] (20) In embodiment (20), a polishing composition described in any one of embodiments (1) to (9) is presented, wherein the amine compound is selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctylamine, octaethylenenonylamine, tris(2-aminoethyl)amine, piperazine, homopiperazine, N,N-diethylethylenediamine, 1,3-diamino-2-propanol, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N'-dimethylethylenediamine, N,N-dimethylethylenediamine, 1-(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, aminoethylpiperazine, and combinations thereof.

[0086]

[0086] (21) In embodiment (21), there is provided the polishing composition according to any one of embodiments (1) to (20), wherein the polishing composition contains about 100 ppm to about 5000 ppm of an amine compound.

[0087] (22) In embodiment (22), there is provided the polishing composition of embodiment (21), wherein the polishing composition contains about 100 ppm to about 3000 ppm of an amine compound.

[0088] (23) In embodiment (23), there is provided the polishing composition of embodiment (22), wherein the polishing composition contains about 100 ppm to about 2000 ppm of an amine compound.

[0089] (24) In embodiment (24), a method for chemical mechanical polishing of a substrate is provided, comprising the following steps: (i) providing a substrate; (ii) providing a polishing pad; (iii) (a) silica abrasive, (b) an amine-based compound containing a carbon to nitrogen ratio of about 1:1 to about 3:1; (c) optionally a buffering agent, and (d) water Including, Has a pH of about 9 to about 12 providing a chemical-mechanical polishing composition; (iv) contacting the substrate with a polishing pad and a chemical-mechanical polishing composition; (v) moving the polishing pad and chemical-mechanical polishing composition relative to the substrate to polish at least a portion of the surface of the substrate, thereby polishing the substrate.

[0090]

[0090] (25) In embodiment (25), the method of embodiment (24) is provided, wherein the polishing composition comprises about 0.001 wt % to about 10 wt % of a silica abrasive.

[0091] (26) In embodiment (26), the method of embodiment (25) is provided, wherein the polishing composition comprises about 0.1 wt % to about 5 wt % of a silica abrasive.

[0092] (27) In embodiment (27), the method according to any one of embodiments (24) to (26) is presented, wherein the polishing composition has a pH of about 10 to about 12.

[0093] (28) In embodiment (28), the method of embodiment (27) is provided, wherein the polishing composition has a pH of about 10 to about 11.

[0094] (29) In embodiment (29), the method according to any one of embodiments (24) to (28) is provided, wherein the polishing composition comprises a buffering agent at a concentration of about 50 ppm to about 5000 ppm.

[0095]

[0095] (30) In embodiment (30), the method of embodiment (29) is provided, wherein the polishing composition comprises about 100 ppm to about 3000 ppm of a buffering agent.

[0096] (31) In embodiment (31), the method according to any one of embodiments (24) to (30) is provided, wherein the polishing composition further comprises a complexing agent.

[0097] (32) In embodiment (32), the polishing composition of embodiment (31) is provided, wherein the polishing composition comprises about 50 ppm to about 1000 ppm of a complexing agent.

[0098] (33) In embodiment (33), the method of any one of embodiments (1) to (32) is provided, wherein the amine compound comprises a carbon to nitrogen ratio of about 1:1 to about 2:1.

[0099] (34) In embodiment (34), the method of embodiment (33) is provided, wherein the amine compound comprises a carbon to nitrogen ratio of about 1.2:1 to about 1.8:1.

[0100]

[0100] (35) In embodiment (35), the method of any one of embodiments (1) to (32) is provided, wherein the amine compound comprises a carbon to nitrogen ratio of about 2:1 to about 3:1.

[0101] (36) In embodiment (36), the method of any one of embodiments (24) to (35) is provided, wherein the amine compound has a molecular weight of about 80 g / mol to about 400 g / mol.

[0102] (37) In embodiment (37), the method of embodiment (36) is provided, wherein the amine compound has a molecular weight of about 100 g / mol to about 300 g / mol.

[0103] (38) In embodiment (38), the method of embodiment (37) is provided, wherein the amine compound has a molecular weight of about 120 g / mol to about 250 g / mol.

[0104] (39) In embodiment (39), the method of any one of embodiments (24) to (38) is provided, wherein the amine-based compound comprises at least one ethylenediamine subunit.

[0105] (40) In embodiment (40), the method of embodiment (39) is provided, wherein the amine-based compound comprises at least two ethylenediamine subunits.

[0106] (41) In embodiment (41), the method of embodiment (40) is provided, wherein the amine-based compound comprises at least three ethylenediamine subunits.

[0107] (42) In embodiment (42), the method according to any one of embodiments (24) to (41) is provided, wherein the amine compound consists of carbon, nitrogen, and hydrogen atoms.

[0108] (43) In embodiment (43), the method of any one of embodiments (1) to (32) is provided, wherein the amine compound is selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctylamine, octaethylenenonylamine, tris(2-aminoethyl)amine, piperazine, homopiperazine, N,N-diethylethylenediamine, 1,3-diamino-2-propanol, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N'-dimethylethylenediamine, N,N-dimethylethylenediamine, 1-(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, aminoethylpiperazine, and combinations thereof.

[0109]

[0108] (44) In embodiment (44), the method of any one of embodiments (24) to (43) is presented, wherein the polishing composition contains about 100 ppm to about 5000 ppm of an amine compound.

[0110]

[0109] (45) In embodiment (45), the method of embodiment (44) is provided, wherein the polishing composition comprises about 100 ppm to about 3000 ppm of the amine compound.

[0111]

[0110] (46) In embodiment (46), the method of embodiment (45) is provided, wherein the polishing composition comprises about 100 ppm to about 2000 ppm of the amine compound.

[0112]

[0111] (47) In embodiment (47), the method of any one of embodiments (24) to (46) is provided, wherein the substrate includes polysilicon on a surface of the substrate, and at least a portion of the polysilicon on the surface of the substrate is polished at a polysilicon removal rate to polish the substrate.

[0113]

[0112] (48) In embodiment (48), the method of embodiment (47) is provided, wherein the substrate further comprises silicon oxide on the surface of the substrate, and at least a portion of the silicon oxide on the surface of the substrate is polished at a silicon oxide removal rate to polish the substrate.

[0114] (49) In embodiment (49), the method of embodiment (48) is presented, wherein the polysilicon removal rate is at least about 50 times the silicon oxide removal rate.

[0115] (50) In embodiment (50), the method of embodiment (49) is presented, wherein the polysilicon removal rate is at least about 75 times the silicon oxide removal rate.

[0116] (51) In embodiment (51), the method of embodiment (50) is presented, wherein the polysilicon removal rate is at least about 100 times the silicon oxide removal rate.

[0117]

[0116] (52) In embodiment (52), the method of any one of embodiments (47) to (51) is provided, wherein the substrate further comprises silicon nitride on a surface of the substrate, and at least a portion of the silicon nitride on the surface of the substrate is polished at a removal rate of the silicon nitride to polish the substrate.

[0118] (53) In embodiment (53), the method of embodiment (52) is presented, wherein the removal rate of polysilicon is at least about 50 times the removal rate of silicon nitride.

[0119] (54) In embodiment (54), the method of embodiment (53) is presented, wherein the removal rate of polysilicon is at least about 75 times the removal rate of silicon nitride.

[0120] (55) In embodiment (55), the method of embodiment (54) is presented, wherein the removal rate of polysilicon is at least about 100 times the removal rate of silicon nitride.

[0121]

[0120] (56) In embodiment (56), the polishing composition or method of any one of embodiments (1) to (55) is provided, further comprising a rate control agent selected from tetrabutylammonium hydroxide and polypropylene glycol.

[0122] Example The following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope.

[0123]

[0122] The following abbreviations are used throughout the examples: removal rate (RR), tetraethylorthosilicate (TEOS), silicon nitride (SiN), polysilicon (polySi), and point of use (POU).

[0124] In the following examples, substrates TEOS (i.e., silicon oxide), SiN (i.e., silicon nitride), and / or poly-Si were coated on patterned wafers and polished using either a MIRRA™ (Applied Materials, Inc.) polishing tool, an AP-300™ (CTS Co., Ltd.) polishing tool, a Logitech™ polishing tool (Logitech, Ltd.), or a REFLEXION™ (Applied Materials, Inc.) polishing tool. For all compositions, an IC 1010™ polishing pad (Rohm and Haas Electronic Materials) or a NEXPLANAR™ E6088 polishing pad (Cabot Microelectronics, Aurora, IL) was used with the same polishing parameters. Unless otherwise noted, the standard polishing parameters for the REFLEXION™ were as follows: IC 1010™ pad, downforce = 13.79 kPa (2 psi), platen speed = 100 rpm, total flow rate = 200 mL / min. Unless otherwise noted, standard Logitech™ polishing parameters are: NEXPLANAR™ E6088 pad, downforce = 2 psi, platen speed = 93 rpm, total flow rate = 200 mL / min. Unless otherwise noted, standard AP-300™ polishing parameters are: IC1010™ pad, downforce = 2 psi, platen speed = 100 rpm, total flow rate = 200 mL / min. Unless otherwise noted, standard MIRRA™ polishing parameters are: IC1010™ pad, downforce = 2 psi, platen speed = 93 rpm, total flow rate = 200 mL / min, or NEXPLANAR™ E6088 pad, downforce = 2 psi, platen speed = 93 rpm, total flow rate = 200 mL / min. The removal rate was calculated by measuring the film thickness using spectroscopic ellipsometry and subtracting the final thickness from the initial thickness.

[0125] Example 1

[0124] This example demonstrates the effect of an amine-based compound (tris-(2-aminoethyl)-amine (TREN)) containing a carbon to nitrogen ratio of about 1:1 to about 3:1 on (i) the poly-Si removal rate and (ii) the amount of surface defects.

[0126] Comparative Polishing Composition 1A was prepared by combining the following ingredients and diluting the composition as needed to provide a point-of-use composition containing: 4430 ppm arginine, 346 ppm DEQUEST™ 2000, 700 ppm KOH, 1161 ppm KHCO, 13.3 ppm 1,2-benzisothiazolin-3-one (BIT), and 1.75 wt. % silica (Nalco DVSTS006 silica particles).

[0127] Inventive Polishing Composition 1B was prepared by combining the following components and diluting the composition as needed to provide a point-of-use composition containing: 222 ppm tris-(2-aminoethyl)-amine (TREN), 346 ppm DEQUEST™ 2000, 700 ppm KOH, 1164 ppm KHCO, 7 ppm 1,2-benzisothiazolin-3-one (BIT), and 0.88 wt. % silica (Nalco DVSTS006 silica particles).

[0128] Individual patterned wafers (e.g., 200 mm or 300 mm diameter wafers) containing 50% poly-Si, TEOS, or SiN features (approximately 20,000 Å thick) with a pattern density were coated on patterned silicon substrates with steps of approximately 8,000 Å and polished with Comparative Polishing Composition 1A and Inventive Polishing Composition 1B using an IC1010™ polishing pad at a downforce of 13.79 kPa (2 psi) in a REFLEXION™ tool. The removal rates of poly-Si, TEOS, and SiN were measured, and the average amounts of surface defects and scratches were determined. The results are shown in Table 1. TIFF2025539023000003.tif31170

[0129] As can be seen from the results shown in Table 1, polishing composition 1B of the present invention containing tris-(2-aminoethyl)-amine (TREN) exhibited an improved poly-Si removal rate while maintaining similar TEOS and SiN removal rates compared to comparative polishing composition 1A containing arginine, despite having a lower solids (i.e., silica particles) content. In other words, polishing composition 1B of the present invention containing tris-(2-aminoethyl)-amine (TREN) exhibited a higher poly-Si removal rate and selectivity than comparative polishing composition 1A containing arginine, despite having a lower solids (i.e., silica particles) content. Furthermore, polishing composition 1B of the present invention containing tris-(2-aminoethyl)-amine (TREN) exhibited significantly fewer surface defects and scratches compared to comparative polishing composition 1A containing arginine.

[0130] Example 2

[0129] This example demonstrates the effect of the concentration of an amine-based compound (tris-(2-aminoethyl)-amine (TREN)) having a carbon to nitrogen ratio of about 1:1 to about 3:1 on the poly-Si removal rate.

[0131] Inventive Polishing Compositions 2A-2D were prepared by combining the following components and diluting the composition as necessary to provide a composition containing the following components: tris-(2-aminoethyl)-amine (TREN), DEQUEST™ 2000, KOH, KHCO₃, 1,2-benzisothiazolin-3-one (BIT), and silica (Nalco DVSTS006 silica particles). Inventive Polishing Compositions 2A-2C had point-of-use concentrations as follows: 350 ppm DEQUEST™ 2000, 700 ppm KOH, 1164 ppm KHCO₃, 7 ppm 1,2-benzisothiazolin-3-one (BIT), and 0.88 wt. % silica (Nalco DVSTS006 silica particles). Inventive Polishing Composition 2D had a point-of-use concentration as follows: 50 ppm DEQUEST™ 2000, 100 ppm KOH, 166 ppm KHCO, 1 ppm 1,2-benzisothiazolin-3-one (BIT), and 0.13 wt. % silica (Nalco DVSTS006 silica particles). The point-of-use concentrations of tris-(2-aminoethyl)-amine (TREN) in each of Polishing Compositions 2A-2D are shown in Table 2.

[0132] Individual patterned wafers (e.g., 200 mm or 300 mm diameter wafers) containing 50% poly-Si, TEOS, or SiN features (approximately 20,000 Å thick) with a pattern density were coated on patterned silicon substrates with steps of approximately 8,000 Å and polished with inventive polishing compositions 2A-2D in a REFLEXION™ tool using an IC1010™ polishing pad at a downforce of 13.79 kPa (2 psi). The removal rates of poly-Si, TEOS, and SiN were measured, and the results are shown in Table 2. TIFF2025539023000004.tif48170

[0133] As can be seen from the results shown in Table 2, polishing compositions 2A to 2D of the present invention containing tris(2-aminoethyl)amine (TREN) exhibited high poly-Si removal rates while maintaining comparable TEOS and SiN removal rates. Although the poly-Si removal rate decreased slightly as the concentration of tris(2-aminoethyl)amine (TREN) decreased, the polishing compositions of the present invention were still highly effective in maintaining high poly-Si removal rates despite the low dose of tris(2-aminoethyl)amine (TREN) and low solids content (i.e., silica particles), as evidenced by polishing compositions 2C and 2D of the present invention, respectively.

[0134] Example 3

[0133] This example demonstrates the effect of an amine-based compound containing a carbon to nitrogen ratio of about 1:1 to about 3:1 on (i) the poly-Si removal rate and (ii) the amount of surface defects.

[0135] Comparative Polishing Composition 3A was prepared by combining the following ingredients and diluting the composition as needed to provide a point-of-use composition containing: arginine, DEQUEST™ 2000, KOH, KHCO, 1,2-benzisothiazolin-3-one (BIT), and silica (Nalco DVSTS006 silica particles).

[0136] Polishing Compositions 3B-3G of the invention were prepared by mixing tris(2-aminoethyl)amine (TREN), triethylenetetramine (TETA), or pentaethylenehexamine (PEHA) with the following components and diluting as necessary to provide a composition containing the following components: DEQUEST™ 2000, KOH, KHCO, 1,2-benzisothiazolin-3-one (BIT), and silica (Nalco DVSTS006 silica particles).

[0137]

[0136] Table 3 shows the point-of-use concentrations of Comparative Polishing Composition 3A and Polishing Compositions 3B to 3G of the present invention. TIFF2025539023000005.tif72170

[0138] Individual patterned wafers (e.g., 200 mm or 300 mm diameter wafers) containing 50% poly-Si, TEOS, or SiN features (approximately 20,000 Å thick) with a pattern density were coated on patterned silicon substrates with steps of approximately 8,000 Å and polished with Comparative Polishing Composition 3A and inventive Polishing Compositions 3B-3G in a REFLEXION™ tool using an IC1010™ polishing pad at a downforce of 13.79 kPa (2 psi). The removal rates of poly-Si, TEOS, and SiN were measured, and the average amounts of surface defects and scratches were determined. The results are shown in Table 4. TIFF2025539023000006.tif69170

[0139] As is evident from the results shown in Table 4, polishing compositions 3B to 3G of the present invention containing TREN, TETA, or PEHA exhibit improved poly-Si removal rates compared to comparative polishing composition 3A containing arginine, while maintaining comparable TEOS and SiN removal rates. In other words, polishing compositions 3B to 3G of the present invention containing TREN, TETA, or PEHA provide higher rates and selectivities of poly-Si removal than comparative polishing composition 3A containing arginine. Furthermore, polishing compositions 3C to 3G of the present invention containing TETA or PEHA demonstrated similar potential for improved polishing performance compared to polishing composition 3B of the present invention containing TREN.

[0140] Example 4

[0139] This example demonstrates the effect of an amine-based compound from about 1:1 to about 3:1 on the removal rate of poly-Si.

[0141] Comparative Polishing Composition 4A was prepared by combining the following ingredients and diluting the composition as needed to provide a point-of-use composition containing: arginine, KOH, KHCO, 1,2-benzisothiazolin-3-one (BIT), and silica (Nalco DVSTS006 silica particles).

[0142] Polishing Compositions 4B-4E of the invention were prepared by combining tris(2-aminoethyl)amine (TREN), triethylenetetramine (TETA), pentaethylenehexamine (PEHA), or homopiperazine with the following components and diluting as necessary to provide a composition containing the following components: KOH, KHCO, 1,2-benzisothiazolin-3-one (BIT), and silica (Nalco DVSTS006 silica particles).

[0143]

[0142] Table 5 shows the point-of-use concentrations of Comparative Polishing Composition 4A and Polishing Compositions 4B-4E of the present invention. TIFF2025539023000007.tif56170

[0144]

[0143] Individual patterned wafers (e.g., 200 mm or 300 mm diameter wafers) containing poly-Si, TEOS, or SiN features (approximately 20,000 Å thick) with a 50% pattern density were coated on patterned silicon substrates with steps of approximately 8,000 Å and polished using comparative polishing composition 4A and inventive polishing compositions 4B-4E on a MIRRA™ tool with a NEXPLANAR™ E6088 polishing pad at a downforce of 13.79 kPa (2 psi). The removal rates of poly-Si, TEOS, and SiN were measured, and the results are shown in Table 6. TIFF2025539023000008.tif54170

[0145] As is evident from the results shown in Table 6, polishing compositions 4B to 4E of the present invention containing TETA, TEPA, PEHA, or homopiperazine exhibit improved poly-Si removal rates compared to comparative polishing composition 4A containing arginine, while maintaining equivalent TEOS and SiN removal rates. In other words, polishing compositions 4B to 4E of the present invention containing TETA, TEPA, PEHA, or homopiperazine provide higher rates and selectivities of poly-Si removal than comparative polishing composition 4A containing arginine.

[0146] Example 5

[0145] This example demonstrates the effect of an amine-based compound from about 1:1 to about 3:1 on the removal rate of poly-Si.

[0147] Comparative Polishing Composition 5A and Inventive Polishing Compositions 5B-5O were prepared by combining the following components and diluting the compositions as necessary to provide point-of-use compositions containing: 14 ppm DEQUEST™ 2000, 280 ppm KOH, 470 ppm KHCO, 1.75 wt. % silica (Nalco DVSTS006 silica particles), and 1.3 mM of the amine-based compound additive described in Table 7.

[0148]

[0147] Individual patterned wafers (e.g., 200 mm or 300 mm diameter wafers) containing poly-Si, TEOS, or SiN features (approximately 20,000 Å thick) with a 50% pattern density were coated on patterned silicon substrates with steps of approximately 8,000 Å, and polished using comparative polishing composition 5A and inventive polishing compositions 4B-4E on a Logitech tool with a NEXPLANAR™ E6088 polishing pad at a downforce of 13.79 kPa (2 psi). The removal rates of poly-Si, TEOS, and SiN were measured, and the results are shown in Table 7. TIFF2025539023000009.tif152170

[0149] As is evident from the results shown in Table 7, when linear ethylenediamine compounds are used, the polysilicon removal rate increases as the molecular weight increases. See, for example, Polishing Compositions 5B-5F of the present invention. The aforementioned trend is also demonstrated by the graph showing the effect of the molecular weight (MW) of the amine-based compound on the poly-Si removal rate (Å / min), TEOS removal rate (Å / min), and SiN removal rate for Polishing Compositions 5B-5F. As shown in the graph, the greatest difference between the poly-Si removal rate and the TEOS / SiN removal rate occurs for Polishing Compositions 5D-5F of the present invention, which contain triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine, respectively.

[0150]

[0149] Table 7 also shows that polishing composition 5J of the present invention containing N,N'-dimethylethylenediamine and polishing composition 5K of the present invention containing N,N-dimethylethylenediamine provide poly-Si removal rates similar to polishing composition 5B of the present invention containing ethylenediamine. These results indicate that converting the terminal amine from a primary amine to a secondary amine or tertiary amine has little effect on performance as long as at least one non-tertiary amine (such as a primary amine or secondary amine) remains.

[0151] Table 7 further shows that polishing composition 5C of the present invention, which contains diethylenetriamine, exhibits a much higher poly-Si removal rate than polishing composition 5J of the present invention, which contains N,N,N',N",N"-pentamethyldiethylenetriamine. These results indicate that primary, secondary, and tertiary amines provide effective poly-Si removal rates, and that primary and secondary amines in particular can be used to maximize the poly-Si removal rate, as needed.

[0152] Furthermore, Table 7 shows that inventive polishing compositions 5L-5O, each containing piperazine, homopiperazine, 1-(2-aminoethyl)piperazine, and 1,4-bis(3-aminopropyl)piperazine, provide poly-Si removal rates similar to inventive polishing composition 5B, which contains ethylenediamine. These results indicate that incorporating methylene or hydroxyl groups into the amine-containing compounds or cyclizing the amine-containing compounds does not adversely affect poly-Si removal rate performance.

[0153] Example 6

[0152] This example demonstrates the effect on poly-Si removal rate of using a rate control agent comprising an amine-based compound having a carbon to nitrogen ratio of about 1:1 to about 3:1.

[0154] All polishing compositions contained, at the point of use, 313 ppm pentaethylenehexamine (PEHA), 470 ppm potassium bicarbonate (KHCO), and 2.625 wt. % colloidal silica abrasive. Abrasive A had an average particle size of approximately 74 nm with a zeta potential of approximately 42 mV, while Abrasive B had an average particle size of approximately 106 nm with a zeta potential of approximately -44 mV. Test wafers were polished in a Reflexion® LK tool using an IC1010 polishing pad and a Saeson C1 conditioner at a downforce of 2.5 psi, a head speed of 97 rpm, a platen speed of 103 rpm, and a test slurry flow rate of 250 ml / min. The concentrations of rate control agents (RCAs) and polishing compositions are listed in Table 8. Polishing Compositions 6A-6F contained tetrabutylammonium hydroxide (TBAH), and 6G contained polypropylene glycol (PPG) as the RCA. The removal rates of poly-Si, TEOS, and SiN were measured, and the results are shown in Table 8. Additionally, random defect counts and scratch counts were measured by scanning wafers using SP2 and generating defect maps using a 120 nm threshold. The defects were imaged with an SEM (Hitachi RS-5500). For SEM classification, 50 random defects were selected for imaging and automatically classified (e.g., particle defects or scratch defects) using Klarity software. After an engineer reviewed the images, the Klarity classification was confirmed. The total number of scratches was estimated by taking the percentage of defects in the classified image and multiplying it by the total defect count from SP2. The results are shown in Table 8. TIFF2025539023000010.tif53170

[0155] As can be seen from the results shown in Table 8, as the concentration of the rate control agent increases, the poly-Si removal rate decreases. The removal rates of TEOS and SiN were not affected by the rate control agent. However, as the concentration of the rate control agent increases, the scratch count decreases. Therefore, by using a rate control agent containing the composition of the present invention, it is possible to adjust the scratch count and the poly-Si removal rate.

[0156]

[0155] All references cited herein, including publications, patent applications, and patents, are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0157]

[0156] In the context of describing the invention (particularly in the context of the claims below), the use of the terms "a," "an," "the," and "at least one" and similar referents shall be construed to include both the singular and the plural, unless otherwise stated herein or clearly contradicted by context. The term "at least one," when followed by a list of one or more items (e.g., "at least one of A and B"), shall be construed to mean one item selected from the listed items (A or B) or a combination of two or more of the listed items (A and B), unless otherwise stated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" shall be construed as open-ended terms (i.e., meaning "including, but not limited to") unless otherwise indicated.

[0127] It will be understood that the recitation of ranges of values ​​is merely intended to serve as a shorthand method of referring individually to each individual value within that range, unless otherwise stated herein, and that each individual value is incorporated herein by reference as if each individual value were individually set forth herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any examples or exemplary language (e.g., "such as") provided herein is solely for the purpose of improving the understanding of the invention and does not impose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0158]

[0157] This specification describes preferred embodiments of the invention, including the best mode known to the inventors for carrying out the invention. Variations of these preferred embodiments will become apparent to those skilled in the art upon reading the foregoing description. The inventors expect those skilled in the art to adopt such variations as necessary, and it is intended that the invention be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, this invention includes any combination of the above-described elements in all possible variations thereof unless otherwise indicated herein or clearly contradicted by context.

Claims

1. 1. A chemical-mechanical polishing composition comprising: (a) a silica abrasive; (b) an amine-based compound containing a carbon to nitrogen ratio of about 1:1 to about 3:1; (c) optionally a buffer; and (d) water and Including, The polishing composition has a pH of about 9 to about 12.

2. 10. The polishing composition of claim 1, wherein the polishing composition comprises from about 0.001% to about 10% by weight of the silica abrasive.

3. 3. The polishing composition of claim 2, wherein the polishing composition comprises about 0.1% to about 5% by weight of the silica abrasive.

4. 10. The polishing composition of claim 1, wherein the polishing composition has a pH of about 10 to about 11.

5. 10. The polishing composition of claim 1, wherein the polishing composition further comprises about 50 ppm to about 1000 ppm of a complexing agent.

6. 10. The polishing composition of claim 1, wherein the amine-based compound comprises a carbon-to-nitrogen ratio of about 1:1 to about 2:

1.

7. 7. The polishing composition of claim 6, wherein the amine-based compound comprises a carbon-to-nitrogen ratio of about 1.2:1 to about 1.8:

1.

8. 10. The polishing composition of claim 1, wherein the amine-based compound comprises a carbon-to-nitrogen ratio of about 2:1 to about 3:

1.

9. 10. The polishing composition of claim 1, wherein the amine-based compound has a molecular weight of about 80 g / mol to about 400 g / mol.

10. 10. The polishing composition of claim 9, wherein the amine-based compound has a molecular weight of about 120 g / mol to about 250 g / mol.

11. The polishing composition of claim 1 , wherein the amine-based compound comprises at least one ethylenediamine subunit.

12. The polishing composition of claim 1 , wherein the amine-based compound comprises at least three ethylenediamine subunits.

13. 2. The polishing composition according to claim 1, wherein the amine compound is selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctylamine, octaethylenenonylamine, tris(2-aminoethyl)amine, piperazine, homopiperazine, N,N-diethylethylenediamine, 1,3-diamino-2-propanol, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N'-dimethylethylenediamine, N,N-dimethylethylenediamine, 1-(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, aminoethylpiperazine, and combinations thereof.

14. 10. The polishing composition of claim 1, wherein the polishing composition comprises about 100 ppm to about 5000 ppm of the amine-based compound.

15. 10. The polishing composition of claim 1, further comprising a rate control agent selected from tetrabutylammonium hydroxide and polypropylene glycol.

16. 1. A method of chemical mechanical polishing a substrate, comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) (a) silica abrasive; (b) an amine-based compound containing a carbon to nitrogen ratio of about 1:1 to about 3:1; (c) optionally, a buffering agent, and (d) Water Including, having a pH of about 9 to about 12 providing a chemical-mechanical polishing composition; (iv) contacting the substrate with a polishing pad and a chemical-mechanical polishing composition; (v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to polish at least a portion of the surface of the substrate, thereby polishing the substrate; A method comprising:

17. 17. The method of claim 16, wherein the polishing composition comprises from about 0.001% to about 10% by weight of the silica abrasive.

18. 17. The method of claim 16 having a pH of about 10 to about 12.

19. 17. The method of claim 16, wherein the amine-based compound comprises a carbon to nitrogen ratio of about 1:1 to about 2:

1.

20. 17. The method of claim 16, wherein the amine compound is selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, heptaethyleneoctylamine, octaethylenenonylamine, tris(2-aminoethyl)amine, piperazine, homopiperazine, N,N-diethylethylenediamine, 1,3-diamino-2-propanol, N,N,N',N",N"-pentamethyldiethylenetriamine, N,N'-dimethylethylenediamine, N,N-dimethylethylenediamine, 1-(2-aminoethyl)piperazine, 1,4-bis(3-aminopropyl)piperazine, aminoethylpiperazine, and combinations thereof.

21. 17. The method of claim 16, wherein the substrate comprises polysilicon on a surface of the substrate, and at least a portion of the polysilicon on the surface of the substrate is polished at a polysilicon removal rate to polish the substrate.

22. 17. The method of claim 16, wherein the substrate further comprises silicon nitride on a surface of the substrate, and at least a portion of the silicon nitride on the surface of the substrate is polished at a removal rate of the silicon nitride to polish the substrate.

Images