Chemical mechanical polishing composition

Abstract

The invention provides a chemical mechanical polishing composition and application thereof, and relates to the technical field of chemical mechanical polishing (CMP). The chemical mechanical polishing composition includes abrasive particles, an additive, and an aqueous carrier, the chemical polishing composition having a pH of less than 7. According to the embodiment of the invention, the step difference of the dielectric layer substrate can be quickly eliminated, and meanwhile, the damage caused by over-polishing is prevented.

Description

Technical Field

[0001] This disclosure relates to the field of chemical mechanical polishing (CMP) technology, and more particularly to chemical mechanical polishing compositions and their applications. Background Technology

[0002] In semiconductor manufacturing, due to the inhomogeneity of photolithography, etching, or deposition processes, dielectric layers such as silicon dioxide layers exhibit highly variable structures in different areas. In integrated circuit manufacturing, this step difference affects subsequent process steps, such as uniformly coating photoresist or fabricating transistor gates, thus requiring planarization techniques. Among these, chemical mechanical polishing (CMP), pioneered by IBM in the 1980s, is considered the most effective method for global planarization. CMP combines chemical etching and mechanical abrasion, achieved by moving the substrate and a CMP composition relative to each other on a soft abrasive pad.

[0003] However, for chemical mechanical polishing of dielectric substrates with step differences, such as silica substrates, how to quickly eliminate the step differences during the polishing process while preventing damage caused by over-polishing has become an urgent technical problem to be solved.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] This disclosure provides a chemical mechanical polishing composition and its application. The chemical mechanical polishing composition can quickly eliminate step differences in the substrate of the dielectric layer while preventing damage caused by over-polishing.

[0006] Other features and advantages of this disclosure will become apparent from the following detailed description, or may be learned in part from practice of this disclosure.

[0007] According to one aspect of this disclosure, a chemical mechanical polishing composition is provided, comprising:

[0008] a) Grinding particles;

[0009] (b) Additives selected from the following:

[0010] Compound of formula (I)

[0011]

[0012] In formula (I), R1 to R3 are each independently selected from hydrogen, saturated or unsaturated C1-C6 alkyl groups, and X(NH2). nCombinations thereof, wherein X is selected from saturated or unsaturated C1-C6 alkylene groups, C6-12 aryl groups and C3-C6 aromatic heterogroups, and n is 1 to 3; each of which may or may not be substituted;

[0013] (c) Aqueous carrier,

[0014] The pH of the chemical mechanical polishing composition is less than 7.

[0015] In one embodiment, at least two of R1 to R3 are different.

[0016] In one embodiment, at least one of R1 to R3 is selected from X(NH2). n X is selected from unsaturated C1-C6 alkylene groups, C6-12 aryl groups and C3-C6 heteroaryl groups, and n is 1 to 3.

[0017] In one embodiment, the C3-C6 heteroaromatic groups are aromatic groups containing nitrogen, oxygen, or sulfur.

[0018] In one embodiment, the additive is present in a mass percentage of 0.3%-15% of the chemical mechanical polishing composition.

[0019] In one embodiment, the abrasive particles are silicon dioxide, cerium dioxide, or a combination thereof, and the abrasive particles are positively charged, with an average particle size of 20-500 nm, and the mass percentage of the abrasive particles in the chemical mechanical polishing composition is 0.5%-30%.

[0020] In one embodiment, the abrasive particles are a combination of silicon dioxide and cerium dioxide, with a mass ratio of silicon dioxide to cerium dioxide of 2-5:1.

[0021] In one embodiment, the average particle size of silicon dioxide is smaller than that of cerium dioxide.

[0022] In one embodiment, the aqueous carrier accounts for 70%-95% by mass of the chemical mechanical polishing composition.

[0023] According to another aspect of this disclosure, an application of the above-described chemical mechanical polishing composition for the mechanical polishing of a silicon oxide substrate having a step difference is provided.

[0024] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0026] Figure 1 The grinding process of the dielectric layer substrate provided in the embodiments of this disclosure is shown; Detailed Implementation

[0027] To facilitate understanding of this disclosure, a more complete description will now be given with reference to the accompanying drawings, in which preferred embodiments of the present disclosure are shown. However, this disclosure may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0028] In semiconductor manufacturing, structures with varying heights in different regions of the dielectric layer, such as silicon dioxide, exhibit step differences. These step differences can occur between adjacent patterns or between different thin film layers, affecting subsequent process steps, such as uniform photoresist coating or transistor gate fabrication. Planarization techniques like chemical mechanical polishing (CMP) can effectively manage these step differences, leading to high-quality semiconductor manufacturing. However, for CMP of dielectric substrates with step differences, such as silicon dioxide substrates, a crucial technical challenge is how to rapidly eliminate these step differences during polishing while preventing damage caused by over-polishing.

[0029] In view of this, the present disclosure provides a chemical mechanical polishing composition comprising: abrasive particles, an additive, and an aqueous carrier. According to embodiments of the present disclosure, it is possible to rapidly eliminate step differences in the dielectric substrate while preventing damage caused by over-polishing.

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In one embodiment, a chemical mechanical polishing composition comprises:

[0032] (a) Grinding particles;

[0033] (b) Additives selected from the following:

[0034] Compound of formula (I)

[0035]

[0036] In formula (I), R1 to R3 are each independently selected from hydrogen, saturated or unsaturated C1-C6 alkyl groups, and X(NH2). n Combinations thereof, wherein X is selected from saturated or unsaturated C1-C6 alkylene groups, C6-12 aryl groups and C3-C6 aromatic heterogroups, and n is 1 to 3; each of which may or may not be substituted;

[0037] (c) Aqueous carrier,

[0038] The pH of the chemical mechanical polishing composition is less than 7.

[0039] The components of the chemical mechanical polishing composition according to an embodiment of the present invention will be described in detail below.

[0040] (a) Grinding particles;

[0041] Abrasive particles are a key component in CMP processes used to remove material. They are typically tiny, hard particles that can be synthetic or natural, such as alumina (Al₂O₃), silicon dioxide (SiO₂), diamond, cerium dioxide, etc. The role of abrasive particles is to help remove material from the wafer surface through mechanical friction.

[0042] (b) Additives selected from the following:

[0043] Compound of formula (I)

[0044]

[0045] In formula (I), R1 to R3 are each independently selected from hydrogen, saturated or unsaturated C1-C6 alkyl groups, and X(NH2). n Combinations thereof, wherein X is selected from saturated or unsaturated C1-C6 alkylene groups, C6-12 aryl groups and C3-C6 aromatic heterogroups, and n is 1 to 3; each of which may or may not be substituted;

[0046] Saturated or unsaturated C1-C6 alkyl groups include, for example, straight-chain or branched, saturated or unsaturated, substituted or unsubstituted hydrocarbon groups having 1 to 6 carbon atoms (e.g., C1-C6 alkyl, C1-C4 alkyl, C1-C2 alkyl), for example having at least 1 carbon atom (i.e., methyl), at least 2 carbon atoms (e.g., ethyl, vinyl), at least 3 carbon atoms (e.g., propyl, isopropyl, propenyl, etc.), at least 4 carbon atoms (butyl, isobutyl, sec-butyl, butane, etc.), at least 5 carbon atoms (pentyl, isopentyl, sec-pentyl, neopentyl, etc.), and at least 6 carbon atoms (hexyl, etc.).

[0047] A substituted group is a group in which one or more carbon bonds have hydrogen atoms replaced by non-hydrogen atoms. Illustrative substituents include, for example, hydroxyl, ketone, ester, amide, halogen (e.g., fluorine, chlorine, bromine, and iodine), amino (primary, secondary, tertiary, and / or quaternary) groups, and combinations thereof.

[0048] The additive carries a positive charge at pH less than 7, while the substrate, such as a silica substrate, carries a negative charge at this pH. The additive can contact and adsorb onto the substrate. Due to the step difference in the substrate, the additive preferentially adsorbs on the side with the lower step height, resulting in a higher concentration of additive on that side. This effectively repels abrasive particles, reducing the grinding rate on that side. Conversely, on the side with the higher step height, the lower additive concentration reduces the repulsion force on abrasive particles, leading to a higher grinding rate during polishing. In other words, by adding the additive, the side with the higher step height exhibits a higher grinding rate, while the side with the lower step height exhibits a lower grinding rate, achieving anisotropic polishing. This allows for the rapid removal of step differences in the substrate, resulting in flattening of the substrate.

[0049] In addition, additives are preferentially selected with heteroaromatic groups as the backbone, that is, using nitrogen-containing aromatic groups as the molecular backbone, where the lone pair electrons of nitrogen can interact with H. + This combination results in the additive carrying a positive charge; simultaneously, the C bonded to N exhibits SP. 2 Hybridization, a hybridization method that allows carbon atoms to form a planar triangular structure with bond angles of approximately 120 degrees, means that through the sp bond of C... 2The hybrid additive has a planar structure, which allows it to be more easily adsorbed onto the substrate of the media layer, improving its resistance to abrasive particles and thus enhancing the diversity of polishing rates. Compared to other amine additives, the molecular skeleton of the additive disclosed herein has a planar structure, making it easier to adsorb onto the substrate of the media layer and achieving the densest adsorption, thereby reducing the amount of additive required.

[0050] The specific types of additives in this embodiment include the following:

[0051]

[0052] (c) Aqueous carrier

[0053] Aqueous carriers for chemical mechanical polishing (CMP) compositions refer to liquid media that use water as the primary solvent to disperse abrasive particles and other chemical components. Aqueous carriers are a common type in CMP processes and have the following characteristics: Environmental friendliness: Water is non-toxic and harmless; compared to organic solvents, using water as a carrier is more environmentally friendly, and waste disposal is relatively simple. Good thermal stability: Water has a high heat capacity, which helps maintain temperature stability during CMP processes and reduces the risk of overheating. Moderate chemical activity: Water has relatively mild chemical properties and can be used as a solvent in neutral or weakly acidic / alkaline environments, making it suitable for processing acid- and alkali-sensitive materials. Easy adjustment: By adding acids, alkalis, or buffers, the pH value of the aqueous polishing slurry can be easily adjusted to meet the chemical reaction requirements of different materials. Low viscosity: The low viscosity of water helps the abrasive particles to be evenly distributed and move on the wafer surface, improving polishing efficiency. Cost-effectiveness: Water is a low-cost resource; using aqueous carriers can reduce the overall cost of the polishing slurry.

[0054] The pH of the chemical mechanical polishing composition can be adjusted using any suitable acid or base. Non-limiting examples of suitable acids include nitric acid, sulfuric acid, phosphoric acid, and organic acids (e.g., acetic acid). Non-limiting examples of suitable bases include sodium hydroxide, potassium hydroxide, and ammonium hydroxide, as well as organic bases (e.g., ethanolamine, diethanolamine, and triethanolamine). The pH of the chemical mechanical polishing composition is less than 7, for example, in the pH range of 1 to 6.5, 2.7 to 6, or 3 to 5.

[0055] In one embodiment, at least two of R1 to R3 are different. That is, R1 is different from R2, or R1 is different from R3, or R2 is different from R3, or R1, R2, and R3 are all different. During polishing, the abrasive particles can affect the additives. For example, during polishing, high mechanical force may cause the chemical bonds inside the additive molecules to break, forming new functional groups or generating fragments; under the high pressure and high temperature conditions of polishing, the additive molecules may undergo structural rearrangement, forming different isomers; polishing may change the chemical environment on the surface of the additive molecules, leading to the formation or disappearance of surface functional groups, affecting their chemical reactivity. By setting at least two of R1 to R3 to be different, that is, at least one of R1 to R3 is not hydrogen, or at least one of R1 to R3 is a saturated or unsaturated C1-C6 alkyl group or X(NH2). n Saturated or unsaturated C1-C6 alkyl groups or X(NH2) n It can protect the skeleton of the additive from the impact of abrasive particles, and also play a role in lubrication and repulsion, thereby preventing the skeleton of the additive from being damaged and thus failing to adsorb onto the substrate of the media layer and repel abrasive particles.

[0056] In one embodiment, at least one of R1 to R3 is selected from X(NH2). n X is selected from unsaturated C1-C6 alkylene groups, C6-12 aryl groups, and C3-C6 heteroaryl groups, and n is 1 to 3. Under conditions where pH is less than 7, the amino group can react with a proton (H). + The additive is combined with the substrate to carry a positive charge; and by forming a positively charged side chain on the additive, the number of binding sites between the additive and the substrate is increased, thereby improving the adsorption force between the additive and the substrate.

[0057] In one embodiment, the C3-C6 heteroaromatic group is an aromatic group containing nitrogen, oxygen, or sulfur. That is, it contains nitrogen, oxygen, or sulfur atoms on its aromatic skeleton; nitrogen, oxygen, or sulfur all contain lone pairs of electrons, making them more likely to react with protons (H atoms). + This combination results in the additive carrying a positive charge. In other words, by designing the side chains of the additive's molecular structure, the amount of positive charge on the additive can be increased under pH conditions less than 7, thereby improving the adsorption force between the additive and the substrate of the medium layer.

[0058] In one embodiment, the additive constitutes 0.3%-15% by mass in the chemical mechanical polishing composition. For example, the chemical mechanical polishing composition may include 0.3wt%-15wt% of the additive when used, such as 0.5wt%, 1wt%, 5wt%, 10wt%, 12wt%, or 15wt%. The amount of additive must be neither too much nor too little. If the amount of additive is too much, the amount adsorbed on the side of the medium layer with a high step height will be excessive, resulting in reduced grinding efficiency on the side of the medium layer substrate with a low step height, thus failing to effectively eliminate the step difference. If the amount of additive is too little, the amount adsorbed on the side of the medium layer with a low step height will be insufficient, failing to effectively repel abrasive particles, thus failing to achieve anisotropy in grinding efficiency in different areas of the medium layer substrate, and consequently failing to eliminate the step difference of the medium layer substrate.

[0059] In one embodiment, the abrasive particles are silicon dioxide, cerium dioxide, or a combination thereof, and the abrasive particles are positively charged, with an average particle size of 20-500 nm, and the mass percentage of the abrasive particles in the chemical mechanical polishing composition is 0.5%-30%.

[0060] Abrasive particles can consist of, or be substantially composed of, cationically charged silica particles, cerium dioxide particles, or combinations thereof. Silica particles, with their moderate hardness, are ideal for grinding and polishing, effectively removing surface material without excessively damaging the substrate. Silica particles are chemically stable, resistant to acids and alkalis, and do not readily react with most substances, allowing them to maintain their performance in various environments. They exhibit good wear resistance, retaining their shape and structure even during grinding, extending their service life. The particle size, shape, and surface roughness of silica particles can be controlled through different preparation methods and grinding processes to meet the needs of various applications. Silica particles are a natural resource, relatively inexpensive, and readily available, giving them an economic advantage in many industrial applications. Compared to some other abrasive materials, silica is relatively safe under proper handling and use conditions.

[0061] Cerium dioxide particles include wet-process cerium oxide, calcined cerium oxide, and metal-doped cerium oxide, as well as other types. Wet-process cerium oxide: This typically refers to cerium dioxide solutions or suspensions prepared through wet chemical methods such as chemical reactions or solvent extraction. This method yields small, uniformly distributed cerium oxide particles, suitable for CMP processes requiring fine polishing. Calcined cerium oxide: High-temperature calcination of cerium oxide alters its crystal structure and physicochemical properties, improving its hardness and wear resistance, making it suitable for applications requiring stronger abrasive power. Metal-doped cerium oxide: Doping cerium oxide with other metal ions (such as aluminum, gallium, lanthanum, etc.) adjusts its chemical activity and catalytic performance to suit specific CMP processes or catalytic applications. Doping can improve polishing selectivity and reduce over-removal of specific materials. Cerium dioxide particles exhibit good polishing effects on materials such as silicon, silicon oxides, silicon carbide, and metals like copper, enabling rapid and effective surface planarization. Under certain conditions, cerium dioxide particles can achieve selective polishing, meaning the removal rate of specific materials is higher than that of other materials. Cerium dioxide particles participate in chemical reactions during CMP (Chemical Mechanical Polishing) to help remove surface materials, while their self-regenerating ability maintains the continued effectiveness of the polishing process. Cerium dioxide particles help reduce scratches and defects during polishing, improving the smoothness and uniformity of the wafer surface. In acidic and alkaline environments, cerium dioxide particles exhibit good stability, which helps maintain the performance and lifespan of the chemical mechanical polishing composition.

[0062] Abrasive particles possess a positive charge, or "zeta potential," when present in a chemical mechanical polishing (CMP) composition at an acidic pH. The charge on the particles in a CMP composition is commonly referred to as the zeta potential (or zeta potential). The zeta potential of a particle is the potential difference between the charge of the ions surrounding the particle and the charge of the bulk solution of the CMP composition (e.g., the liquid carrier and any other components dissolved therein). The zeta potential is typically determined by the pH of the aqueous medium. For a given CMP composition, the isoelectric point of the particles is defined as the pH at which the zeta potential is zero. The zeta potential of dispersions such as CMP compositions can be obtained using electroacoustic spectroscopy.

[0063] When abrasive particles are present in a chemical mechanical polishing (CMP) composition, the zeta potential of the abrasive particles (e.g., silica or cerium dioxide particles) in the CMP composition can be positive, such as having a zeta potential of at least 15 mV, preferably in the range of 15 mV to 80 mV. A specific zeta potential can be affected by the pH of the slurry and can be selected within the applicable range based on the type of CMP process using the CMP composition. Since the object being polished is a dielectric substrate, i.e., a silica substrate, which carries a negative charge under acidic conditions, polishing efficiency would be significantly reduced if negatively charged abrasive particles were used; therefore, positively charged abrasive particles are required.

[0064] The abrasive particles can have a suitable average particle size (i.e., average particle diameter), typically 20-500 nm. If the average particle size is too small, the polishing composition cannot exhibit a sufficient removal rate and cannot effectively eliminate step differences in the substrate. Conversely, if the average particle size is too large, the polishing composition may exhibit undesirable polishing performance, such as an excessively high substrate defect rate or excessively large defects. Therefore, the abrasive particles can have an average particle size of about 20 nm or larger, for example, about 20 nm or larger, about 25 nm or larger, about 30 nm or larger, about 35 nm or larger, about 40 nm or larger, about 45 nm or larger, or about 50 nm or larger. Alternatively, or additionally, the abrasive particles can have an average particle size of about 500 nm or smaller, about 250 nm or smaller, about 150 nm or smaller, about 100 nm or smaller, or about 75 nm or smaller. Thus, the abrasive particles can have an average particle size demarcated by any two of the endpoints mentioned above. For example, abrasive particles may have the following average particle sizes: about 20 nm to about 500 nm, about 25 nm to about 250 nm, about 30 nm to about 250 nm, and about 20 nm to about 75 nm. For non-spherical abrasive particles, the particle size is the diameter of the smallest sphere surrounding the particle. The average particle size of the abrasive particles can be measured using any suitable technique, such as laser diffraction.

[0065] The chemical mechanical polishing (CMP) composition may contain a suitable amount of abrasive particles, i.e., the abrasive particles constitute 0.5% to 30% by mass of the CMP composition. If the CMP composition of this disclosure contains too few abrasive particles, the composition will not exhibit a sufficient removal rate and will not effectively eliminate step differences in the substrate of the media layer. Conversely, if the CMP composition contains too many abrasive particles, it will result in a lack of stability in the CMP composition. The CMP composition may contain about 30% by weight or less of abrasive particles, for example, about 30% by weight or less, about 20% by weight or less, about 15% by weight or less, about 10% by weight or less, about 5% by weight or less, or about 4% by weight or less. Alternatively, or additionally, the CMP composition may contain about 0.5% by weight or more of abrasive particles, for example, about 0.5% by weight or more, about 0.8% by weight or more, about 1% by weight or more, about 2% by weight or more, or about 3% by weight or more. Thus, the polishing composition may contain an amount of abrasive particles defined by any two of the endpoints mentioned above. For example, the polishing composition may contain abrasive particles in amounts of about 0.5 wt% to about 30 wt%, about 0.5 wt% to about 20 wt%, about 0.5 wt% to about 5 wt%, about 1 wt% to about 30 wt%, and about 1 wt% to about 20 wt%.

[0066] In one embodiment, the abrasive particles are a combination of silica and cerium dioxide, with a mass ratio of silica to cerium dioxide of 2-5:1. Silica and cerium dioxide have different hardness and chemical properties; mixing them combines their advantages to achieve more efficient and finer grinding or polishing results. Silica may be cheaper than cerium dioxide, and mixing them can partially reduce costs while maintaining the desired grinding performance. By mixing different types of abrasive particles, scratches and defects can be reduced, improving the quality of the polished surface. Furthermore, by setting the mass ratio of silica to cerium dioxide to 2-5:1, the higher silica content coats the lower cerium dioxide content, which improves grinding efficiency and prevents damage to the dielectric substrate from the abrasive particles.

[0067] In one embodiment, the average particle size of silica is smaller than that of cerium dioxide. The smaller-sized silica will still coat the larger-sized cerium dioxide. The larger-sized cerium dioxide can increase the polishing rate and quickly eliminate step differences in the substrate of the dielectric layer, while the smaller-sized silica produces fewer scratches, helping to reduce surface damage during polishing and achieve a smoother surface. It also helps improve rheology, making it easier for the chemical mechanical polishing composition to distribute evenly on the polished surface.

[0068] In one embodiment, the aqueous carrier accounts for 70%-95% by mass of the chemical mechanical polishing composition.

[0069] The chemical mechanical polishing composition may contain a suitable amount of aqueous carrier, i.e., the aqueous carrier constitutes 70%-95% by mass of the chemical mechanical polishing composition. The aqueous carrier may be deionized water, ultrapure water, natural water, etc. The content of the aqueous carrier may be, for example, about 95% by weight or less, about 90% by weight or less, or about 85% by weight or less. Optionally, or additionally, the chemical mechanical polishing composition may contain about 70% by weight or more of the aqueous carrier, for example, about 70% by weight or more, about 75% by weight or more, or about 80% by weight or more. Therefore, the polishing composition may contain an amount of aqueous carrier defined by any two of the endpoints mentioned above. For example, the polishing composition may contain the following amounts of aqueous carrier: about 70% to about 95% by weight, about 70% to about 85% by weight, about 75% to about 90% by weight, about 75% to about 85% by weight, or about 80% to about 85% by weight.

[0070] In one embodiment, the chemical mechanical polishing composition may include other additives such as stabilizers, corrosion inhibitors, defoamers, antioxidants, etc. Stabilizers prevent abrasive particles from agglomerating or settling in the solution, maintaining their uniform dispersion to ensure the stability of the polishing process. These may include surfactants, polymers, or electrolytes. Corrosion inhibitors protect the wafer surface from excessive corrosion or damage. Defoamers prevent bubbles that may be generated due to mechanical agitation and chemical reactions.

[0071] Based on the above embodiments, this disclosure also provides an application of the above-described chemical mechanical polishing composition for the mechanical polishing of silicon oxide substrates with step differences. This application will be described in detail below.

[0072] Figure 1 The grinding process of the dielectric layer substrate provided in the embodiments of this disclosure is shown;

[0073] Reference Figure 1 As shown, the dielectric substrate 100 is a silicon dioxide substrate. The silicon dioxide substrate carries a negative charge under acidic conditions, especially when the pH is between 2.7 and 6.5. The step difference H of the dielectric substrate is at least 1 micrometer. The dielectric layer is also covered with at least other layers, such as an insulating layer, a conductive layer, or the dielectric layer is also covered with at least other electrical devices, such as capacitors.

[0074] The application is achieved by: (i) providing a dielectric substrate with a step difference; (ii) providing a polishing pad; (iii) providing a chemical mechanical polishing composition comprising the above-described contents; (iv) contacting the dielectric 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, thereby polishing at least a portion of the surface of the dielectric substrate by abrasion. The polishing pad rotates at a speed of 30-150 rot / min, and the chemical mechanical polishing composition flows at a flow rate of 24-150 ml / min. Specific Implementation

[0076] The advantages of the present invention will be further illustrated below with reference to specific embodiments.

[0077] Example 1

[0078] The formulation of the chemical mechanical polishing composition includes:

[0079] 5 kg of silica abrasive particles (average particle size 50 nm); 2 kg of additives; 93 kg of deionized water; pH of the composition is 3.5; wherein the additives are...

[0080]

[0081] Example 2

[0082] The formulation of the chemical mechanical polishing composition includes:

[0083] 5 kg of silica abrasive particles (average particle size 50 nm); 2 kg of additives; 93 kg of deionized water; pH of the composition is 3.5; wherein the additives...

[0084]

[0085] Example 3

[0086] The formulation of the chemical mechanical polishing composition includes:

[0087] 5 kg of silica abrasive particles (average particle size 50 nm); 2 kg of additives; 93 kg of deionized water; pH of the composition is 3.5; wherein the additives are...

[0088]

[0089] Example 4

[0090] The formulation of the chemical mechanical polishing composition includes:

[0091] 4 kg of silica abrasive particles (average particle size 50 nm); 1 kg of cerium dioxide abrasive particles (average particle size 100 nm); 2 kg of additives; 93 kg of deionized water; the pH of the composition is 3.5; wherein the additives are the same as those in Example 3.

[0092] Comparative Example 1

[0093] The formulation of the chemical mechanical polishing composition includes:

[0094] 5 kg of silica abrasive particles (average particle size 50 nm); 95 kg of deionized water; pH of the composition is 3.5; no additives are contained.

[0095] Polishing target: a silicon dioxide substrate with step differences, where the step heights are basically the same and around 1300nm.

[0096] Polishing conditions: The polishing pad rotates at 100 rot / min, and the flow rate of the chemical mechanical polishing composition is 80 ml / min.

[0097] Polishing Steps: The silica substrate with step differences was polished using the chemical mechanical polishing composition prepared above under the aforementioned polishing conditions. The elimination of step differences and the degree of scratches on the dielectric substrate were observed within a specific time period. Specifically, the elimination of step differences and the degree of scratches on the dielectric substrate were observed at the same grinding time T, such as 120 s, and the elimination of step differences and the degree of scratches on the dielectric substrate were observed after grinding in each embodiment and comparative example.

[0098]

[0099] As can be seen from the examples, a step difference of less than or equal to 10 nm is within an acceptable range in the art. It is evident that additives with side chains have a better ability to eliminate steps, and the ability to eliminate step differences is even more pronounced when the side chains of the additives also contain amino groups. Furthermore, the use of composite abrasive particles results in less scratching of the dielectric substrate.

[0100] In the description of this disclosure, it should be understood that the terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this disclosure, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0101] In the description of this disclosure, it should be understood that the terms “comprising” and “having” as used herein, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are expressly listed, but may include other steps or units that are not expressly listed or that are inherent to such process, method, product, or apparatus.

[0102] Unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can be a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit it. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this invention.

Claims

1. A chemical mechanical polishing composition, characterized in that, include: (a) Grinding particles; (b) Additives selected from the following: Compound of formula (I) In formula (I), R1 to R3 are each independently selected from hydrogen, saturated or unsaturated C1-C6 alkyl groups, and X(NH2). n Combinations thereof, wherein X is selected from saturated or unsaturated C1-C6 alkylene groups, C6-12 aryl groups and C3-C6 aromatic heterogroups, and n is 1 to 3; each of which may or may not be substituted; (c) Aqueous carrier; The pH of the chemical mechanical polishing composition is less than 7.

2. The chemical mechanical polishing composition according to claim 1, characterized in that, At least two of R1 to R3 are different.

3. The chemical mechanical polishing composition according to claim 1, characterized in that, At least one of R1 to R3 is selected from X(NH2). n X is selected from unsaturated C1-C6 alkylene groups, C6-12 aryl groups and C3-C6 heteroaryl groups, and n is 1 to 3.

4. The chemical mechanical polishing composition according to claim 3, characterized in that, C3-C6 heteroaromatic groups are aromatic groups containing nitrogen, oxygen, or sulfur.

5. The chemical mechanical polishing composition according to claim 1, characterized in that, The additive is present in the chemical mechanical polishing composition at a mass percentage of 0.3%-15%.

6. The chemical mechanical polishing composition according to claim 1, characterized in that, The abrasive particles are silicon dioxide, cerium dioxide, or a combination thereof, and the abrasive particles are positively charged. The average particle size of the abrasive particles is 20-500 nm, and the mass percentage of the abrasive particles in the chemical mechanical polishing composition is 0.5%-30%.

7. The chemical mechanical polishing composition according to claim 6, characterized in that, The grinding particles are a combination of silicon dioxide and cerium dioxide, and the mass ratio of silicon dioxide to cerium dioxide is 2-5:

1.

8. The chemical mechanical polishing composition according to claim 7, characterized in that, The average particle size of the silicon dioxide is smaller than that of the cerium dioxide.

9. The chemical mechanical polishing composition according to claim 1, characterized in that, The aqueous carrier comprises 70%-95% by mass in the chemical mechanical polishing composition.

10. The application of a chemical mechanical polishing composition as described in any one of claims 1-9 for the mechanical polishing of a silicon oxide substrate having a step difference.

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