Chemical Mechanical Polishing Performance Research Articles

An ethylenediaminetetraacetic acid (EDTA) surface-functionalized CeO2 composite abrasives with the effective improvement of the removal rate on glass CMP

With the increasing demand for surface processing, there has been a growing interest in enhancing the performance of cerium oxide (CeO2) abrasives for glass chemical mechanical polishing (CMP). To enhance the CeO2 abrasives’ CMP performance, we use the surface modification method to combine inorganic CeO2 with organic ethylenediaminetetraacetic acid (EDTA) molecules, thus utilizing the chemical reaction activity of organic substances to raise the chemical reaction between CeO2 and glass. A series of ethylenediaminetetraacetic acid grafted cerium oxide (CeO2-EDTA) composite abrasives were synthesized and characterized. The CMP experiment indicates that CeO2-EDTA with the EDTA content of 8.33 wt%, called CeO2-EDTA(8.33 %), had a splendid polishing performance. Compared with CeO2, the material removal rate of CeO2-EDTA(8.33 %) could be increased by about 40 % while the surface quality concurrently ameliorated. X-ray photoelectron spectroscopy analysis, dynamic friction test, and contact angle test were further used to probe the removal mechanism of composite abrasives. As a result, the correlation between MRR value and the concentration of cerium trivalent ion, particle size, dynamic friction coefficient, and contact angle was found. This provides a reference for the modification of cerium oxide in the future.

Electrochemical corrosion behavior and theoretical simulation of cobalt in chemical mechanical polishing process

The chemical mechanical polishing (CMP) process for cobalt (Co) interconnects is essential for the fabrication of integrated circuits with feature sizes below 10 nm. However, achieving high removal rates coupled with low dissolution rates remains a significant challenge. In this work, we have developed a dual-functional polishing slurry, which integrates ethylenediamine tetramethylphosphonic acid (EDTMPA) as a complexing agent, and octahydroxamic acid (OHA) as a corrosion inhibitor. The novel slurry-derived Co CMP meets ideal situation, delivering a removal rate (RR) of 246 nm/min, a dissolution rate (DR) of 0.8 nm/min, and a root mean square (RMS) roughness (Sq) of 2.31 nm. Experimental data and theoretical calculations reveal that the improved CMP performance results from the effective complexation of EDTMPA with Co ions. Furthermore, the adsorption of OHA as a corrosion inhibitor on the Co surface effectively counteracts the corrosion induced by EDTMPA. The development of this novel polishing slurry presents a strategy that harmoniously combines reduced process time with enhanced surface quality, holding the potential to significantly influence the CMP field.

Effects of Surfactants on the Chemical Mechanical Polishing Performance of a-Plane Sapphire Substrates

The effects of four different types of surfactants, cetyltrimethylammonium bromide (CTAB, cationic type), sodium dodecyl benzene sulfonate (SDBS, anion type), N-Laurylaminoacetic acid (NL, amphoteric type) and primary alcohol ethoxylate (AEO, non-ionic type), on the chemical mechanical polishing (CMP) performance of a-plane sapphire substrates in the range of pH 6–12 were investigated using colloidal silica as abrasive particles. The results demonstrated that cationic surfactants promoted the material removal of the sapphire substrate in the range of pH 9–12, while anionic, amphoteric, and non-ionic surfactants inhibited the material removal of the sapphire substrate in the range of pH 6–10. The mechanism of material removal in sapphire CMP was discussed through AFM observations, zeta potential measurements, particle size distribution tests, and friction behavior analysis.

Monodispersion of SiO2/CeO2 Binary Nano-Abrasives with Adjustable Size in Chemical Mechanical Polishing Performance of Copper

Chemical mechanical polishing (CMP) is an efficient methodology to achieve atomic-level roughness and global planarization. The selection and structural design of the abrasive particles in the polishing slurries play an essential role in the CMP process. In this work, silica (SiO2) microspheres with adjustable size and structure were prepared by a modified Stöber template approach, and ceria (CeO2) nano-shell layers were coated via in situ chemical precipitation on the core surfaces forming core/shell composite particles. The SiO2/CeO2 composites were characterized by XRD, SEM, TEM, XPS, and BET. The polishing performance of SiO2/CeO2 abrasives in copper (Cu) CMP was investigated by AFM. The small-sized (ca. 98 nm), large-sized (ca. 296 nm), and mesoporous (ca. 277 nm) composite abrasives were named as SiO2/CeO2-1, SiO2/CeO2-2, and mSiO2/CeO2, respectively. The best average surface roughness (Ra) and root-mean-square roughness (Rq) were obtained using SiO2/CeO2-1 abrasives, which decreased from 1.485 and 1.832 to 0.363 and 0.511 nm, respectively. The material removal rate (MRR) of the composite abrasives was improved to 279 nm min−1 by SiO2/CeO2-2 abrasives. The mSiO2/CeO2 composites were not manifested with evident superiority in terms of polishing characterization, which was attributed to the coating of CeO2 nanolayers. Finally, the material removal of Cu-CMP mechanisms was discussed.

Defect-Engineered MnO2 as Catalyst for the Chemical Mechanical Polishing of Silicon Carbide Wafer

Chemical mechanical polishing (CMP) of SiC wafer is challenging due to its extreme hardness and inertness. Catalyst assisted CMP is a cost-effective approach to increase material removal rate (MRR) without sacrificing surface quality. Herein, oxygen-deficient α-MnO2 was prepared by mechanochemical synthesis and the effect of catalyst physiochemical structure on the CMP performance of Si-face SiC wafer was systematically studied. The addition of 1% α-MnO2 catalyst increased MRR by 38.8% to 1.11 μm h−1, much higher than commercial γ-MnO2. The synergy of phase structure, oxygen vacancy and surface area & porosity contributed to the high catalytic activity. α-MnO2 is an outstanding oxidation catalyst due to its stable framework, large tunnel size, rich surface area and porosity, which can facilitate the adsorption, activation and transfer of guest species and intermediates and therefore affects the reaction pathway and reaction kinetics. Mechanochemical synthesis generates nano MnO2 particles with rich oxygen vacancies. The presence of more surface oxygen vacancies can improve oxidizing activity of MnO2 catalyst, facilitating the oxidation of C species on wafer surface. The use of defect-engineered α-MnO2 catalyst is promising for overcoming the present bottlenecks of long processing time and high cost of current CMP of SiC wafer.

Effect of the carboxyl group number of the complexing agent on polishing performance of alumina slurry in sapphire CMP

Alumina abrasive has a high polishing rate in the polishing process, but there are issues that need to be addressed with poor dispersion and poor post-polishing surface quality. This study used complexing agents with various numbers of carboxyl groups to prepare a series of alumina slurries. Scanning electron microscope images and zeta potential analysis demonstrated that the complexing agents could effectively increase the absolute value of alumina particles’ zeta potential and significantly enhance their dispersibility. Additionally, utilizing the UNIPOL-1502 polishing machine, the chemical mechanical polishing (CMP) performance of polishing slurries with complexing agents on sapphire substrates was investigated. According to the findings, as the carboxyl group count rises, material removal initially increases and subsequently declines. The material removal rate using alumina slurry added with complexing agent disodium ethylenediaminetetraacetic acid (the number of carboxyl groups is 4) can reach up to about 4.0 μm/h, which is 52% higher than that without complexing agents, while the average surface roughness of 0.96 nm can be obtained, which is 51% less than that without complexing agents. The X-ray photoelectron spectroscopy results showed that the complexing agents can react with the abrasive particles and sapphire substrates. The friction coefficient test and contact angle test revealed that slurries with complexing agents demonstrated excellent wettability and mechanical action. The sapphire surface becomes smoother as a result of the synergistic effect of chemical etching and mechanical removal.

Chemical–Mechanical Polishing of 4H Silicon Carbide Wafers

Abstract4H silicon carbide (4H‐SiC) holds great promise for high‐power and high‐frequency electronics, in which high‐quality 4H‐SiC wafers with both global and local planarization are cornerstones. Chemical–mechanical polishing (CMP) is the key processing technology in the planarization of 4H‐SiC wafers. Enhancing the performance of CMP is critical to improving the surface quality and reducing the processing cost of 4H‐SiC wafers. In this review, the superior properties of 4H‐SiC and the processing of 4H‐SiC wafers are introduced. The development of CMP with chemical, mechanical, and chemical–mechanical synergistic approaches to improve the performance of CMP is systematically reviewed. The basic principle and processing system of each improvement approach are presented. By comparing the material removal rate of CMP and the surface roughness of CMP‐treated 4H‐SiC wafers, the prospect on the chemical, mechanical, and chemical–mechanical synergistic improvement approaches is finally provided.

Structure-Performance Relationships of Complexing Agents on the Chemical Mechanical Polishing of 6063 Aluminum Alloy

Aluminum alloy has wide applications in many industries due to its unique properties. Chemical mechanical polishing (CMP) is commonly used to treat aluminum alloy to generate mirror-finish surface. In this study, the effects of pH and H2O2 concentration on the CMP of 6063 aluminum alloy were studied. Better CMP performance was obtained in basic media with 1.0 wt% H2O2. Moreover, complexing agents with different structures and functional groups were evaluated for the CMP of Al-alloy, and their structure-performance relationship was systematically studied. It was found that complexing power, steric hindrance and electrostatic repulsion of complexing agents were important factors determining material removal rate and surface roughness. The complexing agent with high complexing power can favor the dissolution and Al substrate. The complexing agent with large steric hindrance and high charge density can form a stable boundary layer on the surface of substrate and improve its dispersion ability, thereby improving MRR and surface quality. In addition, the amino functional groups of complexing agents exist in the form of neutral molecules at pH 10, which is inferior to carboxyl complexing agents due to their poor static repulsion. XPS analysis confirmed the anchoring of carboxylate anions on the sample surface.

Improving the Dispersion Stability and Chemical Mechanical Polishing Performance of CeO2 Slurries

The dispersion stability of CeO2 suspensions limits their widespread use in IC manufacturing because unstable slurries can be very damaging to the chemical mechanical polishing (CMP) flattening process. Therefore, this study is based on the use of wet ball milling in synergy with chemical agents to improve the dispersion stability of CeO2 slurry. Different organic acids were used as adjusting agents, including acetic acid, propionic acid, lactic acid, and phytic acid. The characterization of the dispersion stability showed that, compared to other organic acids, the CeO2 suspensions using acetic acid as a modest particle size distribution, good stability (zeta potential > 50 mV), monodispersity (polydispersity index < 0.1) and higher chemical activity (higher content of Ce3+). Moreover, CMP experiments showed that the CeO2 slurry using acetic acid as the adjusting agent had a higher removal rate (4139 Å min−1).

Doping strategy on properties and chemical mechanical polishing performance of CeO2 Abrasives: A DFT assisted experimental study

A series of Ce1-xMxO2 abrasives with different types and amounts of doping were prepared by molten salt method. The properties of abrasives were characterized in detail by XRD, SEM, EDS and XPS. For all doping types, the morphology of abrasives changes from spherical to octahedral and their size decreases continuously with the doping increases. The Ce3+ concentration on the CeO2 abrasive surface is also increased by doping. The density functional theory indicates the vacancy formation energy of CeO2 systems are reduced by doping. The mechanism of transition from Ce4+ to Ce3+ induced in CeO2 system by doping is also discussed. CMP experiments show that the efficiency of the abrasives is significantly enhanced by doping. The MRR of Y3+, La3+ and Pr3+ doped CeO2 abrasives increased by 56 %, 40 % and 44 % compared with the pure. It is also shown that the appropriate amount (x = 0.08) should be considered in order to obtain excellent performance. It is confirmed that the substrate surface with almost no damage and low roughness is obtained after polishing. The removal mechanism of CeO2 abrasives on SiO2 substrate is comprehensively analyzed by considering the size, morphology and defects of the abrasives.

Improvement of oxide chemical mechanical polishing performance by increasing Ce3+/Ce4+ ratio in ceria slurry via hydrogen reduction

Ceria-based abrasive is widely used in the oxide chemical mechanical polishing (CMP) process due to its high polishing performance. Ce3+ ions on the surface of ceria form a Ce–O–Si chemical bond with surface of the SiO2 wafer, significantly affecting the material removal rate (MRR). In this study, the ceria surface was reduced by contact with hydrogen gas in a high temperature isothermal environment. Hydrogen gas forms surface hydroxyls on the ceria. Then, the generated hydroxyls form H2O and oxygen vacancies occur through the desorption of the H2O. The color of ceria changed to blue due to a change of the crystal structure by the reduction reaction. The reducing ability of hydrogen gas increased as the reduction temperature increased and the Ce3+ ion concentration increased by 12.7% under isothermal conditions at 1000 °C. The MRR of reduced ceria was improved by up to 37.7% compared to the original ceria.

Effect of hydroxy carboxylates as complexing agent on improving chemical mechanical polishing performance of M-plane sapphire and action mechanism analysis

As sapphire device performance continues to improve, greater challenges are posed to the chemical mechanical polishing (CMP) of sapphire, with its high degree of hardness and brittleness. M-plane sapphire substrates are not widely used because they are more difficult to process, despite having higher luminous efficiency than C-plane substrates. In this study, the effect of three hydroxyl carboxylates, namely potassium tartrate (PT), potassium citrate (Cit) and sodium gluconate (Gluc), as complexing agents on the CMP of M-plane sapphire was investigated to obtain a high material removal rate (MRR) and low root mean square surface roughness (Sq). First, the chemical reactivities of the three complexing agents were predicted with Material Studio (MS) software. The predicted results showed that the complexing ability of the three complexing agents was greatest for Gluc, followed by Cit, with PT having the least complexing ability. Experimental results confirmed that Gluc was the optimal complexing agent for the M-plane sapphire CMP. The mechanism of action during CMP was revealed by X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR). The results showed that the Al(OH)4‒ ions produced by the sapphire were complexed by Gluc to form the soluble complex Al(OH)4‒/Gluc‒. At the same time, a solid phase reaction also occurred between the M-plane sapphire, SiO2, and water during CMP, and Al2Si2O7∙2H2O was generated. After polishing with the optimized slurry, the M-plane MRR was improved to 5.358 μm/h, a 50% improvement compared with the reference slurry, and the Sq decreased from 0.345 nm to 0.172 nm. These findings provide important guidance for the development of high-performance sapphire devices.

Preparation of CeO2 abrasives by reducing atmosphere-assisted molten salt method for enhancing their chemical mechanical polishing performance on SiO2 substrates

Ce3+ as the active site on the CeO2 abrasive surface is the key to enhancing the material removal rate (MRR). The CeO2 abrasives with high chemical activity were prepared by the molten salt method under a reducing atmosphere. The crystal structure and morphology of CeO2 abrasives were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS), and X-ray photoelectron spectroscopy (XPS). The CeO2 abrasives were obtained under different atmospheres (Air, Ar, and Ar/H2). With the enhancement of the reducing atmosphere, the morphology of the abrasives transforms from spherical to octahedral, while more oxygen vacancies and Ce3+ are generated on the surface of CeO2 abrasives. The CMP experiments show that the MRRs of the CeO2-Air, CeO2-Ar, and CeO2-Ar/H2 abrasives on SiO2 substrates are 337.60, 578.74, and 691.28 nm/min, respectively. Moreover, as confirmed by atomic force microscopy (AFM), the substrate surfaces exhibit low roughness (∼0.5 nm) after being polished using all of the prepared samples. Especially, the MRR of CeO2-Ar/H2 abrasives is increased by 104.76% compared with CeO2-air abrasives. The improved CMP performance is attributed to the increased Ce3+ concentration and the octahedral morphology of the abrasives enhancing the chemical reaction and mechanical removal at the abrasive–substrate interface.

The Effects of Precursors on the Morphology and Chemical Mechanical Polishing Performance of Ceria-Based Abrasives.

Ceria-based abrasives are widely used in precision chemical mechanical polishing (CMP) fields, such as thin film transistor liquid crystal display (TFT-LCD) glass substrates and integrated circuits, because of their excellent physicochemical properties. Rare earth carbonates, as precursors of ceria-based abrasives, directly affect the morphology of ceria-based abrasives, which, in turn, affects the material removal rate (MRR) and the surface roughness (Ra) after polishing. Herein, rare earth carbonates with different morphologies were obtained by adjusting reaction parameters during precipitation, including flake, spindle, and spheroid. Moreover, the phase of precursors was analyzed, and the evolution process of morphology from precursors to ceria-based abrasives was investigated. Furthermore, the effect of precursors on the polishing performance of ceria-based abrasives was explored. The results show that the primary particles of ceria-based abrasives are near-spherical, but the morphology and dispersion of the secondary particles are obviously inherited from precursors. Among them, near-spherical ceria-based abrasives prepared by nearly monodisperse near-spherical precursors show better uniformity and higher dispersion, and they not only achieve the lowest Ra but also obtain a higher MRR of 555 nm/min (9 wt.%) for polishing TFT-LCD glass substrates. The result is significant for the further optimization and application of high-performance ceria-based abrasives.

Effect of Chitosan Oligosaccharide as a Complexing Agent on Chemical Mechanical Polishing Performance of C-, A-, and R-Plane Sapphire Substrate

Sapphire is widely used in high-tech fields such as microelectronics and optoelectronics because of its excellent optical, chemical and mechanical properties. Higher requirements of surface quality and processing efficiency bring more challenges to achieve global planarization of the C-, A- and R-plane sapphire substrate. Enhancing chemical action is one of the effective methods to improve the effect of sapphire chemical mechanical polishing (CMP). In this paper, in order to improve the removal rate, chitosan oligosaccharide (COS) was used as a complexing agent in sapphire slurry. From the results, it was found that higher material removal rate (MRR) and lower surface roughness (Sq) were obtained for C-, A- and R-plane sapphire, when the concentration of COS in the slurry was 0.10 wt%, 0.05 wt%, and 0.05 wt%, respectively. Meanwhile, the reaction mechanism and process between COS and sapphire were revealed. From the Ultraviolet-visible (UV–Vis) and X-ray photoelectron spectroscopy (XPS) analysis, it can be concluded that there was a complexation reaction between sapphire wafers and COS, and the reaction product was soluble complex Al(OH)4 –/COS, which resulted in an increase in removal rate and a decrease in surface roughness. Such study has certain guiding significance for practical production.

Attaining Ultra-Smooth 18CrNiMo7-6 Case Hardening Steel Surfaces with Chemical Mechanical Polishing

Smooth surfaces are conducive to improving the lubrication of gears in mechanical systems. In this study, chemical mechanical polishing (CMP) was used to process 18CrNiMo7-6 case hardening steel, a typical material for gears. The results reveal that compared with formic acid and oxalic acid, citric acid can be used as a suitable complexing agent without causing apparent corrosion, probably due to the fact of its relatively stable adsorption. A synergistic effect exists between citric acid and H2O2. At pH 3, with 0.067 M citric acid and 1 wt% H2O2, a satisfactory CMP performance (i.e., a 514 nm/min material removal rate (MRR) and a 0.85 nm surface roughness Sa) was achieved. After polishing, no observable defects were found on the surface, and no discernible processing damage occurred to the substrate. In terms of the CMP’s mechanism, iron is first oxidized to Fe2+ and Fe3+, which then react with citric acid to form complexes. On the one hand, most of the complexes may stay on the surface to prevent further corrosion and, thus, the surface quality is excellent. On the other hand, the complexes may reduce the surface integrity and, thus, the MRR is high. The findings open new avenues for attaining ultra-smooth steel surfaces with CMP through controlling corrosive wear.

Effect and mechanism analysis of sarcosine on the chemical mechanical polishing performance of copper film for GLSI

With the decrease of integrated circuits feature size, chemical mechanical polishing (CMP) of copper (Cu) film for multilayer wiring is faced with new challenges. In order to reduce the step height of Cu film for cobalt-based Cu interconnect during CMP process, the selection of additives in the slurry is crucial. In this paper, sarcosine was used as an important additive in Cu slurry to improve the planarization properties. Through the polarization curves, dynamic polishing, static etching experiments and scanning electron microscopy (SEM) measurement, it was identified sarcosine as a complexing agent and trace functional reagent could improve the Cu planarization properties. Meanwhile, the adsorption and complexation mechanisms of sarcosine on Cu film surface were analyzed by electrochemical tests and X-ray photoelectron spectroscopy (XPS). The improvement of static etching and surface quality of Cu patterned wafers by sarcosine was verified by laser scanning confocal microscopy (LSCM). Low static etch rate (SER) (1658 Å/min), high removal rate (RR) (5091 Å/min), RR/SER of 3.07 and effective correction of the step height on Cu patterned wafers were achieved by the synergistic effect of sarcosine and benzotriazole (BTA). In this study, a green functional reagent for Cu film CMP in low-tech node multilayer wiring was provided, which is good practical application prospects.

Surface acidity of colloidal silica and its correlation with sapphire surface polishing

Colloidal silica occupies the field of polishing solution application of chemical mechanical polishing (CMP). Si-OH groups dominate the surface of colloidal silica nanoparticles, and their chemical nature, acidity, is a determining factor for CMP. However, due to the delicate nature, very vulnerable to self-condensation at elevated temperatures, of colloidal silica nanoparticles, traditional techniques used for characterizing powder samples are limited to gaining true insights into the chemical reactivity of these Si-OH groups without disturbing the surface chemistry, which hinders the deep exploration of the essential mechanism of CMP on silica. In this manuscript, low-field nuclear magnetic resonance (LF NMR) and freeze-drying-programmed temperature desorption (TPD) techniques were, for the first time, combined to investigate the true acidity of the surface Si-OH groups in colloidal silica with minimized perturbance from sample preparations. The results from both characterization methodologies complemented each other, and are in good agreement about the surface structure and acidity of the surface Si-OH groups on colloidal silica. The results demonstrate that the acidity of Si-OH hydroxyl groups on the surface of silica-soluble nanoparticles spreads in a very broad range from very weak, medium-strong, to very strong. CMP performance of sapphire substrates by using colloidal silica strongly correlates with the acidic nature of surface Si-OH groups at the acidic polishing condition. The stronger acidity of surface Si-OH groups, the higher material removal rates in sapphire polishing through the chemical bonding of deprotonated Si-O- functional surface of colloidal silica with hydrolyzed sapphire Al-OH surface. Therefore, when a large number of Si-O- active centers in the basic environment attack the sapphire Al-OH sites, the rate of the chemical reaction is accelerated.

Copper-incorporated dendritic mesoporous silica nanospheres and enhanced chemical mechanical polishing (CMP) performance via Cu2+/H2O2 heterogeneous Fenton-like system

The structure-dependent properties of abrasive particles play an extremely important role in atomic and close-to-atomic scale manufacturing. In this work, copper-incorporated dendritic mesoporous silica (D-mSiO2) nanoparticles were fabricated via a simple synthesis strategy of solvothermal post-treatment approach. As revealed by XRD, FTIR, HAADF-STEM and the corresponding EDX elemental mapping, some Cu ions were converted into CuO nanocrystals, and others were incorporated into D-mSiO2 frameworks. High-resolution AFM confirmed that the Cu- modified D-mSiO2 abrasives afforded nearly defect-free and atomically planarized dielectric film surfaces with angstrom-level roughness, and at the same time, enabled a significant improvement in removal efficiency. The involved Cu2+-catalyzed heterogeneous Fenton-like reaction in the presence of H2O2 might be responsible for the productions of highly reactive species in polishing slurries, thus contributing to the hydration layer formation and the material removal enhancement. The developed Cu-modified D-mSiO2 material is an efficient candidate for functional abrasive systems with better surface planarization capacity and superior material removal rate. Furthermore, the Cu2+/H2O2 heterogeneous Fenton-like system can be expected to a promising method to supplement in existing free radical-assisted polishing.

Improvement in dispersion stability of alumina suspensions and corresponding chemical mechanical polishing performance

The dispersion stability of alumina suspensions is an obstacle to its large-scale application for chemical mechanical polishing (CMP) since the aggregation of particles will cause scratches on the wafer surface during polishing. Therefore, this study was devoted to improving the physicochemical properties of alumina suspensions using different polymeric dispersants, including polyethylene glycol (PEG) with nonionic properties, sodium polyacrylate (PAAS) with anionic properties, and their triblock copolymer poly(acrylic acid)-b-PEG-b-poly(acrylic acid) (PAEG). The characterization results of dispersion stability showed that, compared with PEG and PAAS, the suspensions containing a suitable dosage of PAEG exhibited the advantages of low-viscosity (Viscosity < 3 mPa·s), good-stability (Zeta potential < -50 mV), and monodisperse (Polydispersity index < 0.1). The adsorption isotherm indicated that the adsorption of dispersants on alumina particles was consistent with Langmuir model. Furthermore, the total potential energy between particles in suspension was calculated for theoretical analysis of the inter-particle interactions. Besides, the dispersion mechanisms of PEG, PAAS, and PAEG were proposed as steric stabilization, electrostatic stabilization and electrosteric stabilization, respectively. Finally, CMP experiments showed that the suspension prepared by using PAEG as a dispersant to polish SiC substrates resulted in better removal rates (382 nm/h) and lower surface roughness (Ra: 1.85 nm).