Post Chemical Mechanical Polishing Research Articles

Cleaning mechanisms during post chemical mechanical polishing (CMP) using particle removal of surfactants via a citric acid-based solution

With the development of circuit integration technology, the requirements for defects in copper interconnects have become more stringent. The residual SiO2 particles on the copper surface can seriously affect circuit performance and require more efficient and thorough removal. This article investigates the effects of a novel cleaning solution composed of citric acid (CA), alkyl polysaccharide glycosides (APG1214), and dodecylbenzene sulfonic acid (LABSA), aimed at improving the removal efficiency of SiO2 and maintaining the integrity of copper surface. The optimal concentrations of APG1214 and LABSA were determined through contact angle and surface tension analysis. It was found that when APG1214 (2000 ppm) and LABSA (1000 ppm) were combined in a 3:2 vol ratio in CA solution (0.6 wt%), the highest particle removal efficiency (99.5 %) could be achieved while minimizing surface roughness. The results of scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirmed these findings. Combining quantum chemical calculations, new insights into the mechanism of action of different components in clean solutions have been proposed: 1. Similar to CA, LABSA and APG1214 demonstrate a strong affinity for copper, synergistically facilitating the cleavage of Cu-Si bonds. 2. Alternating adsorption of LABSA and APG1214 on free silica particles prevents their re-adsorption onto copper surfaces. 3. Furthermore, their orderly adsorption on copper mitigates the corrosive chelation effect of CA, providing a protective mechanism. These findings are pivotal for the development of advanced, multifunctional cleaning solutions.

Effects of two mild amino acids on benzotriazole residue desorption during cobalt post-chemical mechanical polishing cleaning: Experimental and theoretical studies

During the polishing process of the cobalt (Co) interconnect layer, the corrosion inhibitor in the polishing solution will leave an organic residue on the polished cobalt surface, which needs to be removed by the post-chemical mechanical polishing (CMP) cleaning process. However, given the active chemical properties of cobalt, the potent and corrosive complexing agents in traditional cleaning solutions have the drawback of generating new corrosion defects on the cobalt surface. In this study, an eco-friendly cleaning solution is developed utilizing tetraethyl ammonium hydroxide (TEAH), deionized water, and either sarcosine or serine, thereby ensuring the absence of any additional introduction of metal impurities. The removal effect of the cleaning solution on BTA was tested using atomic force microscopy (AFM) and X-ray photoelectron spectrometer (XPS). The results demonstrate that post-CMP cleaning with either sarcosine or serine yielded a cobalt surface with reduced roughness (2.78 nm and 2.63 nm), diminished Co-BTA content (10.6% and 9.5%), and a lowered contact angle (44.3° and 37.9°). To elucidate the mechanism of post-CMP cleaning, electrochemical measurements and molecular dynamics were employed. Initially, in the cleaning solution with a pH of 10.4, the adsorption of BTA and cobalt is minimized. Subsequently, as serine permeates through the BTA residue layer, the desorption of BTA is expedited through competitive adsorption. These findings contribute valuable insights into the mechanism of residue removal in post-CMP cleaning processes.

Development of a pH-independent Post-CMP Cleaning Solution using Phosphoric Acid-based Surfactants for Removal of Ceria Nanoparticles

The global interest and demand for the advancement of semiconductor technology, including 3 nm generation semiconductors and gate-all-around semiconductors, continues to rise. This study presents an improvement plan aimed at enhancing performance and yield in the semiconductor manufacturing process, with particular emphasis on the post-CMP cleaning of SiO2 surface. The removal of residual ceria abrasives from SiO2 surfaces after the SiO2-chemical and mechanical planarization (SiO2-CMP) process is a sincere concern in the post-CMP cleaning process because the strong interaction between ceria nanoparticles and SiO2 makes their removal challenging. Herein, we propose a cleaning solution containing a phosphoric acid-based surfactant to address this issue. Three phosphoric-acid-based surfactants with varying numbers of phosphoric acid groups were evaluated, and etidronic acid (EA) with two phosphoric acid groups was found to be the most suitable surfactant. The EA demonstrated a reasonably negative zeta potential of the ceria nanoparticles, a key factor for efficient cleaning, despite variations in solution pH, pH adjuster cations, and surfactant and oxidizing agent (hydrogen peroxide) concentrations. Furthermore, the efficiency of the cleaning solution containing EA was evaluated, and the results confirmed the potential of EA as a promising surfactant for use in the post-CMP cleaning process.

Experimental characterization and dynamical modeling evaluation for enhanced BTA removal by three amino acids in post-Cu-CMP cleaning

Post-chemical mechanical polishing (CMP) cleaning is an indispensable process to remove organic residues and particles on the wafer surface after CMP. Benzotriazole (BTA), a dominant corrosion inhibitor in Cu-CMP slurry, can easily remain on the copper surface after CMP, affecting the performance and yield of devices, and its removal has attracted more attention. This paper revealed the effect and mechanism of three amino acids, lysine, serine, and proline, on BTA removal in tetraethyl ammonium hydroxide-based alkaline solutions during post-Cu-CMP cleaning. Experimental results showed a diminishing enhancement in the cleaning efficiency of BTA after adding lysine (97.1%), serine (96.7%), and proline (94.1%) with almost the same concentration. Ultraviolet–visible absorption spectrum proved the lysine’s complexing ability was slightly better than the other. Besides, quantum chemical parameters of amino acid molecules calculated by density functional theory further suggested that lysine has more reactive sites and mainly bonds with copper through N2 and N8. The adsorption structures of three amino acids were simulated through the molecular dynamics method, and lysine turned out to be parallel absorbed on the Cu (111) surface with the lowest adsorption energy of −30.24 eV. Finally, the cleaning process simulation revealed the dynamic behaviors of BTA and lysine.

Highest Quality and Repeatability for Single Wafer 150mm SiC CMP Designed for High Volume Manufacturing

Silicon Carbide (SiC) provides excellent characteristics such as superior thermal conductivity, high carrier mobility and extreme chemical stability in comparison with those of Silicon (Si). SiC is already showing significant device performance benefits in power devices, high performance communication, and LED lighting. However, SiC presents many challenges for wafer surface treatment because of its high hardness and remarkable chemical inertness. Today, mechanical polishing techniques on industrial batch CMP tools are the predominant methods for SiC wafer surface treatment, but material removal rate (MRR), surface defects and wafer flatness control are reaching fundamental limits with increasing wafer diameter. Batch processing typically results in a higher amount of surface scratches and defects, higher wafer to wafer variability, and higher wafer breakage rates. A unique single wafer chemical mechanical polishing (CMP) technique on 150mm n-doped, 4° off-axis, single crystal, 4H-SiC wafers was developed to create a virtually defect-free surface. A polishing head has been designed to manipulate polishing pressures at various zones of the wafer. This capability can modulate the removal thickness at each region on the wafer surface, resulting in a highly uniform wafer profile. Additionally, a CMP slurry has been formulated to maximize MRR from 2μm/hr to over 8.5μm/hr. Potassium permanganate has been selected as an oxidant and aluminum oxide particles as the abrasive. The oxidant concentration and abrasive content along with slurry pH level have also been optimized for ideal chemical and mechanical activity. Scratch-free wafer surfaces are observed with atomic force microscopy (AFM) and bright field (BF) and dark field (DF) inspection techniques. Roughness on the Si face is reduced to below 0.08nm. Total length of surface scratches was reduced to 10mm or less. Industrial metrics of wafer flatness, including total thickness variation (TTV) and local thickness variation (LTV) are modulated and improved. A test run completed on 25-wafers shows an overall 31% improvement of TTV post CMP process.

Effect of brush cleaning on defect generation in post copper CMP

Chemical Mechanical Polishing (CMP) has been utilized for surface topography control and planarization since it was introduced in semiconductor fabrication. However, the concept of CMP now encompasses defect control process. Post CMP in-situ cleaning has employed brush scrubber and brush scrubber is considered as highly effective method for particle removal. CMP-induced defects are well defined and easy to identify such as scratches, slurry abrasive particles, metal residue, corrosion and organic residues. Most of them are yield-detracting defects. In this paper, defect generation during the copper (Cu) CMP in-situ cleaning process is explored and the investigation focus is cross contamination by the brush cleaning process. Experiments were conducted with blanket oxide wafers and Cu pattern wafers. Brush gap, brush life, and brush cleaning time were variables for the experiments. After brush cleaning experiment, wafer surface charge characterization was performed by mercury probe method. The experiment results in this paper underscore surface charge variation during the brush cleaning process playing a critical role in defect generation. This is a new finding as to how brush cross contamination occurs during brush cleaning, and results in this paper will provide insights on defect reduction strategy in CMP process development.

Composite complex agent based on organic amine alkali for BTA removal in post CMP cleaning of copper interconnection

The combination of FA/OII chelating agent and double complexing agent ammonium citrate can shift the ionization to the right (the dissolution of Cu-BTA), effectively break the Cu-N bond, and accelerate BTA removal on the copper surface. • Ammonium citrate's nucleophilic attack may occur near C2 and O4 atoms. • The electrophilic attack may occur near N22 and N26 atoms. • The pH value of the cleaning solution is stable at 10.24 for optimal removal of BTA. • Effect and mechanism of composite complex agent were studied by electrochemical, contact angle, SEM, FTIR and XPS. • Composite complex agent can complex copper ions, form copper amine complex and break the ionization balance of Cu-BTA. Benzotriazole (BTA) is a common corrosion inhibitor in chemical mechanical polishing (CMP). It is also the main pollutant to be removed in post CMP cleaning. In this paper, a new type of alkaline cleaning solution based on composite complexing agent was proposed for BTA removal. The optimal concentration and pH value of the cleaning solution were explored using electrochemical measurement and contact angle measurement. When the components were 200 ppm FA/OII chelating agent and 0.1 vol% ammonium citrate (pH = 10.24), BTA residue on copper surface can be effectively removed. Density Functional Theory (DFT) proved that ammonium citrate's nucleophilic attack may occur around C2 and O4 atoms, respectively. The electrophilic attack of ammonium citrate may occur around N22 and N26 atoms, respectively. The results of scanning electron microscopy (SEM) showed that a lower surface roughness was obtained after cleaning. Fourier transform infrared spectrometer (FTIR) and X-ray photoelectron spectroscopy (XPS) measurements confirmed that the cleaning solution could complex copper ions, break the ionization balance of Cu-BTA and accelerate its dissolution, so as to remove BTA effectively.

Effect of Corrosion Inhibitor BTA on Silica Particles and their Adsorption on Copper Surface in Copper Interconnection CMP

In the process of chemical mechanical polishing (CMP) of multilayer copper wiring of integrated circuits, benzotriazole (BTA) as corrosion inhibitors and silica particles as abrasives are important components of polishing slurry. At the same time, they are also the main objects of post CMP cleaning. Under alkaline conditions (pH 10), the addition of BTA will affect the stability of silica particles, such as particle size and zeta potential, so as to affect the adsorption of particles on the copper surface. The effects of different concentrations of BTA on the adsorption of silica particles on copper surface were characterized by scanning electron microscopy (SEM), and the corresponding adsorption mechanism was also analyzed by X-ray photoelectron spectroscopy (XPS). The adsorption energies of BTA molecule and SiO2 molecule on copper surface were calculated by molecular dynamics simulation. The results show that 3 mM BTA reduces the adsorption capacity of SiO2 particles, and increasing the concentration of BTA will increase the adsorption capacity of SiO2 particles on the copper surface.

Effect of Complexing Agents on Surface Composition for Co Post-CMP Cleaning Process

The effect of surface composition change based on complexing agents on cobalt (Co) post-chemical mechanical polishing cleaning (cleaning) is investigated. The change in chemical composition of the Co surface significantly affects Co cleaning performance, as well as dissolution capacity of the complexing agent and pH of cleaning solution. Oxide composition of the Co surface was manipulated using different types of complexing agents. Addition of citric acid and glycine in cleaning solution resulted in predominant formation of Co3O4 and CoOOH on the Co surface, respectively. The citric acid-derived Co3O4 surface embraces abundant –O– terminates, which attracts the complexing agent and silica abrasive relatively weakly, resulting in suppression of recess formation and reduction of surface particle residue after cleaning. On the contrary, the –OH terminated CoOOH surface formed by glycine bound strongly with silica. Therefore, preferential development of Co3O4 on the surface considerably enhances Co cleaning performance, which is achieved by introducing citric acid in the cleaning solution. To sum up, we suggested an unconventional insight to understand the effect of Co surface chemical state on cleaning performance.

Effect of EDTA-based alkaline cleaning solution on TAZ removal in post CMP cleaning of copper interconnection

1,2,4-triazole (TAZ) has been proved to be an alternative to Benzotriazole (BTA) as an corrosion inhibitor in chemical mechanical polishing (CMP) of multilayer copper interconnection for integrated circuit. It has also become the main object to be removed in post CMP cleaning. In this paper, a new type of alkaline cleaning solution based on EDTA was proposed to remove TAZ on copper surface. The optimal concentration ratio and pH value of the alkaline cleaning solution were explored using electrochemical measurement, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) and scanning electron microscopy (SEM). When the components of the cleaning solution were 25mg/L ethylenediaminetetraacetic acid (EDTA) and 600mg/L dodecylbenzene sulfonic acid (LABSA) (pH = 10.6), the Cu-1,2,4-trazole compounds formed by TAZ contamination on the copper surface can be effectively removed. Density Functional Theory (DFT) was used to confirm that EDTA could break the bond of Cu-1,2,4-triazole through the strong interaction between O16、H2、H36 and copper surface. No corrosion was observed on the cleaned copper surface and surface roughness was lower, which indicated that the cleaning solution was suitable for the removal of TAZ on copper surface.

Experimental validation and molecular dynamics simulation of removal of PO residue on Co surface by alkaline cleaning solution with different functional groups

Potassium oleate (PO) is a promising inhibitor for cobalt wiring chemical mechanical polishing (CMP) of integrated circuit (IC) to replace benzotriazole (BTA). The insoluble Co-PO complex formed on cobalt surface in the process of CMP become the main organic residues object of post CMP cleaning. In this paper, tetramethylammonium hydroxide (TMAH) and three complexing agents with different functional groups were used to form alkaline cleaning solution to remove the organic residue of Co-PO complex on cobalt surface. The cleaning effect was characterized by contact angle, electrochemistry, atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). Furthermore, the cleaning mechanism was revealed by molecular dynamics simulation based on density functional theory (DFT). The results show that the carboxyl group in Ethylenediamine tetraacetic acid (EDTA) is more easily to chelate with Co(II), which could break the Co-PO complex to remove PO on the cobalt surface. The mechanism of removing corrosion inhibitors by complexing agents will be helpful to the post-CMP cleaning of new generation Cobalt wiring.

Synergistic effect of LABSA/JFCE combined surfactant system on the removal of particles on copper wafer surface

With the decrease of feature size of integrated circuits, higher requirements are put forward for the surface defects of copper interconnects after chemical mechanical polishing (CMP). Colloidal SiO2 is used as a common abrasive in the CMP slurry for copper interconnect, which is the main contaminant in the post-CMP cleaning process. The interaction parameters of the anionic surfactant Dodecylbenzenesulfonic acid (LABSA) and the nonionic surfactant fatty alcohol polyethylene ether (JFCE) were calculated. It was determined that when the ratio of LABSA/JFCE compound was 2:3 and the concentration was 1000 ppm, the synergistic effect of the two surfactants was the strongest. The effect of the composite surfactant on the particle removal was verified by scanning electron microscopy (SEM). When the compound ratio of LABSA and JFCE is 2:3, the maximum removal efficiency of particles on copper surface was 97.08%. The reactive sites of LABSA and JFCE were studied at B3LYP/6-31G (d,p) level. Their adsorption energies on copper surface were calculated. It was concluded that under the action of composite surfactant agent, the SiO2 particles physically adsorbed on the copper surface could be easily desorbed. The theoretical analysis is consistent with the experimental results; the compound cleaning solution is suitable for particle removal in post CMP cleaning.

A Novel and Unified Full-Chip CMP Model Aware Dummy Fill Insertion Framework With SQP-Based Optimization Method

Dummy filling is widely applied to significantly improve the planarity of topographic patterns for the chemical mechanical polishing process in VLSI manufactures. The main challenge of dummy filling is balancing multiple objectives, such as fill amounts, planarity, parasitic capacitance, etc. An obvious drawback of traditional rule-based dummy filling methods is pattern densities, instead of post-chemical mechanical polishing (CMP) topographies, being included in optimization objectives. Although the quality of post-CMP topography strongly depends on pattern features of layouts, especially the density uniformity, however, experimental results show that chip surface variations are not exactly the same as density variations. In this article, a unified dummy fill insertion optimization framework is proposed, integrated with the multiple starting points-sequential quadratic programming (MSP-SQP) optimization solver, where all objectives are considered without approximation. Inside this framework, a full-chip CMP simulator is first integrated to evaluate the planarity of the chip surface. By selecting the initial points smartly with heuristic prior knowledge, the proposed method can be effectively accelerated. The effectiveness of the proposed algorithm is verified with the average 25.8% improvement of quality compared with rule-based methods.

Synergistic effect of composite complex agent on BTA removal in post CMP cleaning of copper interconnection

Benzotriazole (BTA) is a common corrosion inhibitor for chemical mechanical polishing (CMP) of multilayer copper wiring of integrated circuit. It is also the main object to be removed in post CMP cleaning. In this study, a new type of alkaline cleaning solution based on composite complex agent was proposed to remove BTA effectively. The optimal cleaning concentration ratio and pH value of the new complex complexing agent were explored through electrochemical measurement and contact angle measurement. When the components of cleaning solution were 250 ppm diethylenetriaminepentaacetic acid (DTPA), 1000 ppm FA/OII chelating agent and 100 ppm polyethyleneimine (PEI) (pH = 10.5), the contact angle of copper surface contaminated by BTA can be reduced from 58.1° contaminated by BTA to 25.1°. Density Functional Theory (DFT) proved that DTPA could reduce the adsorption energy of BTA on copper surface. The result of atomic force microscopy (AFM) and scanning electron microscopy (SEM) on copper surface showed that composite complexing agent does not cause corrosion and a lower surface roughness was obtained after cleaning. X-ray photoelectron spectroscopy (XPS) results verified that the cleaning solution could complex copper ions, break the Cu-N bond and promote the decomposition of the Cu-BTA adsorbed chemically on Cu2O, so as to remove BTA effectively.

Post-CMP Cleaning of InGaAs Surface for the Removal of Nanoparticle Contaminants for Sub-10nm Device Applications

In this study, the development of post-chemical mechanical polishing (CMP) protocols for cleaning abrasive nanoparticles from In0.53Ga0.47As surfaces was systematically analyzed. Abrasive silica nanoparticles (130 and 289 nm) were intentionally deposited onto InGaAs surfaces. Various concentration ratios of chemical etchants such as HCl and H2O2 were used to control material loss and surface oxides of InGaAs. The optimal concentration ratio of the HCl/H2O2 cleaning solution exhibited 40% particle removal efficiency (PRE). Application of megasonic (MS) cleaning improved the PRE to 80%. To prevent particle re-contamination, ammonium dodecyl sulfate (ADS) was used as an anionic surfactant to modify surface charge in the InGaAs substrate. Addition of surfactant further improved the PRE to over 96%. Optimal cleaning of InGaAs surfaces was achieved with a combination of HCl/H2O2, surfactant, and MS.

An investigation of the deposition of ceria on silica by quartz crystal microbalance: Observations on the effect of many body interactions

Interaction of ceria and silica is important in a wide variety of applications such as Chemical Mechanical Polish (CMP). In this work, a Quartz Crystal Microbalance (QCM) and mathematical modeling and simulations are used to investigate the dynamics of the attachment of ceria and silica under different flow rate, colloid concentration and pH conditions. The well-known DLVO forces of interaction were successfully used to distinguish between favorable and unfavorable conditions for the attachment of ceria and silica, and to develop a cleaning procedure to obtain reproducible data when using QCM for studying charged particles. The use of the optimized cleaning procedure as well as careful selection of the experimental conditions such as flow rate and concentration led to the important experimental observation that deposition of ceria particles onto silica surface is affected by many body particle–particle interactions in the bulk that can hinder the ability of the ceria particles to successfully attach to the silica surface. These experimental results could not be predicted by using a convection-diffusion-migration model which incorporates a single particle-surface DLVO interaction energy but ignores particle–particle interactions in the bulk. This is an important finding that permits the determination of the proper conditions for applications such as CMP and post CMP cleaning.

The reinforcement of the physical strength of PVA sponge through the double acetalization

Abstract In order to serve as the roller filter used in the post chemical mechanical polishing (post-CMP) cleaning processes of making silicon wafers, the effect of reinforcing the physical strength of Poly(vinyl alcohol) (PVA) sponges through the process of the double acetalization with and without using the pore-forming agent is investigated in the present study. From the measurements of the Young’s modulus, we found that the process of the double acetalization does reinforce the physical strength of PVA sponges with and without using the pore-forming agent because of increasing the conversion rate of formaldehyde. The effect of double acetalization on the water adsorption capacity of PVA sponges will be also investigated in the present study.

Study on the Polishing Performance of Silicon Carbonitride (SiCN)

Chemical mechanical polishing (CMP) becomes a major process in IC integration as gate length shrinkage. Moreover, its usage becomes wider at sub-14nm device manufacturing due to new structure and new material introduction. Enabling new material for planarized structure, polishing performance is required. Silicon carbonitride (nitrogen-doped silicon carbide (SiC) or SiCN) thin film is one of the new materials for sub-14nm device fabrication. SiCN thin film becomes more and more attractive as capping dielectric layer and diffusion barrier in addition to etch stopping layer. We have developed a process to form SiCN with tunable carbon concentration (5-15%). And SiCN thin film is applied for poly opening CMP (POC) process scheme. In order to enable SiCN as POC, polishing performance with enough selectivity between SiCN and silicon dioxide (SiO2) need to be achieved. For this purpose, this paper provides experimental results of SiCN polishing performance with silica-based slurry. Effects of polishing variables and slurry chemistry on the removal rate are intensively explored and post CMP defect performance is investigated as well. The results suggest acidic silica slurry with optimized recipe would be suitable for SiCN polishing.

Simultaneous EUV Flare Variation Minimization and CMP Control by Coupling-Aware Dummification

Extreme ultraviolet (EUV) flare and post-chemical mechanical polishing (CMP) metal thickness are two main manufacturability concerns that introduce critical dimension distortions in nanometer process technology. Dummification, the addition of dummy patterns, is an effective technique to address the two concerns. However, while the two dummification objectives are competing in nature, existing works only tackle them separately, leading to problem-prone solutions because optimizing one would unavoidably deteriorate the other. This paper presents a new and effective method that simultaneously considers both concerns during dummification. Manufacturing sensitivity toward the two concerns are taken into account with a user-specified evaluation model adaptive to the adopted technology. Given the point spread function of a system and the evaluation model, our proposed two-stage method is able to find at the first stage an initial dummy assignment with better EUV flare uniformity than that obtained by a previous quasi-inverse method. With the initial assignment as the starting point, the gradient-guided optimization is then adopted to iteratively refine dummy distribution toward improved CMP quality. Experimental results on industrial test cases show the effectiveness of our method.

Initial Study on the Polishing Performance of Nitrogen-Doped Silicon Carbide (SiC)

Nitrogen-doped silicon carbide (SiC) (Silicon carbonitride or SiCN) thin films which has been generally used as a etch stopping layer. Recently It becomes more and more attractive as capping dielectric layers and diffusion barriers due to their performance is similar to silicon nitride (SiN) but having lower dielectric constant and higher endurance on etching process. But high Carbon concertation SiCN film is hard to form and we have developed a process to form SiCN with tunable high Carbon concentration (5-15%). The SiCN film used in this study is deposited by 300mm Producer PECVD of applied materials at 400°C. The chemical composition and film property can be tuned by a tight control of gas flow and RF power. The overall chemical reaction occurring using TMS is as follows: Si(CH3)3-H + SiH4 + NH3 --> SiCN. VASE analysis shown that the Refractive index (n) is around 2.18 at 633nm, higher than other PECVD SiCN films, while extinction coefficient (k) is comparable with others. Hg-probe for dielectric constant K value is determined and FTIR is used to measure the materials chemicals. To enable this material use in the semiconductor manufacture scheme, such as poly opening polishing process, there is a need to study the other performance of this material, such as polishing performance. As the development of semiconductor manufacturing, chemical mechanical polishing (CMP) becomes a major process in IC integration. Nowadays, CMP is widely used in planarization structure and enable new structure and new material introduced in IC fabrication. To enable SiCN used in the new semiconductor scheme, we need to study the selectivity between removal rates of SiCN and silicon dioxide (SiO2) with silica particles. Two kind of silica nanoparticles slurries (one is acidic and the other one is alkaline) were used in this studied. The materials are polished with different downforce, platen and head rotation speed, as well as polishing time, aim to understand the polishing performance under different situation. In addition, the selectivity between removal rates of SiCN, SiN and Oxide was tested. The post CMP DFU information was also collected. The initial results of the investigations on the optimization of the consumables and process conditions would be given in this presentation. Our study shown that, SiCN has higher removal rate at the beginning of polishing and then the removal rate drops off gradually as polishing longer. The removal rate increase linear as process downforce increase which is similar as most dialectic materials. From defectivity points of view, with longer polishing time and higher downforce, CMP generated more defects. But with increasing RPM, higher removal rate and relative stable defectivity could be achived, which might be a knob to maitain specific removal rate as well as relative low defectivity. The selectivity between removal rates of SiCN and Oxide with acidic and alkaline silica nanoparticles nanoparticles slurry, shown the SiCN material is more prefer to be removed in the acidic slurry. And acidic slurry has better SiCN to oxide selectivity compare to alkaline slurry. In conclusion, this is an initial study of the polishing performance of SiCN (5-15% carbon concentration), and we reported the material’s removal rate and defectivity corresponding polishing time, downforce and RPM with Silica nanoparticles slurry. It indicated that a new type of slurry is needed for this new materials and the slurry is prefer as acidic slurry.