目的 化学机械抛光（CMP）是先进半导体制造过程中实现晶圆全局平坦化的关键工艺。本文制备了一种氨基硅烷改性的二氧化硅磨料,旨在利用磨料表面引入的氨基官能团,在抛光过程中同时增强与硅片表面的化学相互作用与物理机械作用,从而协同提升材料去除效率与表面光滑度。方法 选取N-（β-氨乙基）-γ-氨丙基甲基二甲氧基硅烷（KH602）作为表面改性剂,通过其水解与缩合反应,将含有氨基的有机官能团共价接枝到二氧化硅磨料颗粒表面,成功制备出氨基改性的二氧化硅磨料。随后,将此种功能性磨料应用于抛光液的配制,并对硅片进行系统的化学机械抛光实验,以评估其工艺性能。结果 当KH602加入量为10%时,抛光性能达到最优,峰值材料去除率（MRR）为0.59 μm/min,实现了超光滑表面（Ra=0.26 nm）。结论 通过分子动力学模拟和密度泛函理论验证了改性磨料的性能优势, 分子动力学模拟显示改性磨料展现出较未改性磨料更低的吸附能（-25 863.511 J/g对比-22 934.999 J/g）,这表明使用改性磨料抛光硅片能形成更稳定的结合界面。密度泛函理论（DFT）计算模拟表明,氨基改性使二氧化硅纳米颗粒的静电势能从3.9 eV提升至5.979 eV,这与材料去除率基本一致。
Abstract
This research presents the development and comprehensive evaluation of a novel amino-functionalized silica abrasive for the chemical mechanical polishing (CMP) of silicon wafers. The core innovation lies in the strategic design of the abrasive particle surface to concurrently amplify both chemical and mechanical interactions during polishing. Unlike conventional abrasives that primarily rely on physical actions, this work utilizes N-(β-Aminoethyl)-γ- aminopropyl methyldimethoxysilane (KH602) as a coupling agent to covalently graft organic amino groups onto the silica surface, so as to create a synergistic effect where the introduced amino functionalities enhance chemical adhesion to the silicon wafer while the silica core maintains the necessary mechanical action, thereby jointly improving material removal efficiency and final surface quality.
The amino-modified silica abrasives were synthesized by direct grafting. Specifically, a calculated amount of KH602 silane was hydrolyzed and subsequently underwent condensation reactions with the surface hydroxyl groups of colloidal silica particles. This process established stable Si—O—Si bonds, permanently anchoring the amine-containing organic chains onto the abrasive surface. The functionalized abrasives were then incorporated into a standard alkaline polishing slurry formulation. Systematic CMP experiments were conducted on prime silicon wafers with a bench-top polisher under controlled pressure, platen speed, and slurry flow rate conditions. The polishing performance was meticulously assessed by measuring the material removal rate (MRR) using precise weighing and the post-polish surface topography via atomic force microscopy (AFM) to obtain the average roughness (Ra).
A key finding was the identification of an optimal modifier concentration. When the KH602 addition amounted to 10wt.% relative to the silica, the polishing slurry delivered peak performance. At this optimum, a maximum MRR of 0.59 μm/min was achieved, coupled with the attainment of an ultra-smooth surface characterized by an Ra value of 0.26 nm. This represents a significant simultaneous enhancement in both removal efficiency and surface finish compared with slurries employing unmodified silica.
The superior performance was rigorously validated and explained through advanced computational simulations. Molecular dynamics (MD) simulations were employed to model the interaction between the abrasive and the silicon surface. Calculations revealed a markedly more stable binding interface for the modified abrasive, evidenced by a substantially lower (more negative) adsorption energy of -25 863.511 J/g, compared with -22 934.999 J/g for the pristine silica abrasive. This confirmed that the amino groups facilitated stronger adhesion to the wafer surface, a critical factor for efficient material removal.
Furthermore, density functional theory (DFT) calculations provided electronic-level insights. They demonstrated that the amino modification significantly altered the surface electronic properties of the silica nanoparticle. The calculated electrostatic potential energy increased from 3.9 eV for unmodified silica to 5.979 eV for the KH602-modified variant. This elevation in electrostatic potential correlated directly with the observed enhancement in MRR, as it implied a stronger electrostatic interaction and heightened chemical activity at the abrasive-wafer interface, which promoted the surface reaction rate during the CMP process.
In conclusion, this study successfully demonstrates a material-centric innovation for CMP through the rational surface engineering of abrasives. The covalent grafting of aminosilane creates a dual-functional abrasive that synergistically combines enhanced chemical adhesion (via amino groups) with sustained mechanical action (via the silica core). The optimal formulation (10wt.% KH602) yields excellent polishing metrics. Most importantly, the underlying mechanism, a more stable interfacial binding and an increased surface electrostatic potential leading to synergistic chemo-mechanical removal, is conclusively unveiled through MD and DFT simulations. This work provides a new paradigm for designing high-performance functional abrasives by tailoring surface chemistry to actively participate in the material removal process.
关键词
化学机械抛光 /
磨料改性 /
二氧化硅 /
模拟计算 /
磨损机制
Key words
chemical mechanical polishing /
abrasive modification /
silica /
simulation calculations /
wear mechanism
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] KRISHNAN M, NALASKOWSKI J W, COOK L M.Chemical Mechanical Planarization: Slurry Chemistry, Materials, and Mechanisms[J]. Chemical Reviews, 2010, 110(1): 178-204.
[2] GAO S, KANG R K, GUO D M, et al. Study on the Subsurface Damage Distribution of the Silicon Wafer Ground by Diamond Wheel[J]. Advanced Materials Research, 2010, 126/127/128: 113-118.
[3] ZHOU P, XU S C, WANG Z G, et al.A Load Identification Method for the Grinding Damage Induced Stress (GDIS) Distribution in Silicon Wafers[J]. International Journal of Machine Tools and Manufacture, 2016, 107: 1-7.
[4] FU G H, CHANDRA A, GUHA S, et al.A Plasticity- Based Model of Material Removal in Chemical-Mechanical Polishing (CMP)[J]. IEEE Transactions on Semiconductor Manufacturing, 2001, 14(4): 406-417.
[5] 孟凡宁, 张振宇, 郜培丽, 等. 化学机械抛光液的研究进展[J]. 表面技术, 2019, 48(7): 1-10.
MENG F N, ZHANG Z Y, GAO P L, et al.Research Progress of Chemical Mechanical Polishing Slurry[J]. Surface Technology, 2019, 48(7): 1-10.
[6] LUO Z, ZHANG Z Y, ZHAO F, et al.Advanced Polishing Methods for Atomic-Scale Surfaces: A Review[J]. Materials Today Sustainability, 2024, 27: 100841.
[7] 徐泽超, 尹韶辉, 王哲, 等. Halbach阵列的磁流变化学抛光工艺研究[J]. 表面技术, 2025, 54(14): 141-150.
XU Z C, YIN S H, WANG Z, et al.Magnetorheological Finishing Process with Halbach Array[J]. Surface Technology, 2025, 54(14): 141-150.
[8] 田毅铭, 彭武茂, 王荣沛, 等. 高分散氧化铝磨粒抛光液实现不锈轴承钢高效化学机械抛光研究[J]. 表面技术, 2025, 54(16): 121-130.
TIAN Y M, PENG W M, WANG R P, et al.High- Efficiency Chemical Mechanical Polishing of Stainless Bearing Steel with the Highly-Dispersed Al2O3 Abrasive Slurry[J]. Surface Technology, 2025, 54(16): 121-130.
[9] 张力飞, 路新春. 面向原子级平坦化的化学机械抛光技术: 后摩尔时代的挑战与进展[J]. 表面技术, 2025, 54(23): 47-67.
ZHANG L F, LU X C.Chemical Mechanical Polishing Technology for Atomic-Level Planarization: Challenges and Progress in the Post-Moore Era[J]. Surface Technology, 2025, 54(23): 47-67.
[10] LIN Z W, ZHU J L, HUANG Q, et al.Mechanism Exploration of the Effect of Polyamines on the Polishing Rate of Silicon Chemical Mechanical Polishing: A Study Combining Simulations and Experiments[J]. Nanomaterials, 2024, 14(1): 127.
[11] WANG Y G, ZHANG L C, BIDDUT A.Chemical Effect on the Material Removal Rate in the CMP of Silicon Wafers[J]. Wear, 2011, 270(3/4): 312-316.
[12] BAE K, BAEK K H, KIM J, et al.Highly Selective Chemical Mechanical Polishing of Si3N4 over SiO2 Using Advanced Silica Abrasive[J]. Japanese Journal of Applied Physics, 2017, 56(5): 056501.
[13] GAO B, ZHAI W J, ZHAI Q, et al.Novel Polystyrene/ CeO2-TiO2 Multicomponent Core/Shell Abrasives for High- Efficiency and High-Quality Photocatalytic-Assisted Chemical Mechanical Polishing of Reaction-Bonded Silicon Carbide[J]. Applied Surface Science, 2019, 484: 534-541.
[14] 孙运乾, 李薇薇, 赵之琳, 等. 新型高硬度硅溶胶的制备及其在化学机械抛光中的应用[J]. 表面技术, 2021, 50(11): 383-389.
SUN Y Q, LI W W, ZHAO Z L, et al.Preparation of New High-Hardness Silica Sol and Its Application in Chemical Mechanical Polishing[J]. Surface Technology, 2021, 50(11): 383-389.
[15] WEI K H, WANG Y S, LIU C P, et al.The Influence of Abrasive Particle Size in Copper Chemical Mechanical Planarization[J]. Surface and Coatings Technology, 2013, 231: 543-545.
[16] LEE D, LEE H, JEONG H.Slurry Components in Metal Chemical Mechanical Planarization (CMP) Process: A Review[J]. International Journal of Precision Engineering and Manufacturing, 2016, 17(12): 1751-1762.
[17] XU Q Z, CHEN L, YANG F, et al.Influence of Slurry Components on Copper CMP Performance in Alkaline Slurry[J]. Microelectronic Engineering, 2017, 183: 1-11.
[18] KIM N H, KO P J, SEO Y J, et al.Improvement of TEOS-Chemical Mechanical Polishing Performance by Control of Slurry Temperature[J]. Microelectronic Engineering, 2006, 83(2): 286-292.
[19] BASIM G B, ADLER J J, MAHAJAN U, et al.Effect of Particle Size of Chemical Mechanical Polishing Slurries for Enhanced Polishing with Minimal Defects[J]. Journal of the Electrochemical Society, 2000, 147(9): 3523-3528.
[20] WANG W T, ZHANG B G, SHI Y H, et al.Improvement in Chemical Mechanical Polishing of 4H-SiC Wafer by Activating Persulfate through the Synergistic Effect of UV and TiO2[J]. Journal of Materials Processing Technology, 2021, 295: 117150.
[21] COOK L M.Chemical Processes in Glass Polishing[J]. Journal of Non-Crystalline Solids, 1990, 120(1-3): 152-171.
[22] LIU G R, LIU Y L, NIU X, et al.Effects of Large Particles on MRR, WIWNU and Surface Quality in TEOS Chemical Mechanical Polishing Based on FA/O Alkaline Slurry[J]. ECS Journal of Solid State Science and Technology, 2018, 7(11): P722-P729.
[23] GUO D, XIE G X, LUO J B.Mechanical Properties of Nanoparticles: Basics and Applications[J]. Journal of Physics D: Applied Physics, 2014, 47(1): 013001.
[24] XING Y, WANG W L, LIU W L, et al.Enhancing Slurry Stability and Surface Flatness of Silicon Wafers through Organic Amine-Catalyzed Synthesis Silica Sol[J]. Nanomaterials, 2024, 14(16): 1371.
[25] MUELLER R, KAMMLER H K, WEGNER K, et al.OH Surface Density of SiO2 and TiO2 by Thermogravimetric Analysis[J]. Langmuir, 2002, 19(1): 160-165.
[26] PAN G S, GU Z H, ZHOU Y, et al.Preparation of Silane Modified SiO2 Abrasive Particles and Their Chemical Mechanical Polishing (CMP) Performances[J]. Wear, 2011, 273(1): 100-104.
[27] HUI S, HAN Y, YANG W.Controllable Preparation of Thiol-Modified Silica Particles by an Optimized Stober Method[J]. Langmuir, 2025, 41(27): 18175-18183.
[28] CHEN Y, LI Z N, MIAO N M.Synergetic Effect of Organic Cores and Inorganic Shells for Core/Shell Structured Composite Abrasives for Chemical Mechanical Planarization[J]. Applied Surface Science, 2014, 314: 180-187.
[29] ZHAO Q, XIE S F, WANG H X, et al.Synergistic Effect of Aminosilane and K2CO3 on Improving Chemical Mechanical Polishing Performance of SiO2 Dielectric Layer[J]. Materials Science in Semiconductor Processing, 2022, 146: 106702.
[30] WU P F, ZHANG B G, WANG Y, et al.Effect of Synergetic Inhibition of Nonionic Surfactant and Benzotriazone for Molybdenum in Chemical Mechanical Polishing[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2023, 664: 131164.
[31] YUAN X Y, LEI H, CHEN C D. An Ethylenediaminetetraacetic Acid (EDTA) Surface-Functionalized CeO2 Composite Abrasives with the Effective Improvement of the Removal Rate on Glass CMP[J]. Ceramics International, 2024, 50(1): 293-305.
[32] WANG D, XIE W X, ZHANG Z Y, et al.Atomic Surface of Silicon Wafers Induced by Grafted Silica Nanoparticles and Sodium Carbonate[J]. Applied Surface Science, 2024, 664: 160234.
PDF(15964 KB)
渝公网安备 50010702501715号 渝ICP备15012534号-3
