Analysis model of chemical mechanical polishing process based on fiber aggregates
), Abstract
Chemical mechanical polishing (CMP) is an ultra-precision machining technology for hard and brittle materials. The technology has garnered significant attention from researchers worldwide owing to its low cost of processing equipment and relatively simple operational process. In the CMP process, the polishing pad plays a critical role. It not only serves as the medium for storing the polishing slurry and abrasive particles but also transfers the processing load. This paper presents a fluid-structure coupling analysis framework to elucidate the fiber structure of the polishing pad and the interaction mechanism between the polishing slurry and the workpiece during the polishing process.
An innovative fluid-structure coupling analysis framework is proposed to investigate the interaction mechanism between the fiber structure of the polishing pad, the slurry, and the workpiece during the polishing process. Through comprehensive experimental verification and numerical modeling, the polishing efficiency differences between the ordered plain weave polishing pad and the disordered nonwoven polishing pad were systematically evaluated. To meet the ultra-precision processing requirements of fused silica materials, a green and environmentally friendly polishing slurry was specially developed. The slurry consisted of cerium oxide abrasive, hydrogen peroxide, guar gum, and deionized water. The composition of the polishing slurry and the polishing process were optimized through a single-factor test. Subsequent experiments were conducted on polishing pads with different textures (ordered plain weave fabric and disordered nonwovens) using the optimized slurry and process. The experimental procedure was further optimized through a single-factor test.
The experimental results showed that the surface roughness (Sa) of the nonwoven polishing pad was as low as 0.181 nm, which was significantly better than that of the plain weave pad (0.486 nm). In addition, the thickness of the subsurface damage layer caused by the nonwoven pad was reduced to 4.14 nm, approximately one-third of that of the plain weave pad (about 12.12 nm). A comparison of the surface elements of fused silica before and after polishing revealed that the polished sample had no impurity residue on the surface after cleaning. The difference in fiber structure between the two polishing pads only affected mechanical removal during the polishing process but did not influence the chemical reaction. Furthermore, the fluid-structure coupling model analysis revealed that the nonwoven polishing pad exhibited a more uniform fiber stress distribution during polishing, with the maximum stress value being only about 0.5 MPa, considerably lower than the 6 MPa observed for the plain weave pad. In addition, the stress distribution of the slurry in the system was more random and uniform, which optimized the stress transfer and diffusion efficiency throughout the overall polishing system and promoted uniform material removal.
In conclusion, this paper highlights the advantages of the disordered nonwoven polishing system in the precision processing of fused silica from both experimental and numerical perspectives. It also provides valuable insights for the analysis, design, and manufacturing practices of complex polishing systems involving fiber aggregate polishing pads, slurry, and workpieces.
Keywords
References
SUN H G, ZHANG Z Y, ZENG Z N, et al. Atomic level surface on aspheric quartz crucible with large sizes induced by developed green chemical mechanical polishing with composite rare earth oxides[J]. Surfaces and Interfaces, 2024, 52: 104924.
GUO J, SHI X L, SONG C P, et al. Theoretical and experimental investigation of chemical mechanical polishing of W-Ni-Fe alloy[J]. International Journal of Extreme Manufacturing, 2021, 3(2): 025103.
GUO X G, YUAN S, HUANG J X, et al. Effects of pressure and slurry on removal mechanism during the chemical mechanical polishing of quartz glass using ReaxFF MD[J]. Applied Surface Science, 2020, 505: 144610.
ZHANG Z Y, YAN J W, KURIYAGAWA T. Manufacturing technologies toward extreme precision[J]. International Journal of Extreme Manufacturing, 2019, 1(2): 022001.
ZHAO F, ZHANG Z Y, DENG X Q, et al. Atomic surface achieved through a novel cross-scale model from macroscale to nanoscale[J]. Nanoscale, 2024, 16(5): 2318-2336.
ZHENG J, FANG W C, LI C X, et al. The effect of slurry pH on the chemical mechanical planarization of a carbon-doped Ge2Sb2Te5 phase change material[J]. Journal of Materials Chemistry C, 2022, 10(44): 16739-16750.
ZHANG J, HONG R C, WANG H. 3D-printed functionally-graded lattice structure with tunable removal characteristics for precision polishing[J]. Additive Manufacturing, 2022, 59: 103152.
ZHOU P, SHI H S, WANG L, et al. A quantitative study of removal mechanism of copper polishing based on a single pad-asperity polishing test[J]. International Journal of Mechanical Sciences, 2023, 239: 107878.
ZHOU H, WANG D P, WANG B, et al. Study the application of pad in chemical mechanical polishing for sapphire wafer[J]. Machinery Design & Manufacture, 2009(8): 88-90. (in Chinese)
ZHANG J Q, ZHANG C H. Material removal model for non-contact chemical mechanical polishing[J]. Chinese Science Bulletin, 2008, 53(23): 3746-3752.
TSAI M Y, YAN L W. Characteristics of chemical mechanical polishing using graphite impregnated pad[J]. International Journal of Machine Tools and Manufacture, 2010, 50(12): 1031-1037.
ZHAO F, ZHANG Z Y, ZHOU H X, et al. Novel full-scale model verified by atomic surface and developed composite microfiber and slurry polishing system[J]. Composites Part B: Engineering, 2024, 283: 111598.
GÜRGEN S, SERT A. Polishing operation of a steel bar in a shear thickening fluid medium[J]. Composites Part B: Engineering, 2019, 175: 107127.
MU Q, GAO X, YAN Y, et al. Evolution of ring structures and method for inhibition in polishing of fused silica[J]. Applied Surface Science, 2024, 645: 158830.
WANG L, ZHOU P, YAN Y, et al. Physically-based modeling of pad-asperity scale chemical-mechanical synergy in chemical mechanical polishing[J]. Tribology International, 2019, 138: 307-315.
WANG L, ZHOU P, YAN Y, et al. Modeling the microscale contact status in chemical mechanical polishing process[J]. International Journal of Mechanical Sciences, 2022, 230: 107559.
LING T Y, WANG J, PUI D Y H. Numerical modeling of nanoparticle penetration through personal protective garments[J]. Separation and Purification Technology, 2012, 98: 230-239.
WU L W, ZHAO F, XIE J B, et al. The deformation behaviors and mechanism of weft knitted fabric based on micro-scale virtual fiber model[J]. International Journal of Mechanical Sciences, 2020, 187: 105929.
PARK S. Computational modeling for prediction of the shear stress of three-dimensional isotropic and aligned fiber networks[J]. Computer Methods and Programs in Biomedicine, 2017, 148: 91-98.
WU L W, ZHAO F, LU Z Q, et al. Impact energy absorption composites with shear stiffening gel-filled negative Poisson's ratio skeleton by Kirigami method[J]. Composite Structures, 2022, 298: 116009.
LIU C, XIE J B, SUN Y, et al. Micro-scale modeling of textile composites based on the virtual fiber embedded models[J]. Composite Structures, 2019, 230: 111552.
ZHAO F, WU L W, LU Z Q, et al. Design of shear thickening fluid/polyurethane foam skeleton sandwich composite based on non-Newtonian fluid solid interaction under low-velocity impact[J]. Materials & Design, 2022, 213: 110375.
MA W H, LI J H, HOU X. Rolling model analysis of material removal in elastic emission machining[J]. International Journal of Mechanical Sciences, 2023, 258: 108572.
CUI X X, ZHANG Z Y, SHI C J, et al. Atomic surface induced by novel green chemical mechanical polishing for aspheric thin-walled crucibles with large diameters[J]. Journal of Manufacturing Processes, 2024, 117: 59-70.
ZHANG Z X, GONG Y, XU J W, et al. Dissecting La2Ce2O7 catalyst to unravel the origin of the surface active sites devoting to its performance for oxidative coupling of methane (OCM)[J]. Catalysis Today, 2022, 400-401: 73-81.
DAVIS K M, TOMOZAWA M. An infrared spectroscopic study of water-related species in silica glasses[J]. Journal of Non-Crystalline Solids, 1996, 201(3): 177-198.
ZHANG W F, ZHANG P X, LIU F, et al. Simultaneous oxidation of Cr(Ⅲ) and extraction of Cr(Ⅵ) from chromite ore processing residue by silicate-assisted hydrothermal treatment[J]. Chemical Engineering Journal, 2019, 371: 565-574.
HE S, RUAN C C, SHI Y J, et al. Insight to hydrophobic SiO2 encapsulated SiO2 gel: Preparation and application in fire extinguishing[J]. Journal of Hazardous Materials, 2021, 405: 124216.
XU G H, ZHANG Z Y, MENG F N, et al. Atomic-scale surface of fused silica induced by chemical mechanical polishing with controlled size spherical ceria abrasives[J]. Journal of Manufacturing Processes, 2023, 85: 783-792.
RITZ M, VALÁŠKOVÁ M. Infrared and Raman spectroscopy of three commercial vermiculites doped with cerium dioxide nanoparticles[J]. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2018, 201: 39-45.
SHI C J, FAN Y H, ZHANG Z Y, et al. Development of core-shell SiO2@A-TiO2 abrasives and novel photocatalytic chemical machinal polishing for atomic surface of fused silica[J]. Applied Surface Science, 2024, 652: 159293.
LIU J, ZHANG Z Y, SHI C J, et al. Novel green chemical mechanical polishing of fused silica through designing synergistic CeO2/h-BN abrasives with lubricity[J]. Applied Surface Science, 2023, 637: 157978.
LIU Z S, ZHANG Z Y, SUI Y F, et al. Development of mesoporous abrasives and its unprecedented polishing performance elucidated by a novel atomic model[J]. Materials Today Sustainability, 2024, 25: 100700.
LI C S, DING J J, ZHANG L C, et al. Densification effects on the fracture in fused silica under Vickers indentation[J]. Ceramics International, 2022, 48(7): 9330-9341.
KERMOUCHE G, BARTHEL E, VANDEMBROUCQ D, et al. Mechanical modelling of indentation-induced densification in amorphous silica[J]. Acta Materialia, 2008, 56(13): 3222-3228.
京公网安备11010802044758号