Impact of sodium carboxymethyl cellulose on redispersibility and polishing performance of lanthanum-cerium-based slurry containing sodium hexametaphosphate  

作　　者：Ning Wang Huiqing Han Zhenyu Zhang Zongyu Feng Xianmin Tan Yuanyuan Zheng Juanyu Yang Xiaowei Huang 

机构地区：[1]National Engineering Research Center for Rare Earth,Grirem Advanced Materials Co.,Ltd.,Beijing,100088,China [2]Rare Earth Functional Materials(Xiong'an)Innovation Center Co.,Ltd.,Xiong'an,071700,China [3]Grirem Hi-Tech Co.,Ltd.,Langfang,065201,China [4]General Research Institute for Nonferrous Metals,Beijing,100088,China

出　　处：《Journal of Rare Earths》2025年第4期851-858,I0008,共9页稀土学报(英文版)

基　　金：supported by the National Key Research and Development Program(2021YFB3501103);Guiding Local Funding Projects for Scientific and Technological Development by Central Government in Hebei(216Z1402G);Youth Fund of GRINM Group Co.,Ltd.

摘　　要：The lanthanum-cerium-based slurry(LC-slurry)is extensively utilized in the chemical mechanical polishing(CMP)of TFT-LCD glass substrates,optical lenses,and other glass products.Sodium hexametaphosphate(SHMP),as a dispersant,is commonly employed to enhance the dispersion properties of LCslurry for improved polishing performance.However,the tendency of sedimentation to form a compacted sediment layer,which is challenging to redisperse,increases storage difficulty and polishing equipment failure risk,thereby limiting its utilization in CMP.In the present study,sodium carboxymethylcellulose(CMC-Na),a long-chain organic polymer,was employed to enhance the redispersibility of LC-slurry containing SHMP.A comprehensive investigation was conducted on the influence of CMC-Na dosage and slurry pH on dispersibility,redispersibility and polishing performance.Additionally,an analysis was carried out to elucidate the underlying mechanism behind the effect of CMC-Na.The study demonstrates that the LC-slurry,containing 250 ppm SHMP and 500 ppm CMC-Na,exhibits excellent dispersibility and redispersibility.Further polishing tests demonstrate that compared to the LC-slurry containing only SHMP,utilizing the slurry containing both SHMP and CMC-Na at various pH for polishing thin film transistor liquid crystal display(TFT-LCD)glass substrates results in a reduction of both material removal rate(MRR)and surface roughness(Sa).Specifically,when adjusting the slurry to a pH range of 5-6,the MRR can reach up to 330 nm/min,which closely approximates the MRR achieved by LC-slurry containing only 250 ppm SHMP at corresponding pH values.Meanwhile,after polishing,the surface roughness of the glass substrate measures approximately 0.47 nm.

关 键 词：Lanthanum-cerium-based slurry Sodium hexametaphosphate Sodium carboxymethyl cellulose Redispersibility Chemical mechanical polishing Rare earths 

分 类 号：TQ174[化学工程—陶瓷工业]