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Face-centered-cubic crystallized super-fine (~ 2 nm in size) wet-ceria-abrasives are synthesized using a novel wet precipitation process that comprises a Ce 4+ precursor, C 3 H 4 N 2 catalyst, and NaOH titrant for a synthesized termination process at temperature of at temperature of 25 °C. This process overcomes the limitations of chemical–mechanical-planarization (CMP)-induced scratches from conventional dry ceria abrasives with irregular surfaces or wet ceria abrasives with crystalline facets in nanoscale semiconductor devices. The chemical composition of super-fine wet ceria abrasives depends on the synthesis termination pH, that is, Ce(OH) 4 abrasives at a pH of 4.0–5.0 and a mixture of CeO 2 and Ce(OH) 4 abrasives at a pH of 5.5–6.5. The Ce(OH) 4 abrasives demonstrate better abrasive stability in the SiO 2 -film CMP slurry than the CeO 2 abrasives and produce a minimum abrasive zeta potential (~ 12 mV) and a minimum secondary abrasive size (~ 130 nm) at the synthesis termination pH of 5.0. Additionally, the abrasive stability of the SiO 2 -film CMP slurry that includes super-fine wet ceria abrasives is notably sensitive to the CMP slurry pH; the best abrasive stability (i.e., a minimum secondary abrasive size of ~ 130 nm) is observed at a specific pH (6.0). As a result, a maximum SiO 2 -film polishing rate (~ 524 nm/min) is achieved at pH 6.0, and the surface is free of stick-and-slip type scratches.

In this study, the chemical decomposition of a polyimide-film (i.e., a PI-film)-surface into a soft-film-surface containing negatively charged pyromellitic dianhydride (PMDA) and neutral 4,4′-oxydianiline (ODA) was successfully performed. The chemical decomposition was conducted by designing the slurry containing 350 nm colloidal silica abrasive and small molecules with amine functional groups (i.e., ethylenediamine: EDA) for chemical–mechanical planarization (CMP). This chemical decomposition was performed through two types of hydrolysis reactions, that is, a hydrolysis reaction between OH − ions or R-NH 3 + (i.e., EDA with a positively charged amine groups) and oxygen atoms covalently bonded with pyromellitimide on the PI-film-surface. In particular, the degree of slurry adsorption of the PI-film-surface was determined by the EDA concentration in the slurry because of the presence of R-NH 3 + , that is, a higher EDA concentration resulted in a higher degree of slurry adsorption. In addition, during CMP, the chemical decomposition degree of the PI-film-surface was principally determined by the EDA concentration; that is, the degree of chemical composition was increased noticeably and linearly with the EDA concentration. Thus, the polishing-rate of the PI-film-surface increased notably with the EDA concentration in the CMP slurry.

The rapid advancement of 3D packaging technology has emerged as a key solution to overcome the scaling-down limitation of advanced memory and logic devices. Redistribution layer (RDL) fabrication, a critical process in 3D packaging, requires the use of polyimide (PI) films with thicknesses in the micrometer range. However, these polyimide films present surface topography variations in the range of hundreds of nanometers, necessitating chemical–mechanical planarization (CMP) to achieve nanometer-level surface flatness. Polyimide films, composed of copolymers of pyromellitimide and diphenyl ether, possess strong covalent bonds such as C–C, C–O, C=O, and C–N, leading to inherently low polishing rates during CMP. To address this challenge, the introduction of Fe(NO3)3 into CMP slurries has been proposed as a polishing rate accelerator. During CMP, this Fe(NO3)3 deformed the surface of a polyimide film into strongly positively charged 1,2,4,5-benzenetetracarbonyliron and weakly negatively charged 4,4′-oxydianiline (ODA). The chemically dominant polishing rate enhanced with the concentration of the Fe(NO3)3 due to accelerated surface interactions. However, higher Fe(NO3)3 concentrations reduce the attractive electrostatic force between the positively charged wet ceria abrasives and the negatively charged deformed surface of the polyimide film, thereby decreasing the mechanically dominant polishing rate. A comprehensive investigation of the chemical and mechanical polishing rate dynamics revealed that the optimal Fe(NO3)3 concentration to achieve the maximum polyimide film removal rate was 0.05 wt%.

To satisfy the superior surface quality requirements in the fabrication of HBM (High-Bandwidth Memory) and 3D NAND Flash Memory, high-efficiency Si chemical mechanical planarization (CMP) is essential. In this study, a colloidal silica abrasive-based Si-wafer CMP slurry was developed to simultaneously achieve a high polishing rate (≥10 nm/min) and low surface roughness (≤0.2 nm) without inducing CMP-induced scratches. The proposed Si-wafer CMP slurry incorporates two functional components: triammonium phosphate (TAP) as a hydrolysis reaction accelerator and hydroxyethyl cellulose (HEC) as an abrasive drag force accelerator. The polishing rate enhancement mechanism of TAP was analyzed by monitoring the OH− mol concentration, surface adsorption behavior, and XPS spectra. The results showed that increasing the TAP concentration raised the OH− mol concentration and converted Si–Si and Si–O–Si bonds to Si–OH via a hydrolysis reaction, thereby increasing the polishing rate. However, excessive hydrolysis also led to increased surface roughness. On the other hand, HEC influenced slurry viscosity, abrasive dispersibility, and drag force. At low HEC concentrations, increased abrasive drag force improved the polishing rate. At high concentrations, however, HEC formed a hindrance layer on the Si surface via hydrogen bonding and condensation reactions, reducing the effective contact area of abrasives and thus decreasing the polishing rate. By optimizing the concentrations of TAP (0.0037 wt%) and HEC (≤0.0024 wt%), the proposed slurry formulation achieved high-performance Si-wafer CMP, satisfying both surface roughness and polishing rate targets required for advanced memory packaging applications.

A Fenton reaction and a corrosion inhibition strategy were designed for enhancing the polishing rate and achieving a corrosion-free Ge1Sb4Te5 film surface during chemical-mechanical planarization (CMP) of three-dimensional (3D) cross-point phase-change random-access memory (PCRAM) cells and 3D cross-point synaptic arrays. The Fenton reaction was conducted with 1,3-propylenediamine tetraacetic acid, ferric ammonium salt (PDTA–Fe) and H2O2. The chemical oxidation degree of GeO2, Sb2O3, and TeO2 evidently increased with the PDTA–Fe concentration in the CMP slurry, such that the polishing rate of the Ge1Sb4Te5 film surface linearly increased with the PDTA–Fe concentration. The addition of a corrosion inhibitor having protonated amine functional groups in the CMP slurry remarkably suppressed the corrosion degree of the Ge1Sb4Te5 film surface after CMP; i.e., the corrosion current of the Ge1Sb4Te5 film surface linearly decreased as the corrosion inhibitor concentration increased. Thus, the proposed Fenton reaction and corrosion inhibitor in the Ge1Sb4Te5 film surface CMP slurry could achieve an almost recess-free Ge1Sb4Te5 film surface of the confined-PCRAM cells, having an aspect ratio of 60-nm-height to 4-nm-diameter after CMP.

Current guidelines to treat atopic dermatitis (AD) overlook disease heterogeneity, limiting personalized care. This study assessed NuGel, a topical GPCR19 agonist, for efficacy, safety, and predictive baseline biomarkers in AD patients. In a multicenter, double-blind, randomized, placebo-controlled Phase 2a trial (August 2020-September 2021, five hospitals, 80 participants), patients received placebo, 0.3% NuGel, or 0.5% NuGel twice daily for four weeks. NuGel (0.3% [Nu0.3] and 0.5% [Nu0.5]) was well-tolerated, with no adverse drug reactions or serious adverse events. Nu0.3 showed a significant decrease in EASI score from baseline (-12.2%, [-30.3%, 5.9%], p = 0.04). Treatment with Nu0.5 resulted in a numerically decreased EASI score (-11.9%, [-34.9%, 11.1%], p > 0.05), which is comparable with placebo group (-2.9%, [-21.5%, 15.6%], p > 0.05). No significant difference was observed between groups (p>0.05). Plasma proteomic analysis identified biomarkers associated with blood coagulation, complement activation, and cell adhesion as predictors of response to Nu0.5. Patients with baseline profiles characterized by K2C5 , ENTP6 , or CRK demonstrated significant clinical improvement when treated with Nu0.5 compared to the placebo group. Among these, the CRK subgroup, comprising 54.3% of the biomarker analysis set, showed a ΔEASI of -61.3% [-99.9, -22.8; p = 0.003] and a ΔIGA of -35.2% [-58.2, -12.1; p = 0.004] compared to the placebo group. The biomarker signature demonstrated high predictive accuracy (AUC = 0.92, p = 0.002). Logistic regression analysis revealed that the threshold of predicted probability derived from the baseline plasma level of K2C5 and ENTP6 successfully stratified 100% of participants who responded to Nu0.5 (ΔEASI from baseline ≤ -50%), whereas none (0%) in the placebo group responded (p = 0.035). Baseline biomarkers, such as K2C5, ENTP6, and CRK, may serve as predictors of clinical improvement in AD patients treated with Nu0.5, highlighting the potential for personalized treatment strategies. Further research is required to validate these findings in larger patient cohorts. https://clinicaltrials.gov/, identifier NCT04530643.