Nanoparticle Engineering for Chemical-Mechanical Planarization

Increasing reliance on electronic devices demands products with high performance and efficiency. Such devices can be realized through the advent of nanoparticle technology. This book explains the physicochemical properties of nanoparticles according to each step in the chemical mechanical planarization (CMP) process, including dielectric CMP, shallow trend isolation CMP, metal CMP, poly isolation CMP, and noble metal CMP. The authors provide a detailed guide to nanoparticle engineering of novel CMP slurry for next-generation nanoscale devices below the 60nm design rule. This comprehensive text also presents design techniques using polymeric additives to improve CMP performance

Nanoparticle Engineering for Chemical-Mechanical Planarization

Increasing reliance on electronic devices demands products with high performance and efficiency. Such devices can be realized through the advent of nanoparticle technology. This book explains the physicochemical properties of nanoparticles according to each step in the chemical mechanical planarization (CMP) process, including dielectric CMP, shallow trend isolation CMP, metal CMP, poly isolation CMP, and noble metal CMP. The authors provide a detailed guide to nanoparticle engineering of novel CMP slurry for next-generation nanoscale devices below the 60nm design rule. This comprehensive text also presents design techniques using polymeric additives to improve CMP performance

Fumed Silica-Based Ultra-High-Purity Synthetic Quartz Powder via Sol–Gel Process for Advanced Semiconductor Process beyond Design Rule of 3 nm

Fumed silica-based ultra-high-purity synthetic quartz powder was developed via the sol–gel process to apply to quartz wares and quartz crucibles for use in advanced semiconductor processes. The process conditions of preparing potassium silicate solution, gelation, and cleaning were optimized, i.e., the relative ratio of fumed silica (10 wt%) to KOH (4 wt%) for potassium silicate solution, gelation time 3 h, and cleaning for 1 h with 5 wt% HCl solution. It was observed that the gelation time strongly affected the size distribution of the quartz powder; i.e., a longer gelation time led to a larger size (d50) of the synthesized quartz powder: 157 μm for 2 h and 331 μm for 5 h. In particular, it was found that the morphology of the as-synthesized quartz powder greatly depended on the pulverizing process; i.e., the shape of quartz powder was shown to be rod-shaped for the without-gel-pulverizing process and granular-shaped with the process. We expect that the fumed silica-based ultra-high-purity quartz powder with an impurity level of 74.1 ppb synthesized via the sol–gel process is applicable as a raw material for quartz wares and crucibles for advanced semiconductor processes beyond the design rule of 3 nm

Effect of dispersant addition during ceria abrasive milling process on light point defect (LPD) formation after shallow trench isolation chemical mechanical polishing (STI-CMP)

We examined both the dispersant mixing time during ceria slurry synthesis and a method for reducing the quantity of agglomerated large particles, which influence the number of light point defects (LPDs) formed after chemical mechanical polishing (CMP). We quantified the dispersion stability of slurries with the abrasive particle size by examining with and without ultra-sonic treatment. Without the addition of dispersant before mechanical milling, the dispersion stability was worse than the case with dispersant addition before milling. A lower pH of cerium carbonate improved both the dispersion stability and reduced the number of LPDs formed on an oxide film after CMP.

The effect of cerium precursor agglomeration on the synthesis of ceria particles and its influence on shallow trench isolation chemical mechanical polishing performance

The level of agglomeration in the cerium precursor and its effect on the physicochemical properties of the synthesized ceria particles and how these properties influence shallow trench isolation chemical mechanical polishing (STI CMP) performance were investigated. Two different types of ceria particles were synthesized from cerium precursors of different degrees of agglomeration. The crystallinity and particle size distribution of the synthesized ceria particles were markedly different between these two types of particles. The ceria particles synthesized from agglomerated cerium precursors had a smaller crystallite size than the other particles due to the incomplete decarbonation reaction, which resulted in large agglomerations of particles. The different physical characteristics of the ceria particles resulted in remarkable discrepancies between the STI CMP performances of the ceria slurries, such as the oxide removal rate, the selectivity and the uniformity.

Effect of calcination process on synthesis of ceria particles, and its influence on shallow trench isolation chemical mechanical planarization performance

The effect of the calcination process for cerium carbonate, a precursor of ceria, on the degree of synthesis and colloidal properties of ceria particles in aqueous media, which greatly influence shallow trench isolation (STI) chemical mechanical planarization (CMP) performance, was investigated. A two-step calcination process, consisting of decarbonation and crystal growth, resulted in a higher degree of synthesis for the same crystal size, a narrower particle size distribution, and better dispersion of the ceria particles, than conventional one-step calcination. These properties enhanced certain aspects of STI CMP performance, leading to a higher oxide removal rate, a better selectivity between oxide and nitride, and fewer defects, including remaining particles.