{"id":2588,"date":"2026-08-06T13:44:22","date_gmt":"2026-08-06T05:44:22","guid":{"rendered":"https:\/\/jeez-semicon.com\/?p=2588"},"modified":"2026-08-06T13:44:22","modified_gmt":"2026-08-06T05:44:22","slug":"colloidal-silica-slurry-for-oxide-cmp-optimizing-sti-and-ild-planarization","status":"publish","type":"post","link":"https:\/\/jeez-semicon.com\/ru\/blog\/colloidal-silica-slurry-for-oxide-cmp-optimizing-sti-and-ild-planarization\/","title":{"rendered":"Colloidal Silica Slurry for Oxide CMP: Optimizing STI and ILD Planarization"},"content":{"rendered":"<style>\n@import url('https:\/\/fonts.googleapis.com\/css2?family=Sora:wght@400;500;600;700&family=IBM+Plex+Sans:ital,wght@0,400;0,500;0,600;1,400&display=swap');\n.jcs-wrap *{box-sizing:border-box}.jcs-wrap{font-family:'IBM Plex Sans',system-ui,sans-serif;font-size:16px;line-height:1.8;color:#1a1a2e;max-width:920px;margin:0 auto}\n.jcs-wrap 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2.1rem;border-radius:6px;text-decoration:none}\n.jcs-cta-btn:hover{opacity:.9;color:#0b1840;text-decoration:none}\n.jcs-hr{border:none;border-top:1px solid #e2e8f0;margin:2.25rem 0}\n.jcs-footnote{font-size:.82rem;color:#64748b;line-height:1.65;margin-top:1.75rem}\n.jcs-footnote strong{color:#475569}\n@media(max-width:600px){.jcs-hero{padding:1.75rem 1.4rem}.jcs-cta{padding:1.75rem 1.4rem}.jcs-wrap h2{font-size:1.15rem}}\n<\/style>\n\n<article class=\"jcs-wrap\">\n<div class=\"jcs-hero\">\n  <span class=\"jcs-hero-tag\">Application Guide \u00b7 Cluster C-03<\/span>\n  <p>A detailed technical guide for process engineers on how colloidal silica slurry is formulated and optimized for shallow trench isolation (STI) and interlayer dielectric (ILD) oxide CMP\u2014covering selectivity additive chemistry, Preston equation parameters, endpoint detection, and defect mitigation.<\/p>\n  <div class=\"jcs-hero-meta\">\n    <span class=\"jcs-meta-pill\">\ud83d\udcc5 <b>August 2026<\/b><\/span>\n    <span class=\"jcs-meta-pill\">\u23f1 <b>~15 min read<\/b><\/span>\n    <span class=\"jcs-meta-pill\">\u270d <b>JEEZ Technical Team<\/b><\/span>\n  <\/div>\n<\/div>\n<span class=\"jcs-updated\">Published by Jizhi Electronic Technology Co., Ltd. (JEEZ) \u00b7 August 2026<\/span>\n\n<nav class=\"jcs-toc\" aria-label=\"\u041e\u0433\u043b\u0430\u0432\u043b\u0435\u043d\u0438\u0435\">\n  <p class=\"jcs-toc-label\">\u041e\u0433\u043b\u0430\u0432\u043b\u0435\u043d\u0438\u0435<\/p>\n  <ol>\n    <li><a href=\"#oxide-cmp-context\">Oxide CMP in the Semiconductor Process Flow<\/a><\/li>\n    <li><a href=\"#sti-requirements\">STI CMP: Technical Requirements and Challenges<\/a><\/li>\n    <li><a href=\"#ild-requirements\">ILD and PMD CMP: Requirements<\/a><\/li>\n    <li><a href=\"#slurry-formulation\">Slurry Formulation for High Selectivity<\/a><\/li>\n    <li><a href=\"#process-parameters\">Process Parameter Optimization<\/a><\/li>\n    <li><a href=\"#endpoint\">Endpoint Detection in STI CMP<\/a><\/li>\n    <li><a href=\"#defect-mitigation\">Defect Mitigation in Oxide CMP<\/a><\/li>\n    <li><a href=\"#jeez-products\">JEEZ Product Recommendations<\/a><\/li>\n    <li><a href=\"#faq\">\u0427\u0430\u0441\u0442\u043e \u0437\u0430\u0434\u0430\u0432\u0430\u0435\u043c\u044b\u0435 \u0432\u043e\u043f\u0440\u043e\u0441\u044b<\/a><\/li>\n  <\/ol>\n<\/nav>\n\n<p>Silicon dioxide CMP is the highest-volume CMP application in semiconductor manufacturing, performed dozens of times per wafer across front-end-of-line (FEOL), middle-of-line (MOL), and back-end-of-line (BEOL) process flows. From the shallow trench isolation (STI) step that defines transistor active areas, to the multiple interlayer dielectric (ILD) planarization steps between metal wiring layers, oxide CMP with colloidal silica slurry is a foundational process at every technology node. Getting it right\u2014meaning consistent removal rate, tight within-wafer uniformity, adequate selectivity, and controlled defectivity\u2014has a direct, measurable impact on device yield and performance.<\/p>\n\n<p>This guide focuses specifically on how colloidal silica slurry is formulated and optimized for STI and ILD oxide CMP applications, providing actionable guidance on selectivity chemistry, process parameters, endpoint detection, and defect control.<\/p>\n\n<section id=\"oxide-cmp-context\">\n  <h2>1. Oxide CMP in the Semiconductor Process Flow<\/h2>\n  <p>Oxide CMP steps can be broadly divided into two categories based on their technical requirements:<\/p>\n  <ul>\n    <li><strong>Stop-layer oxide CMP<\/strong>: A silicon nitride (Si\u2083N\u2084) or other material serves as a polish-stop layer. The SiO\u2082 must be removed to precisely this stop layer. High oxide\/nitride selectivity is essential. STI CMP and some MOL dielectric steps fall into this category.<\/li>\n    <li><strong>Non-selective oxide CMP<\/strong>: There is no stop layer; the polish runs for a fixed time or to a target film thickness measured in-situ. Removal rate uniformity and planarization efficiency are the primary concerns. ILD, PMD, and most BEOL pre-metal dielectric steps fall here.<\/li>\n  <\/ul>\n  <p>These two categories require fundamentally different slurry formulations. Stop-layer oxide CMP demands a high-selectivity formulation with carefully engineered polymer additive chemistry; non-selective oxide CMP uses simpler abrasive\/carrier systems where the focus is on MRR uniformity and defect control.<\/p>\n<\/section>\n\n<section id=\"sti-requirements\">\n  <h2>2. STI CMP: Technical Requirements and Challenges<\/h2>\n  <p>Shallow trench isolation (STI) is the standard CMOS device isolation technology from the 130 nm node onward. After the silicon trenches are etched and filled with CVD oxide (typically HDP-CVD SiO\u2082 or SACVD TEOS), the excess oxide overburden must be removed down to the Si\u2083N\u2084 hardmask layer. The key technical requirements for STI CMP are:<\/p>\n  <div class=\"jcs-box\">\n    <div class=\"jcs-box-label\">STI CMP Performance Targets<\/div>\n    <ul>\n      <li><strong>SiO\u2082 removal rate<\/strong>: 1,000\u20133,500 \u00c5\/min at standard CMP tool conditions (3\u20135 psi, 80\u2013120 rpm table speed)<\/li>\n      <li><strong>Oxide\/nitride selectivity<\/strong>: \u226520:1 minimum; \u226550:1 preferred for tight active-area-height control at nodes with \u22645 nm height budget<\/li>\n      <li><strong>Within-wafer uniformity (WIWNU)<\/strong>: \u22643% (1\u03c3) across 300 mm, measured at 49 sites with 5 mm edge exclusion<\/li>\n      <li><strong>Pattern-density loading effect<\/strong>: Minimized\u2014high-STI-density regions should not polish significantly faster than low-density regions<\/li>\n      <li><strong>Defectivity<\/strong>: Scratch count within the process-specific die-kill specification; LPD \u2264 the within-die process control limit<\/li>\n    <\/ul>\n  <\/div>\n  <p>The central challenge in STI CMP is achieving high oxide removal rate simultaneously with high selectivity to the Si\u2083N\u2084 hardmask. Without adequate selectivity, the nitride acts as a poor polish-stop, resulting in excessive erosion of the STI oxide fill and\u2014critically\u2014polishing into the nitride-protected silicon active area, which alters device threshold voltages.<\/p>\n  <p>An additional challenge is the pattern-density loading effect (also called the &#8220;micro-loading&#8221; effect): die areas with a high density of STI trenches (dense patterns) experience higher local removal rates than die areas with sparse STI patterns (isolated features). This is because the slurry has more SiO\u2082 surface area to react with in dense regions, and the pad-wafer contact dynamics differ between dense and isolated feature zones. Managing this effect requires slurry formulation optimization alongside pad selection and conditioning recipe tuning.<\/p>\n<\/section>\n\n<section id=\"ild-requirements\">\n  <h2>3. ILD and PMD CMP: Requirements<\/h2>\n  <p>Interlayer dielectric (ILD) CMP in BEOL processing and pre-metal dielectric (PMD) CMP in MOL share a simpler requirement profile than STI CMP\u2014primarily because most ILD\/PMD steps lack a nitride stop layer, eliminating the selectivity constraint. The primary ILD CMP objectives are:<\/p>\n  <ul>\n    <li><strong>Global planarization<\/strong>: Reducing the step height from underlying metal patterning to the flatness required for next-level photolithographic overlay\u2014typically WIWNU \u22643% and global step height \u226450 nm after CMP<\/li>\n    <li><strong>Low micro-scratch density<\/strong>: Scratches in the dielectric layer create void traps for subsequent metal fill, causing resistive interconnects or open circuits<\/li>\n    <li><strong>Dielectric integrity<\/strong>: For low-k SiCOH dielectrics (k &lt; 2.5), the slurry pH must be controlled below 11 to prevent hydrolytic attack of the Si-C backbone, which increases the dielectric constant<\/li>\n    <li><strong>Post-CMP surface cleanliness<\/strong>: Slurry particle residues and organic additive residues at the dielectric surface must be removed completely by the post-CMP clean, as they interfere with ALD barrier-metal nucleation at vias<\/li>\n  <\/ul>\n  <p>For ILD CMP with colloidal silica at 50\u201380 nm D50, typical removal rates are 500\u20131,500 \u00c5\/min at standard conditions\u2014adequate for typical ILD film thicknesses of 2,000\u20136,000 \u00c5 with acceptable cycle time.<\/p>\n<\/section>\n\n<section id=\"slurry-formulation\">\n  <h2>4. Slurry Formulation for High Selectivity in STI CMP<\/h2>\n  <p>Achieving STI oxide\/nitride selectivity above 20:1 with colloidal silica requires the addition of selectivity-enhancing polymer additives that preferentially suppress Si\u2083N\u2084 removal while leaving SiO\u2082 removal rate largely unaffected. The primary commercially used selectivity additive classes are:<\/p>\n  <h3>4.1 Polymeric Nitride Inhibitors<\/h3>\n  <p>Polyacrylic acid (PAA) and its copolymers are the most widely studied colloidal silica selectivity additives. PAA chains adsorb preferentially on Si\u2083N\u2084 surfaces (due to specific electrostatic and hydrogen-bonding interactions between the carboxylate groups and the amine-like surface species on Si\u2083N\u2084) while showing minimal adsorption on SiO\u2082. This preferential adsorption creates a protective polymer layer on Si\u2083N\u2084 that resists mechanical abrasion and chemical attack by the slurry, reducing Si\u2083N\u2084 MRR by 80\u201395% while SiO\u2082 MRR is reduced by only 10\u201320%\u2014yielding selectivities of 20:1 to 100:1 depending on PAA molecular weight and concentration.<\/p>\n  <p>Other nitride inhibitor polymers include poly-4-styrenesulfonic acid (PSS), polyvinyl alcohol (PVA), and various commercial proprietary copolymers. The choice of polymer affects not just selectivity but also defectivity (some polymers act as mild surfactants, reducing scratch rates) and post-CMP cleanability.<\/p>\n  <h3>4.2 pH as a Selectivity Lever<\/h3>\n  <p>In addition to polymeric inhibitors, pH adjustment is a secondary selectivity lever. The Si\u2083N\u2084 etch rate by aqueous hydroxide increases with pH above 11, while the SiO\u2082 etch rate plateaus at lower pH values. Operating at pH 10.0\u201310.5 (rather than 11.0\u201311.5) provides a mild secondary selectivity benefit by keeping Si\u2083N\u2084 chemical dissolution lower, and is the standard pH range for high-selectivity STI slurries.<\/p>\n  <h3>4.3 Additive Concentration Optimization<\/h3>\n  <p>The optimal inhibitor concentration is not simply &#8220;as high as possible.&#8221; At excess inhibitor concentration, the polymer begins to adsorb on SiO\u2082 surfaces as well (reducing oxide MRR below the process target) and can cause excessive particle bridging that increases LPC. The inhibitor loading must be co-optimized with the colloidal silica solids content and pH to achieve the target selectivity at the target oxide MRR.<\/p>\n  <div class=\"jcs-table-wrap\">\n    <table>\n      <thead><tr><th>PAA Concentration (wt%)<\/th><th>Approximate SiO\u2082:Si\u2083N\u2084 Selectivity<\/th><th>SiO\u2082 MRR Impact<\/th><\/tr><\/thead>\n      <tbody>\n        <tr><td>0 (no additive)<\/td><td>4:1 to 10:1<\/td><td>Baseline (100%)<\/td><\/tr>\n        <tr><td>0.01\u20130.05%<\/td><td>20:1 to 40:1<\/td><td>~5\u201310% reduction<\/td><\/tr>\n        <tr><td>0.05\u20130.15%<\/td><td>40:1 to 100:1<\/td><td>~10\u201320% reduction<\/td><\/tr>\n        <tr><td>&gt;0.20%<\/td><td>&gt;100:1 (nitride polish stop)<\/td><td>&gt;20% reduction; approaching oxide inhibition<\/td><\/tr>\n      <\/tbody>\n    <\/table>\n  <\/div>\n<\/section>\n\n<section id=\"process-parameters\">\n  <h2>5. Process Parameter Optimization<\/h2>\n  <p>Colloidal silica oxide CMP performance is sensitive to all standard Preston equation variables (pressure, velocity) plus slurry-specific variables. Key optimization considerations:<\/p>\n  <ul>\n    <li><strong>Down-force (pressure)<\/strong>: Higher pressure increases MRR proportionally (per Preston&#8217;s equation) but also increases defectivity risk and can cause pad glazing at sustained high pressures. Optimal range for colloidal silica oxide CMP is typically 2\u20134 psi. Lower pressure (&lt;1.5 psi) may produce non-linear MRR behavior as not all particles are in active contact.<\/li>\n    <li><strong>Table and head rotation speed<\/strong>: MRR increases with linear velocity (pad surface speed \u00d7 wafer carrier speed). Typical CMP tool settings of 60\u2013120 rpm table \/ 60\u2013120 rpm head provide linear velocities of 0.5\u20131.5 m\/s at wafer edge. Higher speeds improve planarization efficiency but can cause slurry hydroplaning on the pad at very high speeds.<\/li>\n    <li><strong>Slurry flow rate<\/strong>: Typically 100\u2013300 mL\/min for 300 mm CMP tools. Higher flow rates improve temperature control at the polishing interface but reduce slurry residence time on the pad. The minimum flow rate that maintains a continuous slurry film between pad and wafer is the practical lower limit.<\/li>\n    <li><strong>\u041a\u043e\u043d\u0434\u0438\u0446\u0438\u043e\u043d\u0435\u0440<\/strong>: In-situ conditioning rate (conditioner down-force, sweep speed, and duty cycle) determines the steady-state pad asperity population. More aggressive conditioning maintains higher asperity density, increasing effective MRR but also increasing defectivity from conditioning debris. Optimize conditioner sweep parameters for the target MRR\/defectivity balance.<\/li>\n    <li><strong>Slurry temperature<\/strong>: Most oxide CMP slurries are delivered at 20\u201325\u00b0C. Higher slurry temperature increases the chemical removal rate component, raising MRR; fab-to-fab slurry delivery temperature differences are a common source of MRR variation that is often underappreciated.<\/li>\n  <\/ul>\n<\/section>\n\n<section id=\"endpoint\">\n  <h2>6. Endpoint Detection in STI CMP<\/h2>\n  <p>Accurate endpoint detection is critical in STI CMP, where overpolishing (removing too much Si\u2083N\u2084) directly degrades device performance and underpolishing (leaving oxide overburden) causes step height issues for downstream lithography. Two primary endpoint methods are used with colloidal silica STI slurries:<\/p>\n  <h3>6.1 Motor Current (Friction) Endpoint<\/h3>\n  <p>The current drawn by the CMP table motor (or the wafer carrier motor) changes as the polishing surface transitions from oxide to nitride, because the friction coefficient between the pad and Si\u2083N\u2084 surface differs from pad-and-SiO\u2082. The oxide-to-nitride transition produces a characteristic change in the motor current signal\u2014typically a slight reduction in current as the smoother, harder nitride surface replaces the softer oxide. This signal change is detected algorithmically and used to trigger endpoint or to initiate a timed overpolish sequence.<\/p>\n  <h3>6.2 In-Situ Optical (Interferometric) Endpoint<\/h3>\n  <p>Optical in-situ endpoint systems use a laser beam projected through a transparent window in the polishing pad to measure the reflectance or film thickness of the polished surface in real time. As the oxide film thins, the interferometric signal oscillates and then transitions to the characteristic signal of the underlying nitride or silicon layer. Optical endpoint is more precise than motor current for tight active-area-height control but requires a compatible pad (with optical window) and appropriate slurry transparency at the measurement wavelength\u2014colloidal silica slurries are generally compatible with visible and near-IR optical endpoint systems.<\/p>\n<\/section>\n\n<section id=\"defect-mitigation\">\n  <h2>7. Defect Mitigation in Oxide CMP<\/h2>\n  <p>The most common oxide CMP-specific defects and their mitigation strategies with colloidal silica slurry:<\/p>\n  <ul>\n    <li><strong>Micro-scratches<\/strong>: Caused by large particles (LPC &gt;0.5 \u00b5m) in the slurry or pad debris. Mitigate with: low-LPC slurry specification (&lt;2,000 counts\/mL at &gt;0.5 \u00b5m for STI; &lt;800 for ILD); point-of-use filtration (500 nm filter); conditioning recipe optimization to minimize conditioner debris generation.<\/li>\n    <li><strong>SiO\u2082 residues (slurry residue defects)<\/strong>: Slurry particle residues not fully removed by post-CMP clean. Mitigate with: optimize post-CMP brush scrub chemistry (dilute SC1, citric acid); verify slurry particle pH is compatible with post-CMP clean surfactants; evaluate rinse sequence hold time.<\/li>\n    <li><strong>Dishing of STI oxide<\/strong>: Excessive removal of STI oxide in wide trench areas (dishing) relative to narrow trench areas. Caused by pattern-density loading combined with overpolish time. Mitigate with: optimize inhibitor concentration to increase STI oxide resistance to removal after nitride is reached; minimize overpolish time; use nitride-endpoint triggered time-controlled overpolish.<\/li>\n    <li><strong>Erosion of nitride (active area height loss)<\/strong>: Removal of Si\u2083N\u2084 in dense STI pattern areas during the main oxide removal step. Mitigate with: increase inhibitor concentration to raise oxide\/nitride selectivity; verify selectivity lot-to-lot consistency.<\/li>\n  <\/ul>\n  <div class=\"jcs-link-box\">\n    <span class=\"jcs-link-box-icon\">\u2192<\/span>\n    <span>For a detailed guide to CMP defect root-cause analysis, filtration strategy, and post-CMP clean integration: <a href=\"https:\/\/jeez-semicon.com\/ru\/blog\/Defect-Control-in-Colloidal-Silica-CMP-Minimizing-Scratches-LPDs-and-Particle-Contamination\/\" target=\"_blank\" rel=\"noopener noreferrer\">Defect Control in Colloidal Silica CMP: Minimizing Scratches, LPDs, and Particle Contamination<\/a><\/span>\n  <\/div>\n<\/section>\n\n<section id=\"jeez-products\">\n  <h2>8. JEEZ Product Recommendations for Oxide CMP<\/h2>\n  <p>For STI oxide CMP applications where high MRR and selectivity are required, the <strong>JEEZ CS-100 Series<\/strong> (D50 = 90\u2013110 nm, pH 10.0\u201311.5) is the appropriate platform. JEEZ offers this series with optional selectivity additive packages pre-formulated to achieve SiO\u2082:Si\u2083N\u2084 selectivities of 20:1 to 100:1 depending on the target process window. For ILD oxide CMP where the primary requirement is low defectivity at moderate MRR, the <strong>JEEZ CS-60 Series<\/strong> (D50 = 55\u201370 nm, pH 10.0\u201311.0) provides an optimal balance.<\/p>\n  <p>For the full colloidal silica application landscape and complete technical reference, see: <a href=\"https:\/\/jeez-semicon.com\/ru\/blog\/Colloidal-Silica-Slurry-The-Complete-Guide-to-CMP-Applications-Properties-and-Selection\/\" target=\"_blank\" rel=\"noopener noreferrer\">Colloidal Silica Slurry: The Complete Guide to CMP Applications, Properties, and Selection<\/a>.<\/p>\n  <div class=\"jcs-link-box\">\n    <span class=\"jcs-link-box-icon\">\u2192<\/span>\n    <span>Understand the fundamental science behind colloidal silica particles before diving into process optimization: <a href=\"https:\/\/jeez-semicon.com\/ru\/blog\/What-Is-Colloidal-Silica-Particles-Chemistry-and-How-It-Differs-from-Other-Abrasives\/\" target=\"_blank\" rel=\"noopener noreferrer\">What Is Colloidal Silica? Particles, Chemistry, and How It Differs from Other Abrasives<\/a><\/span>\n  <\/div>\n<\/section>\n\n<section id=\"faq\">\n  <h2>9. Frequently Asked Questions<\/h2>\n  <div class=\"jcs-faq-item\">\n    <div class=\"jcs-faq-q\">What is the typical oxide\/nitride selectivity achievable with colloidal silica for STI CMP?<\/div>\n    <div class=\"jcs-faq-a\"><p>Bare colloidal silica without additives achieves SiO\u2082:Si\u2083N\u2084 selectivity of 4:1 to 10:1. With polymeric inhibitors such as polyacrylic acid (PAA), selectivity can be increased to 20:1 to 100:1 or higher with appropriate additive loading. Advanced STI processes at sub-5 nm nodes may require selectivities of 50:1 to 200:1 to maintain the \u22645 nm active-area-height budget\u2014achievable with proprietary high-selectivity additive systems on a colloidal silica platform.<\/p><\/div>\n  <\/div>\n  <div class=\"jcs-faq-item\">\n    <div class=\"jcs-faq-q\">Why does the pattern density affect STI CMP removal rate?<\/div>\n    <div class=\"jcs-faq-a\"><p>The pattern-density loading effect in STI CMP arises from the interaction between pad asperity mechanics and oxide surface chemistry. In high-STI-density regions, a larger fraction of the wafer surface is oxide (vs. nitride), providing more reactive SiO\u2082 surface area per unit contact area. This increases the local chemical removal rate. Additionally, pad asperities conform more readily to the topography in dense regions, maintaining better abrasive contact. The combined effect is faster oxide removal in dense pattern areas, resulting in within-die active-area-height variation that must be managed through inhibitor chemistry, pad selection, and conditioning recipe design.<\/p><\/div>\n  <\/div>\n  <div class=\"jcs-faq-item\">\n    <div class=\"jcs-faq-q\">Can I use the same colloidal silica slurry for both STI and ILD CMP?<\/div>\n    <div class=\"jcs-faq-a\"><p>Using the same base slurry (abrasive type and particle size) is possible, but STI CMP requires selectivity additives that are not needed for ILD CMP, and the particle size optimum differs (80\u2013120 nm for STI, 50\u201380 nm for ILD). In practice, most fabs operate separate slurry formulations for STI and ILD CMP, even if the base colloidal silica is the same supplier. Using the high-selectivity STI formulation for ILD CMP is acceptable from a process standpoint but adds unnecessary slurry cost due to the polymer additive loading.<\/p><\/div>\n  <\/div>\n  <div class=\"jcs-faq-item\">\n    <div class=\"jcs-faq-q\">How does KOH vs NH\u2084OH pH adjustment affect STI CMP?<\/div>\n    <div class=\"jcs-faq-a\"><p>KOH provides a more stable pH buffer at the target pH 10\u201311 range and is widely used in STI slurries where K\u207a contamination is acceptable (it is not a diffusion contaminant in SiO\u2082 at FEOL temperatures typical of STI). NH\u2084OH is preferred for processes where K\u207a contamination specifications are stringent\u2014particularly for steps close to gate dielectric formation or for fabs with strict total ionic contamination controls. NH\u2084OH-adjusted slurries can exhibit slightly faster pH drift during storage due to NH\u2083 volatilization; verify shelf life with pH monitoring if NH\u2084OH-adjusted slurry is stored for more than 6 months.<\/p><\/div>\n  <\/div>\n<\/section>\n\n<div class=\"jcs-cta\">\n  <h2>Optimize Your Oxide CMP Process with JEEZ Slurry<\/h2>\n  <p>JEEZ CS-100 and CS-60 series colloidal silica slurries are available with optional selectivity additive packages for STI CMP and as clean abrasive-only formulations for ILD CMP. Request technical data sheets or sample quantities for process qualification.<\/p>\n  <a href=\"https:\/\/jeez-semicon.com\/ru\/contact\/\" class=\"jcs-cta-btn\" target=\"_blank\" rel=\"noopener noreferrer\">Contact JEEZ Application Engineering \u2192<\/a>\n<\/div>\n\n<hr class=\"jcs-hr\">\n<p class=\"jcs-footnote\">Published by <strong>Jizhi Electronic Technology Co., Ltd. (JEEZ)<\/strong> \u00b7 August 2026. For process-specific advice, <a href=\"https:\/\/jeez-semicon.com\/ru\/contact\/\" target=\"_blank\" rel=\"noopener noreferrer\">contact our application engineering team<\/a>.<\/p>\n<\/article>\n\n<script type=\"application\/ld+json\">\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"What is the typical oxide\/nitride selectivity achievable with colloidal silica for STI CMP?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Bare colloidal silica achieves 4:1 to 10:1 SiO2:Si3N4 selectivity. With PAA and other polymeric inhibitors, selectivity reaches 20:1 to 100:1 or higher. Advanced STI processes at sub-5 nm nodes may require 50:1 to 200:1\u2014achievable with proprietary high-selectivity additive systems on a colloidal silica abrasive platform.\"}},{\"@type\":\"Question\",\"name\":\"Why does the pattern density affect STI CMP removal rate?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"High-STI-density regions have more reactive SiO2 surface area per unit pad contact area, increasing local chemical removal rate. Pad asperities also conform better in dense regions, improving abrasive contact. The result is faster oxide removal in dense pattern areas\u2014managed through inhibitor chemistry, pad selection, and conditioning recipe design.\"}},{\"@type\":\"Question\",\"name\":\"Can I use the same colloidal silica slurry for both STI and ILD CMP?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Using the same base slurry is possible but suboptimal. STI CMP requires selectivity additives and typically 80\u2013120 nm D50; ILD CMP uses simpler formulations at 50\u201380 nm D50. Most fabs operate separate formulations. Using the high-selectivity STI formulation for ILD CMP adds unnecessary cost without benefit.\"}},{\"@type\":\"Question\",\"name\":\"How does KOH vs NH4OH pH adjustment affect STI CMP?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"KOH provides more stable pH buffering and is widely used where K+ contamination is acceptable. NH4OH is preferred for K+-sensitive processes near gate dielectric formation. NH4OH-adjusted slurries can show faster pH drift from NH3 volatilization; monitor pH regularly if stored more than 6 months.\"}}]}\n<\/script>","protected":false},"excerpt":{"rendered":"<p>Application Guide \u00b7 Cluster C-03 A detailed technical guide for process engineers on how colloidal silica slurry is formulated and optimized for shallow trench isolation (STI) and interlayer dielectric (ILD)  &#8230;<\/p>","protected":false},"author":1,"featured_media":2591,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[9,59],"tags":[],"class_list":["post-2588","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","category-industry"],"acf":[],"_links":{"self":[{"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/posts\/2588","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/comments?post=2588"}],"version-history":[{"count":2,"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/posts\/2588\/revisions"}],"predecessor-version":[{"id":2590,"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/posts\/2588\/revisions\/2590"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/media\/2591"}],"wp:attachment":[{"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/media?parent=2588"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/categories?post=2588"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jeez-semicon.com\/ru\/wp-json\/wp\/v2\/tags?post=2588"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}