{"id":2540,"date":"2026-07-30T15:46:49","date_gmt":"2026-07-30T07:46:49","guid":{"rendered":"https:\/\/jeez-semicon.com\/?p=2540"},"modified":"2026-07-30T15:46:49","modified_gmt":"2026-07-30T07:46:49","slug":"copper-cmp-removal-rate-preston-equation-key-variables-practical-optimization","status":"publish","type":"post","link":"https:\/\/jeez-semicon.com\/ja\/blog\/copper-cmp-removal-rate-preston-equation-key-variables-practical-optimization\/","title":{"rendered":"Copper CMP Removal Rate: Preston Equation, Key Variables &amp; Practical Optimization"},"content":{"rendered":"<style>\n@import url('https:\/\/fonts.googleapis.com\/css2?family=Space+Grotesk:wght@400;500;600;700;800&family=Inter:ital,wght@0,300;0,400;0,500;0,600;1,400&display=swap');\n.jz-cl*{box-sizing:border-box}.jz-cl{font-family:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;font-size:17px;line-height:1.75;color:#1e293b;max-width:860px;margin:0 auto}\n.jz-cl h1{font-family:'Space 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2rem;position:relative;overflow:hidden}\n.jz-cta::before{content:'';position:absolute;top:-70px;right:-70px;width:250px;height:250px;border-radius:50%;background:rgba(184,115,51,.06)}\n.jz-cta h2{font-family:'Space Grotesk',sans-serif;font-size:clamp(1.28rem,3vw,1.62rem);font-weight:800;color:#fff;margin:0 0 10px;border:none;padding:0;position:relative}\n.jz-cta p{opacity:.85;font-size:.96rem;margin:0 0 24px;position:relative}\n.jz-cta-btn{display:inline-block;background:#B87333;color:#fff;text-decoration:none;font-family:'Space Grotesk',sans-serif;font-weight:700;font-size:.97rem;padding:13px 32px;border-radius:8px;transition:background .2s,transform .15s;position:relative}\n.jz-cta-btn:hover{background:#9a6228;color:#fff;text-decoration:none;transform:translateY(-2px)}\n.jz-faq{border-top:1px solid #e2e8f0;margin:.8rem 0}.jz-faq-item{border-bottom:1px solid #f1f5f9;padding:1.15rem 0}\n.jz-faq-q{font-family:'Space Grotesk',sans-serif;font-weight:700;color:#0c2340;font-size:.96rem;margin:0 0 5px}\n.jz-faq-a{font-size:.91rem;color:#475569;margin:0;line-height:1.65}\n.jz-hr{border:none;border-top:1px solid #e2e8f0;margin:2.5rem 0}\n@media(max-width:640px){.jz-cl h1{font-size:1.7rem}.jz-cl h2{font-size:1.15rem}.jz-hero{padding:20px 18px}.jz-cta{padding:26px 20px}}\n<\/style>\n\n<div class=\"jz-cl\">\n\n<div class=\"jz-pillar-banner\">\n  <span>\ud83d\udcda<\/span>\n  <p>Part of the <strong>\u9285CMP\u30b9\u30e9\u30ea\u30fc<\/strong> knowledge series. For the complete process overview, see the <a href=\"https:\/\/jeez-semicon.com\/ja\/blog\/Copper-CMP-Slurry-Complete-Guide-Chemistry-Process-Optimization-Advanced-Node-Applications\/\" target=\"_blank\" rel=\"noopener noreferrer\">Copper CMP Slurry: Complete Guide<\/a>.<\/p>\n<\/div>\n\n\n<div class=\"jz-hero\">\n  <p>Material removal rate (RR) is the primary throughput driver in copper CMP \u2014 and one of the most complex performance metrics to optimize. It depends simultaneously on slurry chemistry, mechanical machine parameters, pad condition, and wafer pattern density. This article explains the foundational Preston equation model, identifies the key chemical and mechanical variables that drive removal rate in copper CMP, and provides <strong>practical optimization guidance<\/strong> for process engineers aiming to maximize throughput while keeping within-wafer non-uniformity (WIWNU) within specification.<\/p>\n<\/div>\n\n<div class=\"jz-toc\">\n  <p class=\"jz-toc-hd\">\u76ee\u6b21<\/p>\n  <ol>\n    <li><span class=\"jz-toc-n\">01.<\/span><a href=\"#importance\">Why Copper CMP Removal Rate Matters<\/a><\/li>\n    <li><span class=\"jz-toc-n\">02.<\/span><a href=\"#preston\">The Preston Equation: Foundation and Limitations<\/a><\/li>\n    <li><span class=\"jz-toc-n\">03.<\/span><a href=\"#chemistry-rr\">Chemical Contribution to Removal Rate<\/a><\/li>\n    <li><span class=\"jz-toc-n\">04.<\/span><a href=\"#mechanical\">Mechanical Parameters: Pressure, Velocity &amp; Pad State<\/a><\/li>\n    <li><span class=\"jz-toc-n\">05.<\/span><a href=\"#flow\">Slurry Flow Rate &amp; POU Delivery<\/a><\/li>\n    <li><span class=\"jz-toc-n\">06.<\/span><a href=\"#wiwnu\">WIWNU Optimization Strategies<\/a><\/li>\n    <li><span class=\"jz-toc-n\">07.<\/span><a href=\"#advanced\">Advanced-Node Constraints on Removal Rate<\/a><\/li>\n    <li><span class=\"jz-toc-n\">08.<\/span><a href=\"#faq\">\u3088\u304f\u3042\u308b\u8cea\u554f<\/a><\/li>\n  <\/ol>\n<\/div>\n\n<h2 id=\"importance\">1. Why Copper CMP Removal Rate Matters<\/h2>\n<p>In a high-volume 300 mm fab, the CMP module is typically one of the top three throughput bottlenecks in the BEOL process flow. A copper CMP Step 1 process that must remove 600 nm of copper at 200 nm\/min will occupy a polishing head for three minutes \u2014 while a process achieving 400 nm\/min completes the same job in 90 seconds, doubling effective tool capacity. At a production scale of tens of thousands of wafer starts per month, this difference translates directly into capital expenditure (fewer CMP tools needed) and operational cost (lower cost per wafer).<\/p>\n<p>However, removal rate cannot be maximized in isolation. Three coupled performance metrics constrain the operating envelope:<\/p>\n<ul>\n  <li><strong>Within-wafer non-uniformity (WIWNU):<\/strong> A higher removal rate achieved through excessive pressure often comes at the cost of worse WIWNU \u2014 the radial and azimuthal variation in copper thickness remaining after polishing.<\/li>\n  <li><strong>Defect count:<\/strong> Aggressive polishing conditions (high pressure, high velocity, excess oxidizer) increase surface scratch density and micro-roughness.<\/li>\n  <li><strong>Dishing and erosion:<\/strong> Over-fast Step 1 processes that over-shoot the endpoint leave too little copper for Step 2 to clear uniformly, or \u2014 if the endpoint is mistimed \u2014 expose the barrier metal prematurely, causing topographic disturbance.<\/li>\n<\/ul>\n<p>The practical optimization goal is to find the highest removal rate that keeps all three secondary metrics within their process specifications simultaneously.<\/p>\n\n<h2 id=\"preston\">2. The Preston Equation: Foundation and Limitations<\/h2>\n<p>The Preston equation, originally developed for glass polishing in the 1920s, remains the foundational model for CMP removal rate:<\/p>\n<div class=\"jz-formula\"><strong>RR = K<sub>p<\/sub> \u00d7 P \u00d7 V<\/strong><\/div>\n<p>where <strong>RR<\/strong> is the material removal rate (nm\/min), <strong>K<sub>p<\/sub><\/strong> is the Preston coefficient (a material- and slurry-specific proportionality constant, units of nm\u00b7min\u207b\u00b9\u00b7kPa\u207b\u00b9\u00b7(m\/s)\u207b\u00b9), <strong>P<\/strong> is the applied downforce pressure (kPa), and <strong>V<\/strong> is the relative velocity between the wafer and pad surface (m\/s).<\/p>\n<p>For copper CMP, the Preston equation is useful as a first-order model but fails in several important regimes:<\/p>\n<ul>\n  <li><strong>Chemical saturation:<\/strong> Above a threshold oxidizer concentration, the copper surface becomes fully oxidized between asperity contact events, and further increasing oxidizer concentration does not increase RR \u2014 only static etch rate. The model predicts linear RR increase with oxidizer concentration, which is not observed experimentally.<\/li>\n  <li><strong>High-pressure non-linearity:<\/strong> Above approximately 5 psi (34 kPa), the pad&#8217;s elastic contact mechanics change, the slurry hydrodynamic film between pad and wafer collapses, and RR increases more slowly than the Preston model predicts.<\/li>\n  <li><strong>Low-pressure chemical dominance:<\/strong> Below approximately 0.5 psi (3.5 kPa) \u2014 required for ELK dielectric compatibility at advanced nodes \u2014 chemical dissolution becomes rate-limiting rather than mechanical abrasion, and the mechanical term in the Preston equation underweights the chemical contribution.<\/li>\n<\/ul>\n<p>A more accurate model for copper CMP uses a modified Langmuir-Hinshelwood kinetic framework that treats the oxidation, passivation, and mechanical removal as parallel rate processes, each with its own concentration and pressure dependence. In practice, however, the Preston equation remains the standard for first-pass process window estimation and fab-to-fab transfer because of its simplicity and the limited availability of kinetic constants for the full mechanistic model.<\/p>\n\n<h2 id=\"chemistry-rr\">3. Chemical Contribution to Removal Rate<\/h2>\n<p>The chemical component of copper CMP removal rate is determined primarily by the slurry&#8217;s oxidizer concentration, complexing agent activity, and corrosion inhibitor loading. These three parameters define the <strong>chemical removal rate envelope<\/strong> \u2014 the maximum rate achievable at any given mechanical condition.<\/p>\n\n<h3>Oxidizer Concentration Effects<\/h3>\n<p>Within the optimal range (typically 1\u20133 wt% H\u2082O\u2082 for most copper CMP formulations), increasing oxidizer concentration increases both static etch rate and dynamic removal rate proportionally. The optimal oxidizer concentration is defined as the point where dynamic RR is maximized without static etch rate exceeding the dishing specification \u2014 typically &lt;1 nm\/min SER.<\/p>\n<p>The oxidizer optimum shifts with other formulation parameters: higher BTA loading requires higher H\u2082O\u2082 to overcome the passivation layer&#8217;s resistance, and lower pH generally allows lower oxidizer concentrations to achieve the same removal rate due to enhanced Cu\u00b2\u207a solubility in acidic conditions.<\/p>\n\n<h3>BTA Loading and Its Inverse Relationship with RR<\/h3>\n<p>BTA acts as a removal rate suppressant as well as a corrosion inhibitor \u2014 by forming a mechanically resistant passivation layer, it effectively requires greater mechanical energy to disrupt and achieve material removal. This inverse relationship between BTA concentration and removal rate is one of the most important process knobs in copper CMP:<\/p>\n<ul>\n  <li>At low BTA loading (0.001\u20130.005 wt%): high removal rate, high static etch rate, poor dishing control<\/li>\n  <li>At optimal BTA loading (0.01\u20130.05 wt%): balanced removal rate, SER &lt;1 nm\/min, good dishing control<\/li>\n  <li>At high BTA loading (&gt;0.1 wt%): low removal rate, very low SER, but process becomes throughput-limited<\/li>\n<\/ul>\n\n<h3>Complexing Agent Influence<\/h3>\n<p>Higher complexing agent (glycine) concentration increases removal rate by driving the Cu ion dissolution equilibrium forward more aggressively. However, as noted in the chemistry cluster article, glycine competes with BTA for copper surface sites, so increasing glycine concentration effectively shifts the optimal BTA concentration upward. In practical formulation work, glycine and BTA concentrations are co-optimized as a pair rather than as independent variables.<\/p>\n\n<h2 id=\"mechanical\">4. Mechanical Parameters: Pressure, Velocity &amp; Pad State<\/h2>\n<p>The mechanical parameters of the CMP process \u2014 downforce pressure, rotation speeds, and pad condition state \u2014 directly control the K<sub>p<\/sub> \u00d7 P \u00d7 V product in the Preston equation and are the primary tools available to the process engineer for in-fab removal rate adjustment without reformulating the slurry.<\/p>\n\n<h3>Downforce Pressure<\/h3>\n<p>Downforce is the most direct lever for removal rate adjustment. In the Preston-linear regime (0.5\u20135 psi for most copper CMP slurries), every 10% increase in downforce produces approximately a 10% increase in removal rate. Multi-zone carrier heads on production 300 mm CMP tools allow independent pressure control across 4\u20137 concentric wafer zones, enabling non-uniform pressure profiles that compensate for radial removal rate gradients and reduce WIWNU.<\/p>\n<p>At advanced nodes with ELK dielectric stacks, the maximum allowable downforce is constrained to &lt;1 psi (6.9 kPa) to prevent dielectric cracking and delamination. This constraint fundamentally limits throughput and requires slurry chemistry to compensate through enhanced chemical activity \u2014 a significant formulation challenge that has driven the development of JEEZ&#8217;s CuELK low-pressure slurry series.<\/p>\n\n<h3>Rotational Velocity<\/h3>\n<p>Both platen and carrier rotation speeds contribute to the relative velocity V. Standard copper CMP operates at 60\u2013120 rpm for both. The velocity distribution across a 300 mm wafer is inherently non-uniform due to the kinematics of orbital motion \u2014 the wafer center experiences lower relative velocity than the edge for any fixed platen and carrier RPM combination. This velocity non-uniformity is a primary contributor to WIWNU and is managed through:<\/p>\n<ul>\n  <li>Differential platen and carrier RPM settings that optimize the velocity uniformity profile<\/li>\n  <li>Multi-zone carrier pressure profiling that compensates for velocity-driven removal rate gradients<\/li>\n  <li>Slurry formulations with reduced K<sub>p<\/sub> pressure-sensitivity that minimize the amplification of velocity non-uniformity into removal rate non-uniformity<\/li>\n<\/ul>\n\n<h3>Pad Condition State and Conditioning<\/h3>\n<p>The polishing pad&#8217;s effective hardness and asperity height distribution \u2014 its &#8220;condition state&#8221; \u2014 is a major determinant of K<sub>p<\/sub> and therefore of removal rate at any given P and V. A freshly conditioned pad has high asperity density and relatively high K<sub>p<\/sub>; a glazed pad (asperities flattened by sustained polishing without conditioning) has a much lower effective K<sub>p<\/sub> and reduced slurry transport capacity.<\/p>\n<p>In-situ conditioning with a rotating diamond disk maintains pad condition state during polishing, but the aggressive conditioning needed for high removal rate stability accelerates pad wear and increases pad debris \u2014 a defect risk. The optimal conditioning recipe balances removal rate stability against pad lifetime and defect count: typically expressed as a conditioning sweep rate (mm\/s), disc RPM, and disc downforce. These parameters must be co-optimized with the slurry formulation, as different slurry chemistries produce different pad surface interactions and wear characteristics.<\/p>\n\n<h2 id=\"flow\">5. Slurry Flow Rate &amp; POU Delivery<\/h2>\n<p>Slurry flow rate determines the replenishment of fresh oxidizer and complexing agent at the pad-wafer interface and the removal rate of polishing byproducts (Cu\u00b2\u207a ions, BTA-Cu complex, abraded particle debris). <strong>Slurry starvation<\/strong> \u2014 insufficient flow to maintain fresh chemistry at the interface \u2014 is one of the most common causes of unexplained removal rate loss and WIWNU degradation in production copper CMP processes.<\/p>\n<p>Signs of slurry starvation include: removal rate that is lower at wafer center than edge (center of the wafer is the last point reached by freshly dispensed slurry), WIWNU that improves when flow rate is increased, and removal rate drift over the course of a polishing run as pad grooves become filled with slurry byproducts.<\/p>\n<p>Typical optimal slurry flow rates for 300 mm copper CMP are <strong>150\u2013250 mL\/min<\/strong> at the pad surface. For H\u2082O\u2082-based slurries, POU mixing systems combine the slurry base concentrate and oxidizer at the dispense arm. The POU mixing ratio (slurry base : H\u2082O\u2082 : DIW) is a critical process parameter that must be precisely controlled through mass-flow controllers rather than volumetric flow control, as the density difference between concentrated H\u2082O\u2082 and slurry base can cause metering errors if volumetric measurement is used.<\/p>\n\n<div class=\"jz-callout jz-ci\">\n  <p><strong>POU mixing tip:<\/strong> Measure H\u2082O\u2082 concentration in the mixed slurry at the dispense point regularly using a simple titrimetric or colorimetric test \u2014 not just at the bulk storage tank. H\u2082O\u2082 decomposition can occur in the delivery lines if trace copper contamination is present from a previous lot. Even a 20% reduction in effective H\u2082O\u2082 concentration at the pad can drop copper removal rate by 10\u201315%.<\/p>\n<\/div>\n\n<h2 id=\"wiwnu\">6. WIWNU Optimization Strategies<\/h2>\n<p>Within-wafer non-uniformity (WIWNU) in copper CMP is measured as the standard deviation of copper thickness (or removal depth) across all measured sites on the wafer, normalized to the mean, expressed as a percentage: WIWNU (%) = \u03c3 \/ mean \u00d7 100. Production targets are typically WIWNU &lt;3% (1\u03c3) for 300 mm copper CMP.<\/p>\n<p>WIWNU is driven by a combination of factors that must be addressed systematically:<\/p>\n\n<div class=\"jz-tw\">\n  <table class=\"jz-tab\">\n    <thead><tr><th>WIWNU Root Cause<\/th><th>Primary Driver<\/th><th>Mitigation Lever<\/th><\/tr><\/thead>\n    <tbody>\n      <tr><td>Radial velocity gradient<\/td><td>Kinematics of orbital polishing \u2014 lower velocity at wafer center<\/td><td>Multi-zone carrier pressure; differential RPM<\/td><\/tr>\n      <tr><td>Slurry distribution non-uniformity<\/td><td>Slurry delivered to one side of pad; uneven dispense<\/td><td>Multi-point dispense; higher flow rate; pad groove optimization<\/td><\/tr>\n      <tr><td>Pad glazing non-uniformity<\/td><td>Conditioning sweep does not cover full pad uniformly<\/td><td>Conditioning sweep profile optimization; continuous conditioning<\/td><\/tr>\n      <tr><td>Pattern density variation<\/td><td>Different local copper density across chip sites<\/td><td>Fill metal insertion; slurry with lower K<sub>p<\/sub> sensitivity to pattern density<\/td><\/tr>\n      <tr><td>Wafer edge effect<\/td><td>Mechanical boundary effects at wafer edge ring<\/td><td>Retaining ring pressure optimization; edge carrier zone tuning<\/td><\/tr>\n    <\/tbody>\n  <\/table>\n<\/div>\n\n<p>APC (advanced process control) run-to-run control is the most powerful tool for maintaining WIWNU within specification across a production lot. By measuring post-CMP copper thickness profiles after each wafer and feeding back adjustments to carrier zone pressures and polishing time, APC systems can compensate for tool-to-tool variation, pad aging effects, and lot-to-lot slurry concentration variation \u2014 maintaining &lt;3% WIWNU even as process conditions drift.<\/p>\n\n<h2 id=\"advanced\">7. Advanced-Node Constraints on Removal Rate<\/h2>\n<p>At 7 nm and below, the freedom to tune removal rate through pressure is severely constrained by ELK dielectric fragility. This forces slurry formulators to compensate chemically \u2014 and creates a different optimization problem than conventional copper CMP.<\/p>\n<p>At &lt;1 psi polishing pressure, removal rate in a Preston-regime slurry drops to &lt;100 nm\/min \u2014 far below what is needed for economically viable throughput on 600+ nm copper overburden. JEEZ&#8217;s CuELK series addresses this by using enhanced chemical activity formulations: slightly higher H\u2082O\u2082 concentration (3\u20135 wt%), optimized glycine loading, and reduced BTA concentration at the lower end of the dishing-safe window. These formulations achieve 180\u2013250 nm\/min removal rate at 0.7 psi by increasing the chemical contribution to K<sub>p<\/sub> \u2014 effectively boosting the &#8220;chemical Preston coefficient&#8221; while keeping mechanical pressure below the ELK damage threshold.<\/p>\n<p>The tradeoff is tighter process window: with higher oxidizer and lower BTA loading, the margin between optimal and excessive dishing is narrower, requiring tighter endpoint detection (typically eddy-current APC rather than friction-based endpoint) and more precise run-to-run time control.<\/p>\n\n<div class=\"jz-deepdive\">\n  <span class=\"jz-deepdive-ico\">\ud83d\udcd6<\/span>\n  <p>For a detailed treatment of the advanced-node challenges driving these constraints, see: <a href=\"https:\/\/jeez-semicon.com\/ja\/blog\/Copper-CMP-at-Advanced-Nodes-7-nm-and-Below-ELK-Dielectrics-Cobalt-Liners-Slurry-Innovations\/\" target=\"_blank\" rel=\"noopener noreferrer\">Copper CMP at Advanced Nodes (7 nm and Below): ELK Dielectrics, Cobalt Liners &amp; Slurry Innovations<\/a>.<\/p>\n<\/div>\n\n<hr class=\"jz-hr\">\n\n<h2 id=\"faq\">8. Frequently Asked Questions<\/h2>\n<div class=\"jz-faq\">\n  <div class=\"jz-faq-item\">\n    <p class=\"jz-faq-q\">What is a typical copper CMP removal rate for Step 1 bulk Cu polishing?<\/p>\n    <p class=\"jz-faq-a\">For conventional copper CMP at 2\u20133 psi (14\u201321 kPa) downforce with an alumina-based slurry, Step 1 bulk Cu removal rates of 300\u2013500 nm\/min are typical on 300 mm wafers. With colloidal silica-based slurries at the same conditions, rates of 200\u2013350 nm\/min are more common. At advanced-node low-pressure conditions (&lt;1 psi), chemical-activity-enhanced slurries achieve 180\u2013250 nm\/min.<\/p>\n  <\/div>\n  <div class=\"jz-faq-item\">\n    <p class=\"jz-faq-q\">Why does my removal rate drift downward over the course of a polishing campaign even with constant settings?<\/p>\n    <p class=\"jz-faq-a\">Downward removal rate drift is most commonly caused by pad glazing \u2014 the progressive compression and smoothing of pad asperities over polishing time. It can also result from gradual H\u2082O\u2082 decomposition in the delivery lines, BTA-Cu particle accumulation on the pad surface reducing asperity-to-wafer contact, and pad temperature increase as the pad warms up during a polishing session. Checking conditioning recipe effectiveness (post-conditioning RMS roughness scan) and verifying POU oxidizer concentration at the dispense arm are the first diagnostic steps.<\/p>\n  <\/div>\n  <div class=\"jz-faq-item\">\n    <p class=\"jz-faq-q\">How does pattern density affect removal rate in copper CMP?<\/p>\n    <p class=\"jz-faq-a\">Pattern density affects removal rate through the &#8220;load effect&#8221;: dense copper arrays present more copper surface area per unit pad contact area, effectively increasing the mechanical load distributed across the pad-wafer interface. Denser patterns typically show higher local removal rates than isolated lines at the same process conditions. This pattern-density-dependent removal rate variation is a primary driver of within-die WIWNU and dishing\/erosion non-uniformity in production copper CMP. Slurry formulations with lower mechanical-contribution sensitivity (higher chemical:mechanical rate ratio) are generally more pattern-density-tolerant.<\/p>\n  <\/div>\n  <div class=\"jz-faq-item\">\n    <p class=\"jz-faq-q\">Can I use removal rate alone to set the polishing time for endpoint?<\/p>\n    <p class=\"jz-faq-a\">Time-based endpoint control using a fixed removal rate estimate is viable for very stable processes but is generally insufficient for advanced-node copper CMP production. Removal rate varies with pad age, slurry lot, tool temperature, and starting copper thickness (which varies from wafer to wafer due to ECD nonuniformity). Production copper CMP endpoint is best controlled using in-situ detection \u2014 eddy-current for Step 1 thickness control, motor current or optical reflectance for Step 1\/Step 2 transition \u2014 combined with run-to-run APC to adjust polishing time based on the measured remaining thickness from the previous wafer.<\/p>\n  <\/div>\n<\/div>\n\n<div class=\"jz-related\">\n  <h3>Related Articles in This Series<\/h3>\n  <ul>\n    <li><a href=\"https:\/\/jeez-semicon.com\/ja\/blog\/Dishing-and-Erosion-in-Copper-CMP-Causes-Pattern-Density-Effects-Mitigation\/\" target=\"_blank\" rel=\"noopener noreferrer\">Dishing and Erosion in Copper CMP: Causes, Pattern Density Effects &amp; Mitigation<\/a><\/li>\n    <li><a href=\"https:\/\/jeez-semicon.com\/ja\/blog\/Two-Step-Copper-CMP-Bulk-Cu-vs-Barrier-Slurry-Chemistry-Selectivity-Endpoint-Detection\/\" target=\"_blank\" rel=\"noopener noreferrer\">Two-Step Copper CMP: Bulk Cu vs. Barrier Slurry \u2014 Chemistry, Selectivity &amp; Endpoint Detection<\/a><\/li>\n    <li><a href=\"https:\/\/jeez-semicon.com\/ja\/blog\/Copper-CMP-at-Advanced-Nodes-7-nm-and-Below-ELK-Dielectrics-Cobalt-Liners-Slurry-Innovations\/\" target=\"_blank\" rel=\"noopener noreferrer\">Copper CMP at Advanced Nodes (7 nm and Below)<\/a><\/li>\n    <li><a href=\"https:\/\/jeez-semicon.com\/ja\/blog\/Copper-CMP-Slurry-Complete-Guide-Chemistry-Process-Optimization-Advanced-Node-Applications\/\" target=\"_blank\" rel=\"noopener noreferrer\">Copper CMP Slurry: Complete Guide (Pillar)<\/a><\/li>\n  <\/ul>\n<\/div>\n\n<div class=\"jz-cta\">\n  <h2>Struggling with Removal Rate or WIWNU in Your Copper CMP Process?<\/h2>\n  <p>Jizhi Electronic Technology Co., Ltd. (JEEZ) offers process optimization support \u2014 from slurry reformulation to machine parameter DoE \u2014 for copper CMP engineers at IDMs, foundries, and advanced packaging facilities worldwide.<\/p>\n  <a href=\"https:\/\/jeez-semicon.com\/ja\/contact\/\" target=\"_blank\" rel=\"noopener noreferrer\" class=\"jz-cta-btn\">Contact JEEZ Application Engineering \u2192<\/a>\n<\/div>\n\n<\/div>\n\n<script type=\"application\/ld+json\">\n{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"What is a typical copper CMP removal rate for Step 1 bulk Cu polishing?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"At 2-3 psi with alumina-based slurry, Step 1 bulk Cu removal rates of 300-500 nm\/min are typical on 300 mm wafers. Colloidal silica slurries yield 200-350 nm\/min. Low-pressure advanced-node processes achieve 180-250 nm\/min with enhanced chemical activity formulations.\"}},{\"@type\":\"Question\",\"name\":\"Why does copper CMP removal rate drift downward during a polishing campaign?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Downward drift is most commonly caused by pad glazing (asperity compression), H2O2 decomposition in delivery lines, BTA-Cu particle accumulation on the pad, and pad temperature increase. Check conditioning effectiveness and verify POU oxidizer concentration at the dispense arm as first diagnostic steps.\"}},{\"@type\":\"Question\",\"name\":\"How does pattern density affect removal rate in copper CMP?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Denser copper patterns show higher local removal rates due to the load effect \u2014 more copper surface area per pad contact zone increases mechanical interaction. This drives within-die WIWNU and dishing\/erosion non-uniformity. Slurries with higher chemical-to-mechanical rate ratios are more pattern-density tolerant.\"}},{\"@type\":\"Question\",\"name\":\"Can removal rate alone be used to set polishing time for endpoint?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Time-based endpoint is insufficient for advanced-node production. Removal rate varies with pad age, slurry lot, and starting copper thickness. In-situ endpoint detection (eddy-current, motor current, or optical reflectance) combined with run-to-run APC is the production standard.\"}}]}\n<\/script>","protected":false},"excerpt":{"rendered":"<p>\ud83d\udcda Part of the Copper CMP Slurry knowledge series. For the complete process overview, see the Copper CMP Slurry: Complete Guide. Material removal rate (RR) is the primary throughput driver  &#8230;<\/p>","protected":false},"author":1,"featured_media":2542,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[9,59],"tags":[],"class_list":["post-2540","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","category-industry"],"acf":[],"_links":{"self":[{"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/posts\/2540","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/comments?post=2540"}],"version-history":[{"count":2,"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/posts\/2540\/revisions"}],"predecessor-version":[{"id":2543,"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/posts\/2540\/revisions\/2543"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/media\/2542"}],"wp:attachment":[{"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/media?parent=2540"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/categories?post=2540"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jeez-semicon.com\/ja\/wp-json\/wp\/v2\/tags?post=2540"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}