{"id":2447,"date":"2026-06-30T16:46:15","date_gmt":"2026-06-30T08:46:15","guid":{"rendered":"https:\/\/jeez-semicon.com\/?p=2447"},"modified":"2026-06-30T16:46:15","modified_gmt":"2026-06-30T08:46:15","slug":"cmp-machine-endpoint-detection-optical-friction-based-in-situ-metrology-methods","status":"publish","type":"post","link":"https:\/\/jeez-semicon.com\/fr\/blog\/cmp-machine-endpoint-detection-optical-friction-based-in-situ-metrology-methods\/","title":{"rendered":"CMP Machine Endpoint Detection: Optical, Friction-Based &amp; In-Situ Metrology Methods"},"content":{"rendered":"<link href=\"https:\/\/fonts.googleapis.com\/css2?family=Syne:wght@600;700&#038;family=Inter:ital,wght@0,500;0,600;1,400&#038;display=swap\" rel=\"stylesheet\">\n\n<style>\n.jcmp-art {\n  --jc-navy:        #0A2547;\n  --jc-blue:        #1B6FC8;\n  --jc-blue-hover:  #1459A8;\n  --jc-blue-light:  #EEF4FF;\n  --jc-blue-border: #C5D9F6;\n  --jc-text:        #1A1F2E;\n  --jc-text-2:      #4B5563;\n  --jc-text-3:      #9CA3AF;\n  --jc-border:      #E5E7EB;\n  --jc-bg:          #F8FAFF;\n  --jc-white:       #FFFFFF;\n  --jc-green:       #059669;\n  font-family: 'Inter', system-ui, -apple-system, sans-serif;\n  color: var(--jc-text);\n  line-height: 1.8;\n  font-size: 16px;\n  max-width: 860px;\n  margin: 0 auto;\n}\n.jcmp-art *, .jcmp-art *::before, .jcmp-art *::after { box-sizing: border-box; }\n.jcmp-art p { margin: 0 0 1.2em; }\n.jcmp-art ul, .jcmp-art ol { margin: 0 0 1.2em; padding-left: 1.5em; }\n.jcmp-art li { margin-bottom: 0.45em; }\n.jcmp-art a { color: var(--jc-blue); text-decoration: none; }\n.jcmp-art a:hover { color: var(--jc-blue-hover); text-decoration: underline; }\n.jcmp-art strong { font-weight: 600; }\n.jcmp-art h1 {\n  font-family: 'Syne', system-ui, sans-serif;\n  font-size: 2.4rem; font-weight: 700; color: var(--jc-navy);\n  line-height: 1.25; margin: 0 0 1.25rem; letter-spacing: -0.02em;\n}\n.jcmp-art h2 {\n  font-family: 'Syne', system-ui, sans-serif;\n  font-size: 1.7rem; font-weight: 700; color: var(--jc-navy);\n  margin: 2.75rem 0 1rem; line-height: 1.3;\n  padding-left: 1rem; border-left: 4px solid var(--jc-blue);\n}\n.jcmp-art h3 {\n  font-family: 'Syne', system-ui, sans-serif;\n  font-size: 1.1rem; font-weight: 700; color: var(--jc-navy);\n  margin: 1.75rem 0 0.55rem;\n}\n.jcmp-meta { display: flex; align-items: center; flex-wrap: wrap; gap: 0.5rem 1.2rem; font-size: 0.82rem; color: var(--jc-text-3); margin-bottom: 1.5rem; }\n.jcmp-meta-dot { width: 3px; height: 3px; border-radius: 50%; background: var(--jc-text-3); display: inline-block; flex-shrink: 0; }\n.jcmp-lead { font-size: 1.1rem; color: var(--jc-text-2); line-height: 1.9; margin-bottom: 2rem; }\n.jcmp-stats { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--jc-border); border: 1px solid var(--jc-border); border-radius: 10px; overflow: hidden; margin-bottom: 2.5rem; }\n.jcmp-stat { background: var(--jc-white); padding: 1.2rem 1rem; text-align: center; }\n.jcmp-stat-num { font-family: 'Syne', sans-serif; font-size: 1.55rem; font-weight: 700; color: var(--jc-blue); line-height: 1; margin-bottom: 0.4rem; }\n.jcmp-stat-label { font-size: 0.73rem; color: var(--jc-text-2); line-height: 1.45; }\n.jcmp-toc { background: var(--jc-bg); border: 1px solid var(--jc-blue-border); border-radius: 10px; padding: 1.4rem 1.75rem; margin-bottom: 2.5rem; }\n.jcmp-toc-title { font-family: 'Syne', sans-serif; font-size: 0.78rem; font-weight: 700; color: var(--jc-navy); text-transform: uppercase; letter-spacing: 0.09em; margin-bottom: 0.8rem; }\n.jcmp-toc ol { margin: 0; padding-left: 1.2rem; column-count: 2; column-gap: 2rem; }\n.jcmp-toc li { margin-bottom: 0.4rem; font-size: 0.88rem; break-inside: avoid; }\n.jcmp-toc a { color: var(--jc-blue); font-weight: 500; }\n.jcmp-callout { background: var(--jc-blue-light); border-left: 4px solid var(--jc-blue); border-radius: 0 8px 8px 0; padding: 0.95rem 1.2rem; margin: 1.5rem 0; font-size: 0.92rem; color: var(--jc-navy); line-height: 1.7; }\n.jcmp-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.875rem; margin: 1.25rem 0 1.5rem; }\n.jcmp-card { background: var(--jc-white); border: 1px solid var(--jc-border); border-radius: 8px; padding: 1.1rem 1.2rem; }\n.jcmp-card-head { font-family: 'Syne', sans-serif; font-size: 0.88rem; font-weight: 700; color: var(--jc-navy); margin-bottom: 0.4rem; display: flex; align-items: flex-start; gap: 0.45rem; }\n.jcmp-card-dot { display: inline-block; width: 8px; height: 8px; background: var(--jc-blue); border-radius: 50%; margin-top: 5px; flex-shrink: 0; }\n.jcmp-card p { font-size: 0.85rem; color: var(--jc-text-2); margin: 0; line-height: 1.6; }\n.jcmp-table-wrap { overflow-x: auto; margin: 1.25rem 0 1.75rem; }\n.jcmp-table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }\n.jcmp-table th { background: var(--jc-navy); color: var(--jc-white); padding: 0.7rem 1rem; text-align: left; font-weight: 600; font-size: 0.82rem; white-space: nowrap; }\n.jcmp-table td { padding: 0.65rem 1rem; border-bottom: 1px solid var(--jc-border); vertical-align: top; color: var(--jc-text-2); line-height: 1.55; }\n.jcmp-table tr:last-child td { border-bottom: none; }\n.jcmp-table tr:nth-child(even) td { background: var(--jc-bg); }\n.jcmp-table td strong { color: var(--jc-text); }\n.jcmp-read-more { background: var(--jc-bg); border: 1px solid var(--jc-blue-border); border-radius: 8px; padding: 0.9rem 1.2rem; margin: 1.5rem 0 2rem; display: flex; align-items: center; gap: 0.75rem; font-size: 0.875rem; }\n.jcmp-read-more-icon { width: 32px; height: 32px; background: var(--jc-blue); border-radius: 6px; display: flex; align-items: center; justify-content: center; flex-shrink: 0; color: white; font-size: 0.85rem; font-weight: 700; }\n.jcmp-read-more-text { color: var(--jc-text-2); }\n.jcmp-read-more-text a { color: var(--jc-blue); font-weight: 600; }\n.jcmp-hr { border: none; border-top: 1px solid var(--jc-border); margin: 2.25rem 0; }\n.jcmp-cta-mid { background: var(--jc-blue-light); border: 1px solid var(--jc-blue-border); border-radius: 10px; padding: 1.5rem 1.75rem; margin: 2rem 0; display: flex; gap: 1.25rem; align-items: center; }\n.jcmp-cta-mid-copy { flex: 1; }\n.jcmp-cta-mid-copy strong { display: block; font-size: 1rem; color: var(--jc-navy); margin-bottom: 0.35rem; }\n.jcmp-cta-mid-copy p { margin: 0; font-size: 0.875rem; color: var(--jc-text-2); line-height: 1.6; }\n.jcmp-btn-outline { display: inline-block; background: var(--jc-white); border: 1.5px solid var(--jc-blue); color: var(--jc-blue); font-weight: 600; font-size: 0.85rem; padding: 0.6rem 1.25rem; border-radius: 6px; text-decoration: none; white-space: nowrap; flex-shrink: 0; }\n.jcmp-btn-outline:hover { background: var(--jc-blue); color: var(--jc-white); text-decoration: none; }\n.jcmp-cta { background: linear-gradient(135deg, #0A2547 0%, #1B6FC8 100%); border-radius: 12px; padding: 2.25rem 2rem; margin: 2.5rem 0; text-align: center; color: var(--jc-white); }\n.jcmp-cta-eyebrow { font-size: 0.72rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase; color: rgba(255,255,255,0.65); margin-bottom: 0.5rem; }\n.jcmp-cta-title { font-family: 'Syne', sans-serif; font-size: 1.45rem; font-weight: 700; color: var(--jc-white); margin-bottom: 0.75rem; line-height: 1.35; }\n.jcmp-cta p { font-size: 0.9rem; color: rgba(255,255,255,0.85); margin-bottom: 1.5rem; line-height: 1.75; }\n.jcmp-cta-btn { display: inline-block; background: var(--jc-white); color: var(--jc-navy); font-weight: 700; font-size: 0.9rem; padding: 0.8rem 2.25rem; border-radius: 6px; text-decoration: none; }\n.jcmp-cta-btn:hover { opacity: 0.92; text-decoration: none; color: var(--jc-navy); }\n.jcmp-faq-item { border: 1px solid var(--jc-border); border-radius: 8px; margin-bottom: 0.75rem; overflow: hidden; }\n.jcmp-faq-q { font-weight: 600; padding: 1rem 1.25rem; font-size: 0.95rem; color: var(--jc-navy); background: var(--jc-bg); line-height: 1.5; }\n.jcmp-faq-a { padding: 0.9rem 1.25rem; font-size: 0.88rem; color: var(--jc-text-2); line-height: 1.8; border-top: 1px solid var(--jc-border); }\n.jcmp-faq-a p { margin: 0 0 0.6em; }\n.jcmp-faq-a p:last-child { margin-bottom: 0; }\n@media (max-width: 640px) {\n  .jcmp-stats { grid-template-columns: repeat(2, 1fr); }\n  .jcmp-grid { grid-template-columns: 1fr; }\n  .jcmp-toc ol { column-count: 1; }\n  .jcmp-art h1 { font-size: 1.8rem; }\n  .jcmp-art h2 { font-size: 1.35rem; }\n  .jcmp-cta { padding: 1.5rem; }\n  .jcmp-cta-mid { flex-direction: column; align-items: flex-start; }\n}\n<\/style>\n\n<div class=\"jcmp-art\" itemscope itemtype=\"https:\/\/schema.org\/Article\">\n\n  <div class=\"jcmp-meta\">\n    <span>Last updated: July 2026<\/span>\n    <span class=\"jcmp-meta-dot\"><\/span>\n    <span>13 minutes de lecture<\/span>\n    <span class=\"jcmp-meta-dot\"><\/span>\n    <span>JEEZ Technical Editorial Team \u2014 Jizhi Electronic Technology Co., Ltd.<\/span>\n  <\/div>\n\n\n  <p class=\"jcmp-lead\">\n    Knowing precisely when to stop polishing is as critical to CMP success as the polishing process itself. Endpoint detection (EPD) systems integrated into modern CMP machines provide the real-time, in-situ measurement capability that enables wafer-to-wafer repeatable, stop-on-film process control \u2014 a level of precision that fixed-time polishing recipes alone cannot achieve. This guide details the three primary endpoint detection methods used in production CMP, their underlying physics, and the application contexts where each is most effective.\n  <\/p>\n\n  <div class=\"jcmp-stats\">\n    <div class=\"jcmp-stat\">\n      <div class=\"jcmp-stat-num\">3<\/div>\n      <div class=\"jcmp-stat-label\">Primary EPD methods used in production CMP<\/div>\n    <\/div>\n    <div class=\"jcmp-stat\">\n      <div class=\"jcmp-stat-num\">\u00c5-level<\/div>\n      <div class=\"jcmp-stat-label\">Typical sensitivity of optical interferometry EPD<\/div>\n    <\/div>\n    <div class=\"jcmp-stat\">\n      <div class=\"jcmp-stat-num\">\u00b10.5\u20131nm<\/div>\n      <div class=\"jcmp-stat-label\">Typical eddy current EPD endpoint precision for copper CMP<\/div>\n    <\/div>\n    <div class=\"jcmp-stat\">\n      <div class=\"jcmp-stat-num\">2+<\/div>\n      <div class=\"jcmp-stat-label\">EPD methods typically combined on leading-edge production tools<\/div>\n    <\/div>\n  <\/div>\n\n  <nav class=\"jcmp-toc\" aria-label=\"Table des mati\u00e8res\">\n    <div class=\"jcmp-toc-title\">Table des mati\u00e8res<\/div>\n    <ol>\n      <li><a href=\"#why-epd-matters\">Why Endpoint Detection Matters<\/a><\/li>\n      <li><a href=\"#optical-epd\">Optical Interferometry (In-Situ OES)<\/a><\/li>\n      <li><a href=\"#friction-epd\">Motor Current and Friction-Based EPD<\/a><\/li>\n      <li><a href=\"#eddy-current\">In-Situ Eddy Current Measurement<\/a><\/li>\n      <li><a href=\"#method-comparison\">Method Comparison and Selection Guidance<\/a><\/li>\n      <li><a href=\"#combined-approaches\">Combined and Redundant EPD Approaches<\/a><\/li>\n      <li><a href=\"#faq\">Questions fr\u00e9quemment pos\u00e9es<\/a><\/li>\n    <\/ol>\n  <\/nav>\n\n  <p>This article is part of the JEEZ CMP knowledge base. For the complete equipment overview, see: <a href=\"https:\/\/jeez-semicon.com\/fr\/blog\/CMP-Machines-The-Complete-Guide-to-Chemical-Mechanical-Planarization-Equipment\/\" target=\"_blank\" rel=\"noopener noreferrer\">CMP Machines: The Complete Guide to Chemical Mechanical Planarization Equipment<\/a>.<\/p>\n\n  <section id=\"why-epd-matters\">\n    <h2>Why Endpoint Detection Matters<\/h2>\n\n    <p>Over-polishing and under-polishing each carry distinct, significant yield consequences. Over-polishing removes excess material beyond the target depth, thinning dielectric layers, creating dishing in copper interconnect lines, or eroding barrier metals \u2014 directly degrading device electrical performance, timing characteristics, and long-term reliability. Under-polishing leaves residual conductive material that can cause inter-layer electrical shorts, or leaves incomplete planarization that propagates as surface topography into subsequent lithography and processing steps, compounding alignment and focus errors at every downstream step.<\/p>\n\n    <p>Fixed-time polishing recipes \u2014 simply running each wafer for a predetermined duration \u2014 cannot reliably achieve the precision required at advanced process nodes, because incoming film thickness variation, consumable wear state, and process drift all introduce wafer-to-wafer variability that a fixed-time approach cannot compensate for. Real-time endpoint detection hardware directly measures material removal progress as it occurs, allowing the CMP machine to terminate polishing at the precise moment the target condition is reached, regardless of these underlying sources of variability.<\/p>\n  <\/section>\n\n  <hr class=\"jcmp-hr\">\n\n  <section id=\"optical-epd\">\n    <h2>Optical Interferometry (In-Situ OES)<\/h2>\n\n    <p>Optical interferometry is the most widely deployed endpoint detection method in production CMP, leveraging the same fundamental optical principle used in thin-film thickness metrology throughout semiconductor manufacturing.<\/p>\n\n    <h3>Operating Principle<\/h3>\n    <p>A monochromatic or broadband light source is focused through a transparent window \u2014 typically fabricated from sapphire or fused quartz \u2014 built directly into the rotating platen surface beneath the polishing pad. As the platen rotates and the window passes beneath the wafer, light reflects from both the top surface of the film being polished and the underlying interface, with these two reflections combining to produce an optical interference pattern. As the film thickness changes during polishing, the optical path length difference between these two reflections changes correspondingly, producing a cyclical interference signal whose oscillation period directly corresponds to the rate of film thickness change.<\/p>\n\n    <h3>Strengths and Application Range<\/h3>\n    <p>Optical EPD provides Angstrom-level sensitivity to film thickness change, enabling real-time, in-situ measurement throughout the polishing process rather than only at a single endpoint trigger moment \u2014 a capability that supports advanced process control approaches using the full optical signal trajectory, not just the endpoint trigger. This method is most effective for transparent or semi-transparent films, including oxide, nitride, and polysilicon layers, where light can meaningfully penetrate and reflect from the underlying interface.<\/p>\n\n    <h3>Limitations<\/h3>\n    <p>Optical EPD is significantly less effective for optically opaque metal films such as copper, tungsten, or aluminum, where light cannot penetrate the film to generate the interference signal that the method relies upon. For these applications, optical EPD is typically used during the dielectric or barrier-layer-adjacent portions of a process sequence, supplemented by alternative methods for opaque metal removal monitoring.<\/p>\n  <\/section>\n\n  <hr class=\"jcmp-hr\">\n\n  <section id=\"friction-epd\">\n    <h2>Motor Current and Friction-Based EPD<\/h2>\n\n    <p>Motor current and friction-based endpoint detection exploits the fact that changes in tribological conditions at the wafer-pad interface produce measurable changes in mechanical friction, detectable through the electrical drive current of the platen or carrier head motors.<\/p>\n\n    <h3>Operating Principle<\/h3>\n    <p>As discussed in our process physics guide, the friction coefficient at the wafer-pad interface depends on the specific material being polished and the lubrication regime in effect. When polishing reaches a film transition point \u2014 for example, when bulk copper clears from a dielectric field region, exposing the underlying barrier metal layer \u2014 the friction coefficient at the interface changes due to the different mechanical and chemical interaction between the new exposed material and the slurry\/pad system. This friction change translates into a detectable shift in the torque required to maintain constant rotational speed, which is measured as a change in the electrical current drawn by the platen or carrier head drive motor.<\/p>\n\n    <h3>Strengths and Application Range<\/h3>\n    <p>Motor current EPD requires no optical access window in the platen, making it mechanically simpler to integrate and effective for any material combination that produces a meaningful friction contrast at the transition point \u2014 including transitions between opaque metal films where optical EPD cannot function. This makes motor current sensing a common primary or supplementary endpoint detection method specifically for metal CMP applications, including both copper and tungsten processing steps.<\/p>\n\n    <h3>Limitations<\/h3>\n    <p>The sensitivity of motor current EPD depends on the magnitude of the friction coefficient change at the specific material transition being monitored, which can be relatively subtle for some material combinations, potentially limiting detection sensitivity and timing precision compared to optical or eddy current methods for certain applications.<\/p>\n  <\/section>\n\n  <hr class=\"jcmp-hr\">\n\n  <section id=\"eddy-current\">\n    <h2>In-Situ Eddy Current Measurement<\/h2>\n\n    <p>In-situ eddy current measurement provides a non-contact, electromagnetic approach to real-time conductive film thickness monitoring, particularly well suited to copper CMP applications where precise endpoint control is especially critical.<\/p>\n\n    <h3>Operating Principle<\/h3>\n    <p>A sensor coil embedded within the platen generates a time-varying electromagnetic field that induces circulating eddy currents within any conductive film present on the wafer surface as it passes over the sensor location. The magnitude of these induced eddy currents \u2014 and the corresponding impedance change measured by the sensor coil \u2014 depends on the thickness and conductivity of the film, providing a continuous, real-time film thickness measurement as polishing proceeds, with spatial resolution that can be mapped across the wafer radius as the wafer rotates relative to the fixed sensor position.<\/p>\n\n    <h3>Strengths and Application Range<\/h3>\n    <p>Eddy current EPD is particularly effective for copper CMP, where it enables closed-loop control of copper removal to extremely tight endpoint targets \u2014 typically within \u00b10.5 to 1nm equivalent thickness \u2014 across the full wafer population. Because the method directly measures conductive film thickness rather than relying on a transition-point signal change, it can support real-time, continuous removal rate feedback throughout the copper removal process, not just a single endpoint trigger.<\/p>\n\n    <h3>Limitations<\/h3>\n    <p>Eddy current measurement is inherently specific to conductive films and provides no useful signal for dielectric material removal monitoring, restricting its application to metal CMP process steps where a conductive film is present throughout the measurement.<\/p>\n  <\/section>\n\n  <hr class=\"jcmp-hr\">\n\n  <section id=\"method-comparison\">\n    <h2>Method Comparison and Selection Guidance<\/h2>\n\n    <div class=\"jcmp-table-wrap\">\n      <table class=\"jcmp-table\">\n        <thead>\n          <tr>\n            <th>EPD Method<\/th>\n            <th>Best Application Fit<\/th>\n            <th>Key Limitation<\/th>\n          <\/tr>\n        <\/thead>\n        <tbody>\n          <tr>\n            <td><strong>Optical Interferometry<\/strong><\/td>\n            <td>Transparent\/semi-transparent films (oxide, nitride, poly-Si)<\/td>\n            <td>Ineffective for opaque metal films<\/td>\n          <\/tr>\n          <tr>\n            <td><strong>Motor Current \/ Friction<\/strong><\/td>\n            <td>Metal CMP transitions (copper, tungsten); no optical window required<\/td>\n            <td>Sensitivity depends on friction contrast magnitude<\/td>\n          <\/tr>\n          <tr>\n            <td><strong>Eddy Current<\/strong><\/td>\n            <td>Copper CMP requiring tight endpoint precision<\/td>\n            <td>Requires a conductive film; not applicable to dielectrics<\/td>\n          <\/tr>\n        <\/tbody>\n      <\/table>\n    <\/div>\n\n    <p>Method selection should be driven primarily by the optical and electrical properties of the film being removed at each specific process step, with most modern multi-step CMP processes employing different EPD methods \u2014 or combinations of methods \u2014 across the sequential platens of a single tool, matched to the specific material transition occurring at each step.<\/p>\n  <\/section>\n\n  <hr class=\"jcmp-hr\">\n\n  <section id=\"combined-approaches\">\n    <h2>Combined and Redundant EPD Approaches<\/h2>\n\n    <p>Leading-edge production CMP tools from Applied Materials and Ebara typically integrate two or more endpoint detection methods simultaneously on advanced process steps, providing both redundant confirmation of the endpoint trigger and the ability to cross-validate signal interpretation when ambiguous transitions occur. This combined approach is particularly valuable for the most yield-critical CMP steps \u2014 such as copper barrier metal clearing, where the consequences of endpoint timing error are especially significant for device reliability \u2014 where the additional engineering cost of integrating multiple EPD methods is well justified by the resulting improvement in endpoint accuracy and confidence.<\/p>\n\n    <div class=\"jcmp-callout\">\n      <strong>Practical implication:<\/strong> Endpoint detection accuracy depends not only on the EPD hardware itself but on consistent slurry optical properties (for optical EPD) and consistent friction characteristics (for motor current EPD). Slurry lot-to-lot variation in these properties can introduce endpoint timing drift independent of any tool-side EPD hardware issue.\n    <\/div>\n\n    <p>JEEZ slurry formulations are characterized for optical and chemical consistency to support stable, predictable endpoint detection signal behavior across production lots, helping minimize endpoint-related process variability that can otherwise complicate root cause analysis when EPD timing shifts are observed.<\/p>\n\n    <div class=\"jcmp-cta-mid\">\n      <div class=\"jcmp-cta-mid-copy\">\n        <strong>Need consumables engineered for stable EPD signal behavior?<\/strong>\n        <p>JEEZ slurries are formulated with consistent optical and chemical properties to support reliable endpoint detection across all major EPD methods and production CMP platforms.<\/p>\n      <\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/fr\/contact\/\" target=\"_blank\" rel=\"noopener noreferrer\" class=\"jcmp-btn-outline\">Contact JEEZ<\/a>\n    <\/div>\n\n    <div class=\"jcmp-read-more\">\n      <div class=\"jcmp-read-more-icon\">\u2192<\/div>\n      <span class=\"jcmp-read-more-text\">For the broader CMP machine subsystem architecture that integrates EPD hardware: <a href=\"https:\/\/jeez-semicon.com\/fr\/blog\/CMP-Machine-Components-Explained-Polishing-Head-Platen-Slurry-Delivery-Pad-Conditioner\/\" target=\"_blank\" rel=\"noopener noreferrer\">CMP Machine Components Explained: Polishing Head, Platen, Slurry Delivery &amp; Pad Conditioner<\/a><\/span>\n    <\/div>\n\n    <div class=\"jcmp-cta\">\n      <div class=\"jcmp-cta-eyebrow\">Jizhi Electronic Technology Co., Ltd. \u2014 JEEZ<\/div>\n      <div class=\"jcmp-cta-title\">Complete CMP Knowledge Base, Backed by Real Technical Support<\/div>\n      <p>From process physics and tool components to consumable selection and endpoint detection, JEEZ provides the technical depth and direct application engineering support semiconductor manufacturers need to run stable, high-yield CMP operations.<\/p>\n      <a href=\"https:\/\/jeez-semicon.com\/fr\/contact\/\" target=\"_blank\" rel=\"noopener noreferrer\" class=\"jcmp-cta-btn\">Contact the JEEZ Technical Team \u2192<\/a>\n    <\/div>\n  <\/section>\n\n  <hr class=\"jcmp-hr\">\n\n  <section id=\"faq\">\n    <h2>Questions fr\u00e9quemment pos\u00e9es<\/h2>\n\n    <div class=\"jcmp-faq-item\">\n      <div class=\"jcmp-faq-q\">What is endpoint detection in CMP and why is it important?<\/div>\n      <div class=\"jcmp-faq-a\">\n        <p>Endpoint detection (EPD) refers to real-time, in-situ measurement systems integrated into a CMP machine that monitor material removal as it occurs, signaling the precise moment to stop polishing. It is essential because both over-polishing (causing dishing, erosion, or film thinning) and under-polishing (causing electrical shorts or incomplete planarization) directly degrade device yield, and fixed-time recipes alone cannot reliably compensate for wafer-to-wafer process variability.<\/p>\n      <\/div>\n    <\/div>\n\n    <div class=\"jcmp-faq-item\">\n      <div class=\"jcmp-faq-q\">Why doesn&#8217;t optical endpoint detection work for copper CMP?<\/div>\n      <div class=\"jcmp-faq-a\">\n        <p>Optical interferometry endpoint detection relies on light reflecting from both the surface and underlying interface of a film to generate an interference signal, which requires the film to be transparent or semi-transparent. Copper and other metal films are optically opaque, preventing light from penetrating to generate the necessary interference signal, which is why copper CMP typically relies on motor current\/friction-based or eddy current endpoint detection methods instead.<\/p>\n      <\/div>\n    <\/div>\n\n    <div class=\"jcmp-faq-item\">\n      <div class=\"jcmp-faq-q\">How does eddy current endpoint detection achieve such tight precision for copper CMP?<\/div>\n      <div class=\"jcmp-faq-a\">\n        <p>Eddy current EPD uses an embedded sensor coil that generates an electromagnetic field, inducing eddy currents in the conductive copper film whose magnitude depends on film thickness. This provides continuous, real-time film thickness measurement throughout the polishing process, enabling closed-loop control of copper removal to endpoint targets typically within \u00b10.5 to 1nm equivalent thickness.<\/p>\n      <\/div>\n    <\/div>\n\n    <div class=\"jcmp-faq-item\">\n      <div class=\"jcmp-faq-q\">Do production CMP tools use just one endpoint detection method?<\/div>\n      <div class=\"jcmp-faq-a\">\n        <p>Leading-edge production CMP tools from manufacturers like Applied Materials and Ebara typically combine two or more endpoint detection methods on advanced process steps, providing redundant confirmation and cross-validation of the endpoint trigger. This is particularly common for the most yield-critical steps, such as copper barrier metal clearing, where endpoint timing accuracy has significant reliability implications.<\/p>\n      <\/div>\n    <\/div>\n\n    <div class=\"jcmp-faq-item\">\n      <div class=\"jcmp-faq-q\">Can slurry quality affect endpoint detection accuracy?<\/div>\n      <div class=\"jcmp-faq-a\">\n        <p>Yes. Optical endpoint detection accuracy can be affected by slurry optical properties, while motor current\/friction-based endpoint detection depends on consistent friction characteristics at the wafer-pad interface. Lot-to-lot slurry variation in these properties can introduce endpoint timing drift independent of any CMP tool hardware issue, making slurry consistency an important factor in stable endpoint detection performance.<\/p>\n      <\/div>\n    <\/div>\n\n  <\/section>\n\n<\/div>\n\n<script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What is endpoint detection in CMP and why is it important?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Endpoint detection refers to real-time, in-situ measurement systems in a CMP machine that monitor material removal and signal when to stop polishing. It is essential because over-polishing and under-polishing both degrade device yield, and fixed-time recipes cannot reliably compensate for wafer-to-wafer variability.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Why doesn't optical endpoint detection work for copper CMP?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Optical interferometry relies on light reflecting from the surface and underlying interface to generate an interference signal, requiring a transparent or semi-transparent film. Copper is optically opaque, preventing this signal, so copper CMP typically relies on motor current or eddy current endpoint detection instead.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How does eddy current endpoint detection achieve such tight precision for copper CMP?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Eddy current EPD uses a sensor coil generating an electromagnetic field that induces eddy currents in the conductive copper film, with magnitude depending on film thickness, enabling closed-loop control of copper removal to endpoint targets typically within plus or minus 0.5 to 1nm equivalent thickness.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Do production CMP tools use just one endpoint detection method?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Leading-edge production CMP tools typically combine two or more endpoint detection methods on advanced process steps for redundant confirmation, particularly for yield-critical steps like copper barrier metal clearing.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Can slurry quality affect endpoint detection accuracy?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. Optical endpoint detection accuracy can be affected by slurry optical properties, while motor current endpoint detection depends on consistent friction characteristics. Lot-to-lot slurry variation can introduce endpoint timing drift independent of any tool hardware issue.\"\n      }\n    }\n  ]\n}\n<\/script>","protected":false},"excerpt":{"rendered":"<p>Last updated: July 2026 13 min read JEEZ Technical Editorial Team \u2014 Jizhi Electronic Technology Co., Ltd. Knowing precisely when to stop polishing is as critical to CMP success as  &#8230;<\/p>","protected":false},"author":1,"featured_media":2449,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[9,59],"tags":[],"class_list":["post-2447","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","category-industry"],"acf":[],"_links":{"self":[{"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/posts\/2447","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/comments?post=2447"}],"version-history":[{"count":2,"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/posts\/2447\/revisions"}],"predecessor-version":[{"id":2450,"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/posts\/2447\/revisions\/2450"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/media\/2449"}],"wp:attachment":[{"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/media?parent=2447"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/categories?post=2447"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jeez-semicon.com\/fr\/wp-json\/wp\/v2\/tags?post=2447"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}