{"id":1761,"date":"2026-04-07T15:54:49","date_gmt":"2026-04-07T07:54:49","guid":{"rendered":"https:\/\/jeez-semicon.com\/?p=1761"},"modified":"2026-04-07T16:28:43","modified_gmt":"2026-04-07T08:28:43","slug":"how-cmp-polishing-pads-work-mechanisms-physics-and-process-science","status":"publish","type":"post","link":"https:\/\/jeez-semicon.com\/zh\/blog\/how-cmp-polishing-pads-work-mechanisms-physics-and-process-science\/","title":{"rendered":"How CMP Polishing Pads Work: Mechanisms, Physics, and Process Science"},"content":{"rendered":"<!-- ============================================================\n     CLUSTER 2 \u2014 How CMP Polishing Pads Work\n     Jizhi Electronic Technology Co., Ltd.\n     jeez-semicon.com  |  April 2026\n     Paste into WordPress Gutenberg \u2192 Custom HTML block\n     URL: \/blog\/How-CMP-Polishing-Pads-Work\n     ============================================================ -->\n\n<style>\n@import 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16px;font-size:15px;color:#3a4255;line-height:1.75}\n\n@media(max-width:640px){\n  .jz-hero{padding:36px 24px 32px}\n  .jz-cta-banner{padding:32px 22px}\n  .jz-related{padding:24px 18px}\n  .jz-btn-outline{margin-left:0;margin-top:10px;display:inline-block}\n}\n<\/style>\n\n<div class=\"jz-art\">\n\n<!-- Back to Pillar -->\n<a class=\"jz-back\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Polishing-Pads-The-Complete-Guide\/\" target=\"_blank\">Back to CMP Polishing Pads: The Complete Guide<\/a>\n\n<!-- Hero -->\n<div class=\"jz-hero\">\n  <div class=\"jz-hero-kicker\">Jizhi Electronic Technology \u2014 Fundamentals Series<\/div>\n  <p class=\"jz-hero-lead\">A rigorous, engineer-level explanation of the mechanical, chemical, and tribological mechanisms that govern material removal in CMP \u2014 and how every key pad property maps to a measurable process outcome.<\/p>\n  <div class=\"jz-hero-meta\">\n    <span>\ud83d\udcc5 April 2026<\/span>\n    <span>\u23f1 16 min read<\/span>\n    <span>\ud83c\udfed Jizhi Electronic Technology Co., Ltd.<\/span>\n  <\/div>\n<\/div>\n\n<!-- Tags -->\n<div class=\"jz-tags\">\n  <span class=\"jz-tag\">How CMP Works<\/span>\n  <span class=\"jz-tag\">CMP Mechanism<\/span>\n  <span class=\"jz-tag\">Preston Equation<\/span>\n  <span class=\"jz-tag\">Material Removal Rate<\/span>\n  <span class=\"jz-tag\">Tribology<\/span>\n  <span class=\"jz-tag\">Pad-Wafer Contact<\/span>\n  <span class=\"jz-tag\">Slurry Transport<\/span>\n<\/div>\n\n<!-- Trust bar -->\n<div class=\"jz-trust\">\n  <div class=\"jz-trust-badge\">R&amp;D<br>Verified<\/div>\n  <div class=\"jz-trust-text\">\n    <strong>Written by Jizhi Electronic Technology Co., Ltd.<\/strong> \u2014 CMP pad manufacturer and process engineering specialist. This article reflects our in-house R&amp;D findings and current (April 2026) academic and industry consensus on CMP removal mechanisms.\n  <\/div>\n<\/div>\n\n<!-- TOC -->\n<div class=\"jz-toc\">\n  <div class=\"jz-toc-title\">\ud83d\udccb \u76ee\u5f55<\/div>\n  <ol>\n    <li><a href=\"#overview\">The CMP System at a Glance<\/a><\/li>\n    <li><a href=\"#contact-mechanics\">Pad-Wafer Contact Mechanics<\/a><\/li>\n    <li><a href=\"#chemical-mechanism\">The Chemical Removal Mechanism<\/a><\/li>\n    <li><a href=\"#mechanical-mechanism\">The Mechanical Removal Mechanism<\/a><\/li>\n    <li><a href=\"#slurry-transport\">Slurry Transport and the Pad&#8217;s Role<\/a><\/li>\n    <li><a href=\"#preston\">Preston&#8217;s Equation and Its Limits<\/a><\/li>\n    <li><a href=\"#tribological-regimes\">Tribological Regimes in CMP<\/a><\/li>\n    <li><a href=\"#pad-properties-impact\">How Pad Properties Drive Outcomes<\/a><\/li>\n    <li><a href=\"#degradation\">Pad Degradation and Performance Drift<\/a><\/li>\n    <li><a href=\"#faq\">FAQ<\/a><\/li>\n  <\/ol>\n<\/div>\n\n<!-- Intro -->\n<p>CMP is often described simply as &#8220;chemical and mechanical polishing,&#8221; but that shorthand masks a rich interplay of solid mechanics, surface chemistry, hydrodynamics, and tribology. Understanding how a CMP polishing pad actually works \u2014 at the level of asperity contact, slurry film dynamics, and chemical reaction kinetics \u2014 is what separates engineers who can diagnose and fix CMP yield excursions from those who can only adjust recipe parameters by trial and error.<\/p>\n\n<p>This article provides a mechanistic, physics-grounded explanation of CMP pad operation. It builds from first principles: what happens at the pad surface when it contacts a wafer, how slurry chemistry and pad mechanics cooperate to remove material, and how that understanding maps to the physical properties specified on a pad data sheet. If you are new to CMP and want to start with the basics first, see: <a class=\"jz-link-chip\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/What-Is-a-CMP-Polishing-Pad-The-Ultimate-Guide\/\" target=\"_blank\">What Is a CMP Polishing Pad? The Ultimate Guide<\/a>.<\/p>\n\n<div class=\"jz-stats\">\n  <div class=\"jz-stat\"><div class=\"jz-stat-num\">3-body<\/div><div class=\"jz-stat-label\">contact model: pad asperity \u2192 abrasive particle \u2192 wafer surface<\/div><\/div>\n  <div class=\"jz-stat\"><div class=\"jz-stat-num\">~5 nm<\/div><div class=\"jz-stat-label\">Typical slurry film thickness in the pad-wafer gap during polishing<\/div><\/div>\n  <div class=\"jz-stat\"><div class=\"jz-stat-num\">10\u207b\u2078<\/div><div class=\"jz-stat-label\">Order of magnitude of Preston coefficient Kp (Pa\u207b\u00b9) for oxide CMP<\/div><\/div>\n  <div class=\"jz-stat\"><div class=\"jz-stat-num\">~60\u00b0C<\/div><div class=\"jz-stat-label\">Typical pad surface temperature rise during aggressive oxide CMP<\/div><\/div>\n<\/div>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 1 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"overview\">1. The CMP System at a Glance<\/h2>\n\n<p>Before diving into the mechanisms, it is useful to establish a clear picture of the physical system. A CMP polishing tool consists of a large rotating platen onto which the pad is mounted, a carrier head that holds the wafer face-down and presses it against the pad under a controlled down-force, and a slurry delivery arm that dispenses abrasive slurry onto the pad surface. Both the platen and the carrier head rotate \u2014 typically in the same direction but at slightly different speeds \u2014 creating a relative velocity between pad and wafer that drives material removal.<\/p>\n\n<div class=\"jz-cycle\">\n  <div class=\"jz-cycle-step\">\n    <div class=\"jz-cycle-num\">1<\/div>\n    <div class=\"jz-cycle-label\">Slurry delivery<\/div>\n    <div class=\"jz-cycle-desc\">Fresh abrasive slurry dispensed onto rotating pad surface<\/div>\n    <div class=\"jz-cycle-arrow\">\u203a<\/div>\n  <\/div>\n  <div class=\"jz-cycle-step\">\n    <div class=\"jz-cycle-num\">2<\/div>\n    <div class=\"jz-cycle-label\">Chemical passivation<\/div>\n    <div class=\"jz-cycle-desc\">Slurry chemistry softens wafer surface film via oxidation or complexation<\/div>\n    <div class=\"jz-cycle-arrow\">\u203a<\/div>\n  <\/div>\n  <div class=\"jz-cycle-step\">\n    <div class=\"jz-cycle-num\">3<\/div>\n    <div class=\"jz-cycle-label\">\u673a\u68b0\u78e8\u635f<\/div>\n    <div class=\"jz-cycle-desc\">Pad asperities and slurry particles abrade the softened surface layer<\/div>\n    <div class=\"jz-cycle-arrow\">\u203a<\/div>\n  <\/div>\n  <div class=\"jz-cycle-step\">\n    <div class=\"jz-cycle-num\">4<\/div>\n    <div class=\"jz-cycle-label\">Byproduct removal<\/div>\n    <div class=\"jz-cycle-desc\">Spent particles and reaction products swept away through grooves<\/div>\n    <div class=\"jz-cycle-arrow\">\u203a<\/div>\n  <\/div>\n  <div class=\"jz-cycle-step\">\n    <div class=\"jz-cycle-num\">5<\/div>\n    <div class=\"jz-cycle-label\">Pad conditioning<\/div>\n    <div class=\"jz-cycle-desc\">Diamond dresser restores pad surface texture between wafer passes<\/div>\n  <\/div>\n<\/div>\n\n<p>These five steps happen concurrently and cyclically during a polishing run. The pad&#8217;s contribution is not limited to a single step \u2014 it participates in steps 1 (groove transport), 3 (asperity mechanics), and 4 (groove drainage), while its surface state is governed by step 5. This interdependence is why pad properties affect so many different process outcomes simultaneously.<\/p>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 2 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"contact-mechanics\">2. Pad-Wafer Contact Mechanics: What Actually Touches What<\/h2>\n\n<p>The most important and least intuitive aspect of CMP physics is the nature of the contact between pad and wafer. At the macroscale, the pad appears to sit flush against the wafer surface under a uniform pressure. At the microscale, the reality is far more complex \u2014 and far more interesting.<\/p>\n\n<h3>The Three-Body Contact Model<\/h3>\n<p>Real contact between pad and wafer does not occur over a continuous interface. The pad surface is covered with asperities \u2014 micro-scale protrusions of polyurethane polymer \u2014 that range from 1 to 20 \u00b5m in height and are spaced several tens of micrometers apart. Under the applied down-force, only the tips of the tallest asperities make direct contact with the wafer surface. The actual contact area at any instant is estimated to be 1\u20135% of the nominal (geometric) pad area.<\/p>\n\n<p>Between the asperity contact points, a thin film of slurry fills the gap. Abrasive particles (typically 60\u2013200 nm in diameter) are trapped in this gap and can be engaged by both the pad asperity above and the wafer surface below. This three-body configuration \u2014 pad asperity \/ slurry particle \/ wafer surface \u2014 is the primary site of material removal in most CMP applications.<\/p>\n\n<div class=\"jz-callout info\">\n  <div class=\"jz-callout-icon\">\u2139\ufe0f<\/div>\n  <div class=\"jz-callout-body\">\n    <strong>Why Asperity Distribution Controls Removal Rate Uniformity<\/strong>\n    If asperities were perfectly uniform in height and distribution, every point on the wafer under the pad would experience identical contact forces and identical abrasive engagement \u2014 yielding perfectly uniform material removal. In practice, asperity height follows a statistical distribution (approximately Gaussian after conditioning). Points where the pad has a locally higher asperity density experience higher contact pressure and higher local removal rate. This is the fundamental origin of within-wafer removal non-uniformity, and it explains why pad surface characterization \u2014 especially after conditioning \u2014 is so important.\n  <\/div>\n<\/div>\n\n<h3>Contact Pressure Distribution<\/h3>\n<p>The nominal applied pressure P (carrier head down-force divided by wafer area, typically 1\u20136 psi on 300 mm tools) is distributed very non-uniformly at the microscale. At asperity tips, local contact stresses can be 10\u2013100\u00d7 the nominal pressure due to the small real contact area. This high local stress is what enables the abrasive particles trapped at the contact to plastically deform and remove material from the much harder wafer surface films.<\/p>\n\n<p>Pad hardness directly governs this local stress amplification. A hard pad (Shore D 60) has stiffer asperities that maintain their geometry under load, generating higher local contact stresses and thus higher material removal rates. A soft pad (Shore D 38) has compliant asperities that flatten under load, spreading the contact area and reducing local stress \u2014 which lowers the removal rate but improves conformance to wafer topography and reduces defect generation. For a practical guide to choosing between these two extremes, see: <a class=\"jz-link-chip\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/Hard-vs-Soft-CMP-Polishing-Pads-Selection-Guide\/\" target=\"_blank\">Hard vs. Soft CMP Polishing Pads: Selection Guide<\/a>.<\/p>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 3 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"chemical-mechanism\">3. The Chemical Removal Mechanism<\/h2>\n\n<p>CMP is not pure mechanical abrasion \u2014 the &#8220;C&#8221; in CMP is doing critical work. The chemical component of material removal operates through a cycle of surface passivation and depassivation that is essential to achieving both the high removal rates and the low defect densities that semiconductor manufacturing requires.<\/p>\n\n<h3>The Passivation-Abrasion Cycle<\/h3>\n\n<div class=\"jz-steps\">\n  <div class=\"jz-step\">\n    <div class=\"jz-step-num\">1<\/div>\n    <div class=\"jz-step-body\">\n      <h4>Chemical Attack: Forming the Passivation Layer<\/h4>\n      <p>Reactive species in the slurry \u2014 oxidizers (H\u2082O\u2082, KIO\u2083, KMnO\u2084), complexing agents (glycine, benzotriazole), and pH-adjusting buffers \u2014 react with the exposed wafer surface to form a thin, chemically modified &#8220;passivation layer.&#8221; For SiO\u2082 CMP, this is a silanol-rich gel layer (~2\u20135 nm thick). For Cu CMP, it is a copper oxide (Cu\u2082O\/CuO) layer. For W CMP, it is a tungsten oxide layer. The passivation layer is softer and more mechanically fragile than the underlying bulk film.<\/p>\n    <\/div>\n  <\/div>\n  <div class=\"jz-step\">\n    <div class=\"jz-step-num\">2<\/div>\n    <div class=\"jz-step-body\">\n      <h4>Mechanical Removal: Stripping the Passivation Layer<\/h4>\n      <p>Abrasive particles, engaged by pad asperities at the three-body contact interface, abrade away the weakened passivation layer. Because the passivation layer is much softer than the bulk film beneath it, the abrasive particles can remove it efficiently without generating deep sub-surface damage in the bulk material. The key insight is that the abrasives are removing the chemically modified surface, not the bulk film directly.<\/p>\n    <\/div>\n  <\/div>\n  <div class=\"jz-step\">\n    <div class=\"jz-step-num\">3<\/div>\n    <div class=\"jz-step-body\">\n      <h4>Re-passivation: The Cycle Repeats<\/h4>\n      <p>Once the passivation layer is removed at a contact point, the fresh bulk film surface is immediately exposed to slurry chemistry and begins forming a new passivation layer. The removal cycle repeats at each asperity contact point with a frequency determined by the relative velocity between pad and wafer and the asperity spacing. At typical process conditions (platen speed 60 rpm, carrier 57 rpm on a 300 mm tool), each point on the wafer surface is contacted by a given pad asperity at a rate of several hundred times per second.<\/p>\n    <\/div>\n  <\/div>\n<\/div>\n\n<h3>Film-Specific Chemistry Examples<\/h3>\n<div class=\"jz-table-wrap\">\n  <table class=\"jz-table\">\n    <thead>\n      <tr>\n        <th>\u76ee\u6807\u7535\u5f71<\/th>\n        <th>Slurry Oxidizer \/ Agent<\/th>\n        <th>Passivation Layer Formed<\/th>\n        <th>Key Pad Requirement<\/th>\n      <\/tr>\n    <\/thead>\n    <tbody>\n      <tr>\n        <td><strong>SiO\u2082 (oxide ILD)<\/strong><\/td>\n        <td>High-pH ceria or silica slurry (pH 10\u201311)<\/td>\n        <td>Silanol-gel layer (Si-OH rich, ~3 nm)<\/td>\n        <td>Hard pad for planarization efficiency; groove for slurry retention<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Cu (damascene)<\/strong><\/td>\n        <td>H\u2082O\u2082 + BTA (benzotriazole), pH 4\u20137<\/td>\n        <td>Cu\u2082O passivation + BTA-Cu complex<\/td>\n        <td>Soft pad to protect low-k dielectric; low-scratch surface<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>W (plug fill)<\/strong><\/td>\n        <td>H\u2082O\u2082 + Fe\u00b2\u207a (Fenton), pH 2\u20134<\/td>\n        <td>WO\u2083 tungsten oxide layer<\/td>\n        <td>Hard pad; high-selectivity to stop on barrier nitride<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>SiC (power device)<\/strong><\/td>\n        <td>KMnO\u2084 or H\u2082O\u2082 (high conc.), pH 8\u201310<\/td>\n        <td>SiO\u2082-like surface oxide (~1\u20132 nm, forms slowly)<\/td>\n        <td>Specialty hard pad with chemical resistance; high-pressure capable<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Low-k dielectric<\/strong><\/td>\n        <td>Mild pH, low oxidizer concentration<\/td>\n        <td>Thin hydroxyl-modified surface<\/td>\n        <td>Very soft pad; ultra-low down-force to prevent film delamination<\/td>\n      <\/tr>\n    <\/tbody>\n  <\/table>\n<\/div>\n\n<div class=\"jz-callout tip\">\n  <div class=\"jz-callout-icon\">\ud83d\udca1<\/div>\n  <div class=\"jz-callout-body\">\n    <strong>Why CMP Achieves Selectivity Between Films<\/strong>\n    One of CMP&#8217;s most powerful capabilities is its ability to stop preferentially on one film material while continuing to remove another \u2014 for example, removing excess copper while stopping on the tantalum nitride barrier layer in a damascene process. This selectivity is primarily chemical: slurry chemistry can be tuned so that the passivation rate on the stop layer is much faster than on the target film, effectively making the stop layer self-protecting. The pad contributes to selectivity by determining the balance between chemical and mechanical removal \u2014 harder pads tend to reduce chemical selectivity by increasing the mechanical component.\n  <\/div>\n<\/div>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 4 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"mechanical-mechanism\">4. The Mechanical Removal Mechanism: Abrasion, Plowing, and Fracture<\/h2>\n\n<p>The mechanical component of CMP operates through three sub-mechanisms, each dominant in different process conditions:<\/p>\n\n<div class=\"jz-card-grid\">\n  <div class=\"jz-card\">\n    <div class=\"jz-card-icon\">\ud83d\udd35<\/div>\n    <h4>Micro-abrasion (dominant)<\/h4>\n    <p>Abrasive particles roll or slide across the passivated surface, removing thin layers of the chemically weakened material through frictional shear. This is the primary mechanism in most semiconductor CMP applications, generating smooth surfaces with Ra &lt; 1 nm.<\/p>\n  <\/div>\n  <div class=\"jz-card\">\n    <div class=\"jz-card-icon\">\ud83d\udfe1<\/div>\n    <h4>Micro-plowing<\/h4>\n    <p>Under high local contact stress \u2014 hard pads, large abrasive particles, or high down-force \u2014 abrasive particles plastically deform (plow through) the surface rather than rolling across it. Plowing achieves higher removal rates but generates deeper surface damage and scratch defects.<\/p>\n  <\/div>\n  <div class=\"jz-card\">\n    <div class=\"jz-card-icon\">\ud83d\udd34<\/div>\n    <h4>Brittle fracture<\/h4>\n    <p>Relevant primarily for ultra-hard materials like SiC (Mohs 9.5), where the material does not deform plastically under abrasion. Instead, sub-surface crack propagation and lateral fracture drive material removal. Pad hardness and abrasive type must be carefully matched to avoid deep sub-surface damage that affects device reliability.<\/p>\n  <\/div>\n<\/div>\n\n<p>The dominant mechanism in any given CMP process is determined by the combination of pad hardness, abrasive particle size and hardness, applied pressure, and target film mechanical properties. For specialty materials such as SiC, where brittle fracture must be carefully managed to avoid sub-surface damage in the final device layer, pad design and slurry selection are significantly more complex. See our detailed treatment in: <a class=\"jz-link-chip\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/SiC-CMP-Polishing-Pads-for-Third-Generation-Semiconductors\/\" target=\"_blank\">SiC CMP Polishing Pads for Third-Generation Semiconductors<\/a>.<\/p>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 5 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"slurry-transport\">5. Slurry Transport and the Pad&#8217;s Structural Role<\/h2>\n\n<p>The pad does not just provide a mechanical surface \u2014 it is also a fluid transport system. Getting fresh slurry to the pad-wafer contact interface and removing spent slurry and reaction byproducts efficiently is critical to process stability, and the pad&#8217;s design directly governs both functions.<\/p>\n\n<h3>Macro-Transport: Groove Networks<\/h3>\n<p>The groove network machined into the pad surface provides the primary channels for bulk slurry flow. When slurry is dispensed onto the rotating pad, centrifugal force drives it radially outward through the groove channels. As the wafer sweeps across the pad surface, grooves passing under the wafer edge feed fresh slurry into the contact zone while simultaneously evacuating spent material. Groove pattern geometry \u2014 concentric, XY grid, spiral \u2014 determines the radial uniformity of slurry delivery and is a major pad design variable. For a full technical analysis of groove design, see: <a class=\"jz-link-chip\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Pad-Groove-Design-and-Slurry-Distribution\/\" target=\"_blank\">CMP Pad Groove Design and Slurry Distribution<\/a>.<\/p>\n\n<h3>Micro-Transport: Pad Pores as Slurry Reservoirs<\/h3>\n<p>Between grooves, slurry reaches the contact interface through a second, subtler mechanism: capillary uptake into the pad&#8217;s open pore network. As the pad rotates past the slurry dispense arm, slurry is drawn into the surface pores by capillary action, creating a distributed reservoir of slurry-soaked pad material beneath the wafer. During polishing, pressure and shear force slurry out of the pores at asperity contact points, replenishing the thin film at the pad-wafer interface continuously.<\/p>\n\n<p>This is why poreless pads behave differently from conventional porous pads: without an internal reservoir, slurry transport relies entirely on the groove network. Poreless pads demand more precise slurry flow rate control but, in return, offer near-zero pad-borne contamination from pore debris. For a detailed comparison, see: <a class=\"jz-link-chip\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/Poreless-CMP-Pads-vs-Porous-Structure\/\" target=\"_blank\">Poreless CMP Pads vs. Porous Structure<\/a>.<\/p>\n\n<h3>Thermal Transport<\/h3>\n<p>Frictional energy at the pad-wafer contact converts to heat, raising the pad and wafer temperature during polishing. Temperature affects both the pad&#8217;s mechanical properties (polymers soften with increasing temperature, reducing effective hardness) and the slurry&#8217;s chemical reaction rates (oxidation and complexation reactions are temperature-dependent). Groove channels also serve as thermal dissipation pathways, carrying heat away from the contact zone in the slurry flow. Elevated operating temperature \u2014 common in SiC and high-pressure oxide CMP \u2014 must be accounted for in pad material selection and groove depth specification.<\/p>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 6 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"preston\">6. Preston&#8217;s Equation: The Governing Model and Its Real-World Limits<\/h2>\n\n<p>The empirical relationship between process parameters and material removal rate in CMP is captured by the Preston equation, first proposed by F.W. Preston in 1927 for glass polishing and adapted for semiconductor CMP in the 1990s. It remains the most widely used framework for CMP process modeling despite its simplifications.<\/p>\n\n<div class=\"jz-equation\">\n  <div class=\"jz-equation-formula\">MRR = K<sub>p<\/sub> \u00d7 P \u00d7 V<\/div>\n  <div class=\"jz-equation-caption\">\n    <strong>MRR<\/strong> = Material Removal Rate (\u00c5\/min or nm\/min) &nbsp;|&nbsp;\n    <strong>K<sub>p<\/sub><\/strong> = Preston coefficient (captures pad + slurry material properties, units: Pa\u207b\u00b9) &nbsp;|&nbsp;\n    <strong>P<\/strong> = Applied pressure (psi or kPa) &nbsp;|&nbsp;\n    <strong>V<\/strong> = Relative velocity between pad and wafer (m\/s)\n  <\/div>\n<\/div>\n\n<p>The Preston equation states that removal rate scales linearly with both applied pressure and relative velocity. Doubling pressure doubles MRR; doubling velocity doubles MRR. The Preston coefficient Kp encapsulates all the pad and slurry material properties \u2014 hardness, porosity, abrasive type, particle size \u2014 into a single constant that must be determined empirically for each pad-slurry-film combination.<\/p>\n\n<h3>Where Preston Breaks Down<\/h3>\n<p>The linear Preston model works well in the mid-pressure, mid-velocity operating regime of most production CMP processes. Outside this regime, important deviations occur:<\/p>\n\n<div class=\"jz-two-col\">\n  <div class=\"jz-col-box\">\n    <h4>\u2b07\ufe0f Low Pressure \/ Low Velocity Regime<\/h4>\n    <ul>\n      <li>Hydrodynamic lubrication dominates \u2014 the slurry film becomes load-bearing and lifts the pad away from the wafer<\/li>\n      <li>Real contact area approaches zero; MRR drops below Preston prediction<\/li>\n      <li>Occurs at P &lt; ~1 psi or V &lt; 0.1 m\/s on 300 mm tools<\/li>\n      <li>Common in soft-pad Cu CMP with ultra-low-k films \u2014 engineers must account for non-linear behavior near process limits<\/li>\n    <\/ul>\n  <\/div>\n  <div class=\"jz-col-box\">\n    <h4>\u2b06\ufe0f High Pressure \/ High Velocity Regime<\/h4>\n    <ul>\n      <li>Pad deformation under high load reduces effective asperity height and contact area \u2014 MRR plateaus or declines<\/li>\n      <li>Frictional heat generation rises rapidly \u2014 pad softening reduces effective hardness, further reducing Kp<\/li>\n      <li>Defect density increases sharply above a critical pressure threshold<\/li>\n      <li>Occurs at P &gt; ~5 psi or high-temperature conditions \u2014 a common trap in aggressive oxide CMP recipes<\/li>\n    <\/ul>\n  <\/div>\n<\/div>\n\n<p>Understanding these deviations is essential for process window engineering. The quantitative relationship between pad parameters and Kp is covered in detail in our article on <a class=\"jz-link-chip\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Material-Removal-Rate-and-Pad-Parameters\/\" target=\"_blank\">CMP Material Removal Rate and Pad Parameters<\/a>.<\/p>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 7 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"tribological-regimes\">7. Tribological Regimes in CMP: From Boundary to Hydrodynamic<\/h2>\n\n<p>CMP tribology \u2014 the study of friction, wear, and lubrication at the pad-wafer interface \u2014 is governed by the Stribeck curve framework adapted for the CMP context. Three tribological regimes define the operating space:<\/p>\n\n<div class=\"jz-steps\">\n  <div class=\"jz-step\">\n    <div class=\"jz-step-num\">1<\/div>\n    <div class=\"jz-step-body\">\n      <h4>Boundary Lubrication Regime (High P, Low V)<\/h4>\n      <p>Direct asperity-to-asperity contact dominates. The slurry film is too thin to separate the surfaces. Friction is high, removal rate is high, and surface damage risk is elevated. This regime is relevant in the early stages of a polishing run when the pad surface is freshly conditioned and asperities are tall and sharp.<\/p>\n    <\/div>\n  <\/div>\n  <div class=\"jz-step\">\n    <div class=\"jz-step-num\">2<\/div>\n    <div class=\"jz-step-body\">\n      <h4>Mixed Lubrication Regime (Optimal Operating Window)<\/h4>\n      <p>Both direct asperity contact and hydrodynamic slurry film bearing contribute to load support. This is the desired operating regime for most production CMP: removal rate follows Preston&#8217;s equation reasonably well, surface quality is acceptable, and the process is stable. Most fab processes operate in this regime by design.<\/p>\n    <\/div>\n  <\/div>\n  <div class=\"jz-step\">\n    <div class=\"jz-step-num\">3<\/div>\n    <div class=\"jz-step-body\">\n      <h4>Hydrodynamic (Full-Film) Lubrication Regime (Low P, High V)<\/h4>\n      <p>The slurry film fully separates pad and wafer \u2014 no direct contact. The fluid film is load-bearing, friction drops dramatically, and material removal essentially stops. This regime is intentionally induced in some &#8220;soft-landing&#8221; CMP endpoint protocols, where a brief low-pressure, high-velocity clearing step removes residual slurry from the wafer surface without further film removal.<\/p>\n    <\/div>\n  <\/div>\n<\/div>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 8 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"pad-properties-impact\">8. How Each Pad Property Drives a Specific Process Outcome<\/h2>\n\n<p>With the mechanisms established, we can now map each physical pad property to its process impact with precision. This is the engineering vocabulary that connects a pad data sheet to a process result.<\/p>\n\n<div class=\"jz-table-wrap\">\n  <table class=\"jz-table\">\n    <thead>\n      <tr>\n        <th>Pad Property<\/th>\n        <th>Mechanism Affected<\/th>\n        <th>Primary Process Outcome<\/th>\n        <th>Secondary Effect<\/th>\n      <\/tr>\n    <\/thead>\n    <tbody>\n      <tr>\n        <td><strong>Hardness (Shore D \u2191)<\/strong><\/td>\n        <td>Asperity contact stress \u2191<\/td>\n        <td>MRR \u2191, planarization efficiency \u2191<\/td>\n        <td>Scratch density \u2191, WIWNU \u2191 on bowed wafers<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Compressibility (% \u2191)<\/strong><\/td>\n        <td>Macro-scale wafer conformance \u2191<\/td>\n        <td>WIWNU \u2193 (edge-to-center uniformity \u2191)<\/td>\n        <td>Planarization efficiency \u2193<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Pore diameter (\u2191)<\/strong><\/td>\n        <td>Slurry reservoir capacity \u2191<\/td>\n        <td>Slurry utilization efficiency \u2191<\/td>\n        <td>Contact area \u2193, debris risk \u2191<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Pore density (\u2191)<\/strong><\/td>\n        <td>Slurry micro-transport to interface \u2191<\/td>\n        <td>MRR stability \u2191, lower sensitivity to slurry flow variation<\/td>\n        <td>Effective hardness \u2193<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Groove depth (\u2191)<\/strong><\/td>\n        <td>Macro slurry transport capacity \u2191<\/td>\n        <td>More uniform slurry distribution, better byproduct removal<\/td>\n        <td>Pad life \u2193 (less usable material above groove floor)<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Groove pitch (\u2193, closer grooves)<\/strong><\/td>\n        <td>Slurry delivery frequency under wafer \u2191<\/td>\n        <td>Radial MRR uniformity \u2191<\/td>\n        <td>Contact area \u2193; risk of particle trapping in dense grooves<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Elastic recovery (\u2191)<\/strong><\/td>\n        <td>Asperity height stability during long runs \u2191<\/td>\n        <td>MRR stability over extended polishing campaigns<\/td>\n        <td>Higher effective hardness under cyclic loading<\/td>\n      <\/tr>\n      <tr>\n        <td><strong>Surface roughness Ra (\u2191)<\/strong><\/td>\n        <td>Asperity tip density \u2191<\/td>\n        <td>MRR \u2191 after conditioning to higher Ra<\/td>\n        <td>Micro-scratch risk \u2191<\/td>\n      <\/tr>\n    <\/tbody>\n  <\/table>\n<\/div>\n\n<p>Understanding these relationships enables systematic pad selection and process optimization. For a focused discussion of how pad material composition determines these properties, see: <a class=\"jz-link-chip\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Pad-Materials-Polyurethane-vs-Other-Options\/\" target=\"_blank\">CMP Pad Materials: Polyurethane vs Other Options<\/a>.<\/p>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 SECTION 9 \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2 id=\"degradation\">9. Pad Degradation Mechanisms and Performance Drift Over Time<\/h2>\n\n<p>A freshly installed pad does not deliver its peak, stable performance immediately \u2014 nor does a pad in service maintain constant performance without active management. Three simultaneous degradation processes govern how pad performance evolves over its operational lifetime.<\/p>\n\n<h3>Glazing (Thermal Surface Vitrification)<\/h3>\n<p>During polishing, frictional heat at asperity contacts partially melts and re-solidifies the polyurethane surface. This &#8220;glazing&#8221; process smooths asperity tips, reducing surface roughness Ra and effective contact stress \u2014 and therefore reducing MRR. An unconditioned pad can lose 30\u201340% of its initial removal rate within 10\u201320 wafer passes purely from glazing. In-situ conditioning with a diamond disk dresser continuously abrades away the glazed surface layer, restoring asperity geometry and maintaining stable MRR.<\/p>\n\n<h3>Pore Clogging<\/h3>\n<p>Spent abrasive particles, polished film fragments, and reaction byproduct precipitates progressively pack into pad pores and grooves, reducing slurry uptake capacity and disrupting the micro-transport mechanism described in Section 5. Clogged pores create &#8220;dead zones&#8221; on the pad surface where slurry starvation causes locally low removal rates \u2014 a direct contribution to within-wafer non-uniformity. Conditioning abrades the clogged surface layer, re-opening pore access to fresh slurry.<\/p>\n\n<h3>Cumulative Thickness Loss<\/h3>\n<p>Both conditioning and polishing remove pad material continuously. The pad thins from its nominal value (typically 2.0\u20132.5 mm) toward the minimum usable thickness above the backing layer (typically 0.5\u20130.8 mm). As the pad thins, its bulk compressibility and stiffness change, gradually altering the macroscale contact mechanics and leading to slow drift in WIWNU over the pad lifetime. Tracking pad thickness \u2014 via optical measurement or contact gauge at each pad installation and at regular intervals \u2014 is a critical process control activity. For a complete protocol on pad conditioning and end-of-life management, see: <a class=\"jz-link-chip\" href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Pad-Conditioning-and-Lifespan-Management\/\" target=\"_blank\">CMP Pad Conditioning and Lifespan Management<\/a>.<\/p>\n\n<div class=\"jz-callout success\">\n  <div class=\"jz-callout-icon\">\u2705<\/div>\n  <div class=\"jz-callout-body\">\n    <strong>Jizhi Pad Characterization: Predicting Performance Before Installation<\/strong>\n    Jizhi Electronic Technology provides production-lot characterization data for every pad shipment, including: measured Shore D hardness (5-point wafer map), pore size distribution histogram, pad thickness uniformity, and baseline MRR data from our in-house process characterization lab (oxide CMP at reference recipe conditions). This data enables fabs to predict the new-pad process window before the first production wafer is polished, reducing break-in waste. Contact our team for sample data packages.\n  <\/div>\n<\/div>\n\n<!-- \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 FAQ \u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550 -->\n<h2>10. Frequently Asked Questions<\/h2>\n\n<div class=\"jz-faq\">\n  <div class=\"jz-faq-item\">\n    <div class=\"jz-faq-q\">Is material removed by the pad itself, or by the slurry particles?<\/div>\n    <div class=\"jz-faq-a\">Primarily by the slurry abrasive particles, but the pad is indispensable as the mechanical intermediary. The pad asperities transmit force to the abrasive particles, pressing them against the chemically weakened wafer surface with the stress amplification needed for material removal. Without pad asperity contact, the particles would simply float in the slurry film without sufficient contact force to abrade the wafer. The pad and slurry are a co-dependent system \u2014 neither can achieve effective CMP alone.<\/div>\n  <\/div>\n  <div class=\"jz-faq-item\">\n    <div class=\"jz-faq-q\">Why does removal rate drop if you increase pressure too much?<\/div>\n    <div class=\"jz-faq-a\">Above a threshold pressure (typically ~4\u20136 psi on 300 mm tools), two effects counteract the Preston prediction. First, pad asperities deform plastically, increasing the real contact area and reducing local contact stress per asperity \u2014 the opposite of what higher pressure should achieve. Second, frictional heat generation rises sharply, softening the polyurethane and further reducing effective hardness. The net result is a plateau or even a decline in MRR at very high pressures, accompanied by a rapid increase in scratch density and defect generation.<\/div>\n  <\/div>\n  <div class=\"jz-faq-item\">\n    <div class=\"jz-faq-q\">How does pad hardness affect planarity?<\/div>\n    <div class=\"jz-faq-a\">A harder pad preferentially concentrates contact pressure on the topographically high features of the wafer surface (the &#8220;hills&#8221;) while bridging over the low regions (the &#8220;valleys&#8221;). This selectivity \u2014 removing from high points while leaving low points intact \u2014 is called planarization efficiency or step-height reduction. Soft pads conform to the wafer topography, distributing contact pressure more uniformly and removing material from both high and low regions at similar rates, which reduces planarization efficiency but improves within-wafer uniformity for processes where incoming topography is already low.<\/div>\n  <\/div>\n  <div class=\"jz-faq-item\">\n    <div class=\"jz-faq-q\">What is the Stribeck curve and why does it matter for CMP?<\/div>\n    <div class=\"jz-faq-a\">The Stribeck curve plots friction coefficient versus a dimensionless lubrication parameter (the Hersey number: viscosity \u00d7 velocity \/ pressure) for a tribological contact. For CMP, it describes the transition from boundary lubrication (high friction, high MRR, pad asperities directly contacting wafer) through mixed lubrication (production operating window) to hydrodynamic lubrication (low friction, near-zero MRR, slurry film fully separates surfaces). Operating in the mixed lubrication regime gives the best balance of removal rate, uniformity, and defect control. Monitoring friction coefficient \u2014 via the CMP tool&#8217;s motor current or torque sensor \u2014 in real time is a powerful method for detecting tribological regime shifts that signal process excursions.<\/div>\n  <\/div>\n  <div class=\"jz-faq-item\">\n    <div class=\"jz-faq-q\">Does pad temperature matter during CMP?<\/div>\n    <div class=\"jz-faq-a\">Yes, significantly. Polyurethane&#8217;s glass transition temperature (Tg) for typical CMP pad formulations is in the range of 80\u2013120\u00b0C. As pad surface temperature approaches Tg during aggressive polishing, the pad softens, effective hardness drops, and Kp shifts \u2014 causing MRR drift over a polishing run. Additionally, slurry chemical reaction rates are temperature-dependent (typically Arrhenius), so temperature fluctuations affect the chemical component of removal. High-throughput oxide CMP and SiC polishing generate the most heat; these processes benefit from pad formulations with higher-Tg matrices and groove designs that maximize thermal dissipation.<\/div>\n  <\/div>\n<\/div>\n\n<!-- Related -->\n<div class=\"jz-related\">\n  <div class=\"jz-related-title\">\ud83d\udcda Continue Reading \u2014 CMP Pad Deep Dives<\/div>\n  <div class=\"jz-related-grid\">\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">PILLAR \u2014 COMPLETE GUIDE<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Polishing-Pads-The-Complete-Guide\/\" target=\"_blank\">CMP Polishing Pads: The Complete Guide<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">FUNDAMENTALS<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/What-Is-a-CMP-Polishing-Pad-The-Ultimate-Guide\/\" target=\"_blank\">What Is a CMP Polishing Pad? The Ultimate Guide<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">MATERIALS<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Pad-Materials-Polyurethane-vs-Other-Options\/\" target=\"_blank\">CMP Pad Materials: Polyurethane vs Other Options<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">SELECTION<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/Hard-vs-Soft-CMP-Polishing-Pads-Selection-Guide\/\" target=\"_blank\">Hard vs. Soft CMP Polishing Pads: Selection Guide<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">ENGINEERING<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Pad-Groove-Design-and-Slurry-Distribution\/\" target=\"_blank\">CMP Pad Groove Design and Slurry Distribution<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">APPLICATIONS<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/SiC-CMP-Polishing-Pads-for-Third-Generation-Semiconductors\/\" target=\"_blank\">SiC CMP Polishing Pads for Third-Generation Semiconductors<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">OPERATIONS<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Pad-Conditioning-and-Lifespan-Management\/\" target=\"_blank\">CMP Pad Conditioning and Lifespan Management<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">PROCESS<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Material-Removal-Rate-and-Pad-Parameters\/\" target=\"_blank\">CMP Material Removal Rate and Pad Parameters<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">QUALITY<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Pad-Defect-Control-Scratches-and-Uniformity\/\" target=\"_blank\">CMP Pad Defect Control: Scratches and Uniformity<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">TECHNOLOGY<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/Poreless-CMP-Pads-vs-Porous-Structure\/\" target=\"_blank\">Poreless CMP Pads vs. Porous Structure<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">SOURCING<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Polishing-Pad-Brands-Comparison\/\" target=\"_blank\">CMP Polishing Pad Brands Comparison<\/a>\n    <\/div>\n    <div class=\"jz-related-item\">\n      <div class=\"jz-related-cat\">PROCUREMENT<\/div>\n      <a href=\"https:\/\/jeez-semicon.com\/zh\/blog\/CMP-Polishing-Pad-Price-Factors-and-Buying-Guide\/\" target=\"_blank\">CMP Polishing Pad Price Factors and Buying Guide<\/a>\n    <\/div>\n  <\/div>\n<\/div>\n\n<!-- CTA -->\n<div class=\"jz-cta-banner\">\n  <h2>Engineered for Your Process \u2014 Not Just Any CMP Pad<\/h2>\n  <p>Jizhi Electronic Technology manufactures CMP polishing pads with precisely controlled hardness, porosity, and groove geometry, backed by production-lot characterization data and application engineering support. Hard pads, soft subpads, SiC-specific formulations, and custom OEM solutions available.<\/p>\n  <a class=\"jz-btn jz-btn-white\" href=\"https:\/\/jeez-semicon.com\/zh\/semi-categories\/polishing-pad\/\" target=\"_blank\">Browse CMP Polishing Pads<\/a>\n  <a class=\"jz-btn jz-btn-outline\" href=\"https:\/\/jeez-semicon.com\/zh\/contact\/\" target=\"_blank\">Talk to Our Engineers<\/a>\n<\/div>\n\n<!--\n  \u2554\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\n  \u2551  SEO NOTES \u2014 Cluster 2\n  \u2560\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\n  \u2551  Title tag:  How CMP Polishing Pads Work: Mechanisms & Process Science (2026)\n  \u2551  Meta desc:  Engineer-level guide to CMP pad mechanics \u2014 three-body contact,\n  \u2551              Preston equation, tribological regimes, slurry transport, and\n  \u2551              pad degradation. By Jizhi Electronic Technology.\n  \u2551  Focus KW:   how CMP polishing pads work\n  \u2551  Secondary:  CMP mechanism, Preston equation CMP, CMP tribology,\n  \u2551              CMP material removal mechanism, pad-wafer contact\n  \u2551  Schema:     Article + FAQPage\n  \u2551  Intent:     Informational \/ Technical research\n  \u255a\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\u2550\n-->\n\n<\/div><!-- .jz-art -->","protected":false},"excerpt":{"rendered":"<p>Back to CMP Polishing Pads: The Complete Guide Jizhi Electronic Technology \u2014 Fundamentals Series A rigorous, engineer-level explanation of the mechanical, chemical, and tribological mechanisms that govern material removal in  &#8230;<\/p>","protected":false},"author":1,"featured_media":1807,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[9,59],"tags":[],"class_list":["post-1761","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","category-industry"],"acf":[],"_links":{"self":[{"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/posts\/1761","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/comments?post=1761"}],"version-history":[{"count":2,"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/posts\/1761\/revisions"}],"predecessor-version":[{"id":1763,"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/posts\/1761\/revisions\/1763"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/media\/1807"}],"wp:attachment":[{"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/media?parent=1761"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/categories?post=1761"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jeez-semicon.com\/zh\/wp-json\/wp\/v2\/tags?post=1761"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}