CMP Polishing Pad with Hydrophilic and Hydrophobic Regions
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Solution Overview
Problem
Conventional chemical mechanical polishing (CMP) processes face challenges in uniformly polishing various surfaces, such as bare substrates, metal layers, oxide layers, and nitride layers, due to inconsistent pressure distribution and damage from grooves in the polishing pad, leading to uneven polishing rates and reduced pad lifespan.
Innovation Solution
A polishing pad with a surface comprising hydrophilic and hydrophobic material regions, where the hydrophilic material is concentrated in the central region and the hydrophobic material in the peripheral region, or vice versa, to optimize slurry distribution and enhance mechanical strength, along with concavities and convexities like concentric grooves, tailored for specific layers like metal or oxide layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If grooves are added to the polishing pad to improve uniformity of polishing, then polishing uniformity is improved, but the useful life of the polishing pad is reduced due to damage in the groove portions
Solution Approach 1:
The polishing pad is designed with different material properties in different regions: the central region uses a softer material (first hardness) while the peripheral region uses a harder material (second hardness greater than the first). This local differentiation allows the central region to maintain uniform polishing across the surface while the harder peripheral region provides structural support and resistance to damage, thereby extending the pad's useful life without compromising polishing uniformity.
2Manufacturing precision
If pressure between polishing pad and substrate is adjusted to ensure uniform polishing, then polishing uniformity is improved, but the technique is difficult to use when polishing various surfaces such as bare substrate, metal layer, oxide layer, nitride layer, and oxynitride layer
Solution Approach 1:
The polishing pad employs region-specific material hardness: a softer central region for uniform polishing contact and a harder peripheral region for structural stability. This local quality differentiation enables the pad to adapt to various surface types (bare substrate, metal, oxide, nitride, oxynitride layers) while maintaining consistent polishing uniformity across all surface types without requiring separate pressure adjustment techniques for each material.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design ensures uniform polishing across different substrate types, maintaining pad strength and extending its lifespan by optimizing slurry distribution and surface topography, thereby preventing damage to fine patterns and ensuring consistent polishing rates.
Implementation Method 1
a surface of the polishing pad has a first portion including hydrophilic material and a second portion including hydrophobic material
Implementation Method 2
the first portion of the polishing surface is located in a first region of the polishing pad and the second portion of the polishing surface is located in a second region of the polishing pad
Implementation Method 3
a surface of the polishing pad has a first portion including hydrophilic material and a second portion including hydrophobic material
Data Source
AI summary
The surface(s) of a polishing pad for polishing an object has a first portion including hydrophilic material and a second portion including hydrophobic material. The first portion of the polishing surface is located in a first region of the polishing pad and the second portion of the polishing surface is located in a second region of the polishing pad juxtaposed with the first region in the radial direction of the pad. The hydrophilic material may be a polymer resin that contains hydrophilic functional groups having OH and/or ═O at bonding sites of the polymer. The hydrophobic material may be a polymer resin that contains hydrophobic functional groups having H and/or F at bonding sites of the polymer. The polishing pad is manufactured by extruding respective lines of the hydrophilic and hydrophobic materials. The extruders and a backing are moved relative to each other such that the lines form concentric rings of the hydrophilic and hydrophobic materials.