Modular CMP Dresser for Uniform Pad Grooves and Wafer Protection

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Solution Overview

Problem

Existing CMP processes face challenges in achieving precise wafer planarization due to issues with conventional dressers that cause wafer scratching, loss of polishing liquid, uneven surface roughness, and inadequate control over groove formation and thermal expansion, leading to suboptimal material removal rates and wafer quality.

Innovation Solution

A CMP process and apparatus utilizing a dresser with high-hardness diamond modules and a modular grinding unit to form regionalized co-height and co-planar grooves, coupled with a monitoring method using AI and optical shearing interferometry to ensure uniform surface roughness and effective polishing liquid retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional dressers are used to create grooves on the polishing pad, then material removal is achieved, but the high ends of cones cause excessive protrusions that scratch the wafer surface

Engineering Contradiction:

Improvematerial removal rateVSAvoidwafer scratching

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The dresser is divided into multiple regionalized modules, each with cones of different heights. This segmentation allows different regions to perform different functions: higher cones create grooves for material removal while lower cones prevent excessive protrusion formation, thereby eliminating wafer scratching while maintaining productivity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the dresser are assigned different cone heights and configurations tailored to local requirements. The high-end cones in specific regions create necessary grooves and fluff, while other regions use lower cones to maintain surface uniformity, applying local quality to resolve the contradiction between material removal and wafer protection.

Inventive Principle:

Principle #3Local quality

2Productivity

If conventional dressers operate at high temperature (above 35°C), then polishing continues, but the variation of material removal rate increases rapidly affecting polishing quality

Engineering Contradiction:

Improvepolishing continuityVSAvoidmaterial removal rate uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The dresser incorporates thermal expansion compensation mechanisms that dynamically adjust the relative positions of cones as temperature changes. This dynamic adjustment maintains the precise spatial relationships between high-end and low-end cones, ensuring consistent material removal rate uniformity even during continuous high-temperature polishing operations.

Inventive Principle:

Principle #15Dynamics

3Quantity of substance

If the high end of the dresser cone is pressed against the polishing pad, then grooves are created for polishing liquid retention, but the polishing pad deforms and generates ridges during lateral movement

Engineering Contradiction:

Improvepolishing liquid retentionVSAvoidpolishing pad uniformity

Core Design Contradiction:

Quantity of substanceVSShape

Solution Approach 1:

The dresser employs asymmetric cone height distribution where only specific high-end cones press against the polishing pad to create grooves, while surrounding lower cones remain engaged to suppress ridge formation. This asymmetric configuration enables selective groove creation without causing excessive pad deformation, maintaining both polishing liquid retention and surface uniformity.

Inventive Principle:

Principle #4Asymmetry

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

Enhances wafer flatness by maintaining consistent groove formation, stabilizes polishing liquid retention, and provides real-time monitoring to adjust for wear, thereby improving material removal rates and overall CMP process efficiency.

Implementation Method 1

a dresser with high-hardness diamond modules and a modular grinding unit to form regionalized co-height and co-planar grooves

Methodology Applied

Scientific EffectAbrasion: Abrasion

Implementation Method 2

monitoring method using AI and optical shearing interferometry to ensure uniform surface roughness

Methodology Applied

Scientific EffectOptical interference: Interference

Data Source

PatentUS20260021556A1Dresser for CMP process and mathod and process for creating and monitoring polishing pad pores

Publication Date: 2026.01.22 H P B OPTOELECTRONICS CO LTD

AI summary

A dresser for a CMP process has a substrate, at least one sheet body, and a modular grinding unit. The least one sheet body is disposed on a side face of the substrate. The modular grinding unit is disposed on the at least one sheet body and has multiple structures disposed on the at least one sheet body at spaced intervals. Each one of the multiple structures has a convex portion, and the convex portions of the multiple structures have different heights.