CMP Polishing Pad Window Structure for Leak-Free Endpoint Detection

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Solution Overview

Problem

Water leakage through gaps between the polished layer and window block in window insert type polishing pads during chemical mechanical polishing (CMP) processes leads to failure and inaccurate sensing of metal layers, necessitating frequent replacement and increased consumption of polishing pads.

Innovation Solution

A window insert type polishing pad design with a top pad layer and window block, where the gap between their upper surfaces and the depth of the groove pattern are controlled within specific ratios (Formulas 1 and 2) to prevent leakage and ensure accurate end-point detection, using a combination of adhesive layers and thermal fusion to maintain structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a window block is inserted into the polishing pad to enable endpoint detection, then sensing capability is improved, but water leakage occurs through gaps between the window block and polishing pad

Engineering Contradiction:

Improveendpoint detection accuracyVSAvoidwater leakage prevention

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The polishing pad is designed with a groove pattern only in the region surrounding the window block insertion hole, creating localized different properties: the window block region remains flat and sealed for water tightness, while the surrounding area has groove patterns for water circulation and polishing function

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The polishing pad is divided into functionally distinct regions: a window block insertion region for sensing, and a groove pattern region for water management, allowing each region to optimize its specific function without compromising the other

Inventive Principle:

Principle #1Segmentation

2Productivity

If the polishing pad is used frequently to reduce consumption, then productivity is improved, but the polishing pad fails due to water leakage and requires replacement

Engineering Contradiction:

Improvepolishing pad service lifeVSAvoidpolishing pad failure

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The groove pattern is pre-formed in the polishing pad at the time of manufacturing, before the polishing process begins. This preliminary structuring ensures proper water circulation paths are established from the start, preventing water leakage issues that would otherwise develop during use and cause premature failure

Inventive Principle:

Principle #10Preliminary action

3Reliability

If the gap between window block and polishing pad is increased to prevent water leakage, then reliability is improved, but sensing accuracy deteriorates

Engineering Contradiction:

Improvewater leakage preventionVSAvoidsensing accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The groove pattern is localized to specific regions around the window block rather than being uniform across the entire pad, creating areas with different functional properties that simultaneously address both sealing and sensing requirements

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS12600006B2Polishing pad with window and method of manufacturing the same

Publication Date: 2026.04.14 SK ENPULSE CO LTD

AI summary

This invention relates to a polishing pad and a method for manufacturing the same. The polishing pad may include a top pad layer and a window block. The top pad layer may include a groove pattern formed on an upper surface of the top pad layer. A first hole may be formed through the top pad layer. The window block may be inserted into the first hole. The top pad layer and the window block may have a structure coincided with following Formula 1.1.1≤Gap+ThkRTPCThkgrv≤3.Formula⁢ 1In Formula 1, the gap may indicate a height difference between an upper surface of the top pad layer and an upper surface of the window block, the ThkRTPC may indicate a thickness of the window block, and the Thkgrv may indicate a depth of the groove pattern.