CMP Polishing Pad Carrier-Compatible Grooves Slurry Distribution

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Solution Overview

Problem

Conventional CMP polishing pads with groove patterns fail to effectively utilize slurry due to the squeegee effect caused by active wafer carrier rings, leading to reduced polishing efficiency and increased costs.

Innovation Solution

The polishing pad features carrier-compatible grooves that align with the carrier grooves, creating larger flow passages and enhancing slurry distribution by determining the groove shape based on the orientation of the carrier grooves, ensuring alignment and increased slurry reach during polishing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional groove patterns are used on polishing pads, then the pad structure is simple and easy to manufacture, but slurry consumption increases due to the squeegee effect

Engineering Contradiction:

Improveslurry consumptionVSAvoidgroove pattern complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The polishing pad employs different groove patterns in different radial zones. The first groove pattern is located at a first radial position while the second groove pattern is at a second radial position, allowing each zone to be optimized for its specific function regarding slurry distribution and carrier ring interaction

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The polishing pad surface is divided into multiple groove patterns rather than using a single uniform pattern. This segmentation allows different regions to handle slurry flow differently, with some grooves designed to align with carrier ring grooves to maintain slurry presence while others provide general distribution

Inventive Principle:

Principle #1Segmentation

2Reliability

If the polishing pad uses more slurry to compensate for the squeegee effect, then polishing effectiveness is maintained, but process costs increase

Engineering Contradiction:

Improvepolishing effectivenessVSAvoidslurry quantity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The groove patterns are pre-configured on the polishing pad to anticipate and counteract the squeegee effect before it occurs. The grooves are positioned and oriented to deliver slurry to specific locations where it is needed, preventing slurry depletion at the carrier ring interface

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The groove pattern design incorporates feedback from the carrier ring groove orientation. By aligning pad grooves with carrier ring grooves, the system creates a self-regulating slurry distribution mechanism that responds to the mechanical interaction between carrier and pad

Inventive Principle:

Principle #23Feedback

3Quantity of substance

If carrier ring grooves are added to admit slurry, then slurry distribution improves, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improveslurry distributionVSAvoidmanufacturing simplicity

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The polishing pad grooves are designed to merge with or align with the carrier ring grooves, creating a continuous slurry pathway. This integration allows the carrier ring structure to serve dual purposes: holding the wafer and facilitating slurry delivery through its grooves

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS7520796B2Polishing pad with grooves to reduce slurry consumption

Publication Date: 2009.04.21 DUPONT ELECTRONIC MATERIALS HLDG INC

AI summary

A chemical mechanical polishing pad having an annular polishing track and a concentric center O. The polishing pad includes a polishing layer having a plurality of pad grooves formed therein. The polishing pad is designed for use with a carrier, e.g., a wafer carrier, that includes a polishing ring having a plurality of carrier grooves. Each of the plurality of pad grooves has a carrier-compatible groove shape configured to enhance the transport of a polishing medium beneath the carrier ring on the leading edge of the carrier ring during polishing.