Polishing Member Profile Control via Dynamic Dresser Speed Adjustment

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Solution Overview

Problem

Conventional dressing methods for polishing members in chemical-mechanical polishing apparatuses often fail to achieve a target profile, leading to variations in polishing rates and potential polishing failures due to unwanted undulations on the polishing member surface.

Innovation Solution

A method that involves oscillating a dresser on the polishing member, measuring surface height at predefined sections, calculating differences between the current and target profiles, and correcting the dresser's moving speeds to achieve the target profile, while also adjusting for film thickness and polishing rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional dressing methods are used, then the polishing member can be dressed, but the target profile cannot be achieved and unwanted undulations are formed on the surface

Engineering Contradiction:

Improveprofile accuracyVSAvoidpolishing rate consistency

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent implements a feedback mechanism where the actual profile of the polishing member is measured and compared with the target profile, and the dressing conditions are adjusted based on the deviation. This closed-loop control enables precise achievement of the target profile while preventing undulations that would cause polishing rate variations.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent systematically adjusts multiple dressing parameters including dresser rotation speed, oscillation amplitude, oscillation frequency, and dressing pressure to optimize the dressing process. By changing these parameters, the system achieves the target profile accurately without generating unwanted surface undulations.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the dresser oscillation speed is increased, then the dressing efficiency is improved, but the profile accuracy deteriorates due to inability to achieve target profile

Engineering Contradiction:

Improvedressing efficiencyVSAvoidprofile accuracy

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs dynamic adjustment of the dresser oscillation speed based on real-time profile measurements. The oscillation speed is not fixed but varies during the dressing process to achieve both efficiency and accuracy, allowing the system to adapt to different stages of the dressing operation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses periodic oscillation of the dresser as a fundamental dressing mechanism. By controlling the period and frequency of this oscillatory motion, the system achieves efficient material removal while maintaining profile accuracy through synchronized oscillation patterns.

Inventive Principle:

Principle #19Periodic action

3Productivity

If the dressing load is increased, then the polishing rate is improved, but unwanted undulations are formed on the polishing member surface

Engineering Contradiction:

Improvepolishing rateVSAvoidsurface uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent optimizes the dressing load parameter to achieve the desired balance between polishing rate and surface uniformity. By precisely controlling the applied load during dressing, the system removes material efficiently without creating undulations that would compromise surface uniformity and cause polishing rate variations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses profile measurement feedback to monitor surface uniformity during the dressing process. When undulations begin to form due to excessive load, the system adjusts the dressing load in real-time to maintain surface uniformity while preserving adequate polishing rate.

Inventive Principle:

Principle #23Feedback

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 approach allows for accurate achievement of the target profile on the polishing member, ensuring consistent polishing rates and preventing polishing failures by dynamically adjusting the dresser's movement based on real-time measurements.

Implementation Method 1

a dresser, having a number of abrasive grains, such as diamond particles, electrodeposited thereon, is used to dress (condition) the surface of the polishing member to regenerate fine irregularities

Methodology Applied

Scientific EffectAbrasion: Abrasion

Implementation Method 2

measuring a surface height of the polishing member at each of plural oscillation sections which are defined in advance on the polishing member along an oscillation direction of the dresser

Methodology Applied

Scientific EffectSurface height measurement:

Implementation Method 3

a polishing process performed by a chemical-mechanical polishing (CMP) apparatus... due to a chemical polishing action and a mechanical polishing action

Methodology Applied

Scientific EffectChemical-mechanical polishing:

Data Source

PatentUS9156130B2Method of adjusting profile of a polishing member used in a polishing apparatus, and polishing apparatus

Publication Date: 2015.10.13 EBARA CORP

AI summary

The method includes the steps of measuring a surface height of a polishing member 10 at each of plural oscillation sections Z1 to Z5 which are defined in advance on the polishing member 10 along an oscillation direction of a dresser 5; calculating a difference between a current profile obtained from measured values of the surface height and a target profile of the polishing member 10; and correcting moving speeds of the dresser 5 in the plural oscillation sections Z1 to Z5 so as to eliminate the difference.