Polishing Device Top Ring Independent Pressing Control

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Solution Overview

Problem

Conventional polishing devices face challenges in achieving an optimal polishing profile due to the interdependence of pressing forces across different areas of the wafer, leading to variations in polishing amounts and profiles, which can result in suboptimal polishing results.

Innovation Solution

A polishing device with a top ring featuring independently controlled pressing portions, where the effect rate of each pressing portion is determined for an area wider than its pressing area, allowing for precise control of pressing forces based on the polishing profile and effect rate to equalize the polishing profile across the wafer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional pressure control is used to adjust polishing amount in specific areas, then local polishing insufficiency is addressed, but the interdependence of pressing forces causes unexpected variations in other areas

Engineering Contradiction:

Improvepolishing amount uniformityVSAvoidpolishing profile predictability

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The system measures the actual polishing profile and uses this feedback to calculate the appropriate pressing forces for each pressing portion. The effect rate provides a quantitative model that predicts how pressing force changes will affect polishing amounts, enabling reliable and predictable control of the polishing profile.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system changes the pressing force parameters for each pressing portion based on the measured polishing profile and the effect rate model. By adjusting these parameters systematically, the controller achieves reliable and predictable polishing results across all areas of the wafer.

Inventive Principle:

Principle #35Parameter changes

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 enables more accurate and consistent polishing profiles by appropriately controlling the pressing forces, reducing variations and improving the overall polishing efficiency and yield.

Implementation Method 1

a substrate, which is a polishing target object, is pressed against a polishing pad formed of a nonwoven or the like, and the substrate and the polishing pad are caused to slide relative to each other for polishing

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

supplying abrasive grains between them

Methodology Applied

Scientific EffectAbrasion: Abrasion

Data Source

PatentUS11331764B2Polishing device, polishing method, and non-transitory computer readable medium

Publication Date: 2022.05.17 EBARA CORP

AI summary

A polishing device includes a polishing table comprising a polishing surface, a top ring configured to press a polishing target surface against the polishing surface and comprising a plurality of pressing portions configured to independently apply a pressing force to a plurality of areas of the wafer, and a controller configured to store a first pressing portion effect rate for a first pressing portion of the plurality of pressing portions in a storage unit, the first pressing portion effect rate being a change in polishing amount of the polishing target surface for a change in pressing force applied by the first pressing portion and control the pressing force applied by the first pressing portion based on the first pressing portion effect rate and a polishing profile of the polishing target surface.