Pressing Pad Elastic Member for Inclined Polishing

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Solution Overview

Problem

Conventional polishing apparatuses face challenges in maintaining a constant width of the polishing tool in contact with the substrate's peripheral portion when the tool is inclined, leading to uneven polishing rates and potential clogging, which affects the yield and efficiency in semiconductor device fabrication.

Innovation Solution

The polishing apparatus incorporates a pressing pad with an elastic member that deforms to maintain a constant width of the polishing tool in contact with the substrate's peripheral portion, even when the tool is inclined, by using a support member with a recess that allows the elastic member to shape along the substrate, ensuring consistent contact and pressure distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the polishing tool is inclined to polish the peripheral portion of the substrate, then the polishing coverage is improved, but the contact width becomes uneven leading to inconsistent polishing rate

Engineering Contradiction:
Improvepolishing coverageVSAvoidpolishing rate consistency
Core Design Contradiction:
Area of stationary objectVSManufacturing precision

Solution Approach 1:

The pressing pad is designed with an elastic member that dynamically adapts its shape to maintain consistent contact. The elastic member deforms elastically under pressure to conform to the substrate surface, allowing the polishing tool to be inclined while maintaining uniform contact width across the peripheral portion, thus resolving the contradiction between improved coverage and consistent polishing rate.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the polishing tool is inclined to reach the bevel portion, then the accessibility is improved, but clogging occurs due to uneven pressure distribution

Engineering Contradiction:
Improveaccessibility to bevel portionVSAvoidclogging prevention
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The pressing pad utilizes an elastic member that functions as a flexible element, allowing it to deform and adapt to the inclined configuration needed to reach the bevel portion. This flexibility ensures uniform pressure distribution across the polishing tool, preventing clogging while maintaining accessibility to the bevel portion.

Inventive Principle:
Principle #30Flexible shells and thin films

3Stability of the object's composition

If a rigid pressing pad is used, then the structural stability is improved, but the contact uniformity deteriorates when the tool is inclined

Engineering Contradiction:
Improvestructural stabilityVSAvoidpressure distribution uniformity
Core Design Contradiction:
Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The pressing pad transitions from a rigid structure to one incorporating an elastic member that changes its physical state under load. The elastic member deforms to alter the contact parameters, distributing pressure uniformly across the polishing tool even when inclined, thus resolving the contradiction between structural stability and pressure uniformity.

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 solution maintains a consistent polishing rate and prevents clogging, enhancing the throughput and efficiency of the polishing process by ensuring uniform contact and pressure across the substrate's peripheral portion, regardless of the inclination angle.

Implementation Method 1

an elastic member (55) having a pressing surface (55a) for pressing the polishing tape (23)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3335832B1Polishing apparatus and pressing pad for pressing polishing tool
Publication Date: 2021.02.03 EBARA CORP
  • EP3335832B1 patent drawingFigure 1
  • EP3335832B1 patent drawingFigure 2
  • EP3335832B1 patent drawingFigure 3

AI summary

A polishing apparatus which can keep a width of a polishing tool constant when a peripheral portion of a workpiece is polished by the polishing tool while the polishing tool is inclined with respect to the workpiece is disclosed. The polishing apparatus includes a workpiece holder 3 configured to hold a workpiece W and rotate it, and a pressing pad 50 configured to press a polishing tool 23 against a peripheral portion of the workpiece W held by the workpiece holder 3. The pressing pad 50 includes an elastic member 55 having a pressing surface 55a configured to press the polishing tool 23 against the peripheral portion of the workpiece W and a support member 56 configured to support the elastic member 55. The support member 56 has a recess 57 formed in a front surface 56a of the support member 56, the elastic member 55 being capable of entering the recess 57.