Polishing Apparatus Fluid Support Wafer Periphery

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Solution Overview

Problem

Existing polishing methods for semiconductor wafers struggle to polish the periphery while maintaining the original angle of the substrate, often bending the wafer or failing to uniformly polish the flat surface, especially when only one side needs to be processed.

Innovation Solution

A polishing apparatus with a substrate-holding mechanism, a polishing mechanism using a polishing tape, and a periphery-supporting mechanism that supports the substrate with fluid pressure, allowing for constant pressing force and movement in the radial direction to maintain the substrate's flatness and polish only the desired side.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a polishing tool is pressed against the periphery of the substrate from one side, then the periphery can be polished, but the substrate bends making it difficult to maintain parallel polishing

Engineering Contradiction:

Improvepolishing uniformityVSAvoidsubstrate flatness

Core Design Contradiction:

Manufacturing precisionVSShape

Solution Approach 1:

The patent applies a counterbalancing force by supporting the periphery of the substrate from the opposite side using a support mechanism. This counterweight approach prevents the substrate from bending under the polishing pressure, maintaining substrate flatness while enabling effective periphery polishing from one side.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent transitions from a single-sided polishing approach to a multi-dimensional support system. By adding vertical support from the opposite side and radial support elements, the system creates a three-dimensional force balance that maintains substrate flatness during one-sided polishing, resolving the contradiction between polishing effectiveness and substrate deformation.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Productivity

If a polishing tool is pressed against the periphery of the substrate, then polishing can be performed, but the pressing force causes the periphery to bend

Engineering Contradiction:

Improvepolishing efficiencyVSAvoidperiphery angle

Core Design Contradiction:

ProductivityVSShape

Solution Approach 1:

The support mechanism positioned opposite to the polishing tool applies an equal and opposite force to counterbalance the polishing pressure. This allows the polishing tool to maintain effective pressing force for efficient polishing while the counterbalancing support prevents periphery bending and angle distortion.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The patent dynamically adjusts the support force parameters based on the polishing conditions. By modifying the magnitude and distribution of the counterbalancing force, the system optimizes both polishing efficiency and periphery angle maintenance, allowing effective polishing without shape distortion.

Inventive Principle:

Principle #35Parameter changes

3Shape

If both-side polishing is performed to prevent substrate bending, then substrate flatness is maintained, but both upper and lower peripheries are processed when only one side needs polishing

Engineering Contradiction:

Improvesubstrate flatnessVSAvoidselective side polishing

Core Design Contradiction:

ShapeVSAdaptability or versatility

Solution Approach 1:

The patent segments the support function from the polishing function. The support mechanism is positioned independently on the opposite side and activates only when needed to counterbalance polishing forces. This segmentation allows selective one-sided polishing while maintaining substrate flatness, avoiding unnecessary processing of the other side.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The support mechanism automatically activates and deactivates based on the polishing operation requirements. When polishing is applied to one side, the support mechanism self-activates on the opposite side to maintain flatness. When polishing is not required, the support mechanism deactivates, allowing the substrate to remain unprocessed on that side.

Inventive Principle:

Principle #25Self-service

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

The apparatus effectively polishes the periphery of the semiconductor wafer without bending it, ensuring a constant pressing force and maintaining the original angle, thus preventing contamination and improving device quality by uniformly removing films from the substrate.

Implementation Method 1

a periphery-supporting mechanism configured to support the periphery of the substrate by a fluid

Methodology Applied

Scientific EffectFluid pressure: Pressure Increase

Data Source

PatentUS10137552B2Polishing apparatus

Publication Date: 2018.11.27 EBARA CORP

AI summary

A polishing apparatus polishes a periphery of a substrate by bringing a polishing tool into sliding contact with the substrate. The polishing apparatus includes a substrate-holding mechanism configured to hold a substrate and rotate the substrate, a polishing mechanism configured to press a polishing tool against a periphery of the substrate so as to polish the periphery, and a periphery-supporting mechanism configured to support the periphery of the substrate by a fluid. The periphery-supporting mechanism is configured to support a surface of the substrate from an opposite side or the same side of the periphery of the substrate.