Polishing Pad Holder Flow Design to Prevent Substrate Surface Damage

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Solution Overview

Problem

Existing substrate polishing technologies face issues of surface damage and reduced polishing rate due to abrasive particles from rotary joints and inadequate supply of fresh polishing liquid, leading to potential substrate damage and decreased efficiency.

Innovation Solution

A substrate processing apparatus with a pad holder featuring a discharge hole and discharge passages in the center, combined with a polishing pad having a spiral groove, ensures efficient supply and distribution of polishing liquid without the need for rotary joints, using nozzles to deliver fresh liquid directly to the substrate surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a rotary joint is used to supply polishing liquid through the rotating polishing tool, then polishing liquid can be supplied to the substrate, but abrasive grains in the polishing liquid may abrade components inside the rotary joint and generate particles that damage the substrate surface

Engineering Contradiction:

Improvepolishing liquid supplyVSAvoidsubstrate surface damage

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent removes the rotary joint from the system entirely. Instead of supplying polishing liquid through the rotating pad holder via a rotary joint, the polishing liquid is supplied from the stationary nozzle to the polishing pad, eliminating the source of abrasive particle generation while maintaining the essential function of polishing liquid delivery to the substrate

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The polishing pad serves as an intermediary medium that receives polishing liquid from the stationary nozzle and transfers it to the substrate during rotation. This allows the polishing liquid supply system to remain stationary while the pad holder rotates, avoiding the need for a rotary joint and its associated particle generation problems

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If polishing liquid is circulated via the polishing tool with a spiral groove, then polishing liquid can be circulated, but fresh polishing liquid cannot be sufficiently supplied to the center of the substrate and polishing rate decreases

Engineering Contradiction:

Improvepolishing rateVSAvoidsubstrate surface quality

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent supplies fresh polishing liquid to the polishing pad before the polishing operation begins. The nozzle is positioned to deliver polishing liquid to the polishing pad in advance, ensuring that the pad is adequately saturated with fresh polishing liquid before it contacts the substrate, thereby maintaining high polishing rate and preventing surface damage

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of circulating polishing liquid through the rotating pad holder as in conventional designs, the patent inverts the approach by using a stationary nozzle to supply polishing liquid directly to the polishing pad. This reversal eliminates the circulation problem and ensures continuous supply of fresh polishing liquid to maintain high polishing rates

Inventive Principle:

Principle #13The other way round (Inversion)

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 configuration prevents substrate damage by eliminating abrasive particle entry and ensures uniform polishing with improved polishing rates by ensuring consistent liquid supply to the substrate surface, enhancing polishing efficiency.

Implementation Method 1

a discharge passage communicated with an outside of the pad holder from the discharge hole

Methodology Applied

Scientific EffectFluid flow through passage:

Implementation Method 2

the polishing liquid supplied from the outer periphery of the polishing tool to the substrate is recovered at the center of the polishing tool by a spiral groove formed on the polishing pad

Methodology Applied

Scientific EffectSpiral flow circulation:

Implementation Method 3

a nozzle for supplying a polishing liquid around the pad holder

Methodology Applied

Scientific EffectLiquid spray delivery: Fluid Spray

Data Source

PatentUS12569957B2Substrate processing apparatus and substrate processing method

Publication Date: 2026.03.10 EBARA CORP

AI summary

To suppress damage to a surface to be polished of a substrate and improve a polishing rate. A substrate processing apparatus includes a table 100 for supporting a substrate WF, a pad holder 226 for holding a polishing pad 222 for polishing the substrate WF supported by the table 100, a nozzle 228 for supplying a polishing liquid around the pad holder 226, and a pad rotation mechanism for rotating the pad holder 226. The pad holder 226 includes a discharge hole 221-2a formed in the center of a holding surface 221-2c configured to hold the polishing pad 222 and a discharge passage 221-2b communicated with an outside of the pad holder 226 from the discharge hole 221-2a.