CMP Pad Dressing With Nanobubble Rinse for Debris Removal

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Solution Overview

Problem

Chemical mechanical planarization (CMP) processes in semiconductor manufacturing are susceptible to equipment failure due to debris particles lodging in the CMP pad, leading to scratches or other damage to integrated circuits that are formed from the wafers, which results in high costs and interruptions.

Innovation Solution

Incorporating a high-pressure rinse with nanobubbles during the pad dressing process to dislodge debris particles from the CMP pad, using ultrasonic generators to create nanobubbles in the rinsing fluid that assist in cleaning the pad.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional pad dressing process is used, then equipment simplicity is maintained, but debris particles remain lodged in the CMP pad causing wafer damage

Engineering Contradiction:

Improvewafer damage preventionVSAvoidpad dressing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A rinsing fluid is introduced as an intermediary substance between the pad dresser and the CMP pad. The rinsing fluid penetrates into the pores of the CMP pad and facilitates the removal of debris particles that the mechanical pad dresser cannot adequately remove alone.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces purely mechanical debris removal with a combined chemical-physical approach. Ultrasonic waves are applied to the rinsing fluid to generate cavitation bubbles that mechanically shock and dislodge debris particles from the pad pores, supplementing the mechanical action of the pad dresser.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If pad dressing is performed frequently to remove debris, then wafer quality is improved, but production time is lost

Engineering Contradiction:

Improvewafer surface qualityVSAvoidproduction efficiency

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The rinsing fluid with ultrasonic nanobubbles is applied during the pad dressing process itself, performing preliminary cleaning action while the pad is being dressed. This prevents debris from becoming deeply lodged in the pad pores during normal operation, reducing the frequency and intensity of subsequent cleaning operations needed.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The rinsing fluid application continues throughout the pad dressing process, maintaining continuous cleaning action rather than intermittent cleaning. This ensures debris is constantly being removed from the pad surface and pores, maintaining consistent wafer quality without interrupting the dressing operation.

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If high-pressure rinse alone is used to clean pad, then debris removal is improved, but energy consumption increases and cleaning effectiveness is limited

Engineering Contradiction:

Improvedebris particle removalVSAvoidrinse energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent changes the physical state and properties of the rinsing fluid by applying ultrasonic energy to generate nanobubbles. This transforms the rinsing mechanism from simple high-pressure liquid impact to a combination of cavitation bubble collapse and liquid flow, significantly enhancing cleaning effectiveness at lower energy consumption.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Ultrasonic waves induce phase transitions in the rinsing fluid by creating cavitation bubbles that rapidly form and collapse. This phase transition between liquid and gas states generates intense localized cleaning action that is far more effective than steady high-pressure liquid flow alone, while consuming less overall energy.

Inventive Principle:

Principle #36Phase transitions

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

Prevents damage to semiconductor wafers and equipment by effectively removing debris particles, increasing wafer yields and reducing the need for repairs or replacements, thus optimizing the CMP process efficiency.

Implementation Method 1

generating nanobubbles in the rinsing fluid with ultrasonic waves

Methodology Applied

Scientific EffectUltrasonic cavitation: Acoustic Cavitation

Data Source

PatentUS20250367786A1CMP method and system with nanobubble cleaning

Publication Date: 2025.12.04 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A chemical mechanical planarization (CMP) system utilizes a high-pressure rinsing fluid with nanobubbles to assist in conditioning of a CMP pad. The CMP system generates nanobubbles in the rinsing fluid prior to dispensing the rinsing fluid onto the CMP pad or while the rinsing fluid is on the CMP pad. The CMP system includes a pad dresser that dresses or conditions the CMP pad while the rinsing fluid and the nanobubbles are present.