CMP Slurry Conduit Heating for Pre-Dispensing Temperature Control

Solution Overview

Problem

The chemical mechanical polishing (CMP) process faces inefficiencies due to the time-consuming pre-heating of CMP slurry, leading to slurry waste and increased costs, with existing methods risking pitting defects or reducing polishing pad life.

Innovation Solution

A post-circulation and pre-dispensary heating scheme is implemented, where the CMP slurry is heated within a conduit to a target temperature before dispensing, using a heating element and thermal control system to maintain stability and efficiency without excessive waste or defect risk.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If CMP slurry is pre-heated before delivery to the polishing platform, then the CMP slurry reaches optimal temperature for efficient polishing, but the process time increases and slurry waste increases

Engineering Contradiction:

ImproveCMP slurry temperatureVSAvoidpre-heating time

Core Design Contradiction:

TemperatureVSLoss of time

Solution Approach 1:

The system performs preliminary heating action by incorporating a heating element within the slurry delivery conduit, heating the slurry as it travels through the conduit before reaching the polishing platform. This preliminary action ensures the slurry is at optimal temperature when it reaches the platform, eliminating the need for separate pre-heating time while maintaining polishing efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the conventional mechanical heating method (heating the polishing platform) with a thermal field approach by incorporating a heating element directly in the slurry delivery conduit. This substitution allows for more efficient and localized heating of the slurry, reducing the overall heating time and energy consumption.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Temperature

If CMP slurry is pre-heated before delivery to the polishing platform, then the CMP slurry reaches optimal temperature for efficient polishing, but slurry waste increases due to extended process time

Engineering Contradiction:

ImproveCMP slurry temperatureVSAvoidCMP slurry waste

Core Design Contradiction:

TemperatureVSLoss of substance

Solution Approach 1:

The system performs preliminary heating action by incorporating a heating element within the slurry delivery conduit, heating the slurry as it travels through the conduit before reaching the polishing platform. This preliminary action ensures the slurry is at optimal temperature when it reaches the platform, eliminating the need for separate pre-heating time while maintaining polishing efficiency.

Inventive Principle:

Principle #10Preliminary action

3Temperature

If CMP slurry is warmed up by increasing downward polishing force during polishing, then the CMP slurry temperature increases, but the risk of scratching the processed wafer increases and polishing pad life decreases

Engineering Contradiction:

ImproveCMP slurry temperatureVSAvoidwafer scratching risk

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the conventional mechanical heating method (heating the polishing platform) with a thermal field approach by incorporating a heating element directly in the slurry delivery conduit. This substitution allows for more efficient and localized heating of the slurry, reducing the overall heating time and energy consumption.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Loss of time

If CMP slurry is circulated within a main supply loop for pre-heating, then the heating time at delivery is reduced, but the composition stability of CMP slurry decreases over time

Engineering Contradiction:

Improveheating timeVSAvoidCMP slurry composition stability

Core Design Contradiction:

Loss of timeVSStability of the object's composition

Solution Approach 1:

The system performs preliminary heating action by incorporating a heating element within the slurry delivery conduit, heating the slurry as it travels through the conduit before reaching the polishing platform. This preliminary action ensures the slurry is at optimal temperature when it reaches the platform, eliminating the need for separate pre-heating time while maintaining polishing efficiency.

Inventive Principle:

Principle #10Preliminary action

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 reduces process time, conserves CMP slurry, and enhances the CMP system's capacity by maintaining the CMP slurry at an optimal temperature range, minimizing waste and defect risks while maintaining the polishing pad's integrity.

Implementation Method 1

heating the CMP slurry while being conducted in the conduit, to a target temperature within a degradation time window before the CMP slurry is dispensed

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 2

the thermal sensor is configured to detect an elevated temperature of the CMP slurry

Methodology Applied

Scientific EffectThermal detection: Thermography

Implementation Method 3

the thermal control circuit is configured to regulate the heating element based on the elevated temperature and a target temperature

Methodology Applied

Scientific EffectThermal control: Feedback

Data Source

PatentUS11318577B2System and method of delivering slurry for chemical mechanical polishing

Publication Date: 2022.05.03 TEXAS INSTRUMENTS INC

AI summary

A chemical mechanical polishing (CMP) system that includes a platen, a conduit having a heating segment and a delivery outlet, and a heater coupled to the heating segment of the conduit. The delivery outlet is positioned adjacent to the platen, whereas the heating segment defines a dispensing distance with the delivery outlet. The dispensing distance is associated with a stability of a CMP slurry at an elevated temperature that is above an ambient temperature.