Radial Thermal Modules for CMP Pad Temperature Uniformity

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Solution Overview

Problem

Chemical mechanical polishing (CMP) processes face challenges in temperature control, leading to variations in polishing pad surface temperature, which affect removal rate, uniformity, and wafer-to-wafer consistency due to the poor thermal conductivity of polishing pads and non-uniform heat generation during the CMP process.

Innovation Solution

A temperature control system with multiple thermal control modules positioned radially above the polishing pad, each equipped with heating or cooling elements, allows for independent temperature control of specific zones on the pad, using infrared light sources, thermoelectric heat pumps, heat exchangers, and fluid dispensers, with sensors to monitor and adjust temperature profiles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If multiple thermal control modules are positioned radially above the polishing pad to control temperature zones independently, then temperature uniformity across the polishing pad is improved, but device complexity increases

Engineering Contradiction:

Improvetemperature uniformityVSAvoiddevice complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The temperature control system is divided into multiple independent thermal control modules positioned at different radial positions above the polishing pad. Each module can independently control the temperature of its corresponding radial zone, allowing segmented temperature management across the polishing surface. This segmentation enables precise local temperature control while maintaining overall system manageability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different radial zones of the polishing pad are provided with different thermal control characteristics through the distributed thermal control modules. Each module can be independently adjusted to provide the specific temperature control needed for its local region, accounting for variations in heat generation and polishing conditions across different radial positions.

Inventive Principle:

Principle #3Local quality

2Temperature

If thermal control modules directly contact the polishing pad or polishing liquid for temperature control, then temperature control effectiveness is improved, but contamination risk and maintenance difficulty increase

Engineering Contradiction:

Improvetemperature control effectivenessVSAvoidmaintenance difficulty

Core Design Contradiction:

TemperatureVSEase of repair

Solution Approach 1:

A body or carrier structure serves as an intermediary between the thermal control modules and the polishing pad or polishing liquid. The thermal control modules are positioned within or on this body, which mediates the thermal interaction with the polishing interface. This intermediary approach enables effective temperature control while preventing direct contact between the thermal control components and the polishing materials, thereby reducing contamination risk and facilitating easier maintenance.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 reduces temperature variations across the polishing pad, improving within-wafer and wafer-to-wafer uniformity, and enhances the predictability and repeatability of the polishing process by maintaining a consistent temperature profile.

Implementation Method 1

Each thermal control module of the plurality of thermal control modules is configured to independently heat or cool a radial region of the polishing pad

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

Each thermal control module can include one or more of an infrared light source, a thermoelectric heat pump, a heat exchanger, a resistive heater, and a fluid dispenser

Methodology Applied

Scientific EffectThermoelectric effect: Peltier Effect

Implementation Method 3

a stack with a thermoelectric heat pump and a heat exchanger. The heat exchanger may be above the thermoelectric heat pump

Methodology Applied

Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

Each thermal control module can include one or more of an infrared light source, a thermoelectric heat pump, a heat exchanger, a resistive heater, and a fluid dispenser

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Implementation Method 5

Each thermal control module can include one or more of an infrared light source, a thermoelectric heat pump, a heat exchanger, a resistive heater, and a fluid dispenser

Methodology Applied

Scientific EffectInfrared radiation: Infrared Radiation

Data Source

PatentUS11597052B2Temperature control of chemical mechanical polishing

Publication Date: 2023.03.07 APPLIED MATERIALS INC

AI summary

A chemical mechanical polishing apparatus includes a platen to hold a polishing pad, a carrier to hold a substrate against a polishing surface of the polishing pad during a polishing process, a dispenser to supply a polishing liquid to the polishing surface, and a temperature control system including a body configured to contact the polishing surface or the polishing liquid on the polishing surface. The body supports a thermal control module positioned over the polishing pad.