Temperature-Controlled Air Chambers for CMP Polishing Rate

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Solution Overview

Problem

The chemical mechanical planarization (CMP) process faces challenges in achieving uniform polishing rates across a wafer surface due to limitations in adjusting pressure, which can induce mechanical stress and affect the integrity of wafer layers, and the polishing pad's glazing condition reduces efficiency.

Innovation Solution

The use of temperature-controlled air in the polishing head's air chambers, in addition to downforce, to control the polishing rate, with temperature modules supplying air between -50° C. and 130° C., allowing for independent temperature adjustment of each polishing zone to modulate the polishing rate without altering pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If pressure is increased to control polishing rate, then polishing rate is improved, but mechanical stress on wafer layers increases affecting integrity

Engineering Contradiction:

Improvepolishing rateVSAvoidmechanical stress

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical parameter of air temperature in the air chambers to control polishing rate. By heating or cooling the air, the polishing rate is adjusted without changing mechanical pressure, thus avoiding mechanical stress on wafer layers while maintaining productivity control.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the mechanical pressure control system with a thermal control system. Instead of using mechanical means to adjust downforce, the invention uses temperature-controlled air to modulate polishing rate, substituting thermal energy for mechanical force.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If polishing continues to maintain productivity, then output is improved, but polishing pad glazing reduces efficiency

Engineering Contradiction:

Improvepolishing outputVSAvoidpolishing efficiency

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent applies periodic temperature variations to the air chambers, alternating between heating and cooling cycles. This periodic thermal action prevents continuous polishing that causes pad glazing, allowing the pad surface to recover while maintaining overall productivity through controlled intermittent operation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent dynamically changes the temperature parameter of the air chambers during polishing operations. By adjusting temperature to prevent pad glazing conditions, the system maintains polishing efficiency over extended periods while sustaining productivity output.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If temperature control is added to polishing head, then polishing uniformity is improved, but device complexity increases

Engineering Contradiction:

Improvepolishing uniformityVSAvoidsystem complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent designs the air chamber system to serve multiple functions: it provides structural support for the polishing head, enables temperature control for uniformity, and maintains pressure differential for wafer handling. This multi-functionality reduces the need for separate components, thereby limiting the increase in device complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the temperature control system with the existing air chamber structure of the polishing head. By integrating heating and cooling elements into the air chambers rather than adding separate thermal control mechanisms, the invention achieves polishing uniformity while minimizing additional complexity.

Inventive Principle:

Principle #5Merging (Combining)

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 enhances polishing uniformity and extends the life of the polishing pad by reducing the need for frequent replacement, while minimizing mechanical stress and maintaining consistent polishing performance across the wafer surface.

Implementation Method 1

temperature modules supplying air between -50° C. and 130° C., allowing for independent temperature adjustment of each polishing zone to modulate the polishing rate

Methodology Applied

Scientific EffectThermal energy transfer: Conduction (thermal)

Data Source

PatentUS10807213B2Chemical mechanical polishing apparatus and method

Publication Date: 2020.10.20 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

The present disclosure describes a method and apparatus to adjust a wafer's polishing rate based on the temperature of the air received by the air chambers of a polishing head. The method includes supplying pressurized air to a temperature module coupled to a polishing head. The temperature module adjusts a temperature of the pressurized air that is supplied to the polishing head. The method further includes supplying the one or more air chambers of the polishing head with the temperature controlled pressurized air from the temperature module and polishing the wafer by rotating the wafer against a polishing pad.