Semiconductor Wafer Thermal Expansion Control

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Solution Overview

Problem

Semiconductor wafers experience thermal expansion when transferred between tools with different ambient and chamber conditions, leading to increased uncertainty and reduced accuracy in processing and inspection, particularly affecting defect detection and image registration.

Innovation Solution

A method and system that involve heating the semiconductor wafer in a first chamber to a second temperature while reducing pressure to a second pressure level, then transferring it to a second chamber with a supporting element at a third temperature closer to the second temperature and pressure level, to minimize thermal expansion and maintain consistent conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the semiconductor wafer is transferred between chambers with different temperature conditions, then the wafer can be processed or inspected in different environments, but thermal expansion occurs leading to increased uncertainty and reduced accuracy in processing and inspection

Engineering Contradiction:

Improveability to transfer between different chamber environmentsVSAvoidaccuracy of processing and inspection

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by heating the semiconductor wafer in a first chamber before transfer to a second chamber. The heating module raises the wafer temperature to match or approach the third temperature of the supporting element in the second chamber, thereby pre-adapting the wafer to the target thermal environment and minimizing thermal expansion during transfer and processing.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the temperature parameter of the semiconductor wafer by applying heat from a heating module. The wafer temperature is adjusted from the first temperature (ambient or lower) to a second temperature that is closer to the third temperature of the supporting element, thereby reducing the temperature differential and minimizing thermal expansion effects during transfer and processing.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If the wafer is heated to match the supporting element temperature, then thermal expansion is reduced, but additional heating equipment and process steps are required

Engineering Contradiction:

Improvereduction of thermal expansion uncertaintyVSAvoidaddition of heating module and pressure control

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The first chamber is designed with multi-functionality, serving both as a transfer chamber and as a heating chamber. The heating module integrated into the first chamber can heat the wafer before transfer, while the pressure control unit manages both atmospheric and vacuum conditions. This eliminates the need for separate heating equipment and reduces overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The first chamber performs self-service by integrating both heating and pressure control functions within itself. The heating module and pressure control unit work together in the same chamber to prepare the wafer thermally and pressure-wise before transfer, eliminating the need for additional dedicated equipment and simplifying the overall system architecture.

Inventive Principle:

Principle #25Self-service

3Adaptability or versatility

If the pressure level is reduced in the first chamber, then the wafer can be transferred to vacuum environment, but the heating and pressure reduction processes may interfere with each other

Engineering Contradiction:

Improveability to maintain different pressure levelsVSAvoidcoordination of heating and pressure control

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system employs feedback control where the heating module and pressure control unit are coordinated based on real-time conditions. The heating process can be adjusted based on the pressure level and vice versa, ensuring that thermal and pressure changes are managed in a coordinated manner that prevents interference and maintains process stability.

Inventive Principle:

Principle #23Feedback

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 thermal expansion uncertainty, enhancing the accuracy and speed of semiconductor wafer processing and inspection by maintaining consistent temperature and pressure conditions, thereby improving defect detection and image registration precision.

Implementation Method 1

when the semiconductor wafer is placed on the chuck it experiences a thermal expansion

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

reducing the pressure level of the first chamber to a second pressure level

Methodology Applied

Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentUS9111971B2System and method for temperature control of a semiconductor wafer

Publication Date: 2015.08.18 APPL MATERIALS ISRAEL LTD

AI summary

A semiconductor wafer is received at a first chamber that is at a first pressure level. The semiconductor wafer is at a first temperature and is heated, by a first heating module, to a second temperature while the pressure level of the first chamber is reduced from the first pressure level to a second pressure level. The semiconductor wafer is then provided to a supporting element of a second chamber which maintains a third pressure level that is closer to the second pressure level than to the first pressure level; the supporting element being at a third temperature that is closer to the second temperature than to the first temperature.