Oscillatory Wafer Stage for Lithography Heat Reduction

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Solution Overview

Problem

Current step-and-scan photolithography systems require substantial time and energy for accelerating and decelerating wafer and mask stages, leading to excessive heat generation and inefficient power consumption during the lithography process.

Innovation Solution

Implementing a wafer stage with oscillatory movement using elastic beams and electromagnetic motors, synchronized with a mask stage, to minimize acceleration and deceleration requirements through simple harmonic oscillations, and regulating the illuminating beam intensity based on the speed of the stages to ensure uniform exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the wafer stage and mask stage are accelerated to constant speed for scanning, then the lithography processing speed is improved, but the power consumption and heat generation increase substantially

Engineering Contradiction:

Improvescanning speedVSAvoidpower consumption

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic oscillatory motion of the wafer stage and mask stage using elastic beams, replacing the traditional constant speed scanning with periodic acceleration and deceleration cycles. This allows the system to maintain high scanning speeds while reducing overall power consumption by eliminating the need for continuous high-power motor operation during constant speed maintenance.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent replaces the traditional motor-driven mechanical scanning system with an elastic beam-based oscillatory system. The elastic beams naturally provide the scanning motion through their elastic properties, eliminating the need for high-power motors and reducing power consumption while maintaining scanning speed.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the wafer stage and mask stage are accelerated and decelerated frequently, then the lithography processing flexibility is improved, but the heat generation from the drive motor increases

Engineering Contradiction:

Improveprocessing flexibilityVSAvoidheat generation

Core Design Contradiction:

Adaptability or versatilityVSTemperature

Solution Approach 1:

The patent replaces the motor-driven acceleration and deceleration system with an elastic beam-based oscillatory system. The elastic beams naturally handle acceleration and deceleration through their elastic properties, eliminating the heat-generating motor operations while maintaining processing flexibility.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the motion parameters from constant speed with frequent acceleration/deceleration cycles to continuous oscillatory motion. This parameter change eliminates the need for repeated motor power cycles, reducing heat generation while maintaining the ability to adapt to different processing requirements.

Inventive Principle:

Principle #35Parameter changes

3Area of stationary object

If the scanning process includes acceleration and deceleration phases, then the wafer coverage is improved, but the processing time increases

Engineering Contradiction:

Improvewafer coverageVSAvoidprocessing time

Core Design Contradiction:

Area of stationary objectVSLoss of time

Solution Approach 1:

The patent uses periodic oscillatory motion to cover the entire wafer surface through multiple scanning cycles. The elastic beams naturally oscillate between extreme positions, ensuring complete wafer coverage while reducing the time spent on acceleration and deceleration phases compared to traditional constant speed scanning.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent maintains continuous useful action through oscillatory motion, where the wafer stage and mask stage are constantly in motion during exposure. This eliminates the idle time associated with acceleration and deceleration phases in traditional scanning, improving processing efficiency while maintaining complete wafer coverage.

Inventive Principle:

Principle #20Continuity of useful 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 power consumption and heat generation, enhances manufacturing efficiency by minimizing pressure waves and maintaining consistent oscillation amplitude, and ensures uniform exposure patterns on the wafer.

Implementation Method 1

The wafer stage may further include an elastic beam mechanically connected between the wafer mounting part and the side member

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

The wafer stage may further include a driving device (e.g., a motor) configured to affect an oscillatory movement of the wafer mounting part in the wafer exposure process

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS10620551B2Lithography system and lithography method

Publication Date: 2020.04.14 SEMICON MFG INT (SHANGHAI) CORP

AI summary

A lithography system may include a wafer stage. The wafer stage may include a wafer mounting part configured to carry a wafer and configured to oscillate along a plane that is parallel to a top surface of the wafer in a wafer exposure process. The wafer stage may further include a driving device configured to affect an oscillatory movement of the wafer mounting part in the wafer exposure process.