Halogen Gas Replenishment Model for Excimer Laser

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Solution Overview

Problem

Current methods for managing gas replenishment in dual-chamber gas discharge lasers, such as excimer lasers, lack accuracy in estimating halogen gas consumption, leading to inefficient operation and frequent refills, which disrupt the manufacturing process.

Innovation Solution

A mathematical model is developed to calculate the amount of halogen gas to be injected into the laser chambers based on prior gas levels, consumption rates, and operational parameters, allowing for precise control of gas concentration and extending the time between refills.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a full refill of gas is performed in the laser chambers, then the gas concentration is restored to desired levels, but the laser operation is interrupted and manufacturing throughput is reduced

Engineering Contradiction:
Improvelaser operation continuityVSAvoidmanufacturing throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies partial action by performing selective replenishment of halogen gas rather than complete refilling of the chamber. The system calculates and injects only the specific amount of halogen gas needed to restore optimal concentration, allowing the laser to continue operating without interruption while maintaining gas composition within desired parameters.

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If a regular refill schedule is implemented, then the laser operation is ensured to never suffer unanticipated interruption, but the refill frequency is overly conservative and reduces productivity for users operating at low pulse usages

Engineering Contradiction:
Improvelaser operation continuityVSAvoidmanufacturing throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system implements feedback by continuously monitoring laser operating parameters such as discharge voltage and pulse energy to detect actual halogen gas consumption rates. Based on this real-time feedback, the system dynamically adjusts the timing and amount of gas replenishment, replacing gas only when actually needed rather than following a fixed conservative schedule.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent applies dynamics by transitioning from a static, predetermined refill schedule to a dynamic replenishment strategy. The gas injection timing and quantity are continuously adjusted based on real-time monitoring of laser performance parameters and calculated halogen consumption rates, allowing the system to adapt to varying operational conditions and usage patterns.

Inventive Principle:
Principle #15Dynamics

3Productivity

If the amount of halogen gas to be injected is accurately calculated, then the time between refills is extended and operational efficiency is improved, but the complexity of the gas management system increases

Engineering Contradiction:
Improveoperational efficiencyVSAvoidgas management system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical/manual gas management with an automated computational system. A mathematical model calculates the precise amount of halogen gas to be injected based on monitored operating parameters, and an automated injection system executes the replenishment without manual intervention, reducing operational complexity despite the sophisticated control algorithm.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 enables more accurate gas replenishment, reducing the frequency of refills and maintaining optimal laser performance, thereby improving operational efficiency and throughput in microelectronic chip manufacturing.

Implementation Method 1

as the light source discharges energy across its electrodes to produce light

Methodology Applied
Scientific EffectElectrical discharge: Electric Arc

Implementation Method 2

the excimer laser derives its name from the fact that under the appropriate conditions of electrical simulation and high pressure, a pseudo-molecule called an excimer is created, which can only exist in an energized state and can give rise to laser light in the ultraviolet range

Methodology Applied
Scientific EffectLaser emission: Laser

Data Source

PatentEP2761709B1System and method for high accuracy gas inject in a two chamber gas discharge laser system
Publication Date: 2016.04.20 CYMER INC
  • EP2761709B1 patent drawingFigure 1
  • EP2761709B1 patent drawingFigure 2
  • EP2761709B1 patent drawingFigure 3

AI summary

[0090} Systems and methods for automatically performing a high accuracy gas inject in a laser chamber of a two chamber gas discharge laser such as an excimer laser are disclosed. A mathematical model, relates the amount of halogen gas in the laser chamber after an inject to the amount of halogen gas present prior to the inject, the amount of halogen gas injected., and the consumption rate of halogen gas in the chamber, A fixed amount of halogen gas is added to the chamber in an initial number of injects to allow transients to settle out, after which the amount of halogen gas to be injected is that calculated to result in a desired amount of halogen gas after the inject according to the model. Measurements are taken after injects to update the actual amount of halogen gas present and the consumption rate of the halogen gas.