EUV Photomask Repair Bias Control for Faster Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing EUV lithography techniques face challenges in efficiently repairing EUV photomasks due to the time-consuming and costly nature of etching operations, which require gentle and slow processes to avoid damaging the capping layer.
Innovation Solution
The method involves revising the etching apparatus's bias voltage to increase the etching rate of the anti-reflection coating (ARC) and light-absorption layer (LAL) while enhancing the capping layer's durability, allowing for faster repair without risking damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the etching process is performed gently and slowly to avoid damaging the capping layer, then the reliability of the photomask is maintained, but the productivity of the photomask repair process deteriorates
Solution Approach 1:
The patent changes the energy parameter of the electron beam by adjusting acceleration voltage and beam current. By optimizing these parameters, the etching rate is enhanced while maintaining selective etching that protects the capping layer, thus resolving the contradiction between etching speed and capping layer integrity
Solution Approach 2:
The patent applies different etching conditions to different regions of the photomask. The defective areas receive targeted etching treatment with optimized electron beam parameters, while the capping layer regions are protected through selective etching, achieving both high etching efficiency and capping layer protection
2Productivity
If the electron beam parameters are optimized to increase etching rate, then the productivity of photomask repair is improved, but the risk of damaging the capping layer increases
Solution Approach 1:
The patent employs real-time monitoring of the etching process with feedback control of electron beam parameters. The system adjusts beam current and acceleration voltage dynamically based on process conditions, enabling high etching rates while preventing capping layer damage through continuous parameter optimization
Solution Approach 2:
The patent makes the etching process dynamic by continuously adjusting electron beam parameters during the etching operation. The acceleration voltage and beam current are varied in real-time to maintain optimal etching rates while preventing damage to the capping layer, transforming a static risky process into a dynamically controlled safe process
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 significantly reduces etching time and enhances the efficiency of photomask repair by optimizing the electron beam writer system's operation, ensuring the capping layer's protection and maintaining the photomask's integrity.
Implementation Method 1
performing the repairing operation on the photomask by the electron beam writer system with the bias voltage
Implementation Method 2
the etching rate of the anti-reflection coating (ARC) and light-absorption layer (LAL)
Data Source
AI summary
A method includes: providing a photomask used in extreme ultra violet (EUV) lithography; determining a bias voltage of an electron beam writer system, the bias voltage applicable to an inspection operation and a repairing operation; and performing the repairing operation on the photomask by the electron beam writer system with the bias voltage.