Energy Correction Module for DUV Optical Source Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In deep ultraviolet (DUV) optical lithography, existing systems face challenges in maintaining consistent energy levels across pulses produced by multiple optical oscillators, leading to energy disturbances and dose errors due to variations in transfer functions, which affect the accuracy and efficiency of the photolithography process.
Innovation Solution
A control system is implemented that determines a corrected excitation signal for each optical oscillator based on energy properties of pulses from other oscillators, using filters and modeled relationships to adjust the excitation signals, ensuring consistent energy output across pulses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple optical oscillators are used to produce DUV light pulses, then the productivity and output of the lithography system is improved, but energy disturbances and dose errors occur due to variations in transfer functions between oscillators
Solution Approach 1:
The control system measures the actual energy output of each optical oscillator and uses this feedback information to determine corrected excitation signals. The control system applies a filter to the input signal based on the measured energy properties, creating a closed-loop feedback mechanism that compensates for transfer function variations between oscillators, thereby maintaining consistent energy output across multiple oscillators.
Solution Approach 2:
The system dynamically adjusts the excitation parameters (input signals) to each optical oscillator based on their individual transfer function characteristics. By changing the excitation signal parameters in response to measured energy output, the system compensates for variations between oscillators and maintains consistent energy levels despite using multiple different oscillator units.
2Manufacturing precision
If the excitation signal is adjusted to compensate for transfer function variations, then the energy consistency is improved, but the device complexity increases due to the control system and filtering requirements
Solution Approach 1:
The control system serves multiple functions: it measures energy output from any oscillator, processes the signal through filtering, determines corrected excitation signals, and applies corrections to maintain energy consistency. This multi-functional approach consolidates what could be multiple separate systems into a single universal control mechanism, managing complexity while achieving precision.
Solution Approach 2:
The filter acts as an intermediary between the raw input signal and the corrected excitation signal. It processes the input signal based on measured energy properties and transfer function variations, mediating the correction process without requiring direct complex interactions between all system components. This intermediary simplifies the overall control architecture while maintaining precision.
3Manufacturing precision
If real-time filtering and correction are applied to excitation signals, then the dose error is reduced, but the processing time and system response time increase
Solution Approach 1:
The control system applies a filter to the input signal in advance, before the excitation signal is fully applied to the optical oscillator. This preliminary filtering action prepares the corrected signal proactively, reducing the need for extensive real-time processing and minimizing the time penalty associated with correction operations.
Solution Approach 2:
The system rapidly processes the filtering and correction operations, rushing through the signal processing steps efficiently. By optimizing the filtering algorithm and control response, the system minimizes the time spent on correction while still achieving the necessary dose accuracy, effectively skipping unnecessary processing delays.
Data Source
AI summary
A system for deep ultraviolet (DUV) optical lithography includes an optical source apparatus including N optical oscillators, N being an integer number greater than or equal to two, and each of the N optical oscillators is configured to produce a pulse of light in response to an excitation signal; and a control system coupled to the optical source apparatus. The control system is configured to determine a corrected excitation signal for a first one of the N optical oscillators based on an input signal, the input signal including an energy property of a pulse of light produced by another one of the N optical oscillators.