EUV Optical Element Wavefront Diagnosis
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Solution Overview
Problem
Current semiconductor processing apparatuses face inefficiencies in monitoring and maintaining the state of individual optical elements, leading to reduced yield and increased costs due to the inability to accurately diagnose issues like contamination and particle presence in the light source, illumination optical system, and optical system.
Innovation Solution
A method involving a diffuser and image sensor setup to irradiate and capture EUV light, generate predictive images using optical prediction models, adjust optical characteristics through forward and backward propagation operations, and diagnose wavefront images to identify and correct aberrations and contamination in the optical elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional monitoring methods are used for optical elements, then the system structure remains simple, but the ability to accurately diagnose contamination and particle presence is insufficient
Solution Approach 1:
The patent segments the optical system into individual optical elements (mirrors, lenses, etc.) and generates separate wavefront images for each element. This segmentation enables precise diagnosis of contamination and particles in specific optical elements by analyzing the corresponding wavefront image regions, thereby improving measurement precision without requiring a complete system overhaul.
Solution Approach 2:
The patent introduces wavefront images as an intermediary diagnostic tool between the optical elements and the final pattern formation. These wavefront images serve as mediators that carry information about the state of individual optical elements, enabling indirect but precise monitoring of contamination and particle presence without directly interfering with the optical path.
2Reliability
If comprehensive monitoring of all optical elements is implemented, then diagnosis accuracy improves, but maintenance time and costs increase
Solution Approach 1:
The patent performs preliminary diagnosis by generating wavefront images during the patterning process itself, before actual production runs. This preliminary action identifies contamination and particle issues in optical elements ahead of time, allowing for proactive maintenance scheduling that minimizes production downtime and reduces overall maintenance costs while maintaining high process yield.
Solution Approach 2:
The patent establishes a feedback mechanism where wavefront images are continuously analyzed to monitor the state of optical elements. This feedback system provides real-time information about contamination and particle presence, enabling dynamic adjustment of maintenance schedules and interventions, thereby improving reliability while optimizing maintenance time allocation.
3Measurement precision
If detailed analysis of each optical element is performed, then contamination and particle detection accuracy improves, but the complexity of optical prediction model adjustment increases
Solution Approach 1:
The patent applies local quality analysis by focusing the optical prediction model adjustment on specific regions of wavefront images corresponding to individual optical elements. Instead of adjusting the entire model uniformly, the system selectively refines predictions for areas showing contamination or particle signatures, thereby improving detection accuracy while minimizing the overall complexity of model adjustment.
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 precise monitoring and maintenance of individual optical elements, improving the efficiency and yield of semiconductor processes by rapidly identifying and addressing issues such as contamination and aberrations, thereby reducing maintenance time and costs.
Implementation Method 1
reflecting or transmitting, by the diffuser, the EUV light
Implementation Method 2
transmitting, by an optical system, the EUV light from the diffuser
Implementation Method 3
irradiating, by a light source, a plurality of regions included in a diffuser on a mask stage with extreme ultraviolet (EUV) light
Data Source
AI summary
Provided is a method of managing a semiconductor processing apparatus, including irradiating, by a light source, a plurality of regions included in a diffuser on a mask stage with extreme ultraviolet (EUV) light, reflecting or transmitting, by the diffuser, the EUV light, transmitting, by an optical system, the EUV light from the diffuser, receiving, by an image sensor, the EUV light from the optical system, obtaining, by the image sensor, a plurality of original images corresponding to the plurality of regions, generating, based on an optical prediction model, a plurality of predictive images estimating a diffraction pattern in the image sensor, adjusting an optical prediction model by comparing the plurality of predictive images with the plurality of original images, and generating, based on the optical prediction model, a plurality of wavefront images corresponding to optical characteristics of each of the plurality of mirrors.