Lithography Control Using Switched Neural Networks for Real-Time Accuracy

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional control apparatuses using neural networks face long calculation times, which degrade real-time control performance.

Innovation Solution

A control apparatus comprising a plurality of neural networks and a selector to choose the appropriate network for each control pattern, reducing the scale of individual networks and enabling rapid calculation by switching between them.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single large-scale neural network is used for control, then control accuracy is improved, but calculation time increases and real-time performance degrades

Engineering Contradiction:
Improvecontrol accuracyVSAvoidcalculation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent divides a single large-scale neural network into multiple smaller neural networks, each specialized for specific control patterns. This segmentation reduces the computational burden of each individual network while maintaining overall control accuracy through selective deployment of appropriate networks for different operating conditions

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically selects which neural network to deploy based on the current control pattern or operating conditions. This dynamic adaptation allows the system to use computationally efficient networks for simple patterns while reserving more complex networks for challenging scenarios, optimizing both accuracy and real-time performance

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If a single large-scale neural network is used for control, then control accuracy is improved, but real-time control performance degrades

Engineering Contradiction:
Improvecontrol accuracyVSAvoidreal-time control speed
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The patent segments the control system into multiple specialized neural networks, each optimized for specific control patterns. This allows the system to achieve high control accuracy for each pattern while maintaining fast real-time response by selecting the appropriate pre-trained network for the current condition

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple neural networks are pre-trained offline for different control patterns before deployment. This preliminary action transfers complex computation to the training phase, allowing the runtime system to simply select and execute pre-computed networks, thereby achieving both high accuracy and real-time performance

Inventive Principle:
Principle #10Preliminary action

3Loss of time

If the scale of neural network is reduced, then calculation time is shortened, but control accuracy may deteriorate

Engineering Contradiction:
Improvecalculation timeVSAvoidcontrol accuracy
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

Each neural network is specialized for specific control patterns or operating conditions, achieving high local accuracy for its designated domain. This local quality approach ensures that while individual networks are smaller and faster, they maintain high accuracy for their specific control patterns through targeted training and specialization

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS12379673B2Control apparatus, lithography apparatus, and article manufacturing method
Publication Date: 2025.08.05 CANON KK
  • US12379673B2 patent drawing
  • US12379673B2 patent drawing
  • US12379673B2 patent drawing

AI summary

A control apparatus for generating a control signal for controlling a control target includes a plurality of neural networks, and a selector configured to select, from the plurality of neural networks, a neural network to be used to generate the control signal, wherein each of the plurality of neural networks is selected by the selector to be used in execution of one corresponding control pattern among a plurality of control patterns for controlling the control target.