Modular Autoencoder for Semiconductor Parameter Estimation

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Solution Overview

Problem

Current data-driven inference approaches for semiconductor metrology operations face challenges in efficiently selecting the best channels for measurement due to time-consuming brute force methods, which can lead to overfitting and introduce channel-specific biases, limiting their predictive consistency and accuracy in estimating semiconductor manufacturing process parameters.

Innovation Solution

A modular autoencoder model is employed to estimate parameters from a combination of available channels by iteratively varying and training on subsets of channels, ensuring the model remains predictive across any channel combination and avoids channel-specific biases, while also embedding known properties during training to reduce inference biases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If brute force methods are used to select the best channels for measurement, then comprehensive channel evaluation is achieved, but measurement time and computational resources increase significantly

Engineering Contradiction:
Improveparameter estimation accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the channel selection process into multiple iterations, where in each iteration only a subset of channels is trained and evaluated. This divides the comprehensive channel evaluation into manageable segments, reducing the computational burden and measurement time for each individual evaluation while still achieving comprehensive selection across all iterations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements partial action by training on subsets of channels rather than all channels simultaneously. This partial training approach allows for faster individual iterations while the cumulative effect across multiple iterations with different subsets achieves comprehensive channel evaluation, effectively reducing overall measurement time.

Inventive Principle:
Principle #16Partial or excessive action

2Reliability

If training is performed on all channel combinations, then complete channel evaluation is achieved, but the model becomes biased toward specific channels

Engineering Contradiction:
Improvepredictive consistencyVSAvoidchannel-specific biases
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent merges the results from multiple iterations, each trained on different channel subsets. By combining the knowledge gained from various subsets across iterations, the final model achieves comprehensive channel evaluation while distributing the training load, thereby preventing over-reliance on any single channel combination and reducing channel-specific biases.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces dynamics by varying the channel subsets across different iterations rather than using a fixed channel combination. This dynamic approach ensures that the model learns from diverse channel configurations, improving predictive consistency across different channel combinations while preventing the model from becoming biased toward any specific static channel set.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If complex monolithic autoencoder models are used, then modeling accuracy is improved, but model interpretability and ease of extension decrease

Engineering Contradiction:
Improveparameter estimation accuracyVSAvoidmodel interpretability
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent segments the autoencoder model into a modular architecture with separate encoder and decoder components. This segmentation improves interpretability by allowing independent analysis of the encoding and decoding processes, while still maintaining the capability to achieve high parameter estimation accuracy through the coordinated work of these modular components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary dimensionality reduction through the encoder component before the main parameter estimation task. This preliminary action simplifies the subsequent processing by working with compressed latent representations, making the overall system more interpretable while maintaining accuracy by preserving essential information in the compressed form.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS20240354552A1Modular autoencoder model for manufacturing process parameter estimation
Publication Date: 2024.10.24 ASML NETHERLANDS BV
  • US20240354552A1 patent drawing
  • US20240354552A1 patent drawing
  • US20240354552A1 patent drawing

AI summary

A modular autoencoder model is described. The modular autoencoder model comprises input models configured to process one or more inputs to a first level of dimensionality suitable for combination with other inputs: a common model configured to: reduce a dimensionality of combined processed inputs to generate low dimensional data in a latent space; and expand the low dimensional data in the latent space into one or more expanded versions of the one or more inputs suitable for generating one or more different outputs; output models configured to use the one or more expanded versions of the one or more inputs to generate the one or more different outputs, the one or more different outputs being approximations of the one or more inputs; and a prediction model configured to estimate one or more parameters based on the low dimensional data in the latent space.