Bayesian Optimization for CVD Process Parameter Design

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Solution Overview

Problem

The transition towards higher quality for graphene and transition metal dichalcogenides (TMDs) using chemical vapor deposition (CVD) synthesis is historically slow due to the complex interplay of thermodynamics and chemical kinetics at the growth front, making it challenging to systematically guide experiments towards high-quality conditions.

Innovation Solution

A computer-implemented method is developed to optimize the CVD synthesis process by using machine learning techniques to determine optimal process parameters with a minimum number of experimental trials. This method involves receiving process data, determining a feasible region using classification and regression models, calculating scores for data points, selecting recommended process parameters, and refining these parameters based on experimental results.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional trial and error experimentation is used to optimize CVD synthesis parameters, then comprehensive exploration of the design space is achieved, but the time, effort, and cost required increase significantly

Engineering Contradiction:
Improvequality of 2D materialsVSAvoidoptimization timeframe
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary computational actions by training machine learning models (classification and regression models) on existing process data before actual experimentation. The system pre-identifies feasible regions and predicts optimal parameters, allowing experiments to be designed more efficiently from the outset rather than through random trial and error

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements iterative feedback loops where experimental results are fed back into the machine learning models to refine predictions. The system continuously updates the feasible region identification and parameter optimization based on accumulated experimental data, progressively improving quality while reducing the number of trials needed

Inventive Principle:
Principle #23Feedback

2Loss of information

If extensive experimental trials are conducted to map the complex design space, then accurate understanding of parameter relationships is achieved, but resources (time, effort, materials) are consumed excessively

Engineering Contradiction:
Improveunderstanding of parameter relationshipsVSAvoidoptimization efficiency
Core Design Contradiction:
Loss of informationVSProductivity

Solution Approach 1:

The patent introduces machine learning models as intermediary components between the complex CVD synthesis process and the experimenter. These models (classification model for feasible region identification and regression model for parameter prediction) act as mediators that process experimental data and provide guided recommendations, reducing the need for direct extensive experimentation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical trial-and-error experimentation system with an intelligent computational system. Instead of relying on physical experimentation alone, the system uses machine learning algorithms to predict outcomes and guide experiments, substituting computational intelligence for brute-force experimental exploration

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the feasible region is broadly defined to ensure coverage of successful outcomes, then the probability of finding optimal parameters increases, but the search space becomes larger and more difficult to navigate

Engineering Contradiction:
Improvesuccess rate of fabricationVSAvoidcomplexity of design space
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by identifying and focusing on specific feasible regions within the broader design space rather than treating all parameter combinations equally. The classification model identifies local regions where successful fabrication is more likely, allowing the system to concentrate computational and experimental resources on promising areas while maintaining high success rates

Inventive Principle:
Principle #3Local quality

Data Source

PatentUS20250036835A1Fabrication Process Design Using Bayesian Optimization with Active Constraint Learning
Publication Date: 2025.01.30 NORTHEASTERN UNIV (US)
  • US20250036835A1 patent drawing
  • US20250036835A1 patent drawing
  • US20250036835A1 patent drawing

AI summary

Provided herein are methods and systems for a computer implemented method for designing and optimizing a fabrication process characterized by one or more process parameters. The outcome of the fabrication process is characterized by a quality metric used to optimize the fabrication process. The method uses a classification model in conjunction with a regression model, both using artificial intelligence and trained using experimental results, to iteratively recommend process parameter values for performing real world fabrication experiments. The experimental results are used to continuously train the models. The outcome is a set of process parameters that yield an optimal fabrication process with less time and effort than using conventional design of experiment methods.