Machine Learning Methods for Automated Macro-Inspection and Improved Defect Identification in Semiconductor Manufacturing

This thesis proposes four methods to improve macro-inspection capability of defects on wafers at a semiconductor wafer fab. First, an investigation into the performance of current inspection tools is done, revealing results that are not reliable nor reproducible. Tool maintenance procedures and spec...

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Main Author: Cheung, Sophia
Other Authors: Boning, Duane
Format: Thesis
Published: Massachusetts Institute of Technology 2023
Online Access:https://hdl.handle.net/1721.1/152700
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author Cheung, Sophia
author2 Boning, Duane
author_facet Boning, Duane
Cheung, Sophia
author_sort Cheung, Sophia
collection MIT
description This thesis proposes four methods to improve macro-inspection capability of defects on wafers at a semiconductor wafer fab. First, an investigation into the performance of current inspection tools is done, revealing results that are not reliable nor reproducible. Tool maintenance procedures and specification adjustments are recommended. Second, a software upgrade to the current inspection software is developed, including enhanced features that address pain points of reviewing wafer images. The image processing and loading time is reduced by over 50%. Third, three binary classification machine learning models are trained to isolate spin-on-glass defects, edge type defects, and center defects. Each of the models exhibits an area under curve (AUC) of over 0.90 on out-of-distribution test sets. Finally, a proof-of-concept for an in-line inspection system is designed and tested on the fab floor. New images from this system appear to be of sufficient quality for inspection. The results of each part of this study can be used to inform investment decisions required to move towards a more automated process. Relevant to the machine learning community are the methods developed to address class imbalance in neural network training. Methods for preparing data to be trained in a meaningful way such as spitting, transforming, and creating synthetic data are proposed. The effect of generating data in such a fashion is shown to be positive, increasing the AUC of the specified model by up to 65%.
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spelling mit-1721.1/1527002023-11-03T03:33:34Z Machine Learning Methods for Automated Macro-Inspection and Improved Defect Identification in Semiconductor Manufacturing Cheung, Sophia Boning, Duane Hardt, David E. Massachusetts Institute of Technology. Department of Mechanical Engineering This thesis proposes four methods to improve macro-inspection capability of defects on wafers at a semiconductor wafer fab. First, an investigation into the performance of current inspection tools is done, revealing results that are not reliable nor reproducible. Tool maintenance procedures and specification adjustments are recommended. Second, a software upgrade to the current inspection software is developed, including enhanced features that address pain points of reviewing wafer images. The image processing and loading time is reduced by over 50%. Third, three binary classification machine learning models are trained to isolate spin-on-glass defects, edge type defects, and center defects. Each of the models exhibits an area under curve (AUC) of over 0.90 on out-of-distribution test sets. Finally, a proof-of-concept for an in-line inspection system is designed and tested on the fab floor. New images from this system appear to be of sufficient quality for inspection. The results of each part of this study can be used to inform investment decisions required to move towards a more automated process. Relevant to the machine learning community are the methods developed to address class imbalance in neural network training. Methods for preparing data to be trained in a meaningful way such as spitting, transforming, and creating synthetic data are proposed. The effect of generating data in such a fashion is shown to be positive, increasing the AUC of the specified model by up to 65%. M.Eng. 2023-11-02T20:09:24Z 2023-11-02T20:09:24Z 2023-09 2023-09-28T15:51:57.530Z Thesis https://hdl.handle.net/1721.1/152700 In Copyright - Educational Use Permitted Copyright retained by author(s) https://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Cheung, Sophia
Machine Learning Methods for Automated Macro-Inspection and Improved Defect Identification in Semiconductor Manufacturing
title Machine Learning Methods for Automated Macro-Inspection and Improved Defect Identification in Semiconductor Manufacturing
title_full Machine Learning Methods for Automated Macro-Inspection and Improved Defect Identification in Semiconductor Manufacturing
title_fullStr Machine Learning Methods for Automated Macro-Inspection and Improved Defect Identification in Semiconductor Manufacturing
title_full_unstemmed Machine Learning Methods for Automated Macro-Inspection and Improved Defect Identification in Semiconductor Manufacturing
title_short Machine Learning Methods for Automated Macro-Inspection and Improved Defect Identification in Semiconductor Manufacturing
title_sort machine learning methods for automated macro inspection and improved defect identification in semiconductor manufacturing
url https://hdl.handle.net/1721.1/152700
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