Soft-Sensing ConFormer: A Curriculum Learning-based Convolutional Transformer

TL;DR

This paper introduces a novel convolutional transformer model called ConFormer, enhanced with curriculum learning, to improve wafer fault diagnostics in noisy, imbalanced soft-sensing data, demonstrating superior performance in industrial applications.

Contribution

The paper presents the first curriculum learning-based convolutional transformer architecture tailored for soft-sensing data in industrial wafer fault diagnostics.

Findings

Outperforms existing models on wafer fault-diagnostic tasks.

Effectively handles noisy and imbalanced soft-sensing data.

Shows strong potential for future soft-sensing research.

Abstract

Over the last few decades, modern industrial processes have investigated several cost-effective methodologies to improve the productivity and yield of semiconductor manufacturing. While playing an essential role in facilitating real-time monitoring and control, the data-driven soft-sensors in industries have provided a competitive edge when augmented with deep learning approaches for wafer fault-diagnostics. Despite the success of deep learning methods across various domains, they tend to suffer from bad performance on multi-variate soft-sensing data domains. To mitigate this, we propose a soft-sensing ConFormer (CONvolutional transFORMER) for wafer fault-diagnostic classification task which primarily consists of multi-head convolution modules that reap the benefits of fast and light-weight operations of convolutions, and also the ability to learn the robust representations through multi-head design alike transformers. Another key issue is that traditional learning paradigms tend to suffer from low performance on noisy and highly-imbalanced soft-sensing data. To address this, we augment our soft-sensing ConFormer model with a curriculum learning-based loss function, which effectively learns easy samples in the early phase of training and difficult ones later. To further demonstrate the utility of our proposed architecture, we performed extensive experiments on various toolsets of Seagate Technology's wafer manufacturing process which are shared openly along with this work. To the best of our knowledge, this is the first time that curriculum learning-based soft-sensing ConFormer architecture has been proposed for soft-sensing data and our results show strong promise for future use in soft-sensing research domain.