Capacity Planning for Cluster Tools in the Semiconductor Industry

TL;DR

This paper introduces a new capacity planning model for cluster tools with two load locks in semiconductor manufacturing, improving efficiency for tools with four or more chambers by optimizing parallel processing.

Contribution

The paper presents a novel model for cluster tools with two load locks, extending previous models to better handle multiple chambers and operational modes in capacity planning.

Findings

The new model performs similarly to existing models for three chambers.

It outperforms previous models for four or more chambers.

The approach effectively reduces makespan through parallel processing.

Abstract

This paper proposes a new model for Cluster-tools with two load locks. Cluster-tools are widely used to automate single wafer processing in semiconductor industry. The load locks are the entry points into the vacuum of the Cluster-tool's mainframe. Usually there are two of them available. Each lot being processed, is dedicated to a single load-lock. Therefore at most two different lots (with possibly different processing times and qualification) can be processed simultaneously. This restriction is one of the major potential bottlenecks. Capacity planning is one of the possible applications for the proposed model and the paper demonstrates the integration into a more general framework that considers different tool types and different operational modes. The paper also generalizes an earlier model that is limited to three processing chambers. The proposed modeling approach is based on makespan reductions by parallel processing. It turns out that the performance of the new approach is similar, when compared to the generalized model for three chambers, but the new approach outperforms the generalized model for four and more chambers.