Today’s wafer fabrication plants must carefully balance the need to increase productivity while simultaneously reducing variable costs. There are a couple of main areas where process control (metrology and inspection) equipment can help minimize variable cost. The first is reducing consumables – minimizing the number of wafers that are processed for non-revenue operations, i.e., test wafers. Se...

In this study, we examine how wafer start peaks affect the performance of a semiconductor wafer fabrication facility. In contrast to other publications, we use a real factory model. In addition, we created two new types of analysis particularly suited for transient phases. The t-test diagram and the disturbance index provide useful support in finding disturbances in the factory and measuring th...

This paper discusses a methodology for quickly investigating problem areas in semiconductor wafer fabrication factories by creating a model for the production area of interest only (as opposed to a model of the complete factory operation). All other factory operations are treated as “black boxes“. Specific assumptions are made to capture the effect of reentrant flow. This approach allows a rapi...

Lot output time prediction is a critical task to a wafer fabrication plant (wafer fab). To enhance the effectiveness, a look-ahead FBPN incorporating the future release plan is constructed in this study. Three nearest exponentially discounted future workloads, modified from Chen’s nearest future discounted workloads, are proposed for the look-ahead function. According to experimental results, t...

While fabrication technologies have been in use in industry for several decades, expiring patents have recently allowed the technology to spill over to technology-enthusiastic “makers”. The big question now is whether the technology will further progress towards consumers, which would allow the technology to scale from hundreds of thousands of users to hundreds of millions of users. Such a tran...

The Engineering and Fabrication Branch of the Technical Services Department provides a wide range of engineering, design, and fabrication services for the Applied Physics Laboratory. The Branch routinely practices a technique known as "statistical process control" in the design, fabrication, testing, calibration, and quality control phases of its work to ensure the quality of designed and fabri...

Equipment throughput is one of the most critical parameters for production planning and scheduling, which is often derived by optimization techniques to achieve business goals. However, in semiconductor manufacturing, up-to-date and reliable equipment throughput is not easy to estimate and maintain because of the high complexity and extreme amount of data in the production systems. This article...

The process of wafer fabrication is arguably the most technologically complex stage in semiconductor manufacturing. This manufacturing environment has a number of unusual features. Probably reentrancy of lots and unbalanced production facilities are two of the most important and unique features of semiconductor wafer fabrication facilities (fabs) that necessitate lot flow control and effective ...

In this paper, we investigate the performance of different dispatching and scheduling heuristics for batching tools in a semiconductor wafer fabrication facility (wafer fab) by means of discrete event simulation. Because the processing times of lots on batching tools are quite large compared to those of other processes, careful batching decisions may have a great impact on the performance of th...