We are studying the manufacturing performance of semiconductor wafer fabrication plants in the US, Asia, and Europe. There are great similarities in production equipment, manufacturing processes, and products produced at these plants. Nevertheless, data reported here show that important quantitative measures of productivity vary by factors of 3 to as much as 5 across an international sample of ...

In numerous wafer fabrication facilities (wafer fabs) the load changes dynamically. Current load release control schemes are usually developed and tested in a constant load environment. In this paper, we discuss four CONWIP-like lot release policies and assess their ability to buffer variability generated by the load changes and to keep the lot release variability as low as possible. All contro...

The authors discuss the concept and design criteria for a framework that facilitates the performance assessment of shop-floor control systems. Their basic concept includes a simulation model that emulates the shop floor of a wafer fab, sends information to the control system, and receives information back from the control system. The shop-floor control system is realized as a separate module th...

In this paper, a brief summary of different methods of fabrication of optical preform and fiber is reviewed. Several methods of incorporation of erbium ions into optical preforms are studied. Characterization of the fabricated erbium doped fibers including measurements of refractive index profile, absorption, fluorescence and gain spectra and metastable lifetime are described. It is also expres...

This paper presents the design and a new low-cost process for fabrication of a second-order micromechanical filter using UV-LIGA technology. The micromechanical filter consists of two identical bulk-mode ring resonators, mechanically coupled by a flexural-mode beam. A new lumped modeling approach is presented for the bulk-mode ring resonators and filter. The validity of the analytical derivatio...

A clear distinction generally exists between processes of design generation and processes of design production. The profusion of digital fabrication tools and technologies make evident such distinctions in the context of design production but at the same time carry potential for material and fabrication-based processes promoting generative design methods. Such strategic application and customiz...