A simulation-based evaluation of the cost of cycle time reduction in Agere Systems wafer fabrication facility—a case study

摘要

With the vast amount of capital invested in the semiconductor industry and the high level of competitiveness, semiconductor manufacturers are continuously searching for new methods to gain more market share and increase their profits. New technologies are continuously in demand, and are pushing the semiconductor manufacturers to seek better market position through constant improvement in their processes and products. Agere Systems is one of the leading companies in the microelectronics industry. This paper presents a comprehensive framework for strategic capacity expansion of production equipment at Agere Systems wafer fabrication facility (fab). We integrate simulation modeling, design of experiments, statistical analysis, and economic justification tools to aid in this highly complex decision-making process. We compliment the framework with a particular implementation. The procedure involved studying the factors in the fab that significantly impact the cycle times of the four main technologies that are currently in process and will stay in demand for at least the next few years. Moreover, the goal was to quantify the economic impact of reducing cycle times. To accomplish the objectives of this research, a valid simulation model of the production line of the fab was built. The production equipment (tool sets) that significantly influence production cycle time were identified through factor screening experiments. Based on these factors, several scenarios involving the acquisition of additional tools, aimed at cutting down cycle times, were identified and the operating characteristics curves were constructed. These characteristics curves were used to relate cycle time to production volume capabilities. Finally, an economic analysis was conducted to evaluate the return on investment in additional tools. The outcome of the case study was the identification of bottleneck facilities in the fab that have a significant impact on the cycle time of the four technologies. In the economic analysis, the cost of adding machines to these facilities was compared with the benefits resulting from the increase in production capacities.