Development of Parametric Material, Energy, and Emission Inventories for Wafer Fabrication in the Semiconductor Industry

Abstract

Currently available data suggest that most of the energy and material consumption related to the production of an integrated circuit is due to the wafer fabrication process. The complexity of wafer manufacturing, requiring hundreds of steps that vary from product to product and from facility to facility and which change every few years, has discouraged the development of material, energy, and emission inventory modules for the purpose of insertion into life cycle assessments. To address this difficulty, a flexible, process-based system for estimating material requirements, energy requirements, and emissions in wafer fabrication has been developed. The method accounts for mass and energy use atthe unit operation level. Parametric unit operation modules have been developed that can be used to predict changes in inventory as the result of changes in product design, equipment selection, or process flow. A case study of the application of the modules is given for energy consumption, but a similar methodology can be used for materials, individually or aggregated.

Life-Cycle Assessment of Semiconductors

“…In 2003, Cynthia Murphy at the University of Texas at Austin described a plan to create parametric process models for semiconductor LCI [62]. Murphy measured power consumption and gas flows for several types of furnace-based thermal processes and provided an equation to estimate power and gas consumption based on oxide film thickness.…”

“…While a logic chip may weigh only a few grams, the chemicals and water required to produce it weigh many kilograms. In many LCA studies of electronics, the lack of LCA data for computer chips has been noted as an important topic for future work and the need for a more detailed and transparent life-cycle inventory for semiconductor products has been noted previously [76,75,62,109,11,104].…”

“…These studies also do not report data uncertainty or discuss the influence of data uncertainty on results. Several researchers have noted that the lack of LCA data for semiconductor devices is a stumbling block in LCA of electronics, and that there is particular need for more complete or transparent LCA of semiconductors [76,75,62,109,11,104,10]. Academic work related to semiconductor LCA includes a study from Murphy which presents a methodology for parametric semiconductor life cycle inventory (LCI) models based on process specifications [62].…”

Requerimientos de Energía en los Procesos de Fabricación a Nanoescala

“…Existen, sin embargo, estudios de tecnologías maduras de fabricación de semiconductores bien documentados (Williams et al, 2002) (Murphy et al, 2003) (Williams, 2004). Debido a las similitudes entre los semiconductores y las tecnologías de fabricación a nanoescala, es conveniente utilizar algunos de estos datos como las estimaciones de límite inferior para el uso de energía en la fabricación a nanoescala.…”

Quantifying the Environmental Footprint of Semiconductor Equipment Using the Environmental Value Systems Analysis (EnV-S)

“…To provide the flexibility needed to develop predictive life cycle inventories within facilities, Murphy has developed a module-based parametric analysis of semiconductor environmental impacts [12]. This module-based analysis is not directly equipment-centric, but it could support equipment DFE efforts.…”