In recent years, vibration has become increasingly important as a factor to consider in the design of microelectronics fabrication facilities. As the demand for higher precision tools increases, the importance of vibration control also increases. In fact, at the present time, many aspects of structure/foundation design are controlled by vibration considerations rather than the traditional needs for load-carrying capacity. Vibration design involves geotechnical considerations such as site soils characteristics, soil type, depth of soil medium to bedrock; foundation considerations such as native soil preparation, fill material selection and preparation, types of foundation; and structural considerations such as the type of floor/column system, location of isolation breaks, etc. This paper examines soil characteristics and foundation design considerations as they apply to vibration transmission and performance in a typical fabrication facility. Dynamic soil-structure interaction analysis is employed to perform a parametric study of the important geotechnical factors affecting vibration performance of such a facility. Different foundation types are investigated in an attempt to arrive at optimum foundation design systems for various areas of the facility. Guidelines are provided in the areas of site selection, soil preparation, and foundation design.