Dry vacuum pumps for semiconductor processes: Guidelines for primary pump selection

Each of the many processes used for the production of ultralarge scale inte grated devices or flat panel displays has its own chemical and physical req uirements. Many require a vacuum environment that may range from slightly b elow atmospheric pressure to ultrahigh vacuum. Requirements for system clea nliness often dictate an oil-free pumping system. This article discusses ea ch of the process classes which require a dry primary vacuum pump and offer s guidelines for the selection of the proper Dump type. There are three cla sses of pump needed depending on the severity of the process-clean, moderat e, and harsh-with escalating complexity and cost for pumps made for the har sher environments. In addition to reviewing some of the latest developments in materials and vacuum design, particular attention is paid to operating experience with the very harshest processes-dielectric deposition and metal etch. (C) 2000 American Vacuum Society. [S0734-2101(00)07504-7].