Early Vacuum Science and Technology

Abstract

Various aspects of early vacuum science and technology are discussed in the chapter. The use of vacuum equipment for deposition (and etching) processes introduces problems associated with pumping and disposing of possibly toxic, flammable, and corrosive processing gases, as well as reactive gases used for in situ cleaning of vacuum systems. Specialized vacuum equipment and in situ chamber plasma-etch-cleaning techniques are developed to address these concerns. With the advent of reactive deposition and hybrid processing, the control of gas composition and mass flow has become an important aspect of vacuum engineering and technology. This includes partial pressure control and gas manifolding in processing chambers. Differentially pumped mass spectrometers can be used to monitor and control partial pressures of gases. Optical emission spectroscopy is also used to control the partial pressures of reactive gases in reactive sputter deposition. Optical emission has been used for many years to detect the end-point in plasma etching for semiconductor processing.