Technique, for controlling flow of reactive gas in plasma vacuum deposition process, involves using optical spectroscopy to measure the particle stream intensities in the coating material and the reactive gas

摘要

To control the flow of a reactive gas, in a reactive plasma vacuum deposition process, a control value is set by a plasma from the vacuum chamber (1) in a monitoring stretch. A measurement unit (9) uses optical spectroscopy, and the values are processed at an electronic control unit (13) to set the volume of delivered gas according to any deviations from the required control settings. The control value is computed from a measurement of the intensity of a spectral line in the particle stream of the coating material (3), and the measured intensity of a particle stream of the reactive gas (6). The measurement unit has an acoustic/optical spectrometer (12) with a control input and a regulating output linked to it.