A setup for study of co-deposited films

Abstract

A setup for investigation of thermal desorption spectra of gases accumulated in thin films deposited by plasma sputtering of solid targets is described. Deposition and thermal desorption spectroscopy (TDS) are performed in two different vacuum chambers separated by a gate valve with the sample transferred between the chambers in-vacuo. The temperature of the substrate for deposited films can be varied in the range of 300-800 K; and the deposition rate is controlled by a quartz microbalance. Thermal desorption of co-deposited gases is analyzed by a quadrupole mass spectrometer. Sputtering rate and evaporation of the film during TDS are measured by quartz microbalances. Three experiments are described 1) trapping of deuterium by the growing chemically active Li film with subsequent decomposition and evaporation of the film, 2) temperature dependent deuterium trapping in the growing W film resulting in trapping with several binding energies, and 3) chemical interaction of D-Li layer with water vapor leading to isotopic H-D exchange and chemical transformation of the deposited film.

A new compact linear beam-plasma discharge simulator BPD-PSI

“…After plasma exposure experiment, the sample mounted on the holder can be used for postmortem in-vacuo TDS measurements. Unlike conventional TDS systems [23], where the samples to be analyzed are heated by thermal radiation, BPD-PSI uses focused electron beam heating to maximize heating efficiency. The application of this method requires precise control of electron gun parameters during the heating, because the heating power of the focused electron beam is proportional to the ohmic scale 𝑃 heat ∼ 𝐼 beam 𝑈 acc .…”