KINETICS OF TUNGSTEN ETCHING BY ATOMIC AND MOLECULAR CHLORINE.

Article abstract of DOI:10.1149/1.2096215

The reactions of atomic and molecular chlorine with tungsten were studied by modulated beam-mass spectrometric methods over the temperature range 300-1350 K. The atomic beam was generated by an rf plasma discharge. With both atomic and molecualr beams, the main reaction product up to about 1000 K was WCl//4. The reaction probability with atomic chlorine was a factor of approximately ten higher than that obtained with molecular chlorine. The reaction was nonlinear with respect to Cl//2 intensity at low beam fluxes but approached linearity at high beam intensities. Above 1000 K the main reaction product was atomic chlorine. Its reaction probability increased rapidly with temperature; at 1300 K nearly complete dissociation of Cl//2 was observed. A kinetic model based on the Eley-Rideal mechanism was proposed and compared with the data. AA. 20 Refs.