Axial and radial distributions of electron temperature and density in a conventional and a shielded vacuum arc deposition apparatus for TiN film fabrication were measured using Langmuir probe method, and intensities of spectra radiated from the plasma were also measured along the arc axis. Moreover, radial distributions of deposition rates were obtained.
The results obtained were as follows. (1) Electron temperature was constant of about 2 eV at any position. (2) Electron density drastically decreased behind the shield plate. (3) Spectral intensities of Ti++ and Ti+ also decreased behind the shield plate, whereas those of Ti, N2+, and N2 were similar for both the conventional and the shielded arc. (4) Deposition rates at the position shadowed by the shield plate decreased, while similar deposition rate were obtained at the outer position for with and without shield plate.
From above results, particle behavior in the shielded arc was discussed as follows. Ti ions emitted toward the shield plate were trapped and shadowed by the shield plate although the electrons were not. As a result, behind the shield plate, Ti ions outside the shadow of the shield plate were attracted to the apparatus axis due to ambipolar diffusion between the ions and the electrons.