Optical emission spectroscopic study on H-assisted plasma for anisotropic deposition of Cu films

Abstract

We have studied dependence of Hα intensity and electron density on the discharge power and gas flow rate ratio R = H2/(H2 + Ar), to obtain information on a discharge condition bringing about a high H flux to film surfaces, because irradiation of H atoms on surfaces removes impurities in films and enhances the deposition rate. The highest Hα intensity, which is obtained for the discharge power of 500 W and R = 3.3%, is 10 times as high as that for previous deposition condition of the discharge power of 150 W and R = 11%. Moreover emission spectra suggest Ar metastable contribute to H generation for R = 3.3–33%.