Discharge power dependence of Hα intensity and electron density of Ar + H2 discharges in H-assisted plasma CVD reactor

We have realized anisotropic deposition of Cu, for which Cu is preferentially filled from the bottom of trenches without being deposited on the sidewall of trenches, using H-assisted plasma CVD. To obtain information about a discharge condition to realize a high deposition rate, we have studied dependence of Hα 656.3 nm and Ar 811.5 nm intensities and electron density in the main discharge on the main discharge power, Pm, and in the discharge of H atom source on the discharge power of H atom source, PH, as a parameter of a gas flow rate ratio R = H2/(H2 + Ar). The results suggest that a high electron density in the main discharge and high fluxes of ions and H atoms to a substrate, all of which are needed for deposition of high purity Cu at a high deposition rate, are realized for Pm = 45 W, PH = 500 W, and R = 3.3%.