Control of deposition profile of Cu for large-scale integration (LSI) interconnects by plasma chemical vapor deposition

Abstract

H-assisted plasma chemical vapor deposition (HAPCVD) realizes control of deposition profile of Cu in trenches. The key to the control is ion irradiation to surfaces. With increasing the flux and energy of ions, the profile changes from conformal to subconformal and then to an anisotropic one, for which Cu material is filled from the bottom of the trench without deposition on the sidewall. H3+ and ArH+ are identified as the major ionic species which contribute to the control, and hence the deposition profile also depends on a ratio R = H2/(Ar + H2).