Hiroshi Shinriki

Novel PEALD-Ru formation technique using H 2 & H 2 /N 2 plasma as a seed layer for direct CVD-Cu filling

In this paper, novel Ru film formation technique by plasma enhanced atomic layer deposition (PEALD) is reported to be extremely promising as a seed layer for direct CVD-Cu full filling. PEALD-Ru film property can be controlled by H<inf>2</inf> to N<inf>2</inf> gas flow ratio in plasma step. PEALD-Ru film using H<inf>2</inf>/N<inf>2</inf> mixed gas based plasma can provide low resistivity (20µΩ-cm), sufficient Cu barrier property and 100% step-coverage. PEALD-Ru film using H<inf>2</inf> gas based plasma can provide (002) oriented Ru film, which is confirmed as good nucleation layer for CVD-Cu formation. Stacked film of Ru(H<inf>2</inf>)/ Ru(H<inf>2</inf>/N<inf>2</inf>) is demonstrated to be attractive as an underneath for direct CVD-Cu full filling without void generation in 50 nm via pattern.

Plasma Enhanced Atomic Layer Deposition of Ru-Ta composite film as a Seed Layer for CVD Cu filling

In this paper, a novel Ru-Ta composite seed layer is shown to improve Cu-CVD filling capability for high-aspect (≫5) vias. Cu-CVD filling capability strongly depended on Ru/Ta atomic ratios of the films. Ru/Ta atomic ratio was controlled by plasma ALD cycle number of each precursor pulses. Ru-Ta composite layer can improve Cu filling capability more than a pure Ru seed layer, thus resulting in completely Cu filling of 70 nm vias without void and seam.