Inhibitor-Free Area-Selective Atomic Layer Deposition with Feature Size Down to Nearly 10 nm

Area-selective atomic layer deposition (AS-ALD) is gaining widespread attention due to the urgent demand for a self aligned and bottom-to-top fabrication process in advanced semiconductor technology. In this study, an innovative concept of the atomic layer nucleation engineering (ALNE) and surface recovery (SR) techniques is proposed to realize AS-ALD of Al2O3 between metal (W) and dielectric (SiO2) without the involvement of inhibitors. The ALNE treatment is utilized to selectively remove the weakly adsorbed precursors on the metal surface, and the SR process can eliminate the oxidized layer on the metal surface caused by the exposure of oxidants in the ALD process. Accordingly, the AS-ALD with similar to 100% selectivity is achieved up to 100 ALD cycles with a considerable difference in an Al2O3 thickness of similar to 11.2 nm between the SiO2 and W surfaces. The accomplishment of AS-ALD is also demonstrated on the SiO2/W patterned substrates with the feature size scaling from 75 mu m to similar to 10 nm. Hence, the inhibitor-free AS-ALD implemented by the ALNE and SR techniques is a critical breakthrough for the further progress of Moore's law.

Automated summary

This study proposes an innovative concept of atomic layer nucleation engineering (ALNE) and surface recovery (SR) techniques to achieve area-selective atomic layer deposition (AS-ALD) of Al2O3 between metal (W) and dielectric (SiO2) without the use of inhibitors. The ALNE treatment selectively removes weakly adsorbed precursors on the metal surface, while the SR process eliminates the oxidized layer caused by exposure to oxidants during the ALD process. With these techniques, AS-ALD with nearly 100% selectivity and a significant difference in Al2O3 thickness between SiO2 and W surfaces is achieved, even on patterned substrates with feature sizes as small as 10 nm.