Area-selective deposition (ASD), a "bottom-up" substrate-selective material deposition process, is a promising solution to overcome the current limitations experienced in semiconductor manufacturing processes, which rely on "top-down" patterning techniques. To achieve this selective material growth, atomic layer deposition (ALD) is frequently employed in conjunction with a blocking layer to suppress material nucleation on the nongrowth areas. ASD is suitable on many levels of wafer manufacturing; notably, its "bottom-up" nature makes it more impactful at the smallest critical dimensions (CDs), such as sub-10 nm. Nevertheless, the ASD studies at such relevant nanoscale dimensions are very limited or nonexistent. Therefore, we studied ASD enabled by 1-octadecanethiol (ODT)-derived self-assembled monolayer (SAM) passivation on unprecedented scaled-down Cu/SiO2 patterns, targeting ASD of hafnium nitride on 10 nm-wide dielectric spacings. Pulsed force atomic force microscopy nanomechanical characterization proved the tight confinement of the organic layer to the metal lines even on such high-density patterns. In addition, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy (SEM) measurements reveal the selective and conformal deposition of similar to 5.0 nm hafnium nitride film on the 10 nm-wide SiO2 spacings. Nevertheless, it is shown that, as the pattern features shrink, the undesired lateral expansion of the isotropically growing ALD film becomes a more stringent limitation to the ASD resolution. The "monolayer trade-off" associated with the employed passivation to enable ASD is analyzed in this work. In fact, a monolayer-thick blocking film is desired to avoid poisoning of the growth surface, whereas the ASD film lateral expansion could be effectively prevented if thicker passivation films are employed instead.

Understanding Selectivity Loss Mechanisms in Selective Material Deposition by Area Deactivation on 10 nm Cu/SiO 2 Patterns

Valentina Spampinato;
2022-01-01

Abstract

Area-selective deposition (ASD), a "bottom-up" substrate-selective material deposition process, is a promising solution to overcome the current limitations experienced in semiconductor manufacturing processes, which rely on "top-down" patterning techniques. To achieve this selective material growth, atomic layer deposition (ALD) is frequently employed in conjunction with a blocking layer to suppress material nucleation on the nongrowth areas. ASD is suitable on many levels of wafer manufacturing; notably, its "bottom-up" nature makes it more impactful at the smallest critical dimensions (CDs), such as sub-10 nm. Nevertheless, the ASD studies at such relevant nanoscale dimensions are very limited or nonexistent. Therefore, we studied ASD enabled by 1-octadecanethiol (ODT)-derived self-assembled monolayer (SAM) passivation on unprecedented scaled-down Cu/SiO2 patterns, targeting ASD of hafnium nitride on 10 nm-wide dielectric spacings. Pulsed force atomic force microscopy nanomechanical characterization proved the tight confinement of the organic layer to the metal lines even on such high-density patterns. In addition, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy (SEM) measurements reveal the selective and conformal deposition of similar to 5.0 nm hafnium nitride film on the 10 nm-wide SiO2 spacings. Nevertheless, it is shown that, as the pattern features shrink, the undesired lateral expansion of the isotropically growing ALD film becomes a more stringent limitation to the ASD resolution. The "monolayer trade-off" associated with the employed passivation to enable ASD is analyzed in this work. In fact, a monolayer-thick blocking film is desired to avoid poisoning of the growth surface, whereas the ASD film lateral expansion could be effectively prevented if thicker passivation films are employed instead.
2022
area-selective deposition
atomic layer deposition
self-assembled monolayer
alkanethiol
interfaces
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/559944
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