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Area-selective deposition (ASD) is a promising bottom-up manufacturing solution for catalysts and nanoelectronic devices. However, industrial applications are limited as highly selective ASD proces...

Patterns down to 21nm metal pitch (MP) have been used in the hybrid metallization scheme of Ru via prefill followed by a Cu trench metallization. The via resistance for Ru in hybrid with TaNRu/Cu trench fill is benchmarked to Co and Ru dual-damascene (DD) metallization schemes. At 30nm MP, a 40% via resistance reduction is observed upon introducing the Ru prefill prior to the Cu metallization. The Ru prefill significantly improved the via yield for the Cu metallization in 21nm MP. At this dimension, a 35% lower resistance is obtained with the Ru-Cu hybrid system when benchmarked to Co and Ru full fill with a 1nm TiN barrier. The electromigration of the Ru-Cu hybrid system does not a show a performance degradation, making it a viable scaling scenario for DD metallizations in N5 technologies and beyond.

Alkyl-terminated surfaces have received significant interest as growth-blocking surfaces in area-selective deposition (ASD). Gas-phase chemical functionalization is attractive in this context due to its short process times, potentially wide applicability, and ease of integration in industrial process flows. However, the relation between the surface chemistry, the passivating agent, and the growth-blocking efficacy of such treatments is not well understood which can lead to suboptimal passivation performance. This work investigates the reaction between dimethylamino-trimethylsilane (DMA-TMS) and SiO2 surfaces with varying composition, and identifies the impact of surface composition on passivation efficacy and selectivity. DMA-TMS reacts rapidly with Si–OH groups on SiO2 in a self-limiting surface reaction, resulting in an –O–Si(CH3)3 covered surface. In contrast, Si–O–Si groups are either unreactive or significantly less reactive towards DMA-TMS. Increasing the number of Si–OH versus Si–O–Si groups on the initial SiO2 surface therefore results in a higher –O–Si(CH3)3 density after DMA-TMS treatment. As a consequence, the selectivity of an ASD process towards SiO2 improves, as demonstrated for ruthenium atomic layer deposition from 1-ethylbenzyl-1,4-cyclohexadienyl-ruthenium and oxygen. This work illustrates the impact of tuning surface composition on passivation and selectivity for ASD.

Area-selective deposition (ASD) enables the growth of materials on target regions of patterned substrates for applications in fields ranging from microelectronics to catalysis. Selectivity is often achieved through surface modifications aimed at suppressing or promoting the adsorption of precursor molecules. Here, we show instead that varying the surface composition can enable ASD by affecting surface diffusion rather than adsorption. Ru deposition from (carbonyl)-(alkylcyclohexadienyl)Ru and H2 produces smooth films on metal nitrides, and nanoparticles on SiO2. The latter form by surface diffusion and aggregation of Ru adspecies. Kinetic modeling shows that changing the surface termination of SiO2 from −OH to −CH3, and thus its surface energy, leads to larger and fewer nanoparticles because of a 1000-fold increase in surface diffusion rates. Kinetic Monte Carlo simulations show that even surface diffusion alone can enable ASD because adspecies tend to migrate from high- to low-diffusivity regions. This is corroborated by deposition experiments on three-dimensional (3D) TiN–SiO2 nanopatterns, which are consistent with Ru migrating from SiO2 to TiN. Such insights not only have implications for the interpretation of experimental results but may also inform new ASD protocols, based on chemical vapor and atomic layer deposition, that take advantage of surface diffusion. © 2020 American Chemical Society., Chemistry of Materials, 32 (22), ISSN:0897-4756

© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Understanding the growth mechanisms during the early stages of atomic layer deposition (ALD) is of interest for several applications including thin film deposition, catalysis, and area-selective deposition. The surface dependence and growth mechanism of (ethylbenzyl)(1-ethyl-1,4-cyclohexadienyl)ruthenium and O2 ALD at 325 °C on HfO2, Al2O3, OH, and SiOSi terminated SiO2, and organosilicate glass (OSG) are investigated. The experimental results show that precursor adsorption is strongly affected by the surface termination of the dielectric, and proceeds most rapidly on OH terminated dielectrics, followed by SiOSi and finally SiCH3 terminated dielectrics. The initial stages of growth are characterized by the formation and growth of Ru nanoparticles, which is mediated by the diffusion of Ru species. Mean-field and kinetic Monte Carlo modeling show that ALD on OSG is best described when accounting for (1) cyclic generation of new nanoparticles at the surface, (2) surface diffusion of both atomic species and nanoparticles, and (3) size-dependent nanoparticle reactivity. In particular, the models indicate that precursor adsorption initially occurs only on the dielectric substrate, and occurs on the Ru nanoparticles only when these reach a critical size of about 0.85 nm. This phenomenon is attributed to the catalytic decomposition of oxygen requiring a minimum Ru nanoparticle size. ispartof: ADVANCED MATERIALS INTERFACES vol:5 issue:24 status: published

CMOS area scaling to N5 dimensions will have interconnect metal pitch around 30nm. Patterning such small features, using 193 ArF immersion lithography (193i), is only possible with pitch multiplication techniques such as SADP, SAQP, SAOP, etc. An additional keep or block patterning process is often used to achieve line interruptions and turns essential to have functional electrical devices. In this paper, we review three block patterning approaches experimented on imec's 32nm metal pitch N5 test vehicles. We discuss the merits and challenges of each patterning option and describe, qualitatively, process interactions with lithography parameters such as alignment and overlay. Lastly, we show that EUV block approach is a simpler benchmark in terms of process complexity and cost.

ispartof: ADVANCED MATERIALS INTERFACES vol:6 issue:20 status: published