Title Participants Abstract "Area-Selective ALD of Ru on Nanometer-Scale Cu Lines through Dimerization of Amino-Functionalized Alkoxy Silane Passivation Films" "Ivan Zyulkov, Stefan De Gendt" "The selective deposition of materials on predefined areas on a substrate is of crucial importance for various applications, such as energy harvesting, microelectronic device fabrication, and catalysis. A representative example of area-confined deposition is the selective deposition of a metal film as the interconnect material in multilevel metallization schemes for CMOS technology. This allows the formation of multilevel structures with standard lithographical techniques while minimizing pattern misalignment and overlay and improving the uniformity of the structures across the wafer. In this work, area-selective deposition of Ru by atomic layer deposition (ALD) is investigated using alkoxy siloxane dielectric passivation layers. In this work, a comparison of several silane organic SAM precursors in terms of Ru ALD ASD performance is reported. The importance of the surface areal concentration of the passivation molecules is demonstrated. According to the in situ X-ray photoelectron spectroscopy film characterization, the ALD blocking layers derived from a (3-trimethoxysilylpropyl) diethylenetriamine (DETA) precursor have the ability to polymerize under ALD-compatible temperatures, such as 250 °C, which leads to a significant inhibition of Ru growth up to 400 ALD cycles. At the same time, the DETA layer can be selectively removed from the oxidized Cu surface by rinsing in acetic acid, which allows selective deposition of ca. 14 nm of Ru on Cu with no Ru detected on the DETA-coated surface by RBS. The approach is successfully tested on 50 nm half-pitch patterned SiO2/Cu lines." "High sensitivity Rutherford backscattering spectrometry using multidetector digital pulse processing" "Wilfried Vandervorst, Ivan Zyulkov, Johan Meersschaut" "© 2018 Author(s). Rutherford backscattering spectrometry is a primary reference method for the quantity of materials, but has a limit-of-detection (LOD) presently at ∼1015 at/cm2 for analyses with traceable accuracy near 1%. A multidetector assembly is demonstrated which increases the count rate without decreasing the signal/noise due to pulse pile-up. A LOD of 6 × 1012 at/cm2 is achieved with the multidetector assembly and applied to quantify the onset of an atomic layer deposition (ALD) process for an in-depth study of the growth selectivity of ALD Ru on a-C:H and on SiCN. Besides, the spectrometer enables" "Use of high order precursors for manufacturing gate all around devices" "Ivan Zyulkov" "© 2016 Elsevier Ltd Epitaxial growth of strained and defect free SiGe layers grown with disilane and digermane was investigated. This precursors set allows to cover a broad range of Ge concentration (15–65%) at low temperatures (400–550 °C). It was shown that change of carrier gas (from H2 to N2) does not increase SiGe growth rate but significantly reduces Ge concentration. Increase of total process pressure considerably reduces SiGe growth rate which is attributed to peculiarities of digermane decomposition and influence of hydrogen surface passivation on disilane decomposition. It was shown that both disilane and digermane can be successfully combined with conventional precursors like silane and germane. These experiments suggested that digermane decomposition is the main driver of the growth rate increase during SiGe growth. Based on the presented data we demonstrated growth of different SiGe/Si and SiGe/Ge stacks with high quality necessary for production of gate all around field effect transistors." "Selective Ru ALD as a Catalyst for Sub-Seven-Nanometer Bottom-Up Metal Interconnects" "Ivan Zyulkov, Mikhail Krishtab, Stefan De Gendt" "Integrating bottom-up area-selective building-blocks in microelectronics has a disruptive potential because of the unique capability of engineering new structures and architectures. Atomic layer deposition (ALD) is an enabling technology, yet understanding the surfaces and their modification is crucial to leverage area-selective ALD (AS-ALD) in this field. The understanding of general selectivity mechanisms and the compatibility of plasma surface modifications with existing materials and processes, both at research and production scale, will greatly facilitate AS-ALD integration in microelectronics. The use of self-assembled monolayers to inhibit the nucleation and growth of ALD films is still scarcely compatible with nanofabrication because of defectivity and downscaling limitations. Alternatively, in this Research Article, we demonstrate a straightforward H2 plasma surface modification process capable of inhibiting Ru ALD nucleation on an amorphous carbon surface while still allowing instantaneous nucleation and linear growth on Si-containing materials. Furthermore, we demonstrate how AS-ALD enables previously inaccessible routes, such as bottom-up electroless metal deposition in a dual damascene etch-damage free low-k replacement scheme. Specifically, our approach offers a general strategy for scalable ultrafine 3D nanostructures without the burden of subtractive metal patterning and high cost chemical mechanical planarization processes." "Selective Metal Deposition for Advanced Metallization Schemes" "Ivan Zyulkov" "Starting from critical dimensions below 10 nm, the continuation of CMOS scaling requires the Cu replacement as an IC interconnect material by a barrierless metal with lower resistivity and better electromigration performance than Cu. Co and Ru are currently considered to be the most attractive candidates for the Cu replacement as they offer a tradeoff between material properties, cost, precursor and manufacturing processes availability. In addition, narrow dimensions of interconnect features require implementation of bottom-up metal fill schemes to mitigate defects in metal structures such as voids and seams. At the same time, significant technological improvements are required to mitigate the pattern overlays and litho-based edge placement errors when forming multilevel structures with a half-pitch at or below 10 nm. The transition from standard multiple litho-etch deposition schemes to bottom-up area-selective deposition (ASD) is a very promising way to enable self-alignment of multilevel structures. Integrating bottom-up area-selective building-blocks in a microelectronic processing flow has a disruptive potential because of the unique capability of engineering new structures and architectures, through selective growth in one area over other areas. The approaches to achieve selectivity of the (metal) deposition can be classified in three categories: i) intrinsic selectivity, ii) selectivity enabled by passivation of the ""non-growth area"" and iii) selectivity enabled by activation of the ""growth area"". Among deposition processes, electroless deposition (ELD) and atomic layer deposition (ALD) can be effectively used in selective deposition schemes due to their chemical nature and surface sensitivity. This work explores all three categories of ASD approaches for BEOL technology application, utilizing the above listed deposition techniques and metals, considered as promising candidates for Cu replacement. Intrinsically selective metal deposition can be realized for very limited number of material combinations used in IC manufacturing process flow. The surface functionality of a ""growth area"" must be favorable for metal ALD, while the surface termination of ""non-growth area"" of the substrate must simultaneously inhibit ALD nucleation. This work focuses on various H-based plasma treatments, which allow forming appropriate surface functionalities enabling selective ALD nucleation and growth in one area of the substrate, while ALD is blocked in the other part of the substrate. Among various combinations of materials, the focus was set on amorphous carbon (a-C) as ""non-growth"" surface and Si-based materials, such as SiCN, as ""growth"" surface, since both: a-C and Si-based dielectrics are already present in the process flow as sacrificial pattern transfer layer and dielectric barrier / etch stop layer respectively. An interaction of various compounds of H-based plasma, namely: H ions and H radicals with a-C layer was investigated experimentally. In order to support experimental observations, molecular dynamic modeling of a-C interaction with H plasma was performed, which allowed to understand the mechanisms of a-C chemical modification by H ions and radicals. Effectivity of H plasma treatment on ALD selectivity was studied for the case of selective Ru ALD using (ethylbenzyl) (1-ethyl-1,4-cyclohexadienyl) Ru(0) (EBECHRu) precursor with O2 co-reactant. In addition, an initial study of Ru ASD integration into patterned test structures of technological relevant dimensions was performed. Direct implementation of intrinsically selective processes into production is a rare case in microelectronic technology. In most of the cases, however, blocking layers can be used to inhibit ALD growth on certain areas on the substrate. This work explores self-assembled monolayers (SAMs) as blocking layers for ALD. SAMs can convert chemically reactive substrate groups into non-reactive sites to inhibit the nucleation and growth on the non-growth area. Siloxane SAMs are typically used to functionalize Si-based dielectric surfaces, while thiol and phosphonic acid SAMs are used for the functionalization of metals and metal oxides, respectively. However, to achieve a successful ASD by ALD, the SAM blocking layers should be defect-free to avoid undesired growth on the non-growth region. Unfortunately, preparing a defect-free SAM is extremely difficult and even a high-quality SAM layer can be easily damaged under the ALD process conditions, such as oxidizing environment, precursor gases and/or high deposition temperatures. In this work, screening of various siloxane SAM precursors was performed in order to study the impact of SAM's functional group, length of alkyl chain and deposition conditions on surface density of SAM molecules and, specifically, passivation properties of SAM layer against Ru ALD. An additional study was performed in order to analyse modification of (3-trimethoxysilylpropyl) diethylenetriamine (DETA)-derived SAM under ALD conditions (250 °C and O2 co-reactant). In-situ XPS measurements as well as molecular dynamic modelling were employed to investigate the mechanisms of DETA modification. Lastly, a removal of DETA-derived SAM from Cu ""growth area"" selectively with respect to SiO2 ""non-growth area"" using acetic acid was investigated to mitigate defectivity. Further, surface functionalization by SAMs can also be used to form appropriate surface terminal groups for further attachment of a metal catalyst or metal seed, used in subsequent selective ELD deposition. ELD is based on redox reactions on the metal substrate; therefore, it can be used for intrinsically selective metal deposition on metal substrates or metal seeds. SAMs-enabled selectivity can be used for metal growth on a dielectric surface selectively with respect to another type of the dielectric material. A relevant example of the selective metal deposition on a dielectric is a bottom-up filling of the interconnect trenches, where Si-based dielectrics, such as organosilicate glass or SiCN are located at the bottom of the trench. Sidewalls of the trench can be made of amorphous carbon playing a role of the sacrificial dielectric material. In the case of ELD bottom-up growth in a trench, the metal catalyst should be selectively deposited at the trench bottom dielectric layer. In this work, the selectivity of Pd metal catalyst promoted by selective surface functionalization by SAMs was investigated. It has been shown that SAMs with amino functional groups form covalent bonds with Pd catalyst, which is commonly used as a seed for subsequent ELD of various metals including Co on the Pd seed. Since the electrical properties of interconnect material are of crucial importance, an additional study of ELD Co resistivity was performed, including in-depth analysis of Co recrystallization revealing Co grain size dependency on the film resistivity. In conclusion, area-selective metal deposition processes are an important part of future microelectronic technology. This work explores ASD of Ru and Co, as the most promising Cu replacement metals. For the deposition of these metals, surface sensitive techniques are used, namely ALD and ELD. For the cases, where intrinsic selectively of the deposition technique cannot be realized for the combination of materials used in the process flow, SAM-based passivation and SAM-based activation layers were investigated."