Abstract: One of the challenges in the semiconductor industry is to find new barrier materials and copper (Cu) alternative solutions in interconnects. In this work, we focused to find alternative diffusion barrier materials. Different binary (CoMo, CoRu, CoTa, CoW, MoRu, RuTa, RuW) and ternary (CoMoTa, CoRuTa, MoRuTa) metal alloys were evaluated theoretically with the Miedema model to find the amorphous phase composition range. Afterward, thin films of the alloys with various compositions were deposited by magnetron sputtering and theoretical values were compared to the experimental results. From the experimental measurements, which included grazing incidence x-ray diffraction analysis and resistivity measurements, suitable binary and ternary alloys were chosen for diffusion analysis. By annealing thin film stacks at temperatures ranging from 500 to 675°C, diffusion was induced and detected by x-ray photoelectron spectroscopy depth profiles. Seventeen alloys were evaluated by their diffusion barrier effectiveness, and five of those, which include Ru60Ta40, Ru45W55, Mo47Ru53, Mo36Ru50Ta14, and Co40Mo35Ta25, showed excellent barrier properties against copper diffusion. Furthermore, all of the stated materials have a lower resistivity than TaN. Last, the adhesion of the best performing alloys to SiCOH and Cu was evaluated by the modified edge lift-off test. Only Ru45W55 had reasonable adhesion at both interfaces. The other materials showed low adhesion strength to Cu, which would make an adhesion promoter (liner), such as cobalt, necessary for the integration.

Abstract: We present a novel bipolar resistive switching memory based on TaOx, featuring a Ru/Al2O3/Ta2O5/TaOx/Al2O3/W structure. Thin Al2O3 layers play a crucial role as diffusion barriers, preventing undesirable interfacial reactions at the top and bottom interfaces. They support the stable formation of the Schottky barrier near the Ru top electrode through redox reactions during operation, resulting in highly reliable bipolar resistive switching. The device exhibits excellent memory performance, including a fast operation speed (∼10 ns), good switching endurance (∼106 cycles), and robust data retention (>104 s at 200 °C).

Abstract: This study focuses on amorphous boron nitride ($\rm \alpha$-BN) as a novel diffusion barrier for advanced semiconductor technology, particularly addressing the critical challenge of copper diffusion in back-end-of-logic (BEOL) interconnects. Owing to its ultralow dielectric constant and robust barrier properties, $\rm \alpha$-BN is examined as an alternative to conventional low-k dielectrics. The investigation primarily employs theoretical modeling, using a Gaussian Approximation Potential, to simulate and understand the atomic-level interactions and barrier mechanisms of $\rm \alpha$-BN. This machine learning-based approach allows for realistic simulations of its amorphous structure, enabling the exploration of the impact of different film morphologies on barrier efficacy. Complementing the theoretical study, experimental analyses are conducted on Plasma-Enhanced Chemical Vapor Deposition (PECVD) grown $\rm \alpha$-BN films, evaluating their effectiveness in preventing copper diffusion in silicon-based substrates. The results from both the theoretical and experimental investigations highlight the potential of $\rm \alpha$-BN as a highly effective diffusion barrier, suitable for integration in nanoelectronics. This research not only proposes $\rm \alpha$-BN as a promising candidate for BEOL interconnects but also demonstrates the synergy of advanced computational models and experimental methods in material innovation for semiconductor applications.

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Abstract: Exploration of new dielectrics with large capacitive coupling is an essential topic in modern electronics when conventional dielectrics suffer from the leakage issue near breakdown limit. To address this looming challenge, we demonstrate that rare-earth-metal fluorides with extremely-low ion migration barriers can generally exhibit an excellent capacitive coupling over 20 $\mu$F cm$^{-2}$ (with an equivalent oxide thickness of ~0.15 nm and a large effective dielectric constant near 30) and great compatibility with scalable device manufacturing processes. Such static dielectric capability of superionic fluorides is exemplified by MoS$_2$ transistors exhibiting high on/off current ratios over 10$^8$, ultralow subthreshold swing of 65 mV dec$^{-1}$, and ultralow leakage current density of ~10$^{-6}$ A cm$^{-2}$. Therefore, the fluoride-gated logic inverters can achieve significantly higher static voltage gain values, surpassing ~167, compared to conventional dielectric. Furthermore, the application of fluoride gating enables the demonstration of NAND, NOR, AND, and OR logic circuits with low static energy consumption. Notably, the superconductor-to-insulator transition at the clean-limit Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ can also be realized through fluoride gating. Our findings highlight fluoride dielectrics as a pioneering platform for advanced electronics applications and for tailoring emergent electronic states in condensed matters.

Abstract: Abstract The influence of cobalt and cobalt–manganese oxide coating thickness on its ability to be a good diffusion barrier against Cr outward diffusion was investigated for stainless steel interconnects (AISI 441) of a solid oxide cell (SOC). The coatings were all synthesized using a DLI-MOCVD (Direct Liquid Injection-Metal Oxide Chemical Vapor Deposition) hot wall reactor. The study shows that a minimum cobalt oxide thickness of 300 nm was needed to be a good diffusion barrier against Cr for the 500-h exposure test. This observation was linked to the Mn concentration reached in the cobalt spinel during exposure. Indeed, during exposure at high temperature, Mn diffused from the substrate into the cobalt coating and transformed cobalt spinel into Co-Mn spinel. Whereas pure cobalt spinel was a good Cr diffusion barrier, cobalt-manganese spinel, Co 3-x Mn x O 4 , was not when x > 2. The thickness of the cobalt coatings must be chosen so that the Mn quantity coming into it from diffusion from the substrate does not degrade the protectiveness of the coating.

Abstract: Controlling the contact properties of a copper (Cu) electrode is crucial for enhancing the performance of InSnZnO (ITZO) thin-film transistors (TFTs) in high-speed applications. This is due to the inherently low resistance–capacitance product constant of Cu. High diffusivity of Cu, when integrated into ITZO, poses a major challenge as it leads to the formation of detrimental electron trap states, resulting in performance degradation of ITZO TFTs. A self-assembled monolayer (SAM) serves a dual purpose, effectively functioning as a diffusion barrier (DB) for Cu and a passivation layer. The study showcases the efficacy of vapor-phase SAM with suitable functional groups in enhancing the electrical properties of ITZO TFTs, with SAMs featuring -SH groups being particularly effective. The impressive electrical performance of SAMs with -SH groups makes them highly effective as Cu DBs and passivation layers. These versatile SAMs exhibit potential as a great choice for a thin copper DB in upcoming electronic technologies.

Abstract: Cued Speech (CS) is an advanced visual phonetic encoding system that integrates lip reading with hand codings, enabling people with hearing impairments to communicate efficiently. CS video generation aims to produce specific lip and gesture movements of CS from audio or text inputs. The main challenge is that given limited CS data, we strive to simultaneously generate fine-grained hand and finger movements, as well as lip movements, meanwhile the two kinds of movements need to be asynchronously aligned. Existing CS generation methods are fragile and prone to poor performance due to template-based statistical models and careful hand-crafted pre-processing to fit the models. Therefore, we propose a novel Gloss-prompted Diffusion-based CS Gesture generation framework (called GlossDiff). Specifically, to integrate additional linguistic rules knowledge into the model. we first introduce a bridging instruction called \textbf{Gloss}, which is an automatically generated descriptive text to establish a direct and more delicate semantic connection between spoken language and CS gestures. Moreover, we first suggest rhythm is an important paralinguistic feature for CS to improve the communication efficacy. Therefore, we propose a novel Audio-driven Rhythmic Module (ARM) to learn rhythm that matches audio speech. Moreover, in this work, we design, record, and publish the first Chinese CS dataset with four CS cuers. Extensive experiments demonstrate that our method quantitatively and qualitatively outperforms current state-of-the-art (SOTA) methods. We release the code and data at https://glossdiff.github.io/.

Abstract: Cu has served as the interconnect metal in various chip generations, typically with the presence of a TaN/Ta diffusion barrier/liner. The size-scaling demand for future nodes requires thinning down TaN/Ta bi-layer. The thickness of TaN/Ta has reached the limit of its barrier/liner capability, necessitating the exploration of alternative diffusion barrier/liner materials. In this paper, we report the 300mm wafer-scale atomic layer deposited MoS2 as a promising candidate for Cu diffusion barrier/liner interconnect. MoS2 was deposited on thermal SiO2 substrate at the temperatures ranging from 200–550 °C. Good conformality of MoS2 was demonstrated on high aspect ratio structure. The resistivity of Cu/MoS2/SiO2 stack is lower than that of Cu/SiO2 stack. Time dependent dielectric breakdown of Cu/MoS2/SiO2 will be discussed and benchmarked with Cu/Ta/TaN/SiO2.

Abstract: As the integration of chips in 3D integrated circuits (ICs) increases and the size of micro-bumps reduces, issues with the reliability of service due to electromigration and thermomigration are becoming more prevalent. In the practical application of solder joints, an increase in the grain size of intermetallic compounds (IMCs) has been observed during the reflow process. This phenomenon results in an increased thickness of the IMC layer, accompanied by a proportional increase in the volume of the IMC layer within the joint. The brittle nature of IMC renders it susceptible to excessive growth in small-sized joints, which has the potential to negatively impact the reliability of the welded joint. It is therefore of the utmost importance to regulate the formation and growth of IMCs. The following paper presents the electrodeposition of a Ni-W layer on a Cu substrate, forming a barrier layer. Subsequently, the barrier properties between the Sn/Cu reactive couples were subjected to a comprehensive and systematic investigation. The study indicates that the Ni-W layer has the capacity to impede the diffusion of Sn atoms into Cu. Furthermore, the Ni-W layer is a viable diffusion barrier at the Sn/Cu interface. The “bright layer” Ni2WSn4 can be observed in all Ni-W coatings during the soldering reflow process, and its growth was almost linear. The structure of the Ni-W layer is such that it reduces the barrier properties that would otherwise be inherent to it. This is due to the “bright layer” Ni2WSn4 that covers the original Ni-W barrier layer. At a temperature of 300 °C for a duration of 600 s, the Ni-W barrier layer loses its blocking function. Once the “bright layer” Ni2WSn4 has completely covered the original Ni-W barrier layer, the diffusion activation energy for Sn diffusion into the Cu substrate side will be significantly reduced, particularly in areas where the distortion energy is concentrated due to electroplating tension. Both the “bright layer” Ni2WSn4 and Sn will grow rapidly, with the formation of Cu-Sn intermetallic compounds (IMCs). At temperatures of 250 °C, the growth of Ni3Sn4-based IMCs is controlled by grain boundaries. Conversely, the growth of the Ni2WSn4 layer (consumption of Ni-W layer) is influenced by a combination of grain boundary diffusion and bulk diffusion. At temperatures of 275 °C and 300 °C, the growth of Ni3Sn4-based IMCs and the Ni2WSn4 layer (consumption of Ni-W layer) are both controlled by grain boundaries. The findings of this study can inform the theoretical design of solder joints with barrier layers as well as the selection of Ni-W diffusion barrier layers for use in different soldering processes. This can, in turn, enhance the reliability of microelectronic devices, offering significant theoretical and practical value.

Abstract: In this study, a quantitative evaluation of Cu barrier properties with different thicknesses and compositions of ultrathin physical vapor deposited (PVD) Co(W) films was conducted through a comprehensive analysis using the modified time-lag method. Compared to the 20-nm-thick PVD-Co(W) films, which crystallized after annealing, the PVD-Co(W) films with 1~3-nm-thickness remained amorphous and exhibited enhanced barrier properties. The amorphous structure of the thinner films improved the barrier properties by eliminating the grain boundaries as the primary diffusion path for Cu atoms. More importantly, a 1-nm-thick PVD-Co(W) film with a W composition of 35 at. % exhibited exceptional Cu diffusion barrier properties, surpassing other compositions. This superior performance can be attributed to the high thermal stability that preserves the amorphous structure and overall integrity of the film, resulting from the optimal atom packing. This film also displayed the lowest Cu diffusivity (D) and highest activation energy (Ea = 2.5 eV) among all the investigated barrier candidates. In addition, ultrathin PVD-Co(W) films can function effectively as both a barrier against Cu diffusion and an oxygen diffusion block, underscoring their application superiority to Cu interconnects in next-generation ultra-large-scale integration (ULSI) devices.

Abstract: Hydrogen sulfide corrosion is one of the most often noted negative appearances during operating of oil and gas equipment.Its origination is connected with large amount of hydrogen sulfide in processed raw materials (hydrogen sulfide content in watered oil can reach 500 mg/l for several oil wells) or with high operating temperature, which lead to splitting of substances with hydrogen sulfide content and hydrogen sulfide extraction [1,2].So, the number of rejects for downhole equipment, caused by hydrogen sulfide corrosion, reaches 20 % of total number of rejects [1].Steel 30KhGSN2A is considered as one of the widely distributed materials for fabrication of components of oil and gas equipment.This steel is used for manufacture of heavyloaded components, because it is characterized by high corrosion resistance and workability.However, application of this steel in hydrogen sulfide media requires use of the technologies decreasing its corrosion rate.To provide protection, two approaches are used: development of corrosion inhibitors and development of materials which are resistant to hydrogen sulfide action [3][4][5][6][7].Crea-This paper investigates the effect of diffusion alloying from a medium of low melting liquid metal solutions (DALMMS) of 30KhGSN2A steel with Ni-Cu and Ni-Cr elemental compositions on the structure, elemental composition of surface layers and corrosion resistance in hydrogen sulphide containing media.When DALMMS of 30KhGSN2A steel with Ni-Cu is used, coatings consisting of 3 layers are formed on the surface of the steel: a surface layer, a transition layer saturated with copper, a transition layer of a base layer.The coatings have a low microhardness (133 HV), the maximum concentration of nickel is 44 %, of copper -80 %.The total thickness of the coatings is up to 30 μm.When DALMMS of 30KhGSN2A steel with Ni-Cr is used, coatings consisting of 2 layers are formed on the steel surface: a surface carbide layer, a transition layer of a base coating.The coatings are characterized by high surface microhardness (2000 HV).The total thickness of the coatings is up to 20 μm.The maximum concentration of chromium was 75 %, of nickel -20 %.When tested for hydrogen cracking resistance, samples with both types of coatings showed no corrosion.The average value of total (continuous) corrosion for the Ni-Cu coating was 0.031 mm/year and for the Ni-Cr coating 0.048 mm/year.When tested for stress-sulfide cracking test, the maximum time to fracture for a Ni-Cr coated sample was 313 hours, while the Ni-Cu coated samples withstood the test completely (720 hours) without destruction or coating failure.It was revealed that diffusion Ni-Cu coatings were found to be effective in protecting the base metal from general hydrogen sulphide corrosion at the temperatures up to 150 °C, with a protection rate of over 98 % (tested according to the standard NACE MR0175/ISO 15156).

Abstract: Making ingestible devices edible facilitates diagnosis and therapy inside the body without the risk of retention; however, food materials are generally soft, absorb water molecules, and are not suitable for electronic devices. Here, we fabricated an edible water diffusion barrier film made by gelatin-beeswax composites for the encapsulation of transient electronics. Hydrophobic beeswax and hydrophilic gelatin are inherently difficult to mix; therefore, we created an emulsion simply by raising the temperature high enough to melt the materials and vigorous stirring them. As they cool, the beeswax with a relatively high solidification temperature aggregates and forms microspheres, which increases the gelatin gel's viscoelasticity and immobilizes the emulsion structure in the film. The thermoresponsive gelatin imparts degradability to the barrier and its stickiness also enables transfer of metal patterned electronics. Furthermore, we designed an edible resonator on the film and demonstrated its operation in an abdominal phantom environment; the resonator was made to be degradable in a warm aqueous solution by optimizing the composition ratio of the gelatin and beeswax. Our findings provide insight into criteria for making transient electronics on hydrophilic substrates with hydrophobic water diffusion barriers. This proof-of-concept study expands the potential of operating edible electronics in aqueous environments in harmony with the human body and nature.