The advancement of ultra-large-scale integration (ULSI) technology has significantly improved semiconductor performance through the miniaturization of chip feature sizes. However, this scaling has led to increased resistance-capacitance (RC) delays in back end of line (BEOL) processes. To mitigate these issues, the semiconductor industry has transitioned from silicon dioxide (SiO2) to low-k dielectric materials such as organosilicate glass (SiCOH). This study investigates the deposition of SiCOH films using plasma-enhanced chemical vapor deposition (PECVD) with a novel precursor, C6H16OSi, focusing on the impact of the oxygen/carbon (O/C) ratio on film properties. Fourier-transform infrared (FT-IR) spectroscopy confirms the presence of various hydrocarbon and organosilicon bonds including C-Hx (3100-2800 cm-1), Si-CH3 (1260 cm- 1), and Si(CH3)x (775, 805, 845 cm- 1) as well as the Si-O-Si asymmetric stretching band at 1250-950 cm- 1. Systematic deconvolution of these peaks reveals how increasing O/C shifts the balance between siloxane suboxide, network, and cage structures, alongside changes in Si-(CH3)x and C-Hx contributions. X-ray photoelectron spectroscopy (XPS) analysis corroborates these trends, showing that increased O2 flow enhances the deposition rate and lowers the refractive index. Mechanical tests further indicate that hardness and elastic modulus follow similar tendencies. Computational simulations further demonstrate that higher carbon content leads to the formation of CH3 bonds, which increase free volume, reduce density, and lower the dielectric constant. These findings highlight the potential of this novel precursor to produce SiCOH films with enhanced electrical, mechanical, and thermal properties for next-generation BEOL applications.

Recent advancements in neuromorphic computing driven by memristors, which emulate biological synapses and neurons, have spurred the development of innovative information technologies. To extend memristor applications to artificial nervous systems, electronic receptors are crucial for converting external stimuli into signals for the internal nervous system. Key requirements for integrating neuron devices into neuromorphic computing include achieving threshold behavior, minimizing power consumption, and ensuring compatibility with complementary metal-oxide semiconductor (CMOS) technology. Hafnium-based ferroelectric memristors are known for their robust ferroelectric properties at nanoscales and compatibility with CMOS technology. However, their non-volatile resistive switching has historically limited their suitability for neuron sensory applications requiring threshold switching. This study demonstrates threshold switching behavior in a TiN/Hf0.67Zr0.33O2(HZO)/TiOx/TiN heterostructure by incorporating a nanoscale TiOx interfacial layer as an oxygen reservoir. This layer facilitates the formation of oxygen vacancies within the ferroelectric HZO layer, serving as internal charge trap sites. As a result, hafnium-based ferroelectric memristors exhibit volatile switching characteristics, enabling them to function as nociceptive devices through internal charge trapping and detrapping mechanisms. These volatile memristors are suitable for artificial nociceptor systems requiring responses such as threshold detection, relaxation, allodynia, and hyperalgesia to external stimuli. This capability opens avenues for developing advanced humanoid robots capable of rapid adaptation and response in challenging environments such as outer space or hazardous conditions, leveraging real-time sensory processing for effective operation and survival.

To protect the active layer, which are inter layer dielectrics (ILD) and metal lines, from being damaged by UV laser during the etching process, etch stop layers (ESL) are used in patterning process of the integrated circuits (ICs) fabrication in back end of line (BEOL). The ESL material should have a higher etch selectivity than the active layer. Therefore, it must have a low dielectric constant and high chemical resistance. Aluminum oxide compounds (AlOx, AlOC, AlON, etc.) are highly suitable for use as ESL due to the low dielectric constant between about 4 and 9, high etch selectivity, high density (2.5-3.8 g/cm3) and pattern transfer capability. We focused on lowering the dielectric permittivity and increasing the density by controlling the precursor/reactant pulsed time of atomic layer deposition (ALD).

Photoelectrochemical (PEC) water splitting using photo-active nanomaterials is a promising technique to generate hydrogen in a sustainable way. The charge-transfer and charge separation in photoelectrode are important factors in determining the performance of PECs. Here, we utilize single layer graphene as a photocatalyst on WO3 thin film / Nb:SrTiO3 (100) structure to enhance oxygen evolution reaction in alkaline electrolyte. The graphene-decorated photoelectrodes exhibit efficient charge transfer due to electronic and electrochemical properties of graphene edges, which leads to decreasing onset potential and increasing photo current density from 237 μA/cm2 to 763 μA/cm2 at 1.23 V vs RHE. In addition, such extremely thin layer can protect the photoelectrode from chemical corrosion without disturbing the light absorption. We discuss the role of graphene edges for photoelectrochemical water oxidation. Thus, these results can provide a new route for advanced designs of nanomaterial-based PECs devices. Acknowledgments This research was supported by next generation engineering researcher program of national research foundation of Korea (NRF) funded by the Ministry of Science, ICT (NRF-2019H1D8A2106002).

Eco-friendly harnessing of both ocean chemical energy and solar energy would represent a sustainable solution for future energy conversion/storage systems, but it has been challenging to enhance the energy efficiency of such systems for practical applications. Here, we demonstrate an efficient photoelectrochemical-assisted rechargeable seawater battery. By integrating TiO2 nanostructure-based photoelectrodes with the seawater battery, we achieved significant enhancement of the voltage efficiency during the charging/discharging processes; effective photocharging with the TiO2 photoanode reduced the charging voltage to similar to 2.65 V, while the heated carbon felt (HCF) cathode in the seawater battery exhibited charging/discharging voltages of similar to 3.8 V and similar to 2.9 V, respectively. Such a charging voltage reduction led to a voltage efficiency of similar to 109%. Moreover, interestingly, we found that TiO2 nanostructures showed excellent photoelectrochemical performances in seawater in association with the efficient photocharging. As a result, the utilization of TiO2 nanostructures as photocharging/discharging electrodes provides a feasible strategy to optimize the cell configuration for highly efficient solar seawater batteries. (C) 2019 Elsevier Ltd. All rights reserved.

Synergistically designing porous nanostructures and appropriate band alignment for TiO2 heterophase junctions is key to efficient charge transfer, which is crucial in enhancing photoelectrochemical (PEC) water splitting for hydrogen production. Here, we investigate the efficiency of PEC water oxidation in anatase–rutile TiO2 nanostructured heterophase junctions that present the type-II band alignment. We specifically prove the importance of a phase alignment in heterophase junction for effective charge separation. The TiO2 heterophase junctions were prepared by transferring TiO2 nanotube (TNT) arrays onto FTO substrate with the help of a TiO2 nanoparticle (TNP) glue layer. The PEC characterization reveals that the rutile (R)-TNT/anatase (A)-TNP heterophase junction has a higher photocurrent density than those of A-TNT/R-TNP junction and anatase or rutile single phase, corresponding to twofold enhanced efficiency. This type-II band alignment of R-TNT/A-TNP for water oxidation, in which photogenerated electrons (holes) will flow from rutile (anatase) to anatase (rutile), enables to facilitate efficient electron-hole separation as well as lower the effective bandgap of heterophase junctions. This work provides insight into the functional role of heterophase junction for boosting the PEC performances of TiO2 nanostructures.