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Results for “Film deposition”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

Investigation of silicon surface passivation by silicon nitride film deposition

The use of Sin sub x grown by plasma enhanced chemical vapor deposition (PECVO) for passivating silicon surfaces was studied. The application of PECVO SiN sub x films for passivations of silicon N+/P or P+/N solar cells is of particular interest. This program has involved the following areas of investigation: (1) Establishment of PECVO system and development of procedures for growth of SiN sub x; (2) Optical characterization of SiN sub x films; (3) Characterization of the SiN sub x/Si interface; (4) Surface recombination velocity deduced from photoresponse; (5) Current-Voltage analyses of silicon N+/P cells; and (6) Gated diode device studies.

Olsen, L. C.↗
DOE OSTI2023

Ultra‐Low‐Loss Silicon Nitride Photonics Based on Deposited Films Compatible with Foundries

Abstract The fabrication processes of silicon nitride (Si 3 N 4 ) photonic devices used in foundries require low temperature deposition, which typically leads to high propagation losses. Here, it is shown that propagation loss as low as 0.42 dB cm −1 can be achieved using foundry compatible processes by solely reducing waveguide surface roughness. By postprocessing the fabricated devices using rapid thermal anneal (RTA) and furnace anneal, propagation losses down to 0.28 dB cm −1 and 0.06 dB cm −1 , respectively, are achieved. These low losses are comparable to the conventional devices using high temperature, high‐stress LPCVD films. The dispersion of the devices is also tuned, and it is proved that these devices can be used for linear and nonlinear applications. Low threshold parametric oscillation, broadband frequency combs, and narrow‐linewidth laser are demonstrated. This work demonstrates the feasibility of scalable photonic systems based on foundries.

Ji, Xingchen↗
NASA NTRS1990

Calculating The Resistivity Of A Deposited Film

Iterative procedure computes resistivity from measurements by four-probe method. Computer program and technique developed to aid in solution of class of problems in which measurements of electrical resistivity needed for substance deposited on substrate of higher resistivity than deposited layer.

Oberle, Lawrence G.↗
DOE OSTI2024

Hopping crossover and high-temperature superspin glass behavior in Ni films deposited on MoS 2

Realizing the potential of MoS 2 and other two-dimensional semiconductors in spintronic devices requires a fundamental understanding of their interaction with ferromagnetic metals. We have investigated the transport and magnetic properties of thin Ni films grown on single-crystal MoS 2 substrates. The Ni is found to have a granular morphology with an average grain size of approximately 2 nm. Like previously investigated granular Ni/insulator composites below the percolation threshold, transport is found to proceed via hopping. However, our Ni/MoS 2 sample exhibits a dual crossover: activated hopping to 𝑇−1/2 variable-range hopping at a higher temperature and then a transition to power-law behavior at a lower temperature. The magnetoresistance was used as a novel probe for uncovering superspin-glass-like behavior above room temperature in the Ni/MoS 2 nanostructure, which also exhibits a collective ferromagnetic state at very low temperatures, reminiscent of superferromagnetism.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2024

Properties of Nb x Ti (1–x) N thin films deposited on 300 mm silicon wafers for upscaling superconducting digital circuits

Scaling superconducting digital circuits requires fundamental changes in the current material set and fabrication process. The transition to 300 mm wafers and the implementation of advanced lithography are instrumental in facilitating mature CMOS processes, ensuring uniformity, and optimizing the yield. Here, this study explores the properties of Nb x Ti (1–x) N films fabricated by magnetron DC sputtering on 300 mm Si wafers. As a promising alternative to traditional Nb in device manufacturing, Nb x Ti (1–x) N offers numerous advantages, including enhanced stability and scalability to smaller dimensions, in both processing and design. As a ternary material, Nb x Ti (1–x) N allows engineering material parameters by changing deposition conditions. The engineered properties can be used to modulate device parameters through the stack and mitigate failure modes. We report characterization of Nb x Ti (1–x) N films at less than 2% thickness variability, 2.4% T c variability and 3% composition variability. Film resistivity (140–375 Ωcm) shows a strong correlation with the film oxygen content, while the critical temperature T c (4.6 K–14.1 K) is strongly affected by film stoichiometry and its microstructure has only a moderate effect on modifying T c . Our results offer insights about the interplay between film stoichiometry, film microstructure and critical temperature.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
NASA NTRS1986

A computer program to calculate the resistivity of a thin film deposited on a conductive substrate from four-point probe measurements

A series of FORTRAN-77 programs is described which correct for the effect of a conducting substrate when a linear four-point probe is used to measure the resistivity of a thin film. The resistivity of the film is given in terms of the thicknesses of the film and substrate, the known resistivity of the substrate, and the measured delta V/I. A full development is given as well as a complete description of the operation of the programs. The programs themselves can be obtained through COSMIC, and are identified as LEW No. 14381.

Oberle, L. G.↗
DOE OSTI2026

Final Scientific/Technical Report: Simultaneous Lithium Extraction and Thin-Film Deposition of Lithium Metal for Low-Cost, High-Energy Anodes from Brine Resources

This report describes the scale-up and pilot validation of Alpha-En's Reductive Lithium Extraction (RLE) process, which directly converts lithium ions from aqueous brine-derived feedstocks into thin-film lithium metal anodes, demonstrating greater than 50% extraction efficiency, battery performance matching or exceeding commercial lithium metal controls in coin and pouch cells, and continuous roll-to-roll production of a meter-scale lithium metal anode strip.

25 ENERGY STORAGE↗
DOE OSTI2023

Decoding the Atomic Structure of Ga 2 Te 5 Pulsed Laser Deposition Films for Memory Applications Using Diffraction and First-Principles Simulations

Neuromorphic computing, reconfigurable optical metamaterials that are operational over a wide spectral range, holographic and nonvolatile displays of extremely high resolution, integrated smart photonics, and many other applications need next-generation phase-change materials (PCMs) with better energy efficiency and wider temperature and spectral ranges to increase reliability compared to current flagship PCMs, such as Ge 2 Sb 2 Te 5 or doped Sb 2 Te. Gallium tellurides are favorable compounds to achieve the necessary requirements because of their higher melting and crystallization temperatures, combined with low switching power and fast switching rate. Ga 2 Te 3 and non-stoichiometric alloys appear to be atypical PCMs; they are characterized by regular tetrahedral structures and the absence of metavalent bonding. The sp 3 gallium hybridization in cubic and amorphous Ga 2 Te 3 is also different from conventional p-bonding in flagship PCMs, raising questions about its phase-change mechanism. Furthermore, gallium tellurides exhibit a number of unexpected and highly unusual phenomena, such as nanotectonic compression and viscosity anomalies just above their melting points. Using high-energy X-ray diffraction, supported by first-principles simulations, we will elucidate the atomic structure of amorphous Ga 2 Te 5 PLD films, compare it with the crystal structure of tetragonal gallium pentatelluride, and investigate the electrical, optical, and thermal properties of these two materials to assess their potential for memory applications, among others.

36 MATERIALS SCIENCE↗
NASA NTRS1979

Control of dielectric film deposition

Airgap capacitor in deposition chamber is used to monitor deposition. Coating process is completely uniform over edges, points, and internal areas. Areas not requiring coating can be marked. Since deposition process is accomplished at or near room temperature, there is no risk of thermal damage to coated components. With control method, deposition material is fully utilized and no excess coating is necessary to insure protection of coated parts.

Graebner, E. C.↗
NASA NTRS1979

Controlled metal-film deposition on alumina substrates

Report describes results of investigation of preparation, nucleation and controlled growth of particulate deposits (palladium and iron) on electron-transparent alumina substrates. Results indicate that characteristic properties of metal deposits are strongly dependent on cleanliness, phase, and crystallographic orientation of substrate.

Lee, E. H.↗
NASA NTRS1986

Inexpensive Masks for Film Deposition

Sputtered sprayed lines less than 2 millimeters wide made by superimposing masks with partially overlapping openings. Slits first cut in masks by stamping or other economical process. Masks superimposed so slits define new openings narrower than original slits.

Conley, W. R.↗