Atomic layer deposition

About: Atomic layer deposition is a research topic. Over the lifetime, 19821 publications have been published within this topic receiving 477332 citations. The topic is also known as: ALD.

Externally Assembled Gate-All-Around Carbon Nanotube Field-Effect Transistor

Abstract: In this letter, we demonstrate a gate-all-around single-wall carbon nanotube field-effect transistor. This is the first successful experimental implementation of an off-chip gate and gate-dielectric assembly with subsequent deposition on a suitable substrate. The fabrication process and device measurements are discussed in the letter. We also argue in how far charges in the gate oxide are responsible for the observed nonideal device performance.

Ozone-Based Atomic Layer Deposition of Crystalline V2O5 Films for High Performance Electrochemical Energy Storage

Abstract: A new atomic layer deposition (ALD) process for V2O5 using ozone (O3) as oxidant has been developed that resulted in crystalline V2O5 thin films which are single-phase and orthorhombic on various substrates (silicon, Au-coated stainless steel, and anodic aluminum oxide (AAO)) without any thermal post-treatment. Within a fairly narrow temperature window (170–185 °C), this low temperature process yields a growth rate of ∼0.27 A/cycle on Si. It presents good uniformity on planar substrates. Excellent conformality enables deposition into high aspect ratio (AR) nanopores (AR > 100), as needed for fabrication of three-dimensional (3D) nanostructures for next generation electrochemical energy storage devices. V2O5 films obtained using O3-based ALD showed superior electrochemical performance in lithium cells, with initial specific discharge capacity of 142 mAh/g in the potential range of 2.6–4.0 V, as well as excellent rate capability and cycling stability. These benefits are attributed primarily to the crystalli...

High-Responsivity Deep-Ultraviolet-Selective Photodetectors Using Ultrathin Gallium Oxide Films

Abstract: Wavelength-selective photodetectors responding to deep-ultraviolet (DUV) wavelengths (λ = 200–300 nm) are drawing significant interest in diverse sensing applications, ranging from micrometer biological molecules to massive military missiles. However, most DUV photodetectors developed thus far have suffered from long response times, low sensitivity, and high processing temperatures, impeding their practical use. Here, we report fast, high-responsivity, and general-substrate-compatible DUV photodetectors based on ultrathin (3–50 nm) amorphous gallium oxide (GaOX) films grown by low-temperature (∼<250 °C) atomic layer deposition (ALD) for the first time. ALD-grown GaOX films on glass substrates display a typical amorphous nature, which is identified by electron beam diffraction and X-ray diffraction measurements, while their band gap is sharply featured at ∼4.8 eV. Metal–semiconductor–metal photodetectors (active area of 30 × 30 μm2) using the 30-nm-thick GaOX films work reliably only for DUV wavelengths; t...

Excellent c-Si surface passivation by low-temperature atomic layer deposited titanium oxide

Abstract: In this work, we demonstrate that thermal atomic layer deposited (ALD) titanium oxide (TiOx) films are able to provide a—up to now unprecedented—level of surface passivation on undiffused low-resistivity crystalline silicon (c-Si). The surface passivation provided by the ALD TiOx films is activated by a post-deposition anneal and subsequent light soaking treatment. Ultralow effective surface recombination velocities down to 2.8 cm/s and 8.3 cm/s, respectively, are achieved on n-type and p-type float-zone c-Si wafers. Detailed analysis confirms that the TiOx films are nearly stoichiometric, have no significant level of contaminants, and are of amorphous nature. The passivation is found to be stable after storage in the dark for eight months. These results demonstrate that TiOx films are also capable of providing excellent passivation of undiffused c-Si surfaces on a comparable level to thermal silicon oxide, silicon nitride, and aluminum oxide. In addition, it is well known that TiOx has an optimal refractive index of 2.4 in the visible range for glass encapsulated solar cells, as well as a low extinction coefficient. Thus, the results presented in this work could facilitate the re-emergence of TiOx in the field of high-efficiency silicon wafer solar cells.

A low-temperature-grown TiO2-based device for the flexible stacked RRAM application.

Abstract: Flexible TiO(2) crossbar memory device arrays were fabricated on plastic substrates using amorphous titanium oxide thin films grown by the low-temperature plasma-enhanced atomic layer deposition method. Al/ TiO(2)/Al memory cells on polyethersulfone (PES) showed an enhanced endurance property (up to 10(4) cycles) and low switching voltages compared to the cells on rigid substrates. The multi-stacked memory arrays were constructed by forming the additional Al/ TiO(2)/Al layer on the first memory device layer. Memory cells on each layer exhibited stable switching characteristics and mechanical robustness without interlayer cell-to-cell interference.