Atomic Layer Deposition (ALD) has been traditionally regarded as an extremely powerful but slow thin-film deposition technique. The (perceived) limitation in terms of deposition rate has resulted in a slow penetration of the technology into mass manufacturing beyond established applications in the semiconductor industry until recently. At present, several developments have resulted in a significant increase in the use of ALD in a number of mass manufacturing applications. On the one hand, there is an increasing demand from the device makers side to incorporate nanotechnology in their products that relies on the unique advantages of ALD. On the other hand, a number of technical improvements have been implemented in the ALD method allowing it to be much faster. In this paper, we provide an overview of different High Throughput (HT) ALD approaches, putting them in perspective with other common HT deposition techniques already used in the industry. As an example, the use of HT ALD for Organic Light-Emitting Diodes (OLED) thin-film encapsulation is discussed.
The so-called buffer layer (BL) is a carbon rich reconstructed layer formed during SiC (0001) sublimation. The covalent bonds between some carbon atoms in this layer and underlying silicon atoms makes it different from epitaxial graphene. We report a systematical and statistical investigation of the BL signature and its coupling with epitaxial graphene by Raman spectroscopy. Three different BLs are studied: bare buffer layer obtained by direct growth (BL0), interfacial buffer layer between graphene and SiC (c-BL1) and the interfacial buffer layer without graphene above (u-BL1). To obtain the latter, we develop a mechanical exfoliation of graphene by removing an epoxy-based resin or nickel layer. The BLs are ordered-like on the whole BL growth temperature range. BL0 Raman signature may vary from sample to sample but forms patches on the same terrace. u-BL1 share similar properties with BL0, albeit with more variability. These BLs have a strikingly larger overall intensity than BL with graphene on top. The signal high frequency side onset upshifts upon graphene coverage, unexplainable by a simple strain effect. Two fine peaks (1235, 1360 cm-1), present for epitaxial monolayer and absent for BL and transferred graphene. These findings point to a coupling between graphene and BL.
Interfacial properties of SiO 2 /n-type 3C-SiC structures fabricated by rapid thermal processing have been investigated for various oxidizing and annealing atmospheres. In this work, we show that the growth of SiO 2 films can be, at least, 1 order of magnitude faster than in a conventional furnace. Besides being fast, this technique provides oxide films with quality comparable to those grown in a classical furnace. Analyzing the depth profiles of N and C species in the SiO 2 films and the electrical properties of the oxides, we found that incorporating N 2 during the growth in O 2 or annealing under N 2 is not favorable for the improvement of the SiO 2 /3C-SiC interface. Instead, we demonstrated that combining the beneficial effect of N 2 O oxide growth with the one of Ar anneal, the density of interface traps is reduced and leads to significantly improved oxide quality.Silicon carbide ͑SiC͒ is, by far, the most promising material for high-power and high temperature electronics applications. Compared to other wide bandgap semiconductors, SiC has the unique potential to be thermally oxidized to form a SiO 2 film. This provides a unique opportunity to develop metal oxide semiconductor ͑MOS͒ power devices. 1-3 Compared to the commonly used hexagonal 4H-SiC polytype, the cubic 3C-SiC polytype seems to be more promising with regard to MOS devices because it yields a higher electron mobility and results in a better SiO 2 /3C-SiC interface. With a bandgap of only 2.3 eV compared to 3.2 eV for 4H-SiC, 3C-SiC is regarded as a perfect material for medium power metal-oxide field effect transistors ͑MOSFETs͒.The 3C-SiC polytype has a unique advantage over 4H-SiC: it is the only polytype which can be grown on Si substrates. For this reason, this material was mainly investigated for microelectromechanical systems ͑MEMS͒ application because it allows the easy release of the SiC devices through Si etching. Recently, many works have demonstrated the feasibility of such mechanical devices. 4-6 However, to imagine a possible industrialization of the 3C-SiC MEMS, it is indispensable to dispose of the associated electronics and thus of transistors for the eventual circuitry integration, such as the complementary metal oxide semiconductor extensively used in the Si technology. One of the main issues to realize such circuitry integration is the fabrication of MOSFET devices on 3C-SiC/Si. While many high-performance power MOSFET devices have been demonstrated on 4H-SiC, few devices on 3C-SiC/Si have been demonstrated due to the high defect density in the 3C-SiC epilayers and poorly developed process techniques for 3C-SiC/Si devices. 7 Therefore, several crucial fabrications issues must be solved before truly advantageous 3C-SiC/Si MOSFET devices can be integrated. The gate oxide formation is one key process. When using a standard thermal oxidation the capability to form a grown SiO 2 dielectric with a good quality of the SiO 2 /3C-SiC interface and high oxide reliability is not obvious. 8 As a consequence, for a long time the density of...
A series of asymmetric and potentially bidentate amino alcohols and amino fluoro alcohols (RNOH) having a different number of methyl/trifluoromethyl substituents at the α-carbon atom, [HOC(R1)(R2)CH2NMe2] (R1 = R2 = H (dmaeH); R1 = H, R2 = CH3 (dmapH); R1 = R2 = CH3 (dmampH); R1 = H, R2 = CF3 (F-dmapH); R1 = R2 = CF3 (F-dmampH)) have been used to develop new monomeric and heteroleptic tin(IV) amino(fluoro)alkoxides [Sn(OR)2(ORN)2] (R = Et, Pr i , Bu t ). These new complexes, which were thoroughly characterized by spectroscopy (IR and multinuclei NMR (1H, 13C, 19F, and 119Sn)) as well as single-crystal X-ray studies on representative samples, were investigated for their thermal behavior to determine their suitability as MOCVD precursors for the deposition of metal oxide thin films. The two most suitable compounds, [Sn(OBu t )2(dmamp)2] and [Sn(OBu t )2(F-dmamp)2], were used in a direct liquid injection chemical vapor deposition (DLI-CVD) process to deposit undoped SnO2 and F-doped SnO2 thin films, respectively, on silicon and quartz substrates. Film growth rates at different temperatures (from 400 to 700 °C), film thickness, crystalline quality, and surface morphology were investigated. The films deposited on quartz showed high transparency (above 80%) in the visible region and low carbon contamination on the surface (11–13% from XPS), which could easily be removed completely with 2 min of Ar+ sputtering.
Silicon carbide (SiC) sublimation is the most promising option to achieve transfer-free graphene at the wafer-scale. We investigated the initial growth stages from the buffer layer to monolayer graphene on SiC(0001) as a function of annealing temperature at low argon pressure (10 mbar). A buffer layer, fully covering the SiC substrate, forms when the substrate is annealed at 1600 °C. Graphene formation starts from the step edges of the SiC substrate at higher temperature (1700 °C). The spatial homogeneity of the monolayer graphene was observed at 1750 °C, as characterized by Raman spectroscopy and magneto-transport. Raman spectroscopy mapping indicated an A/A ratio of around 3.3%, which is very close to the experimental value reported for a graphene monolayer. Transport measurements from room temperature down to 1.7 K indicated slightly p-doped samples (p ≃ 10 cm) and confirmed both continuity and thickness of the monolayer graphene film. Successive growth processes have confirmed the reproducibility and homogeneity of these monolayer films.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.