Atomic Layer Deposition Of Amorphous Hafnium Based Thin Films With Enhance Thermal Stabilities
Download Atomic Layer Deposition Of Amorphous Hafnium Based Thin Films With Enhance Thermal Stabilities full books in PDF, epub, and Kindle. Read online free Atomic Layer Deposition Of Amorphous Hafnium Based Thin Films With Enhance Thermal Stabilities ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Author | : Tuo Wang |
Publisher | : |
Total Pages | : 280 |
Release | : 2010 |
Genre | : |
ISBN | : |
The continuous scaling of microelectronic devices requires high permittivity (high-k) dielectrics to replace SiO2 as the gate material. HfO2 is one of the most promising candidates but the crystallization temperature of amorphous HfO2 is too low to withstand the fabrication process. To enhance the film thermal stability, HfO2 is deposited using atomic layer deposition (ALD), and incorporated with various amorphizers, such as La2O3, Al2O3, and Ta2O5. The incorporation is achieved by growing multiple ALD layers of HfO2 and one ALD layer of MO[subscript x] (M = La, Al, and Ta) alternately (denoted as [xHf + 1M]), and the incorporation concentration can be effectively controlled by the HfO2-to-MO[subscript x] ALD cycle ratio (the x value). The crystallization temperature of 10 nm HfO2 increases from 500 °C to 900 °C for 10 nm [xHf + 1M] film, where x = 3, 3, and 1 for M = La, Al, and Ta, respectively. The incorporation of La2O3, and Ta2O5 will not compromise the dielectric constant of the film because of the high-k nature of La2O3, and Ta2O5. Angle resolved X-ray photoelectron spectroscopy (AR-XPS) reveals that when the HfO2-to-MO[scubscript x] ALD cycle ratio is large enough (x> 3 and 4 for La and Al, respectively), periodic structures exist in films grown by this method, which are comprised of repeated M-free HfO2 ultrathin layers sandwiched between HfM[subscript x]O[scubscript y] layers. Generally, the film thermal stability increases with thinner overall thickness, higher incorporation concentration, and stronger amorphizing capability of the incorporated elements. When the x value is low, the films are more like homogeneous films, with thermal stabilities determined by the film thickness and the amorphizer. When the x value is large enough, the periodically-repeated structure may add an extra factor to stabilize the amorphous phase. For the same incorporation concentration, films with an appropriately high periodicity may have an increased thermal stability. The manner by which the periodic structure and incorporated element affect thermal stability is explored and resolved using nanolaminates comprised of alternating layers of [scubscript y]HfO2 and [xHf + 1M] x n, where y varied from 2 to 20, x varied from 1 to 2, and n varied from 4 to 22.
Author | : Cheol Seong Hwang |
Publisher | : Springer Science & Business Media |
Total Pages | : 266 |
Release | : 2013-10-18 |
Genre | : Science |
ISBN | : 146148054X |
Offering thorough coverage of atomic layer deposition (ALD), this book moves from basic chemistry of ALD and modeling of processes to examine ALD in memory, logic devices and machines. Reviews history, operating principles and ALD processes for each device.
Author | : Yutao Dong |
Publisher | : |
Total Pages | : 0 |
Release | : 2023 |
Genre | : |
ISBN | : |
Atomic layer deposition (ALD) is a powerful manufacturing approach for amorphous thin film growth. With the advantages of excellent conformity, pinhole-free and concise thickness control, ALD has been widely applied in many energy systems, including batteries, catalysts and photoelectrochemical (PEC) cells, to achieve surface modification and good protection performance. In this dissertation, a series of works will be exhibited to discuss ALD amorphous film coating on batteries electrode and separator, semiconductor photoelectrodes, demonstrating its enormous prospects to enable stable performance in electrochemical systems. Chapter 1 is an overview of photoelectrochemistry and ALD technique to provide principal background to inspire our ALD amorphous film studies in electrochemical systems. ALD protective coatings on batteries electrodes and semiconductor photoelectrodes have been reviewed to illustrate the advantage of homogenous amorphous ALD film. Structure inhomogeneity and chemical composition impurities in ALD amorphous film are discussed to present unsolved problems to optimize ALD amorphous film properties. Chapter 2 discusses the development of bioresorbable zinc anode coated by ALD amorphous Al2O3 film. With the protective ALD Al2O3 protective shell, the zinc anode filament exhibited directional dissolution behavior with a tunable lifetime and output, providing an effective pathway toward bioresorbable transient batteries powering biomedical implantable devices. Chapter 3 exhibited the surface modification performance of ALD amorphous Al2O3 film on ferroelectric P(VDF-TrFE) film, severing as dendrite-suppression separator in aqueous rechargeable zinc ions batteries. The separator surface hydrophilicity is largely improved with the ferroelectric properties maintained after ALD amorphous Al2O3 coating, generating uniform zinc ions diffusion during plating/stripping cycling. This works depicts ALD amorphous film modified ferroelectric film as promising separator candidates in aqueous rechargeable batteries systems. Chapter 4 discusses the ALD amorphous film protection on Si photoanode and reveals the detrimental role of unreacted Cl ligands to film stability in PEC water splitting. In addition to crystalline phase, the residual Cl impurities can become the weak point of ALD amorphous TiO2 film due to local high hole conductivity and discontinuous Ti-O-Ti networks. Furthermore, post-ALD in-situ water treatment approach is demonstrated to effectively decouple the ALD reaction completeness from crystallization. The as-processed TiO2 film has a much lower residual Cl concentration and thus an improved film stoichiometry, while its uniform amorphous phase is well preserved. Thus, this water-treated ALD amorphous TiO2 film enabled record-high protection stability with high photocurrent density, demonstrating a significant advancement toward sustainable hydrogen generation. Inspired by the stoichiometry influence on ALD amorphous TiO2 film properties, the residual ligands in plasmas-enhanced chemical vapor deposition (PECVD) amorphous silicon nitride (SiNx) film are also investigated and demonstrated to largely affect the film mechanical properties in Chapter 5. The high residual N-H ligands from the NH3 precursor induces excessive tensile strain at the SiNx/Si wafer interface and consequently aggravates SiNx film crack formation. With a long-soak pretreatment, residual H ligands are effectively reduced to achieve homogenous chemical composition in both thin and thick long-soak SiNx film. As a result, the crack number and the remaining crack length are substantially reduced in contrast to the original SiNx film. This work further demonstrates the crucial role of residual ligands on internal strain regulation and points out a pathway to achieve crack-free PECVD SiNx films in industrial manufacturing. Chapter 6 provides summaries of ALD amorphous film applications in electrochemical system and concludes the film stoichiometry influence on amorphous film chemical/mechanical stability. Based on the substantial performance enhancement with improved stoichiometry, promising research outlooks have been proposed for ALD amorphous film optimization.
Author | : |
Publisher | : |
Total Pages | : 8 |
Release | : 2015 |
Genre | : |
ISBN | : |
Hafnium Oxide (HfO2) amorphous thin films are being used as gate oxides in transistors because of their high dielectric constant ([kappa]) over Silicon Dioxide. The present study looks to find the atomic structure of HfO2 thin films which hasn't been done with the technique of this study. In this study, two HfO2 samples were studied. One sample was made with thermal atomic layer deposition (ALD) on top of a Chromium and Gold layer on a silicon wafer. The second sample was made with plasma ALD on top of a Chromium and Gold layer on a Silicon wafer. Both films were deposited at a thickness of 50nm. To obtain atomic structure information, Grazing Incidence X-ray diffraction (GIXRD) was carried out on the HfO2 samples. Because of this, absorption, footprint, polarization, and dead time corrections were applied to the scattering intensity data collected. The scattering curves displayed a difference in structure between the ALD processes. The plasma ALD sample showed the broad peak characteristic of an amorphous structure whereas the thermal ALD sample showed an amorphous structure with characteristics of crystalline materials. This appears to suggest that the thermal process results in a mostly amorphous material with crystallites within. Further, the scattering intensity data was used to calculate a pair distribution function (PDF) to show more atomic structure. The PDF showed atom distances in the plasma ALD sample had structure up to 10 Å, while the thermal ALD sample showed the same structure below 10 Å. This structure that shows up below 10 Å matches the bond distances of HfO2 published in literature. The PDF for the thermal ALD sample also showed peaks up to 20 Å, suggesting repeating atomic spacing outside the HfO2 molecule in the sample. This appears to suggest that there is some crystalline structure within the thermal ALD sample.
Author | : Ihsan Barin |
Publisher | : |
Total Pages | : 894 |
Release | : 1993 |
Genre | : Thermochemistry |
ISBN | : |
Author | : Tony Schenk |
Publisher | : BoD – Books on Demand |
Total Pages | : 194 |
Release | : 2017-03-15 |
Genre | : Technology & Engineering |
ISBN | : 3743127296 |
In 2011, Böscke et al. reported the unexpected discovery of ferroelectric properties in hafnia based thin films, which has since initiated many further studies and revitalized research on the topic of ferroelectric memories. In spite of many efforts, the unveiling of the fundamentals behind this surprising discovery has proven rather challenging. In this work, the originally claimed Pca21 phase is experimentally proven to be the root of the ferroelectric properties and the nature of this ferroelectricity is classified in the frame of existing concepts of ferroelectric materials. Parameters to stabilize this polar phase are examined from a theoretical and fabrication point of view. With these very basic questions addressed, the application relevant electric field cycling behavior is studied. The results of first-order reversal curves, impedance spectroscopy, scanning transmission electron microscopy and piezoresponse force microscopy significantly advance the understanding of structural mechanisms underlying wake-up, fatigue and the novel phenomenon of split-up/merging of transient current peaks. The impact of field cycling behavior on applications like ferroelectric memories is highlighted and routes to optimize it are derived. These findings help to pave the road for a successful commercialization of hafnia based ferroelectrics.
Author | : Wilfried G. J. H. M. van Sark |
Publisher | : Springer Science & Business Media |
Total Pages | : 588 |
Release | : 2011-11-16 |
Genre | : Technology & Engineering |
ISBN | : 3642222757 |
Today’s solar cell multi-GW market is dominated by crystalline silicon (c-Si) wafer technology, however new cell concepts are entering the market. One very promising solar cell design to answer these needs is the silicon hetero-junction solar cell, of which the emitter and back surface field are basically produced by a low temperature growth of ultra-thin layers of amorphous silicon. In this design, amorphous silicon (a-Si:H) constitutes both „emitter“ and „base-contact/back surface field“ on both sides of a thin crystalline silicon wafer-base (c-Si) where the electrons and holes are photogenerated; at the same time, a-Si:H passivates the c-Si surface. Recently, cell efficiencies above 23% have been demonstrated for such solar cells. In this book, the editors present an overview of the state-of-the-art in physics and technology of amorphous-crystalline heterostructure silicon solar cells. The heterojunction concept is introduced, processes and resulting properties of the materials used in the cell and their heterointerfaces are discussed and characterization techniques and simulation tools are presented.
Author | : Nathan J Patmore |
Publisher | : Royal Society of Chemistry |
Total Pages | : 210 |
Release | : 2018-11-16 |
Genre | : Science |
ISBN | : 1788010671 |
With the increase in volume, velocity and variety of information, researchers can find it difficult to keep up to date with the literature in their field. Providing an invaluable resource, this volume contains analysed, evaluated and distilled information on the latest in organometallic chemistry research and emerging fields. The reviews range in scope and include π-coordinated arene metal complexes and catalysis by arene exchange, rylenes as chromophores in catalysts for CO2 photoreduction, metal nodes and metal sites in metal–organic frameworks, developments in molecular precursors for CVD and ALD, and multiphoton luminescence processes in f-element containing compounds.
Author | : Suneth Kalapugama |
Publisher | : |
Total Pages | : 156 |
Release | : 2010 |
Genre | : Dielectric films |
ISBN | : |
Author | : Babak Anasori |
Publisher | : Springer Nature |
Total Pages | : 534 |
Release | : 2019-10-30 |
Genre | : Technology & Engineering |
ISBN | : 3030190269 |
This book describes the rapidly expanding field of two-dimensional (2D) transition metal carbides and nitrides (MXenes). It covers fundamental knowledge on synthesis, structure, and properties of these new materials, and a description of their processing, scale-up and emerging applications. The ways in which the quickly expanding family of MXenes can outperform other novel nanomaterials in a variety of applications, spanning from energy storage and conversion to electronics; from water science to transportation; and in defense and medical applications, are discussed in detail.