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Monday, September 14, 2015
JVSTA Most Read Atomic Layer Deposition Articles Published in 2014
Friday, September 11, 2015
Chalmers University of Technology have developed a new way to study nanoparticles one at a time
Yet another recent innovative application using Gold! Scientists at Chalmers University of Technology have developed a new way to study nanoparticles one at a time, and have discovered that individual particles that may seem identical in fact can have very different properties. The results, which may prove to be important when developing new materials or applications such as hydrogen sensors for fuel cell cars, have been published in Nature Materials.
A single gold plasmonic nanoantenna probes the hydrogen absorption in an adjacent palladium nanocube. Illustration by Ella Marushchenko and Alex Tokarev.
– We were able to show that you gain deeper insights into the physics of how nanomaterials interact with molecules in their environment by looking at the individual nanoparticle as opposed to looking at many of them at the same time, which is what is usually done, says Associate Professor Christoph Langhammer, who led the project.
By applying a new experimental approach called plasmonic nanospectroscopy, the group studied hydrogen absorption into single palladium nanoparticles and found that particles with exactly the same shape and size may exhibit differences as great as 40 millibars in the pressure at which hydrogen is absorbed. The development of sensors that can detect hydrogen leaks in fuel cell powered cars is one example of where this new understanding could become valuable in the future.
– One main challenge when working on hydrogen sensors is to design materials whose response to hydrogen is as linear and reversible as possible. In that way, the gained fundamental understanding of the reasons underlying the differences between seemingly identical individual particles and how this makes the response irreversible in a certain hydrogen concentration range can be helpful, says Langhammer.
Others have looked at single nanoparticles one at a time, but the new approach introduced by the Chalmers team uses visible light with low intensity to study the particles. This means that the method is non-invasive and does not disturb the system it is investigating by, for example, heating it up.
– When studying individual nanoparticles you have to send some kind of probe to ask the particle ‘what are you doing?’. This usually means focusing a beam of high-energy electrons or photons or a mechanical probe onto a very tiny volume. You then quickly get very high energy densities, which might perturb the process you want to look at. This effect is minimized in our new approach, which is also compatible with ambient conditions, meaning that we can study nanoparticles one at a time in as close to a realistic environment as possible.
Interdisciplinary collaboration
The project has been a successful collaboration initiative within the Chalmers Area of Advance Nanoscience and Nanotechnology, with a strong ambition to work interdisciplinarily. It involves researchers from the groups of Christoph Langhammer, Fredrik Westerlund and Kasper Moth-Poulsen at the departments of Physics, Biology and Chemistry. The Area of Advance also funded PhD student and first author of the published paper, Svetlana Syrenova, who performed all the single particle experiments, and a postdoctoral fellow, Yuri Diaz Fernandez who developed the colloidal self-assembly process used to make the samples together with PhD student Tina Gschneidtner.
– Svetlana Syrenova has patiently done hundreds of experiments over the last three years. And though it has been tempting at times to publish the results earlier, she was always ready to give it one more try and improve things further. This was one of the keys to succeed with publishing our work in such a prestigious journal, together with the fantastic collaboration with the Moth-Poulsen group stimulated by the Area of Advance, says Langhammer.
A new scientific paradigm
Even though they have now reached the level where their results are ready to be published, Christoph Langhammer believes they have just scratched the surface of what their discovery and developed experimental methodology will lead to in relation to further research. He hopes that they have helped to establish a new experimental paradigm, where looking at nanoparticles individually will become standard in the scientific world.
– It is not good enough to look at, and thus obtain an average of, hundreds or millions of particles if you want to understand the details of how nanoparticles behave in different environments and applications. You have to look at individual ones, and we have found a new way to do that. My own long-term vision is to apply our method to more complex processes and materials, and to push the limits in terms of how small nanoparticles can be for us to be able to measure them. Hopefully, along the way, we will gain even deeper insights into the fascinating world of nanomaterials.
TAU researcher harnesses gold nanoparticles to engineer novel biocompatible cardiac patch
After recent success by Barry Lab realizing precursors for gold ALD I see gold application appearing all the time. Here is a lifesaving recent application of gold nano particles from Tel Aviv University, Israel.
Because heart cells cannot multiply and cardiac muscles contain few stem cells, heart tissue is unable to repair itself after a heart attack. Now Tel Aviv University researchers are literally setting a new gold standard in cardiac tissue engineering.
Picture from TUA press release
Dr. Tal Dvir and his graduate student Michal Shevachof TAU's Department of Biotechnology, Department of Materials Science and Engineering, and Center for Nanoscience and Nanotechnology, have been developing sophisticated micro- and nanotechnological tools — ranging in size from one millionth to one billionth of a meter — to develop functional substitutes for damaged heart tissues. Searching for innovative methods to restore heart function, especially cardiac "patches" that could be transplanted into the body to replace damaged heart tissue, Dr. Dvir literally struck gold. He and his team discovered that gold particles are able to increase the conductivity of biomaterials.
In a study published by Nano Letters, Dr. Dvir's team presented their model for a superior hybrid cardiac patch, which incorporates biomaterial harvested from patients and gold nanoparticles. "Our goal was twofold," said Dr. Dvir. "To engineer tissue that would not trigger an immune response in the patient, and to fabricate a functional patch not beset by signalling or conductivity problems."
Tuesday, September 8, 2015
Semiconductor Engineering about triple and quadruple patterning after 20/16/14nm [video]
David Abercrombie, advanced physical verification methodology program
manager at Mentor Graphics, talks with Semiconductor Engineering about
triple and quadruple patterning after 20/16/14nm.
Saturday, September 5, 2015
Role of Surface Termination in Atomic Layer Deposition of Silicon Nitride
Yet another fundamental publication from Eindhoven and Oxford Instruments on one of the most important (PE)ALD processes for scaled semiconductor devices - silicon nitride. This time Tyndall has helped them out to sort out the growth mechanism to better understand growth promotion and inhibition that has been reported previously - BTBAS Silicon nitride PEALD by TU Eindhoven, Oxford Instruments and ASM Microchemistry
Role of Surface Termination in Atomic Layer Deposition of Silicon Nitride
Chaitanya Krishna Ande†, Harm C. M. Knoops†‡, Koen de Peuter†, Maarten van Drunen†, Simon D. Elliott§, and Wilhelmus M. M. Kessels*†
† Department of Applied Physics, Eindhoven University of Technology, Den Dolech 2, 5600 MB Eindhoven, The Netherlands
‡ Oxford Instruments Plasma Technology, North End, Bristol BS49 4AP, United Kingdom
§ Tyndall National Institute, University College Cork, Dyke Parade, Lee Maltings, Cork, Ireland
J. Phys. Chem. Lett., 2015, 6, pp 3610–3614
DOI: 10.1021/acs.jpclett.5b01596
There is an urgent need to deposit uniform, high-quality, conformal SiNx thin films at a low-temperature. Conforming to these constraints, we recently developed a plasma enhanced atomic layer deposition (ALD) process with bis(tertiary-butyl-amino)silane (BTBAS) as the silicon precursor. However, deposition of high quality SiNx thin films at reasonable growth rates occurs only when N2 plasma is used as the coreactant; strongly reduced growth rates are observed when other coreactants like NH3 plasma, or N2–H2 plasma are used. Experiments reported in this Letter reveal that NHx- or H- containing plasmas suppress film deposition by terminating reactive surface sites with H and NHx groups and inhibiting precursor adsorption. To understand the role of these surface groups on precursor adsorption, we carried out first-principles calculations of precursor adsorption on the β-Si3N4(0001) surface with different surface terminations. They show that adsorption of the precursor is strong on surfaces with undercoordinated surface sites. In contrast, on surfaces with H, NH2 groups, or both, steric hindrance leads to weak precursor adsorption. Experimental and first-principles results together show that using an N2 plasma to generate reactive undercoordinated surface sites allows strong adsorption of the silicon precursor and, hence, is key to successful deposition of silicon nitride by ALD.
The ALD Hot Guys at Picosun has launched a new Picohot™ 400 source
Picosun Oy, leading supplier of industrial
scale Atomic Layer Deposition (ALD) thin film coating solutions, now
offers its customers an extensive range of new precursor sources
especially designed for high volume manufacturing.
The
now launched Picohot™ 400 source system is the latest addition to
Picosun's highly sought-after product line of production-compatible high
temperature sources. The Picohot™ 400 source system's ALD valves can be
heated up to over 400oC to enable efficient delivery of both
solid and liquid very low volatility chemicals in large doses optimal
for batch processing. The source is especially suitable for metal
chloride precursors, ensuring particle-free processing of e.g. hafnium
oxide and many other materials on up to 300 mm wafers. The large
internal volume of the source container guarantees long, continuous
process uptime with effective precursor utilization and minimized number
of service breaks. A separate, production-compatible purge valve speeds
up the maintenance procedures even further.
Picosun's
industry-scale precursor delivery solutions are further complemented by
a temperature-stabilized, high volume Picosolution™ 2000 source system
for up to two liters of liquid precursor chemicals.
"As
the number of industrial ALD applications keeps booming there is a
growing need to widen the selection of precursor chemicals. Precursors
for several important production processes only exist as solids or low
volatility liquids. Our leading experience in ALD system design now
enables the first, true production-scale high temperature source systems
designed solely based on the requirements of the ALD method and
fulfilling the strictest quality standards of the semiconductor
industries. We are pleased to provide our customers with these systems
to make their most advanced novel products come true in high
manufacturing volumes," states Mr. Juhana Kostamo, Managing Director of Picosun.
Friday, September 4, 2015
Top down, bottom up, and in-between approaches to new materials by ALD and MLD
A highly interesting review by Keith Gregorczyk and Mato Knez on Top down, bottom up, and in-between approaches to new materials by ALD and MLD. I haven´t red it yet but I will do asap!
Hybrid nanomaterials through molecular and atomic layer deposition: Top down, bottom up, and in-between approaches to new materials
Keith Gregorczyk and Mato Knez
Progress in Materials Science, Volume 75, January 2016, Pages 1–37, Available online 11 August 2015
The ability to produce or alter materials to obtain drastically different or improved properties has been the driving goal of materials science since its inception. Combining multiple elements, compounds, or materials while maintaining the beneficial aspects of each constituent is a complex problem often involving highly interdisciplinary research. Hybrid materials, i.e. materials that incorporate organic and inorganic parts, have become popular in a variety of fields. Though not entirely new, the modern embodiment of hybrid materials has led to a large variety of new materials and techniques to produce them. One of the most recent being combination of atomic layer deposition (ALD), which produces inorganic materials, and molecular layer deposition (MLD), which produces organic materials. Furthermore, a variation on these techniques, commonly referred to as infiltration, has allowed for the modification of a variety of natural and synthetic polymers with surprising results related to their bulk mechanical properties. In this review three approaches are taken. First, hybrid materials through bottom-up combinations of ALD and MLD are reviewed, focusing on the process and properties of the resulting materials. Second, the modification of biomaterials through coating is discussed, and finally the relatively new concept of vapor phase infiltration is considered as a new and unique method to produce hybrid materials from a top down perspective.
Principles of Precursor Design for Vapour Deposition Methods
Here is a fresh and excellent publication from Barry Lab at Department of Chemistry, Carleton University on CVD and ALD precursor design.
Principles of Precursor Design for Vapour Deposition Methods
Sara E. Koponen, Peter G. Gordon, Seán T. Barry
Polyhedron, Received 6 June 2015, Accepted 24 August 2015
From the graphical abstract: Precursor design is central to the advancement of CVD and ALD technologies. These thin film deposition techniques rely on molecular precursors which have low melting points, high volatility, stability and specific reactivity. These properties are discussed through examples of group 11 and 13 precursors.
Chemical vapour deposition (CVD) and atomic layer deposition (ALD) are attractive techniques for depositing a wide spectrum of thin solid film materials, for a broad spectrum of industrial applications. These techniques rely on volatile, reactive, and thermally stable molecular precursors to transport and deposit growth materials in a kinetically controlled manner, resulting in uniform, conformal, high purity films. Developments in these fields depend on careful precursor design. We discuss the qualities that make successful CVD or ALD precursors (low melting point, high volatility, stability and specific reactivity) and the widely applicable design principles used to achieve them, through examples of group 11 and 13 precursors including amidinates, guanidinates and iminopyrrolidinates. We highlight the most valuable techniques that we use to asses potential precursors on the basis of the discussed qualities, and to elucidate relevant mechanisms of decomposition and surface reactivity. There is a strong focus on thermogravimetric analysis (TGA), and solid state (SS) and solution NMR studies.
Wednesday, September 2, 2015
TiC PEALD workfunction tuning by SK Hynix and KAIST
Here is an interesting paper on TiC PEALD workfunction tuning by SK Hynix and KAIST. They show how the workfunction of PEALD TiC film is affected by growth temperature and a tunable WF of TiC film is compatible with a gate-first and/or gate-last process.
TiC ALD was deposited by cycling TiCl4 and TMA, in this case TMA was used as a source of carbon and H2 as a reactant gas with a plasma power of 300 W and argon as a purge gas and carrier gas.The films were characterized as MOS capacitor consisting of a TiC/SiO2/Si stack and the WF was extracted classically by having various SiO2 thicknesses.
Temperature control for the gate workfunction engineering of TiC film by atomic layer deposition
Choong-Ki Kim, Hyun Jun Ahn, Jung Min Moon, Sukwon Lee, Dong-II Moon, Jeong Soo Park, Byung-Jin Cho, Yang-Kyu Choi, Seok-Hee Lee,
Abstract
The effects of the deposition temperature on titanium carbide film formed by atomic layer deposition are investigated for gate workfunction (WF) engineering. As the deposition temperature increases from 250 °C to 500 °C, the WF of the TiC decreases from 5.24 eV to 4.45 eV. This WF dependency on the deposition temperature is mainly attributed to the average WF of each orientation of the sub-planes of the TiC film. An investigation of a tunable WF is conducted through Auger electron spectroscopy, transmission electron microscopy, and X-ray diffraction.
The effects of the deposition temperature on titanium carbide film formed by atomic layer deposition are investigated for gate workfunction (WF) engineering. As the deposition temperature increases from 250 °C to 500 °C, the WF of the TiC decreases from 5.24 eV to 4.45 eV. This WF dependency on the deposition temperature is mainly attributed to the average WF of each orientation of the sub-planes of the TiC film. An investigation of a tunable WF is conducted through Auger electron spectroscopy, transmission electron microscopy, and X-ray diffraction.
Nanocrystalline Ferroelectric BiFeO3 by Low-Temperature ALD
Joint research from Spain, Germany, UK, and USA present a low temperature process for ferroelectric BeFeO3 which opens possibilities for ferroelectric oxides on 3D substrates. BeFeO3 is a room temperature multiferroic material and due to its ferroelectric photovoltaic (FPV) effect bismuth ferrite have several applications in the field of magnetism, spintronics, photovoltaics etc.
Nanocrystalline Ferroelectric BiFeO3 Thin Films by Low-Temperature Atomic Layer Deposition
Mariona Coll*†, Jaume Gazquez†, Ignasi Fina‡§, Zakariya Khayat∥, Andy Quindeau‡, Marin Alexe§, Maria Varela⊥, Susan Trolier-McKinstry∥, Xavier Obradors†, and Teresa Puig†
† Institut de Ciencia de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193, Bellaterra, Catalonia, Spain
‡ Max Planck Institute of Microstructure Physics, Weinberg 2, Halle (Saale), D-06120, Germany
§ Department of Physics, University of Warwick, Coventry CV 4 7AL, United Kingdom
∥ The Pennsylvania State University, N-227 Millennium Science Complex, University Park, Pennsylvania 16802, United States
⊥ Departamento de Física Aplicada III, Instituto Pluridisciplinar, Universidad Complutense de Madrid, 28040, Madrid, Spain
Chem. Mater., Article ASAP
DOI: 10.1021/acs.chemmater.5b02093
Publication Date (Web): August 20, 2015
Abstract
In this work, ferroelectricity is identified in nanocrystalline BiFeO3 (BFO) thin films prepared by low-temperature atomic layer deposition. A combination of X-ray diffraction, reflection high energy electron diffraction, and scanning transmission electron microscopy analysis indicates that the as-deposited films (250 °C) consist of BFO nanocrystals embedded in an amorphous matrix. Postannealing at 650 °C for 60 min converts the sample to a crystalline film on a SrTiO3 substrate. Piezoelectric force microscopy demonstrates the existence of ferroelectricity in both as-deposited and postannealed films. The ferroelectric behavior in the as-deposited stage is attributed to the presence of nanocrystals. Finally, a band gap of 2.7 eV was measured by spectroscopic ellipsometry. This study opens broad possibilities toward ferroelectric oxides on 3D substrates and also for the development of new ferroelectric perovskites prepared at low temperature.
UPDATE :Technical Program for Russia ALD 2015
Her is an updated version of the Technical Program for Russia ALD 2015! As you can see Dr. Riikka Puurunen from VTT Finland totally dominate the morning of the first day! Go Riikka!
Download : http://ald-conf.ru/assets/files/technical-program_v2.pdf
Download : http://ald-conf.ru/assets/files/technical-program_v2.pdf
Monday, August 31, 2015
Extreme high apspect ratio nanotubes in polymer membranes produced by catalytic ALD
German scientists from Darmstadt and Hamburg has shown that the combination of ion-track technology and ALD provides unique opportunities for highly homogeneous and conformal coatings of extremely long nanochannels. The results clearly demonstrate successful conformal coating of cylindrical 30 μm long nanochannels with initial diameter between 55 and 18 nm by three different inorganic materials (TiO2, SiO2, and Al2O3). The ALD process was carefully adjusted to temperatures low enough to avoid damage to the ion-track etched polymer membranes.
(a) Flexible SiO2 nanotubes exhibiting an outer diameter of ~50 nm and a wall thickness of ~20 nm. (b) Al2O3
nanotubes (outer diameter ~50 nm, wall thickness ~15 nm), which are
broken due to their rather high brittleness. They are attached to the
flat Al2O3-film deposited on the polycarbonate surface. (c) TiO2
nanotubes (outer diameter ~100 nm due to 240 s of etching time, wall
thickness ~10 nm) with a length corresponding to the template thickness.
Interestingly they have used the pyridine catalyzed process for H2O low temperature SiO2 (SiCl4) and for TiO2 (titanium isopropoxide). I have never seen it used for other than SiCl4 and HCDS for growing SiO2. This got me curious to know if there is any work done with other metal chlorides - you know the usual suspects - Zr, Hf, Ta, ...
Check out all the details and the experimental part especially in the OPEN ACCESS paper below!
TiO2, SiO2, and Al2O3 coated nanopores and nanotubes produced by ALD in etched ion-track membranes for transport measurements [OPEN ACCESS]
Anne Spende, Nicolas Sobel, Manuela Lukas, Robert Zierold, Jesse C Riedl, Leonard Gura, Ina Schubert, Josep M Montero Moreno, Kornelius Nielsch, Bernd Stühn, Christian Hess, Christina Trautmann and Maria E Toimil-MolaresPublished 30 July 2015 • © 2015 IOP Publishing Ltd, Nanotechnology, Volume 26, Number 33
Scheme of fabrication of TiO2, SiO2, and Al2O3 coated track-etched membranes. (a) Polycarbonate foils are irradiated with high-energy heavy ions; each projectile creates an individual ion track; (b) chemical etching converts ion tracks into cylindrical nanochannels of well-defined diameter; (c) ALD of TiO2, SiO2, and Al2O3 produces conformal homogeneous coatings.
Low-temperature atomic layer deposition (ALD) of TiO2, SiO2, and Al2O3 was applied to modify the surface and to tailor the diameter of nanochannels in etched ion-track polycarbonate membranes. The homogeneity, conformity, and composition of the coating inside the nanochannels are investigated for different channel diameters (18–55 nm) and film thicknesses (5–22 nm). Small angle x-ray scattering before and after ALD demonstrates conformal coating along the full channel length. X-ray photoelectron spectroscopy and energy dispersive x-ray spectroscopy provide evidence of nearly stoichiometric composition of the different coatings. By wet-chemical methods, the ALD-deposited film is released from the supporting polymer templates providing 30 μm long self-supporting nanotubes with walls as thin as 5 nm. Electrolytic ion-conductivity measurements provide proof-of-concept that combining ALD coating with ion-track nanotechnology offers promising perspectives for single-pore applications by controlled shrinking of an oversized pore to a preferred smaller diameter and fine-tuning of the chemical and physical nature of the inner channel surface.
GEMStar-CAT Dual™ Dual Reactor ALD and Catalyst Synthesis System by Arradiance
US ALD company Arradiance has released a new version of their GEMStar series of ALD tools -The GEMStar-CAT Dual™ Dual Reactor ALD and Catalyst Synthesis System. The custom GEMStar-DUAL CatalystTM System developed in partnership with the Chemical Sciences and Engineering Division of Argonne National Laboratory has unique capabilities. Arradiance used its skill combining Atomic Layer Deposition, System Design and Controls to produce a system that is unparalleled for Catalyst synthesis research
Catalyst synthesis and evaluation using an integrated atomic layer deposition synthesis–catalysis testing tool
Jeffrey Camacho-Bunquin, Heng Shou, Payoli Aich, David R. Beaulieu, Helmut Klotzsch, Stephen Bachman, Christopher L. Marshall, Adam Hock, and Peter Stair
(Received 24 June 2015; accepted 4 August 2015; published online 24 August 2015)
An integrated atomic layer deposition synthesis-catalysis (I-ALD-CAT) tool was developed. It combines an ALD manifold in-line with a plug-flow reactor system for the synthesis of supported catalytic materials by ALD and immediate evaluation of catalyst reactivity using gas-phase probe reactions. The I-ALD-CAT delivery system consists of 12 different metal ALD precursor channels, 4 oxidizing or reducing agents, and 4 catalytic reaction feeds to either of the two plug-flow reactors. The system can employ reactor pressures and temperatures in the range of 10−3 to 1 bar and 300–1000 K, respectively. The instrument is also equipped with a gas chromatograph and a mass spectrometer unit for the detection and quantification of volatile species from ALD and catalytic reactions. In this report, we demonstrate the use of the I-ALD-CAT tool for the synthesis of platinum active sites and Al2O3 overcoats, and evaluation of catalyst propylene hydrogenation activity. © 2015 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4928614]
(Received 24 June 2015; accepted 4 August 2015; published online 24 August 2015)
An integrated atomic layer deposition synthesis-catalysis (I-ALD-CAT) tool was developed. It combines an ALD manifold in-line with a plug-flow reactor system for the synthesis of supported catalytic materials by ALD and immediate evaluation of catalyst reactivity using gas-phase probe reactions. The I-ALD-CAT delivery system consists of 12 different metal ALD precursor channels, 4 oxidizing or reducing agents, and 4 catalytic reaction feeds to either of the two plug-flow reactors. The system can employ reactor pressures and temperatures in the range of 10−3 to 1 bar and 300–1000 K, respectively. The instrument is also equipped with a gas chromatograph and a mass spectrometer unit for the detection and quantification of volatile species from ALD and catalytic reactions. In this report, we demonstrate the use of the I-ALD-CAT tool for the synthesis of platinum active sites and Al2O3 overcoats, and evaluation of catalyst propylene hydrogenation activity. © 2015 AIP Publishing LLC. [http://dx.doi.org/10.1063/1.4928614]
Japanese researchers provide record low Dit in ALD Al2O3/La2O3/InGaAs gate stacks
InGaAs is one of the most promising III/V semiconductor
materials for n-channel MOSFETs because of its extremely high electron mobility of
∼13 800 cm2/V s. However, there is a major issue with InGaAs not having a high quality native oxide like Silicon resulting in a high interface state density at InGaAs MOS interfaces degrades the MOSFET performance because of Ga dangling bonds and/or As-As dimers created during the oxidation process at InGaAs surfaces. It has been reported that the passivation of trivalent oxides such as Gd2O3 or Al2O3 with InGaAs surfaces can eliminate such dangling bonds and dimers because of the abrupt and chemical-bond-well-arranged interface between the trivalent oxides and InGaAs.
TEM image of Au/Al2O3 (3.5 nm)/La2O3 (0.4 nm)/InGaAs gate stacks. Citation: J. Appl. Phys. 118, 085309 (2015); http://dx.doi.org/10.1063/1.4929650
ALD HfO2 has already been introduced at 45 nm CMOS and is still the dominating high-k material in high performance CMOS including recent Si FinFET technologies. Therefore, many have chosen to combine HfO2 with the Al2O3/InGaAs structure by in-situ
continuously ALD has been employed for CET scaling. Thin CET of ∼1.08 nm and
low Dit of ∼5 × 1012 cm−2 eV−1 have been realized in the HfO2/Al2O3/InGaAs gate stacks.
Another high-k that has commonly been used and is used e.g. as a dopant in the IBM Alliance 28 nm planar CMOS technology is La2O3, which is also trivalent oxide. It has been shown on InGaAs that La2O3 can further improve the MOS interface quality by the formation of Ga-O-La and In-O-La bonds. [ref]
Another high-k that has commonly been used and is used e.g. as a dopant in the IBM Alliance 28 nm planar CMOS technology is La2O3, which is also trivalent oxide. It has been shown on InGaAs that La2O3 can further improve the MOS interface quality by the formation of Ga-O-La and In-O-La bonds. [ref]
In a very good study presented below by University of Tokyo, JST-CREST and Sumitomo Chemicals a high quality La2O3 films were deposited on InGaAs by ALD. It was found that the La2O3/InGaAs interfaces provide recorded-low Dit of ∼3 × 1011 cm−2 eV−1 as the InGaAs MOS interfaces, which is attributable probably to the intermixing reaction between La2O3 and InGaAs. It is concluded, as a result, that the Al2O3/La2O3/InGaAs gate stacks can realize Dit lower than in the conventional Al2O3/InGaAs MOS interfaces with maintaining small hysteresis and low gate leakage by optimizing the thickness of Al2O3 and La2O3.
For me now some questions remains - why not combine the best of the best in one stack, i.e., HfO2/La2O3/InGaAs? Perhaps with only a slight touch of blend with Al2O3. Another question that worries me when reading HKMG InGaAs papers is the very low thermal budget that has to be used. The first high-k layer is deposited at 150 deg. C not destroy the super sensitive InGaAs interface. Most high-k materials needs to be deposited in the ranger 250 to 300 deg.C in order to perform at its best in addition PDAs or PMAs will bring out even more out of the material. Here and in other studies that I have seen a PMA of only 300 deg. C is used. Just imagine bringing this stack on to a silicon based channel material and it will not perform too much better than old poly/SiON with respect to CET / Leakage performance. I guess in the end it is all about the higher mobility given by a III/V channel. It just hurts every time seeing all these smart guys using a relatively low performing high-k.
Please find the OPEN ACCESS publication below!
Impact of La2O3 interfacial layers on InGaAs metal-oxide-semiconductor interface properties in Al2O3/La2O3/InGaAs gate stacks deposited by atomic-layer-deposition [OPEN ACCESS]
C.-Y. Chang, O. Ichikawa, T. Osada, M. Hata, H. Yamada, M. Takenaka and S. Takagi
(a) D it of the Al2O3 (3.5 nm)/La2O3/InGaAs gate stacks as a parameter of the La2O3 ALD cycle numbers, and (b) the La2O3 ALD cycle number dependence of D it of Al2O3 (3.5 nm)/La2O3/InGaAs at the surface energy of 0.1 eV from midgap (E – E i). Citation: J. Appl. Phys. 118, 085309 (2015); http://dx.doi.org/10.1063/1.4929650
We examine the electrical properties of atomic layer deposition
(ALD) La2O3/InGaAs and Al2O3/La2O3/InGaAs metal-oxide-semiconductor (MOS) capacitors. It is found that the thick ALD La2O3/InGaAs interface provides low interface state density (D
it) with the minimum value of ∼3 × 1011 cm−2 eV−1, which is attributable to the excellent La2O3
passivation effect for InGaAs surfaces. It is observed, on the other hand, that there are a large amount of slow traps and border traps in La2O3. In order to simultaneously satisfy low D
it and small hysteresis, the effectiveness of Al2O3/La2O3/InGaAs gate stacks with ultrathin La2O3
interfacial layers is in addition evaluated. The reduction of the La2O3 thickness to 0.4 nm in Al2O3/La2O3/InGaAs gate stacks leads to the decrease in hysteresis. On the other hand, D
it of the Al2O3/La2O3/InGaAs interfaces becomes higher than that of the La2O3/InGaAs ones, attributable to the diffusion of Al2O3 through La2O3 into InGaAs and resulting modification of the La2O3/InGaAs interface structure. As a result of the effective passivation effect of La2O3 on InGaAs, however, the Al2O3/10 cycle (0.4 nm) La2O3/InGaAs gate stacks can realize still lower D
it with maintaining small hysteresis and low leakage current than the conventional Al2O3/InGaAs MOS
interfaces.
Sunday, August 30, 2015
BTBAS Silicon nitride PEALD by TU Eindhoven, Oxford Instruments and ASM Microchemistry
Silicon nitride is one of the fastest growing single ALD layer applications in advanced CMOS (hard mask, liner, spacers, multi-patterning, ...). Here is a very good fundamental investigation of PEALD using a rather well known silicon precursor BTBAS in an ICP remote plasma ALD system from Oxford instruments.This is a joint publication between Oxford Instruments and ASM Microchemistry and University partners at Eindhoven University of Technology and Queen Mary University of London
Atomic Layer Deposition of Silicon Nitride from Bis(tert-butylamino)silane and N2 Plasma
Harm C. M. Knoops, Eline M. J. Braeken, Koen de Peuter, Stephen E. Potts, Suvi Haukka, Viljami Pore, and Wilhelmus M. M. KesselsACS Appl. Mater. Interfaces, Article ASAP
DOI: 10.1021/acsami.5b06833
Atomic layer deposition (ALD) of silicon nitride (SiNx) is deemed essential for a variety of applications in nanoelectronics, such as gate spacer layers in transistors. In this work an ALD process using bis(tert-butylamino)silane (BTBAS) and N2 plasma was developed and studied. The process exhibited a wide temperature window starting from room temperature up to 500 °C. The material properties and wet-etch rates were investigated as a function of plasma exposure time, plasma pressure, and substrate table temperature. Table temperatures of 300–500 °C yielded a high material quality and a composition close to Si3N4 was obtained at 500 °C (N/Si = 1.4 ± 0.1, mass density = 2.9 ± 0.1 g/cm3, refractive index = 1.96 ± 0.03). Low wet-etch rates of ∼1 nm/min were obtained for films deposited at table temperatures of 400 °C and higher, similar to that achieved in the literature using low-pressure chemical vapor deposition of SiNx at >700 °C. For novel applications requiring significantly lower temperatures, the temperature window from room temperature to 200 °C can be a solution, where relatively high material quality was obtained when operating at low plasma pressures or long plasma exposure times.
Researchers at Case Western Reserve University directly photo-charged lithium batteries with 7.8 percent efficiency
As reported bu Phys.org : Researchers at Case Western Reserve University, however, have wired
four perovskite solar cells (PSC) in series to enhance the voltage and
directly photo-charged lithium batteries (LIB) with 7.8 percent efficiency—the
most efficient reported to date, the researchers believe.
The research, published in the Aug. 27 issue of Nature Communications, holds promise for cleaner transportation, home power sources and more.
Efficiently photo-charging lithium-ion battery by perovskite solar cell [Open Access]
Jiantie Xu, Yonghua Chen & Liming Dai Nature Communications 6, Article number:8103 doi:10.1038/ncomms9103
Schematic diagram of the fabricated system of PSC–LIB. (Nature Communications 6, Article number:8103)
Abstract: Electric vehicles using lithium-ion battery pack(s) for propulsion have recently attracted a great deal of interest. The large-scale practical application of battery electric vehicles may not be realized unless lithium-ion batteries with self-charging suppliers will be developed. Solar cells offer an attractive option for directly photo-charging lithium-ion batteries. Here we demonstrate the use of perovskite solar cell packs with four single CH3NH3PbI3 based solar cells connected in series for directly photo-charging lithium-ion batteries assembled with a LiFePO4 cathode and a Li4Ti5O12 anode. Our device shows a high overall photo-electric conversion and storage efficiency of 7.80% and excellent cycling stability, which outperforms other reported lithium-ion batteries, lithium–air batteries, flow batteries and super-capacitors integrated with a photo-charging component. The newly developed self-chargeable units based on integrated perovskite solar cells and lithium-ion batteries hold promise for various potential applications.
The structure and the preparation procedures of CH3NH3PbI3 perovskite films (Supplementary information)
Friday, August 28, 2015
ЗАО «НПО СЕРНИЯ» приглашает посетить международный семинар «Atomic Layer Deposition Russia 2015 (ALD Russia 2015)»
[JSC "NPO sulfuric" invites you to visit the international seminar «Atomic Layer Deposition Russia 2015 (ALD Russia in 2015)"]
Вам интересны передовые разработки в области ALD? ЗАО «НПО СЕРНИЯ» приглашает посетить международный семинар «Atomic Layer Deposition Russia 2015 (ALD Russia 2015)», который пройдет в городе Долгопрудном 21-23 сентября, МФТИ.
Атомно-слоевое осаждение (ALD) представляет собой метод нанесения пленочных покрытий. Это мощный инструмент для изготовления ультратонких, высокооднородных и конформных слоев для применения в полупроводниковой промышленности для производства интегральных микросхем, датчиков, микро/наноэлектромеханических систем (MЭMS / НЭМС), для производства оптики, оптоэлектроники, солнечных батарей, биосовместимых покрытий для медицинских устройств, и т.д. Подробнее о применении метода ALD>>
Хотя российские (советские) ученые сыграли значительную роль в развитии научных принципов данного метода в 1960-е годы, до недавнего времени технология ALD не в полной мере применялась в России. Таким образом, целью Международного семинара ALD-2015 является консолидация быстро растущего ALD-сообщества в России и ознакомление российских исследователей с новыми разработками ведущих международных экспертов в этой области. Подробнее о конференции ALD Russia 2015>>
HERALD website with member profiles is going live www.european-ald.net
Check out the new HERALD website with member profiles just went live www.european-ald.net
HERALD promotes European research activity in Atomic Layer Deposition (ALD)
HERALD (COST action MP1402) aims to structure and integrate European research activity in atomic layer deposition (ALD), bringing together existing groups, promoting young scientists and reaching out to industry and the public. ALD is a unique technique for growing ultra-thin films that is enabling new developments in high-tech manufacturing sectors such as electronics, energy and coatings. With interest growing worldwide, the time is right to coordinate European activity in this field. HERALD supports collaboration through lab visits, workshops and training schools.
Wednesday, August 26, 2015
Low temperatture ALD of Copper by Peking University
Low-Temperature Atomic Layer Deposition of High Purity, Smooth, Low Resistivity Copper Films by Using Amidinate Precursor and Hydrogen Plasma
Zheng Guo, Hao Li, Qiang Chen, Lijun Sang, Lizhen Yang, Zhongwei Liu, and Xinwei Wang
Chem. Mater., Article ASAP
DOI: 10.1021/acs.chemmater.5b02137
Chem. Mater., Article ASAP
DOI: 10.1021/acs.chemmater.5b02137
Agglomeration is a critical issue for depositing copper (Cu) thin films, and therefore, the deposition should be preferably performed below 100 °C. This work explores an atomic layer deposition (ALD) process for copper thin films deposited at temperature as low as 50 °C. The process employs copper(I)-N,N′-diisopropylacetamidinate precursor and H2 plasma, which are both highly reactive at low temperature. The deposition process below 100 °C follows an ideal self-limiting ALD fashion with a saturated growth rate of 0.071 nm/cycle. Benefitting from the low process temperature, the agglomeration of Cu thin films is largely suppressed, and the Cu films deposited at 50 °C are pure, continuous, smooth, and highly conformal, with the resistivity comparable to PVD Cu films. In-situ reaction mechanism studies by using quartz crystal microbalance and optical emission spectroscopy are followed, and the results confirm the high reactivity of the Cu amidinate precursor at low temperature. To the best of our knowledge, this is the first successful implementation of metal amidinate precursors for low-temperature (∼50 °C) ALD process. The strategy of using metal amidinate precursors in combination with highly reactive H2 plasma is believed to be extendable for the depositions of other pure metals at low temperature.
JVSTA Issue on ALD Deadline Extended to: Septemeber 5, 2015
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Monday, August 24, 2015
ALD Lab Dresden sends away Varun Sharma to Helsinki, Finland
ALD Lab Dresden, Institut für Halbleiter- ind Mikrosystemtechnik at TU Dresden takes farewell and sends away Varun Sharma to Helsinki, Finland to learn from the masters how to ALD. Please take good care of Varun for us because he too was born to ALD. (Varun Sharma, Christoph Hossbach, Jonas Sundqvist, Martin Knaut)
ALD and VTT in Finland mentioned in report on the Global Packaging Coatings Market, 2015
Crazy day first a call on non-semi applications with a dear old friend and then multiple reports popping up on the same topic. Yeah I know I once owned a Citroen and since then I see them all the time. Anyhow, here is another non-semi ALD future where ALD and VTT in Finland mentioned in report on the Global Packaging Coatings Market, 2015. However a CAGR of 4.2% is not that much to hang in the christmas tree as we say in Sweden compared to many reports saying ALD growth is above CAGR 30%. But then again ALD can for sure grow at high speed within a large market!
Research and Markets (http://www.researchandmarkets.com/research/qk7q2n/global_packaging) has announced the addition of the "Global Packaging Coatings Market 2015-2019" report to their offering.
The increase in consumer preference for eco-friendly products is an important trend being witnessed in the global packaging coatings market. The manufacturers of packaging coatings, which include beverage packaging and food packaging, and are developing new and eco-friendly coatings to comply with regulations and to meet the increasing demand for sustainable products that do not harm the ecosystem.
This in turn is expected to propel the growth of the market during the forecast period. The VTT technical research center has developed technology for recyclable and eco-friendly packaging coatings solutions. These coatings help in the manufacture of thin, lightweight, fully recyclable, and air-tight packaging materials. They use the atomic layer deposition (ALD) method, which are helpful in food and pharmaceutical packaging as they have a good gas permeation resistance. Moreover, these recyclable coatings do not use barrier materials such as aluminum film, thereby using less raw materials compared to traditional packaging coatings materials.
According to the report, the global packaging coatings market to grow at a CAGR of 4.2% over the period 2014-2019. The growth of the global packaging industry is a major driving factor in the growth of the global packaging coatings market. The packaging industry is expected to grow by 2018. The growth will be characterized by the growing demand for packaging coatings from the packaging industry because of the increased demand for plastic packaging from the food and beverage industry.
Suppliers of raw materials determine the prices of raw materials, which in turn has a negative impact on the growth of the packaging market, thereby increasing the price of packaging coatings.
Here is an rather old press release form VTT on the topic :
Here is an rather old press release form VTT on the topic :
The ALD thin coating considerably reduces the need for aluminium in packaging solutions
VTT Technical Research Centre of Finland has developed an environmentally-friendly packaging coating solution. Especially suitable for food and pharmaceutical packaging, the coating offers a new method for manufacturing fully recyclable, thin, light and air-tight packaging materials.
ALD Encapsulation technologies for flexible electronics
Here is an overview on encapsulation technologies for flexible electronics covering the main technologies and players. So just scroll down to the interesting part about ALD sating the main OEMs:
- BENEQ
- Lotus
- Encapsulix
- Synos (Veeco)
From a market perspective tehr is a forecast from IDTechEx Barrier Layers for Flexible Electronics 2015-2025: Technologies, Markets, ForecastsRead more at: http://www.idtechex.com/research/reports/barrier-layers-for-flexible-electronics-2015-2025-technologies-markets-forecasts-000409.asp
Barrier layer market forecasts in US$ million
Status of flexible encapsulation to enable flexible electronics
In 2020, flexible barrier manufacturing for flexible electronic devices such as displays will be a market worth more than US$184 million, according to IDTechEx Research. That equates to 3.8 million square meters of flexible barrier films for electronics.
Although multilayer approaches – usually organic and inorganic layers – have been the most popular solution for flexible encapsulation so far, there is significant development work with solutions based on single layer approaches such as flexible glass or atomic layer deposition (ALD) which could, in later years, capture part of the market. The table below, compiled by IDTechEx analysts shows some of the characteristics of flexible glass and ALD films as developers are looking to bring them to market.
[...]
Atomic layer deposition (ALD) present and future outlook/market share
ALD is another flexible encapsulation technology receiving a lot of attention with several players currently developing solutions based on it. It seems like it is not a short-term solution, if it will ever be one as a stand-alone layer but ALD may be a solution in a multi-layer stack in combination with a sputtered or PECVD layer if it would be possible to find a good cost structure. Regarding the intrinsic properties of the material, ALD film deposited at low temperature (T<80 C) have a superior quality when tested at room temperature. A single ALD layer less-than 50 nm thick can perform better than thicker layers deposited by sputtering or PECVD.
However, the inherent stability of the films at higher temperature/humidity (e.g. 85C/85%RH) is a problem. If PE-CVD is used, ALD film stability improves, as well as for mixed oxides, but it is still an issue. A second problem comes with particles and substrates non-uniformity. Any defect may lead at an initial non-uniform nucleation that propagates into the growing film. Furthermore, loose particles on substrates may be partially covered, but because of the extreme thinness, the thin film does not have the mechanical strength to keep them in place under mechanical stress. Any mechanical stress leads to film fracture with consequent creation of an ingress path for moisture. That is why multilayer structures are necessary.
Deposition tools are in development from Lotus, Beneq, Encapsulix and others. Exploration at Samsung SDC with ALD films for TFE was very much advertised by Synos, but resulted in failure and any further evaluation was halted. ALD for barrier on foil has better results although there are doubts and hurdles in scaling up and reaching the deposition speed required for a cost effective process.
Thursday, August 20, 2015
ALD of single atom Pd on grapheme using a Arradiance Benchtop reactor
Here is an interesting report on the fabrication of single-atom Pd catalyst on graphene using ALD by researchers in Hefei, China. Pd ALD was carried out on a GEMSTAR-6TM Benchtop ALD from Arradiance at 150 °C using palladium hexafluoroacetylacetate (Pd(hfac)2) and formalin (37% HCHO and 15% CH3OH in aqueous solution).
Single-Atom Pd1/Graphene Catalyst Achieved by Atomic Layer Deposition: Remarkable Performance in Selective Hydrogenation of 1,3-Butadiene
Huan Yan, Hao Cheng, Hong Yi, Yue Lin, Tao Yao, Chunlei Wang, Junjie Li, Shiqiang Wei, and Junling Lu
Journal of the American Chemical Society
DOI: 10.1021/jacs.5b06485
We reported that atomically dispersed Pd on graphene can be fabricated using the atomic layer deposition technique. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy both confirmed that isolated Pd single atoms dominantly existed on the graphene support. In selective hydrogenation of 1,3-butadiene, the single-atom Pd1/graphene catalyst showed about 100% butenes selectivity at 95% conversion at a mild reaction condition of about 50 °C, which is likely due to the changes of 1,3-butadiene adsorption mode and enhanced steric effect on the isolated Pd atoms. More importantly, excellent durability against deactivation via either aggregation of metal atoms or carbonaceous deposits during a total 100 h of reaction time on stream was achieved. Therefore, the single-atom catalysts may open up more opportunities to optimize the activity, selectivity, and durability in selective hydrogenation reactions.
New precursors for Atomic Layer Deposition presented at AVS ALD 2015 Portland
Here is a very good review from AVS ALD 2015 in Portland with respect to some of the new ALD precursor chemistries presented and discussed during the meeting by the ALD leading research labs and ALD industry like Intel, Adeka, BASF anad others.
New Reagents For Atomic Layer Deposition
Tailored ALD precursors form atomically thin layers of metals, dielectrics, and other compounds
By Mitch JacobyChemical & Engineering News, Volume 93 Issue 32 | pp. 54-55, Issue Date: August 17, 2015
One way to shrink the nanosized wires (cross sections shown here) that interconnect electronic circuit components is to replace the “thick” tantalum nitride-like film used today to encapsulate the copper core (left) with a thinner manganese silicate film made via ALD.
Depositing thin films of copper is one thing. Making the metal stay put is quite another. “Copper has a nasty habit of diffusing if it’s not encapsulated with a protective barrier,” Gordon said. Running electric current through the tiny wires that interconnect transistors and other circuitry causes copper atoms to start migrating out of the wires, which eventually can lead to chip failure.
Gordon thinks ALD can help solve this problem. His group has developed an ALD process for making manganese silicate, a material that prevents copper diffusion at a film thickness of less than 2 nm. The chemistry is based on a reaction between a manganese amidinate compound and a silanol with tert-butoxy groups or other organic ligands. Gordon noted that there are other non-ALD ways to make manganese silicate films. But the Harvard group’s ALD method offers greater control over deposition and higher uniformity in chemical composition.
Shinjita Acharya reported on a proprietary barium pyrrole compound developed by BASF that is compatible with low-temperature ALD. Acharya is a postdoctoral researcher working with Stanford University mechanical engineer Friedrich B. Prinz, whose group is collaborating with BASF.
Tuesday, August 18, 2015
Picosun see increased sale for PICOPLATFORM™ cluster tools for high volume ALD manufacturing
According to a recent press release from Picosun Oy, leading supplier of Atomic Layer
Deposition (ALD) thin film coating solutions for industrial production,
delivers several new PICOPLATFORM™ cluster tools for high volume ALD
manufacturing in semiconductor industries.
The
PICOPLATFORM™ cluster systems have quickly become a favorite of
Picosun's production customers. The systems, designed to accommodate
wafers up to 300 mm size, comprise Picosun's state-of-the-art
technological solutions and unparalleled ALD knowhow with the most
extensive selection of vacuum loading solutions for single wafer and
batch processing. This makes the PICOPLATFORM™ cluster tools ideal for
e.g. III-V semiconductor, LED, and MEMS device manufacturing. The now
sold PICOPLATFORM™ cluster tools will be installed in the production
facilities of leading, multi-billion semiconductor device manufacturers
in USA and Asia.
"The
PICOPLATFORM™ product family is one of the strongholds of our
industrial ALD technology. The repeat sales of these systems to our core
markets such as microelectronic component and sensor manufacturing
prove again the unmatched level of our ALD equipment design and our
excellence in hardware integration, software, and process development.
Combined with our leading selection of automated batch handling systems
designed to fulfill the strictest requirements of the semiconductor
industries, the PICOPLATFORM™ cluster systems offer the most
comprehensive turn-key solutions to fast, productive, and cost-efficient
ALD manufacturing," states Mr. Juhana Kostamo, Managing Director of Picosun.
Mr. Juhana Kostamo, Managing Director of Picosun.
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