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The mechanisms of forming fluoropolymer coatings on silicon substrates via condensation from an active gas phase using directed flows of accelerated electrons and ions are studied. It is demonstrated that electrical properties of the resulting fluoropolymer films strongly depend on the technological parameters of the deposition process. Their most optimal properties are reported when condensation takes place at the temperatures within ~373-386 K. It is shown that thermal annealing of the films in vacuum at 430-470 K improves their electrophysical parameters by re-evaporating the low-molecular complexes from the structure and decreasing the concentration of defects and spin-radicals, while annealing in air gives rise to formation of additional polar groups. [ABSTRACT FROM AUTHOR]

In recent years, poly(3-hexylthiophene) (P3HT) nanowires have attracted great interest because of their unique physical and electronic properties. The annealing effects on the properties and morphologies of P3HT nanowires, however, are still not fully understood. In this work, the effects of thermal annealing and solvent annealing on the morphologies and crystallinities of P3HT nanowires prepared by the whisker method are studied. P3HT is first dissolved in heated p-xylene, followed by a cooling process to room temperature, and P3HT nanowires are formed by self-assembly. The crystallinities of the P3HT nanowires are observed to increase by both thermal annealing and solvent annealing, as confirmed by differential scanning calorimetry and X-ray diffraction. The device performances of organic field-effect transistors based on the annealed nanowires are also examined. After annealing, an enhancement of the charge mobility by one order is observed. [ABSTRACT FROM AUTHOR]

Co-implantation, with overlapping implantation projected ranges, of Si and doping species (P, As, B) followed by a thermal annealing step is a viable route to form doped Si nanocrystals (NCs) embedded in SiO2. This presentation deals with optical characterizations of both doped and undoped Si-NC prepared by this method. The NC effective presence in the oxide layer and their crystallinity is verified by Raman spectrometry. Photoluminescence (PL) and PL excitation measurements reveal quantum confinement effects and a gradual PL quenching with increasing dopant concentrations. The measured Stokes shift remains constant and its value ∼ 0.2 eV is almost twice the Si-O vibration energy. This suggests that a possible radiative recombination path is a fundamental transition assisted by a local phonon. Lifetime investigations show that PL time-decays follow a stretched exponential. Atomic probe tomography analyses demonstrate that n-type dopants (P, As) are efficiently introduced in the NC core, whereas p-type dopant (B) are located at the NC/SiO2 interface. All together these experimental observations question on possible different carrier recombination paths in P or As doped NC compared to B one's. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

We demonstrate chemical doping of a topological insulator Bi2Se3 using ion implantation. Ion beam-induced structural damage was characterized using grazing incidence X-ray diffraction and transmission electron microscopy. Ion damage was reversed using a simple thermal annealing step. Carrier-type conversion was achieved using ion implantation followed by an activation anneal in Bi2Se3 thin films. These two sets of experiments establish the feasibility of ion implantation for chemical modification of Bi2Se3, a prototypical topological insulator. Ion implantation can, in principle, be used for any topological insulator. The direct implantation of dopants should allow better control over carrier concentrations for the purposes of achieving low bulk conductivity. Ion implantation also enables the fabrication of inhomogeneously doped structures, which in turn should make possible new types of device designs. [ABSTRACT FROM AUTHOR]

In this paper, high-performance InGaZnO (IGZO) thin-film transistors were fabricated with film-profile-engineering scheme. The impacts of gate dielectric, O2/Ar ratio during the sputtering of the IGZO, and annealing ambient on the device performance were investigated. It is found that the turn-ON voltage of the device is closely related to the gate dielectric material. For the devices with Al2O3 as the gate dielectric, decent performance in terms of high ON/OFF current ratio (> 10^\mathrm \mathbf 8 ), extremely steep subthreshold swing (62 mV/decade), and good mobility (19.8 cm2/V $\cdot $ s) is obtained. The influences of O2/Ar flow ratio are distinct for the devices with Al2O3 gate oxide. Significant improvement in the stability of the devices to the environment is achieved with the anneal done in a low-pressure N2 ambient. [ABSTRACT FROM PUBLISHER]

Monodisperse 5 nm AuMn nanoparticles were synthesized by hydride reduction of manganese acetylacetonate in the presence of Au nanoparticles. The alloy was formed through fast Mn diffusion into the Au structure. The AuMn nanoparticles were converted to Au-MnO composite particles through air annealing at 170°C. These Au-MnO particles, especially the core/shell Au/MnO nanoparticles, were active for the electrochemical reduction of H2O2, with a detection limit reaching 8 nm. This highly sensitive electrochemical sensor based on the Au/MnO nanoparticles was used to monitor H2O2 concentrations released from living cells, from which tumorigenic cells were discovered to release higher levels of H2O2 than the non-tumorigenic cells. [ABSTRACT FROM AUTHOR]

In this work, the authors fabricated 1-transistor ferroelectric random access memory based on polycrystalline-silicon (poly-Si) on a glass substrate. A novel technique was used to form a large single-grained Pb(Zr,Ti)O3 (PZT) layer as the gate insulator. Generally, the crystallization temperature of PZT is 800 °C, which is beyond the limits for a glass substrate; however, here the authors developed a selectively nucleated lateral crystallization technique to minimize the crystallization temperature and grow 40 µm grains of PZT. Pt layer using rapid thermal annealing at 650 °C for a short time, and grew a single seed by tube-furnace at 550 °C for 2 h. Our device demonstrated excellent electrical properties with long retention time, which only decreased by 9% after 104 s, and good fatigue characteristics, which only decreased by 4% after 104 cycles. [ABSTRACT FROM AUTHOR]

In this paper, the authors report the growth of diluted oxygen doped ZnTe films (ZnTe:O) by metal-organic chemical vapor deposition (MOCVD). The effect of a post thermal annealing on the properties of the highly mismatched films has been investigated. It is found that the in-situ doping leads to an effective incorporation of oxygen into ZnTe films with different occupation configurations, either on Zn or on Te site. The subsequent annealing process in a vacuum ambient leads to an enhancement of the oxygen incorporation into the ZnTe:O films due to the diffusion of the residual oxygen, while the annealing with the same as-grown sample covered on top of the surface (denoted as "face-to-face" annealing in the text) is beneficial to the improvement of the film quality with manifest intermediate band emission at around 1.9 eV as revealed by the low-temperature photo-luminescence. This study indicates that the mass-productive MOCVD technique may be suitable for the growth of highly mismatched ZnTe:O films for the application of the intermediate band solar cell. [ABSTRACT FROM AUTHOR]

It is shown experimentally that, in contrast to the stable configuration of (interstitial carbon)-(interstitial oxygen) complexes (CO), the corresponding metastable configuration (CO*) cannot be found in n-Si based structures by the method of capacitance spectroscopy. The rates of transformation CO* →CO are practically the same for both n- and p-Si with a concentration of charge carriers of no higher than 10 cm. It is established that the probabilities of the simultaneous formation of stable and metastable configurations of the complex under study in the case of the addition of an atom of interstitial carbon to an atom of interstitial oxygen is close to 50%. This is caused by the orientation dependence of the interaction potential of an atom of interstitial oxygen with an interstitial carbon atom, which diffuses to this oxygen atom. [ABSTRACT FROM AUTHOR]

InAs quantum dots (QDs) are receiving attention as next‐generation E‐band light source that offers high‐temperature operation and temperature insensitive operation. However, high‐density crystal defects occur at the interface between the InGaAs buffer layer and GaAs, resulting in reduced device performance and shortened lifetime. Here, E‐band QD lasers are demonstrated on InGaAs buffer layer, which suppressed the spread of dislocation by introducing a high‐temperature annealing and a strained layer superlattice filter. In the device, the peak wavelength at room temperature is measured to be 1427 nm and the threshold current density was 440 A/cm2. This result indicates that E‐band QD laser structures on low threading dislocation density are promising for the realisation of high‐performance E‐band lasers. [ABSTRACT FROM AUTHOR]

Two-dimensional hybrid perovskites are used as absorbers in solar cells. Our first-generation devices containing (PEA)2(MA)2[Pb3I10] ( 1; PEA=C6H5(CH2)2NH3+, MA=CH3NH3+) show an open-circuit voltage of 1.18 V and a power conversion efficiency of 4.73 %. The layered structure allows for high-quality films to be deposited through spin coating and high-temperature annealing is not required for device fabrication. The 3D perovskite (MA)[PbI3] ( 2) has recently been identified as a promising absorber for solar cells. However, its instability to moisture requires anhydrous processing and operating conditions. Films of 1 are more moisture resistant than films of 2 and devices containing 1 can be fabricated under ambient humidity levels. The larger bandgap of the 2D structure is also suitable as the higher bandgap absorber in a dual-absorber tandem device. Compared to 2, the layered perovskite structure may offer greater tunability at the molecular level for material optimization. [ABSTRACT FROM AUTHOR]

The microstructural characterization of Ni-GaSb junctions in samples annealed at 300 °C, 350 °C, and 400 °C in a N2 atmosphere was elucidated using transmission electron microscopy in conjunction with energy-dispersive spectrometry, nanobeam electron diffraction, and grazing-incident X-ray diffraction. Only the NiSb(Ga) phase is formed at the interface of Ni/GaSb when the annealing temperature is below 350 °C. However, three phases--NiSb, Ni2Ga3, and NiSb(Ga)--are formed simultaneously at the interface between Ni/GaSb when the annealing temperature is increased to 400 °C, which causes a significant increase in the sheet resistance of the Ni-GaSb alloy. These results indicate that the annealing temperature of the Ni/GaSb structure should be maintained below 350 °C for the formation of low-resistance metal Ni/GaSb contacts in GaSb-based p-type metal-oxide-semiconductor field-effect transistors. [ABSTRACT FROM AUTHOR]

Deuterium (D) incorporation in GeO2/Ge structures following D2 annealing was investigated. Higher D concentrations were obtained for GeO2/Ge samples in comparison to their SiO2/Si counterparts annealed in the same conditions. Oxygen vacancies produced during the annealing step in D2 constitute defect sites for D incorporation, analogous to defects at the SiO2/Si interfacial region. Besides D incorporation, volatilization of the oxide layer is also observed as a consequence of D2 annealing, especially in the high temperature regime of the present study (>450 °C). In parallel to this volatilization, the stoichiometry and chemical structure of remnant oxide are modified as well. These results evidence the broader impact of forming gas annealing in dielectric/ Ge structures with respect to SiO2/Si counterparts. [ABSTRACT FROM AUTHOR]

We have used synchrotron-based critical dimension small-angle x-ray scattering (CD-SAXS) to monitor the impact of hydrogen annealing on the structural characteristics of silicon FinFET structures fabricated using self-aligned double patterning on both bulk silicon and silicon-on-insulator (SOI) substrates. H2 annealing under different conditions of temperature and gas pressure allowed us to vary the sidewall roughness and observe the response in the two metrology approaches. In the case of the simpler bulk Si FinFET structures, the CD-SAXS measurements of the critical dimensions are in substantive agreement with the top-down critical dimension scanning electron microscopy metrology. Corresponding characterizations on SOI-based FinFET structures showed less agreement, which is attributed to the more complex structural model required for SOI FinFET CD-SAXS modeling. Because sidewall roughness is an important factor in the performance characteristics of Si FinFETs, we have compared the results of roughness measurements using both critical dimension atomic force microscopy (CD-AFM) and CD-SAXS. The measurements yield similar estimates of sidewall roughness, although the CD-AFM values were typically larger than those generated by CD-SAXS. The reasons for these differences will be discussed. [ABSTRACT FROM AUTHOR]

The results of X-ray diffraction and optical studies of CuZnSnS films produced by the flash evaporation of binary sulfide compounds under different technological conditions is reported. It is shown that it is possible to produce CuZnSnS films, rather perfect in structural and optical respects, by choosing the optimal annealing temperatures at different Ar vapor pressures. The lattice parameters of the compounds are determined. The systematic shift in the photoluminescence bands under variations in the excitation level is established. It is found that the characteristics of the bands depend to a large extent on the annealing temperature, the Ar pressure during thermal treatment, and the resultant stoichiometry composition of the samples. It is shown that Raman studies and luminescence measurements can be used to assess the quality of the synthesized CuZnSnS films and to obtain data on the energy structure of defects in the band gap. [ABSTRACT FROM AUTHOR]

This paper explores the physical and chemical laws of energy variations in adsorption centers and the influence exerted on gas-sensitive properties by the targeted doping of semiconductor resistive sensors. The authors establish that minimization of the degradation processes in multisensors requires making each element of these sensors from a same material. In doping by modifiers, an important role belongs to many factors, particularly, the ratio of the squared charge of an impurity ion and its radius. As this factor takes smaller values than that of the parent-ray material, the number of Bronsted centers on the surface goes down and the influence of Lewis centers grows accordingly. The major impact on the energy of surface centers is introduced by the defect rate of the crystal structure (the degree of deviation from stoichiometry). [ABSTRACT FROM AUTHOR]

A germanium n+/p shallow junction formed by a combination of low-temperature preannealing (LTPA) and excimer laser annealing at a low fluence of 150 mJ/cm2 for phosphorus-implanted germanium is demonstrated. The LTPA step plays a critical role in annihilating the implantation damages and significantly suppressing phosphorus diffusion during laser annealing process, resulting in a very small dopant diffusion length with high activation level of phosphorus. A well-behaved Ge n+/p shallow junction diode with a record rectification ratio of \(\sim 10^{7}\) and low leakage current density of \(8.3 \times 10^{-5}\) A/cm2 is achieved, which is greatly beneficial to the scaled Ge MOSFET technology. [ABSTRACT FROM PUBLISHER]

Organic photovoltaic cells (OPVs) have been a hot topic for research during the last decade due to their promising application in relieving energy pressure and environmental problems caused by the increasing combustion of fossil fuels. Much effort has been made toward understanding the photovoltaic mechanism, including evolving chemical structural motifs and designing device structures, leading to a remarkable enhancement of the power conversion efficiency of OPVs from 3% to over 15%. In this brief review, the advanced progress and the state-of-the-art performance of OPVs in very recent years are summarized. Based on several of the latest developed approaches to accurately detect the separation of electron-hole pairs in the femtosecond regime, the theoretical interpretation to exploit the comprehensive mechanistic picture of energy harvesting and charge carrier generation are discussed, especially for OPVs with bulk and multiple heterojunctions. Subsequently, the novel structural designs of the device architecture of OPVs embracing external geometry modification and intrinsic structure decoration are presented. Additionally, some approaches to further increase the efficiency of OPVs are described, including thermotics and dynamics modification methods. Finally, this review highlights the challenges and prospects with the aim of providing a better understanding towards highly efficient OPVs. [ABSTRACT FROM AUTHOR]

CuSnS (CTS) is a simple and potential material for low-cost thin film solar cells. The present work incorporates the study of changes in structural and optical properties of layer-by-layer solution deposited CTS films with annealing. Raman spectroscopy is used to ascertain structural modification upon annealing. Increase in annealing temperature leads to a structural transition from tetragonal to cubic phase. Effect of annealing on optical properties of the films is evaluated in the wavelength range of 400-2,400 nm. It is proposed that layer-by-layer growth method fundamentally defines the optical behaviour of these films. Optical constants and parameters such as refractive indices, dielectric constants and electron energy loss function are calculated from transmittance and reflectance data. The refractive indices, n and k are determined to be in ranges of 1.8-2.2 and 0.18-1.2, respectively. The real and imaginary dielectric constants vary from 1.5 to 4.6 and 0.7 to 5, respectively. Dispersion of refractive index is analyzed using two different theoretical models of Wemple-diDomenico and Spitzer-Fan. [ABSTRACT FROM AUTHOR]

Selected glasses of FeO-PbO-TeO system have been transformed into nanomaterials by annealing at a temperature close to the crystallization temperature (T). The effects of the annealing of the present samples on the structural and electrical properties were studied by transmission electron micrograph (TEM), X-ray diffraction (XRD), differential scanning calorimeter, density (d) and dc conductivity (σ). TEM and XRD of glass-ceramic naocrystals indicated nanocrystals embedded in the glassy matrix with average particle size of 20-35 nm. The glass-ceramic naocrystals obtained by annealing at T exhibit improvement of electrical conductivity up to four orders of magnitude than the starting glasses. This considerable improvement of electrical conductivity after nanocrystallization is attributed to formation of extensive and dense network of electronic conduction paths which are situated between FeO nanocrystals and on their surface. The conduction is attributed to non-adiabatic hopping of small polaron. [ABSTRACT FROM AUTHOR]

In the present study, we have reported on the effect of annealing time variations for spin coated magnesium oxide (MgO) thin films. The various time annealed MgO thin films structural, surface morphological, compositional, electrical and optical absorption properties were studied by X-ray diffraction, scanning electron microscopy, energy dispersive analysis by X-rays, I-V studies and UV-vis spectroscopy, respectively. The cubic structure formation with preferential orientation along the (200) plane was confirmed from structural analysis. In addition, the influence of the annealing on the microstructural properties of MgO was plausibly explained. The optical properties of MgO thin films were estimated using the transmission spectrum in the range of 400-800 nm. The optical band gap energy of MgO thin films was found to be in the range between 3.81 and 3.93 eV. The morphological studies depicted that the spherical and ellipsoid shaped grains were distributed evenly over the entire surface of the film. The sizes of the grains are found to be in the range between 200 and 250 nm. The composition analysis was performed by EDX for various temperatures annealed MgO thin films. [ABSTRACT FROM AUTHOR]

Cu-poor electrodeposited CuInAlSe (CIAS) precursor films were prepared to investigate the alteration in surface morphology of post-annealed CIAS films through post-annealing temperature adjustment. Scanning electron microscopy (SEM) and atomic force microscope (AFM) analyses demonstrated that surface morphology and root-mean-square (RMS) roughness of post-annealed CIAS films exhibited uneven and rough triangular structures. The crystal size of post-annealed CIAS films can be increased by increasing post-annealing temperature. The precursor film structure was modified by substituting Cu-Se/CIAS binary structure with CIAS single structure to proceed with the investigation. The apparent variation in surface morphology of post-annealed CIAS films changed from rough triangular structures to smooth round structures, and the RMS roughness of post-annealed CIAS films was reduced to <100 nm. The reduction was attributed to the formation of Cu-Se liquid phases during the post-annealing process, which enhanced elemental migration, recombination, and promotion of large grains and smooth surface formation. X-ray diffraction patterns showed three preferred growth orientations along the (112), (204/220), and (116/312) planes with chalcopyrite structures for all species. In addition, the characteristics of surface morphology, RMS roughness, and current measurement of subsequently deposited cadmium sulfide (CdS) film were studied and examined via SEM and AFM analyses. The surface morphology of CdS films deposited on binary structure post-annealed CIAS films exhibited smoothness, compactness, small RMS roughness, and large crystals with round and film-like structure. The AFM current images indicated that the distribution of leakage current paths was greatly diminished by changing the precursor film structure from CIAS single structure to Cu-Se/CIAS binary structure. The dark current-voltage characteristics of the CdS/CIAS heterojunctions showed that the reverse dark current density was decreased by approximately one order of magnitude from 4.02 × 10 (single structure) to 4.26 × 10 A/cm (binary structure). Furthermore, the conversion efficiency of CIAS solar cells was enhanced from 0.52 (single structure) to 1.44 % (binary structure) with increase in V and J. [ABSTRACT FROM AUTHOR]

High-k gate dielectric HfO thin films have been deposited on Si and quartz substrates by radio frequency magnetron sputtering. The structural characteristics, surface morphology, and optical properties of the HfO/Si gate stacks at various post-annealing temperatures were examined by X-ray diffraction (XRD), atomic force microscopy (AFM), fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis spectroscopy), and spectroscopic ellipsometry (SE). XRD measurement indicates that the 80 W-deposited HfO films demonstrate a polycrystalline structure. AFM measurements illustrate that the root mean square of the HfO thin films demonstrates an apparent increase with increasing the annealing temperature. Analysis from FTIR indicates that the Si-O-Si bonds vibration peak position shift toward lower wave numbers with increasing the annealing temperature. Combined with UV-Vis spectroscopy and SE measurements, it can be noted reduction in band gap with an increase in annealing temperature has been confirmed. Additionally, increase in refractive index ( n) has been confirmed by SE. [ABSTRACT FROM AUTHOR]

We have observed several unexpected phenomena when a trace amount of Fe atoms is deposited onto the CoFeB/MgO interface in Ta/CoFeB/MgO/Ta multilayers. With the nominal thickness of the introduced Fe atoms (tFe) varying from 0 to 0.1 Å, the effective magnetic anisotropy energy (Keff) of annealed multilayers is remarkably enhanced from 1.28 x 106 erg/cm³ to 2.14 x 106 erg/cm³. As tFe further increasing, the Keff decreases and even becomes negative when tFe > 1 Å, indicating the change from perpendicular magnetic anisotropy to in-plane magnetic anisotropy. The analysis by X-ray photoelectron spectrometer reveals that the Fe atoms at annealed CoFeB/MgO interface show different electronic structures as tFe increasing, which combine with O atoms to form FeOx (x < 1), Fe2O3, and Fe3O4, respectively, leading to modulation of Fe 3d-O 2p orbital hybridization and thus the Keff. On the other hand, we find that the introduction of Fe atoms also helps to reduce the multilayers' magnetic damping. [ABSTRACT FROM AUTHOR]

We investigated the electrical properties of zinc tin oxide (ZTO) films deposited via atomic layer deposition and compared them to ZnO and SnO2 films as a function of the annealing temperature. The ZTO and ZnO, except for SnO2, films exhibited an electrical transition from a metal to semiconductor characteristics when annealed above 300 ° C. The X-ray photoelectron spectroscopy analyses indicate that the relative area of the oxygen vacancy-related peak decreased from 58% to 41% when annealing at temperatures above 400 ° C. Thin film transistors incorporating ZTO active layers demonstrated a mobility of 13.2 cm² /V s and a negative bias instability of -0.2 V. [ABSTRACT FROM AUTHOR]

Group-III elements act as donors in ZnO when incorporated on the Zn site. Their incorporation and behavior upon annealing is governed by diffusion, which proceeds mainly through a vacancy-assisted process. We report first-principles calculations for the migration of Al, Ga, and In donors in ZnO, based on density functional theory using a hybrid functional. From the calculated migration barriers and formation energies, we determine diffusion activation energies and estimate annealing temperatures. Impurity-vacancy binding energies and migration barriers decrease from Al to In. Activation energies for vacancy-assisted diffusion are lowest for In and highest for Al. [ABSTRACT FROM AUTHOR]

We report the effects of high-pressure annealing (HPA) on solution-processed InGaZnO (IGZO) thin-film transistors (TFTs). HPA increased the density of IGZO films. In particular, annealing in O2 at 1.0 MPa and 350 °C resulted in a high-density and low-porosity IGZO film, as characterized using X-ray reflectivity (XRR) and ellipsometry measurements. This was attributed to the oxidative and compressive effects on the oxygen-deficient solution-processed IGZO film. TFTs annealed in O2 at 1.0 MPa and 350 °C exhibited an increase in the field-effect mobility by a factor of approximately five compared with TFTs annealed in air at 0.1 MPa and 350 °C. Furthermore, improvements in reliability under negative and positive bias stresses were also observed following HPA. [ABSTRACT FROM AUTHOR]

The ordering processes of PS- b-P2VP block copolymer thin films with different processing histories were studied during solvent vapor annealing by in situ grazing incidence small-angle X-ray scattering (GISAXS). We compared cylinder-forming PS- b-P2VP thin films with 34 kg/mol molecular weight that were prepared in three different ways: spin coating, spin coating and subsequent solvent vapor annealing where the solvent vapor was removed instantaneously, and spin coating and subsequent solvent vapor annealing where the solvent vapor was removed slowly. Block copolymer thin films retained the morphology resulting from the different 'processing histories' at smaller swelling ratios. This processing history was erased when the samples reached a higher swelling ratio (~1.4). After the solvent was slowly removed from the swollen film, the surface morphology was characterized by ex situ AFM. All samples showed the same morphology after solvent annealing regardless of the initial morphology, indicating the morphology of solvent annealed samples is determined by the polymer concentration in the swollen film and the solvent vapor removal rate, but not the processing history. [ABSTRACT FROM AUTHOR]

We report the use of molecular beam epitaxy to achieve p-type doping of CdTe grown on Si(211) substrates, by use of an arsenic cracker and post-growth annealing. A high hole density in CdTe is crucial for high efficiency II-VI-based solar cells. We measured the density of As in single-crystal CdTe by secondary ion mass spectroscopy; this showed that high As incorporation is achieved at low growth temperatures. Progressively higher incorporation was observed during low-temperature growth, presumably because of degradation of crystal quality with incorporation of As at such defect sites as dislocations and defect complexes. After As activation annealing under Hg overpressure, hole concentrations were obtained from Hall measurements. The highest doping level was ∼2.3 × 10 cm, and near-10 cm doping was readily reproduced. The activation efficiency was ∼50%, but further optimization of the growth and annealing conditions is likely to improve this value. [ABSTRACT FROM AUTHOR]

An efficient electrical spin injection into an InGaAs/GaAs quantum well light emitting diode is demonstrated thanks to a CoFeB/MgO spin injector. The textured MgO tunnel barrier is fabricated by two different techniques: sputtering and molecular beam epitaxy. The maximal spin injection efficiency is comparable for both methods. Additionally, the effect of annealing is also investigated for the two types of samples. Both samples show the same trend: an increase of the electroluminescence circular polarization (Pc) with the increase of annealing temperature, followed by a saturation of Pc beyond 350°C annealing. Since the increase of Pc starts well below the crystallization temperature of the full CoFeB bulk layer, this trend could be mainly due to an improvement of chemical structure at the top CoFeB/MgO interface. This study reveals that the control of CoFeB/MgO interface is essential for an optimal spin injection into semiconductor. [ABSTRACT FROM AUTHOR]

In this paper, we present the fabrication of dilute nitride semiconductor GaAs1-xNx by nitrogen-ion-implantation and flash lamp annealing (FLA). N was implanted into the GaAs wafers with atomic concentration of about ximp1=0.38% and ximp2=0.76%. The GaAs1-xNx layer is regrown on GaAs during FLA treatment in a solid phase epitaxy process. Room temperature near band-edge photoluminescence (PL) has been observed from the FLA treated GaAs1-xNx samples. According to the redshift of the near band-edge PL peak, up to 80% and 44% of the implanted N atoms have been incorporated into the lattice by FLA for ximp1=0.38% and ximp2=0.76%, respectively. Our investigation shows that ion implantation followed by ultrashort flash lamp treatment, which allows for large scale production, exhibits a promising prospect on bandgap engineering of GaAs based semiconductors. [ABSTRACT FROM AUTHOR]

Oxide-assisted growth of Si nanocrystals includes deposition of a silicon-enriched SiOx film at the first stage and annealing at the second one. The ion-plasma sputtering method has been used for deposition of the SiOx film. The influence of thermal and laser annealing on SiOx film properties has been investigated. Formation of silicon nanoislands on oxide film surface has been observed by AFM both after thermal and laser annealing. The height and surface density of the nanoislands depends both on the silicon content in the initial SiOx film and temperature of thermal annealing. The higher annealing temperature causes formation of large nanoislands, but their surface density decreases. Comparison of nanoislands created at thermal and laser annealing shows that in case of laser annealing the nanoislands are higher and their surface density is lower. The intensity of laser irradiation influences on nanoisland parameters significantly. The growth of electrical conductivity with thermal annealing temperature has been observed. The influence of gas atmosphere during annealing is also significant in case of higher temperatures. In case of laser annealing at the beginning at low laser irradiation intensities, the SiOx film conductivity increases, but the following growth of intensity causes the decrease in electrical conductivity. [ABSTRACT FROM AUTHOR]

Ternary Zn1-xCdxO (x ≤ 0.12) alloy crystalline films with highly preferred orientation (002) have been successfully deposited on sapphire c-Al2O3 substrates using the direct current (dc) reactive magnetron sputtering technique and annealed at temperature 600 °C in air. The structural and optical properties of Zn1-xCdxO thin films were systematically studied using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), micro-Raman and photoluminescent (PL) spectroscopy. XPS measurements clearly confirmed Cd incorporation into ZnO lattice. XRD data revealed that the growth of wurtzite Zn1-xCdx O films occurs preferentially in the (002) direction. Also, when the Cd content is increased, the XRD peaks shift towards smaller angles and the full width at half-maximum of the lines increases. When the Cd content increases, A1LO (Zn1-xCdxO)-like Raman modes show composition dependent frequency decrease and asymmetrical broadening. The near band-edge PL emission at room temperature shifts gradually to lower energies as the Cd content increases and reaches 2.68 eV for the highest Cd content (x = 0.12). The analysis of NBE band emission and Raman A1LO (Zn1-xCdxO) mode shows that at a higher Cd content the coexistence of Zn1-xCdxO areas with different concentrations of Cd inside the same film occurs. The presence of CdO in annealed Zn1-xCdxO films with the higher Cd content was confirmed by Raman spectra of cubic CdO nanoinclusions. The XRD data also revealed phase segregation of cubic CdO in annealed Zn1-xCdxO films (Tann = 600 °C) for x ≥ 0.013. [ABSTRACT FROM AUTHOR]

The effect of thermal annealing and exposure to oxygen plasma on the phase composition, structure, and microprofile of titanium-dioxide films deposited by high-frequency magnetron sputtering on silicon substrates is studied. The influence exerted by processing modes on the capacitance-voltage and conductance-voltage characteristics of Me-TiO-Si-Me structures and on the density of surface states at the semiconductor-insulator interface is examined. It is shown that TiO films are amorphous upon their fabrication. Upon the annealing of films at 500°C in an argon atmosphere, crystallites of anatase and rutile appear in the amorphous matrix. The treatment of a titanium-dioxide film in oxygen plasma gives rise to rutile crystallites with new crystallographic planes. As a result of annealing at 750°C, the anatase phase disappears and the film becomes polycrystalline, containing only rutile crystallites. The capacitance of Me-TiO-Si-Me structures in the accumulation mode reaches the maximum value upon annealing at 750°C, which is due to the transformation of titanium dioxide to the rutile phase. The specific capacitance is 5.9 × 10 F/cm. The decrease in the capacitance of the structures and in the amount of fixed charge in the insulator upon exposure to oxygen plasma is due to the diffusion of oxygen atoms across the titanium-dioxide layer to give a SiO film at the TiO-Si interface. As a result of the annealing and treatment of a titanium-dioxide film in oxygen plasma, the energy density of surface states decreases by more than an order of magnitude as compared with the unannealed samples. [ABSTRACT FROM AUTHOR]

Strontium titanate (STO) thin films 90 nm in thickness were grown on a Pt substrate throughatomic layer deposition (ALD). The as-deposited ALD STO grown with an ALD cycle ratio of 1:1 (Sr:Ti) was in an amorphous phase, and annealing at 800 °C in air crystallized the films into the perovskite phase. This phase change was confirmed by x-ray diffraction and transmission electron microscopy. The as-deposited ALD STO exhibited no discernible switching mechanism, whereas unipolar switching behavior was reproducibly observed with a high resistance ratio (108-109) and strict separation of the set/reset voltages and currents in the annealed ALD STO. Mechanisms for charge transport in both the low- and high-resistance states and for resistive switching in the annealed ALD STO are also proposed. [ABSTRACT FROM AUTHOR]

The electrical quality of functionalized, oxide-free silicon surfaces is critical for chemical sensing, photovoltaics, and molecular electronics applications. In contrast to Si/SiO2 interfaces, the density of interface states (Dit) cannot be reduced by high temperature annealing because organic layers decompose above 300 °C. While a reasonable Dit is achieved on functionalized atomically flat Si(111) surfaces, it has been challenging to develop successful chemical treatments for the technologically relevant Si(100) surfaces. We demonstrate here that recent advances in the chemical preparation of quasi-atomically-flat, H-terminated Si(100) surfaces lead to a marked suppression of electronic states of functionalized surfaces. Using a non-invasive conductance-voltage method to study functionalized Si(100) surfaces with varying roughness, a Dit as low as 2.5×1011 cm-2eV-1 is obtained for the quasi-atomically-flat surfaces, in contrast to >7×1011 cm-2eV-1 on atomically rough Si(100) surfaces. The interfacial quality of the organic/quasi-atomically-flat Si(100) interface is very close to that obtained on organic/atomically flat Si(111) surfaces, opening the door to applications previously thought to be restricted to Si(111). [ABSTRACT FROM AUTHOR]

Rare earth-doped fluorides with strong up-conversion (UC) luminescence have attracted growing attention due to their potential applications in photonics and biological areas. However, current techniques to process these fluorides into thin films have not been sufficiently developed. Here, we report for the first time the preparation of NaYF4 thin film doped with Yb3+, and Tm3+ by electro-deposition and subsequent annealing. The as-deposited thin film was characterized by X-ray diffraction, scanning electron microscopy, thermogravimetry, differential thermal analysis and photoluminescence. Under excitation by a near infrared laser diode at 980 nm, the transparent NaYF4:Yb-Tm thin film exhibits bright visible upconversion luminescence from Tm3+ as a result of energy transfer from Yb3+. The results demonstrate that the electro-deposition process provides facile access to UC fluoride thin films which may have applications in photovoltaic devices. [ABSTRACT FROM AUTHOR]

The thermal donor (TD) generation in dopant-rich compensated Czochralski silicon was studied by pulling an ingot from a feedstock containing large amounts of donors and acceptors. In a wafer located in the vicinity of the change of conductivity type, thermal donors were formed and the evolution of their concentration was similar to that in noncompensated lowly boron-doped silicon. Thus, simultaneous high densities of both boron and phosphorus do not have a significant impact on the TD formation. This brings the experimental evidence that for a given oxygen concentration and annealing temperature, the TD formation is controlled by the electron density. [ABSTRACT FROM PUBLISHER]

We studied the influence of two different kind of annealing, conventional annealing and current annealing, on the magnetic and magneto-transport properties of amorphous Co-Fe rich glass-coated microwires with the nominal composition Co69.2Fe4.1B11.8Si13.8C1.1 fabricated by Taylor-Ulitvosky technique. At a certain annealing conditions we have been able to obtain high domain wall velocity with perfectly rectangular hysteresis loop, high giant magneto-impedance response (GMI) and almost linear with low hysteretic off-diagonal GMI response simultaneously in the same sample. Such results could be essential from application's point of view. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

We studied giant magneto-impedance (GMI) effect, magnetic and structural properties of thin Finemet-type (FeCuNbSiB) glass-coated microwires fabricated by Taylor-Ulitovsky technique with different composition and diameters, with the aim to achieve the optimal conditions for improving the final GMI response. We observed that GMI can be tailored either by controlling the microwires microstructure through the thermal annealing, or by controlling the quenching rate velocity during the fabrication processes. Finally, we obtained up to 50% GMI in the as-prepared samples and up to 100% in annealed microwires. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

New doping techniques are needed for the formation of abrupt, ultrashallow junctions with high doping concentration in the source/drain or source/drain extension regions of metal-oxide-semiconductor field-effect transistors (MOSFETs) at advanced technology nodes. In addition, 3-D device structures, such as fin field-effect transistors, require a good doping conformality. In this paper, the formation of monolayers of silicon on InGaAs by disilane or silane treatment of the InGaAs surface is studied as a conformal dopant source that does not introduce ion implant damage into the InGaAs, and laser anneal is used to drive in and activate the dopants to form an ultrashallow and very abrupt n^++-junction. This novel doping technique is first demonstrated in planar InGaAs MOSFETs. [ABSTRACT FROM PUBLISHER]

We have investigated the effects of air-annealing on the electrical performance of the p-type tin oxide thin-film transistors (TFTs). The air-annealing of the tin oxide thin-film was made using a mini furnace at various temperatures. From the x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) data, it is demonstrated that the phase of tin oxide partially transforms from SnO to SnO2 with an air-annealing process, and it accelerates as the annealing temperature increases. The electrical performance of the p-type tin oxide TFT with a channel thickness of 25 nm exhibits much improved electrical performance when air-annealed at 230 °C for 1 h, but a decrease of the on-current is observed with an ambipolar operation in 260 and 290 °C air-annealed devices. Based on the XPS, XRD, and Hall measurement data, the reduced hole concentration inside the channel due to the recombination with electrons from SnO2 is believed to be the reason for the electrical performance improvement in 230 °C air-annealed p-type tin oxide TFTs, and a partial formation of n-type SnO2 channel is considered as the plausible reason for the ambipolar operation in tin oxide TFTs with high annealing temperatures. Our experimental results show that there is an optimum air-annealing temperature which can improve the electrical performance in p-type tin oxide TFTs. [ABSTRACT FROM AUTHOR]

We show that the quality of Nd1.85Ce0.15CuO4 films grown by pulsed laser deposition can be enhanced by using a non-stoichiometric target with extra copper added to suppress the formation of a parasitic (Nd, Ce)2O3 phase. The properties of these films are less dependent on the exact annealing procedure after deposition as compared to films grown from a stoichiometric target. Film growth can be followed by a 1 bar oxygen annealing, after an initial vacuum annealing, while retaining the superconducting properties and quality. This enables the integration of electron-doped cuprates with their hole-doped counterparts on a single chip, to create, for example, superconducting pn-junctions. [ABSTRACT FROM AUTHOR]

Composites formed from ZnO nanorods in combination with CuO or Ag nanoparticles are produced by the deposition of CuO or Ag nanoparticles onto ZnO nanorod arrays grown by the hydrothermal technique. The CuO nanoparticles are synthesized by the vacuum thermal deposition of a Cu layer followed by vacuum annealing at a temperature of 350°C for 1 h. CuO particles covered with a layer of nanoneedles are obtained. The current-voltage characteristics of the ZnO/CuO layers are indicative of the formation of a p-n junction. The ZnO/Ag composites are produced by the electrical deposition of Ag nanoparticles synthesized in an aqueous solution of silver nitrate and sodium citrate. The surface morphology and the optical and electrical properties of the samples are studied. [ABSTRACT FROM AUTHOR]

This paper compares the behavior of the gate oxide in 4H-SiC lateral MOSFETs subjected to post-deposition annealing (PDA) in N2O and POCl3. A significantly higher channel mobility was measured in 4H-SiC MOSFETs subjected to PDA in POCl3 (108 cm2 V-1s-1) with respect to NO (19 cm2 V-1s-1), accompanying a reduction of the interface traps density. Hence, a different temperature coefficient of the mobility and of the threshold voltage was observed in the two cases. According to structural analysis, the gate oxide subjected to PDA in POCl3 showed a different surface morphology than that treated in N2O, as a consequence of the strong incorporation of phosphorous inside the SiO2 matrix during annealing. This latter explained the instability of the electrical behavior of MOS capacitors annealed in POCl3. [ABSTRACT FROM AUTHOR]