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We report herein the analysis of the properties of copper(I) oxide thin films deposited by an optimized ammonium-free successive ion layer adsorption and reaction (SILAR) technique. The Cu2O thin film deposition process was carried out at room temperature using copper acetate monohydrate, sodium citrate as complexing agent, and hydrogen peroxide as precursors of copper and oxygen ions, respectively. The harmless and easy-to-handle sodium citrate replaces the volatile NH4OH commonly employed as complexing agent in the SILAR technique for the deposition of metal oxide thin films. The optical, structural, morphological, and electrical properties of the as-deposited Cu2O thin films were studied as a function of the number of cycles during deposition, as well as their modifications produced by the effect of rapid thermal annealing (RTA) in vacuum in a temperature range of 200–250°C for 1 min, 3 min, and 5 min. The as-deposited thin films had cubic crystalline structure corresponding to the Cu2O phase as determined by x-ray diffraction (XRD), with a direct energy bandgap of 2.43–2.51 eV depending on the number of cycles, and electrical resistivity of the order of 103 Ω cm. The XRD and x-ray photoelectron spectroscopy (XPS) analysis of the Cu2O thin films treated by RTA demonstrated an increase of the crystal size with time and temperature of the RTA and reduction effects from Cu2+ to Cu1+ oxidation states. On the other hand, the RTA treatments also decreased their energy bandgap to 2.38 eV and electrical resistivity to 102 Ω cm. The high energy bandgap values of the Cu2O thin films were attributed to quantum confinement effects produced by their small crystal size in the range of 3.6–8.6 nm. [ABSTRACT FROM AUTHOR]

Single-crystal c-Ge plates implanted with Ag+ ions with an energy of E = 30 keV, current density of the ion beam J = 5 μA/cm2 and a dose of D = 2.5 × 1016 ions/cm2 were subjected to rapid thermal annealing by single light pulses of various durations from 1 up to 9.5 s. By scanning electron microscopy and optical reflection spectroscopy measurements it was shown that after ion implantation an amorphous porous Ag:PGe layer of spongy structure, consisting of Ge nanowires, is formed on the surface of c-Ge substrates. It was found that the annealing with an increase in the pulse duration up to 5 s successively leads to an increase in the Ge nanowire diameters from 26 to 35 nm. With longer pulses, the porous Ag:PGe structure is destroyed and Ag evaporates from the implanted layers. [ABSTRACT FROM AUTHOR]

In recent years, the growing demand for renewable energy sources has led to an increased interest for searching some ways to improve the factors affecting the power conversion efficiency (PCE) of solar cells. Silicon solar cells technology has reached a high level of development in relation to efficiency and stability. This study presents the effect of rapid thermal annealing (RTA) at different annealing temperatures and times on the characteristics of solar cells fabricated by Nd:YAG laser doping of p-type crystalline silicon wafer with phosphorus dopant to a depth of 3.7 µm and concentration of approximately 1020 cm−3. The conversion efficiency (η) was studied before and after rapid thermal annealing, which increased from 3.67 to 12.8% after RTA at 1073 K for 6 s. The large increase of the short-circuit current density (JSC) and open-circuit voltage (VOC) indicated an enhanced absorption coefficient, reduced lattice defects, and a redistribution of impurities, which improved the electrical activity of impurities. Furthermore, the results demonstrated increased minority carrier lifetime, diffusion length, and improved responsivity after rapid thermal annealing. Solar cells annealed at 1073 K for 6 s exhibited the best photovoltaic properties. [ABSTRACT FROM AUTHOR]

Finely dispersed Y2O3:Eu, Y2Si2O7:Eu, YF3:Ce and YF3:Eu luminescent phosphors are synthesized using a hydrothermal method. A process is developed for obtaining Y2O3:Eu phosphors with a reduced particle size by hydrothermal precipitation with the addition of an inert finely dispersed filler (Aerosil) followed by rapid thermal annealing (RTA). Another process is suggested for the synthesis of finely dispersed Y2Si2O7:Eu phosphor via hydrothermal precipitation followed by microwave annealing. The effect of the synthesis conditions on the properties of YF3:Ce and YF3:Eu nanosized phosphors is studied and hydrothermal processing conditions were determined so as to provide the adjustment of their luminescence spectra due to the variation of the activator valency (Eu3+/Eu2+ and Ce3+/Ce2+). Besides earlier defined luminescence centers comprising Eu2+ ions in orthorhombic and cubic coordination positions of YF3 crystal lattice, the studied phosphors involve two additional types of luminescence centers relating to Eu(II), supposedly corresponding to Eu2+ in the same coordination positions located on the surface of the phosphor particles. Using the obtained data, an energy chart of Eu(II)-based luminescence centers in YF3:Eu nanosized phosphors is suggested. The resulting nanoscale particle size and luminescence spectra features of the synthesized phosphors YF3:Ce and YF3:Eu make them potentially useful for photodynamic therapy of cancer in combination with the photosensitizer Rose Bengal. The composition involving the synthesized Y2O3:Eu phosphor and photosensitizer Photoditazine was shown to provide an effective destruction of tumor cell cultures. Highlights: Y2O3:Eu nanosized phosphor is synthesized via hydrothermal precipitation followed by RTA. Finely dispersed Y2Si2O7:Eu is synthesized via hydrothermal precipitation with the addition of Aerosil followed by microwave annealing. An energy chart of Eu(II)-based luminescence centers in YF3:Eu nanosized phosphors is defined. Nanosized phosphors promising for the application in photodynamic therapy of cancer coupled with the photosensitizer Rose Bengal are obtained. [ABSTRACT FROM AUTHOR]

The post-processing of CuInGaSe2 (CIGS) thin films deposited using a single-target sputtering method was studied. Post-processing annealing was performed in a traditional muffle furnace and rapid thermal processing (RTP) tube furnace. The samples were annealed at 450°C for 10 min in a muffle furnace and subsequently quenched, whereas multiple quenching cycles were performed in RTP. The structural, optical, elemental, and morphological properties of the samples were analyzed. The obtained XRD data were refined using the Rietveld refinement algorithm, which showed that the c/a value approaches the ideal tetragonal crystal structure in the RTP-treated sample and that the crystallinity of the RTP-treated sample was better than that of the traditional furnace-annealed samples. Optical measurements showed increased absorbance values in the RTP-treated samples compared with the furnace-annealed samples. Bandgap was estimated to be 1.30 eV, 1.22 eV, and 1.18 eV for as-deposited, furnace annealing, and RTP-treated samples. Our experiment showed that better results were obtained in the RTP-treated samples, with a similar parameter used for annealing. [ABSTRACT FROM AUTHOR]

Improving the detection limit of surface-enhanced Raman scattering (SERS) is a significant issue for the design and application of plasmon substrate. It always suffers from the weak affinity of probe molecules on the nanoscale surface, uncontrollable aggregation behaviors of nanoparticles, and strong fluorescence of the detected substance. In this paper, AgNPs/SiO2 substrate is prepared by a rapid thermal annealing method with a mean size of 87.9 ± 30.7 nm. A layer of 5–30 nm PVA (polyvinyl alcohol) film is used as the stabilizer of AgNPs. With PVA coating, AgNPs can improve the detection limit of gentian violet by three magnitudes, compared with the one on undecorated AgNPs which is just 10−5 mol/L. In the sensitive detection using coated AgNPs/SiO2 substrate, PVA possibly plays three significant roles, affinity increaser between gentian violet and silver nanoparticles, fluorescence inhibiter of gentian violet, and stabilizer of Ag nanoparticles. The results provide a modification method for improving SERS sensitivity of plasmon substrate, which uses convenient and low-cost rapid thermal annealing as the patterning method and PVA as the coater, an advantageous technology for plasmon substrate application into trace detection. [ABSTRACT FROM AUTHOR]

The electrical and optical properties of Ag/p–GaN contacts have been investigated as a function of the annealing temperature, oxygen concentration, and annealing time. Specific contact resistance (ρc) values as low as 1.2 × 10–4 Ω·cm2 were obtained from the Ag/p–GaN contact annealed at 400 °C for 60 s in ambient O2/N2 (1:10). We found that the participation of oxygen improves the formation of ohmic contacts. Oxygen might remove the H in Mg–H complexes to activate the Mg acceptors and enhance Ga out-diffusion to form an Ag–Ga solid solution. We also found that the reflectivity of the Ag layer decreases with increasing annealing temperature in the O2-containing ambient environment. Thus, an optimal annealing condition of Ag/p–GaN for blue and green LEDs is suggested based on these results. We also used the suggested annealing conditions to form ohmic contacts on DUV LEDs and achieved good electrical performance. The forward voltages of UVC LEDs fabricated with annealed Ag contacts were 6.60 V (7.66 V) at a 40 mA (100 mA) injection current. [ABSTRACT FROM AUTHOR]

Crystal ion slicing (CIS) technology has been widely applied to fabricate single-crystalline quality thin film, although the ion implantation process can cause lattice strain and electric properties changes in the fabricated film. In this paper, CIS-fabricated Z-cut LiTaO3 (LT) thin films were annealed under different temperatures and times by rapid thermal annealing (RTA). The effects of annealing parameters on microstructure and dielectric properties of LT films were studied. It is found that the lattice strain can be partially released by RTA according to the XRD diffraction peak shift and this lattice release also has an influence on the permittivity and dielectric loss. Additionally, anomalous recrystallization behavior has been observed in the samples annealed at higher temperature or longer time according to the abnormal grain growth revealed by AFM. Besides, unusual permittivity and dielectric loss increase in sample annealed at 600℃ was measured and it may result from the abnormal grain growth. In summary, it is indicated by the results that RTA is an effective way to release lattice strain and it can impact electric properties of CIS-fabricated LT thin film. [ABSTRACT FROM AUTHOR]

This work reports Ag-doped Sb2Te3 (A-ST) thin films synthesized by DC magnetron sputtering method onto SiO2 (SO) and polyimide (PI) substrates based on atomic composition optimization. The effect of post-depositional rapid thermal annealing on the crystallinity, morphology, composition, and thermoelectric properties of thin films was investigated. It was found that thin films on crystalline SO substrate yielded higher crystallinity and eventually a higher thermoelectric power factor in comparison to those grown on a polyimide substrate. The maximum room-temperature power factors achieved were 0.53 mW m−1 K−2 (PI) and 3.95 mW m−1 K−2 (SO). [ABSTRACT FROM AUTHOR]

A conductive metal thin film Al is deposited as a buffer to form Al/AZO double layers. The Taguchi method, based on the Al thickness, annealing temperature and duration, is used to determine the optimum synthesis conditions. The quality and thickness of the layers are analyzed by field emission scanning electron microscopy. The atomic resolution microstructures and the interface between Al/AZO are observed using high resolution transmission electronic microscopy. The optoelectronic properties of the layers are measured using a four-point probe and UV–VIS-NIR spectrophotometer. Using the appropriate parameters as derived by the Taguchi method, it is verified that the optimized results correspond with the experimental results for this study. The thickness of the Al metal layer is about 10 nm and the double layers are thermally annealed for 10 min at 500°C; the best figure␣of merit (FOM) is calculated as 0.0375 (Ω−1). [ABSTRACT FROM AUTHOR]

We have investigated the influence of rapid thermal annealing (RTA) on the surface defects of CdZnTe (CZT) crystals by using low-temperature photoluminescence (PL) measurements. In the low-temperature PL spectrum for the as-grown CZT crystals, the donor–acceptor pair (DAP) recombination peak is dominant. Overlapping of the free-exciton (FE) and the neutral donor bound exciton (D0,X) luminescence peaks leads to broadening of the (D0,X) peak. In the low-temperature PL spectra for CZT crystals annealed at 523 K and 623 K for 5 min, the A-center peak is dominant. The deterioration of the intensity and FWHM of the (D0,X) peak indicates worsening of the crystal quality under the two RTA conditions. In the low-temperature PL spectra for CZT crystals annealed at 723 K, 773 K and 873 K for 5 min, an FE peak gradually becomes evident as the annealing temperature increases. The full-width half-maximum (FWHM) of the (D0,X) peak decreases from 7.95 meV before annealing to 2.85 meV after annealing at 873 K. The neutral acceptor bound exciton (A0,X) peak intensity increases with the annealing temperature increasing. The peak intensity ratio I(D0,X)/I(DAP) increases from ∼ 0.24 before annealing to ∼ 1.62 after annealing at 873 K. The A-center peak intensity decreases with the increase in annealing temperature. These phenomena demonstrate better surface structure and higher crystal quality under the three RTA conditions, especially for the annealing at 873 K. RTA treatment can be an effective way to improve the surface properties of CZT crystals by modifying the technical parameters. [ABSTRACT FROM AUTHOR]

The structural model and fabrication process of the Si-based blocked-impurity-band (BIB) detector were proposed. The numerical simulation of phosphorus ion implantation and rapid thermal annealing was investigated. Various implantation conditions were analyzed to meet the requirements of good electrical contact. Moreover, the carrier activation effect of phosphorus ion implantation and rapid thermal annealing was demonstrated by Hall test. Then the relationship between blackbody responsivity and annealing temperature was analyzed. According to the measurement results, the blackbody responsivity and response wavelength range of Si-based BIB detector we fabricated can reach 2.2A/W and 5–45 μm, respectively. Our work shows that the good electrical contact can improve the blackbody responsivity. It provides an effective method to fabricate Si-based BIB detector with good performances. [ABSTRACT FROM AUTHOR]

Studies of the characteristics of ohmic contacts to epitaxial and ion-doped gallium-nitride layers, based on the Cr/Pt/Au metallization system, are reported. The possibility of forming low-resistance contacts without the application of high-temperature treatment is shown. It is demonstrated, for AlGaN/GaN-based heterostructures, that the characteristics of Ti/Al/Ni/Au ohmic contacts are improved upon using ion implantation through a silicon-dioxide mask. [ABSTRACT FROM AUTHOR]

Synthesis of nanoparticles in insulators attracts tremendous attention due to their unique electrical and optical properties. Here, the gallium (Ga) and gallium nitride (GaN) nanoclusters have been synthesized in the silicon nitride matrix by sequential ion implantation (gallium and nitrogen ions) followed by either furnace annealing (FA) or rapid thermal annealing (RTA). The presence of Ga and GaN nanoclusters has been confirmed by Fourier-transform infrared, Raman and X-ray photoelectron spectroscopy. Thereafter, the effect of RTA and FA on the conduction of charge carriers has been studied for the fabricated devices. It is found from the current–voltage measurements that the carrier transport is controlled by the space charge limited current conduction mechanism, and the observed values of parameter m (trap density and the distribution of localized state) for the FA and RTA devices are ~2 and ~4.1, respectively. This reveals that more defects are formed in the RTA device and that FA provides better performance than RTA from the viewpoint of opto- and nano-electronic applications. [ABSTRACT FROM AUTHOR]

The performance of materials in perovskite solar cells has garnered a fair amount of interest because they are solution processable and thus a prime target for roll-to-roll coating. The precursor materials are typically prepared in solutions and deposited using common evaporative techniques, some that can be adapted to roll-to-roll manufacturing. However, there are some existing challenges that should be overcome to allow for the films to be stable in ambient conditions such that they can be deposited more cost-effectively. In this work, we report on solution engineering that enables deposition of the perovskite materials in an ambient environment using roll-to-roll applicable technologies. These engineered chemistries were also designed to enable rapid post-processing steps to limit the web length within a conventional oven. Scanning electron microscopy and X-ray diffraction analysis showed that the films achieved consistent morphology and crystallinity, and performed well in solar cell devices. Results of several chemistries and processes will be presented. [ABSTRACT FROM AUTHOR]

Four specimen patterns with the microstructure of a microcopper wire are deposited on the Si-wafer substrate plus thermal oxide (SiO2) film as the top layer. Each pattern was prepared to have two kinds of specimens, including with and without ultrathin carbon film between the copper wire and the top layer (SiO2). The effect of carbon film on electrical properties is evaluated via the measurements of the I (current)–V (voltage) curve, sheet electrical resistance, current leakage, and its ratio and effective permittivity. A rapid thermal annealing (RTA) technique is provided as an economic and efficient method to grow the ultrathin carbon film rapidly as the interlayer. Appropriate choices of 900 °C and 3 min as the annealing temperature and time can produce ultrathin carbon film with nearly 100% coverage of the copper surface. The sheet resistance of specimen demonstrates the behavior exactly opposite to that of the carbon film coverage of wire surface. The combined effect of elevating the voltage and annealing temperature of the specimen with carbon film on the current leakage is much lower than that arising in the specimen without carbon film, so long as the carbon films operating at that temperature (between 350 and 500 °C) are still sustainable. The differences in current leakage and effective permittivity between these two kinds of specimen are significantly increased by raising the temperature. The intensity (IC) of copper diffusions into the SiO2 layer in the specimens with the carbon film demonstrates behavior similar to that of current leakage (CL). The IC and CL values for the temperatures ≦ 350 °C are much lower than those obtained at 500 °C. [ABSTRACT FROM AUTHOR]

Anisotropic nanomaterial-modified carbon fibers attract increasing attention because of their superior properties over traditional ones. In this study, activated carbon fibers (ACFs) 'thickly overgrown' by Ag nanohair were prepared through self-assembly and rapid thermal annealing. Viscose fibers with well-dispersed silver nanoparticles (AgNPs) on surfaces were first prepared through self-assembly of hyperbranched poly(amino-amine) (HBPAA)-capped AgNPs on viscose surfaces. HBPAA endowed the AgNP surfaces with negative charges and abundant amino groups, allowing AgNPs to monodispersively self-assemble to fiber surfaces. Ag nanohair-grown ACFs were prepared by sequential pre-oxidation and carbonization. Because the carbonization furnace was open-ended, ACFs are immediately transferrable to the outside of the furnace. Therefore, the Ag liquid adsorbed by ACF pores squeezed out to form Ag nanowires through thermal contraction. FESEM characterization indicated that Ag nanohairs stood on ACF surface and grew from ACF caps. XPS and XRD characterization showed that Ag successfully assembled to fiber surfaces and retained its metallic state even after high-temperature carbonization. TG analysis suggested that Ag nanohair-grown ACFs maintained their excellent thermal stabilities. Finally, the fabricated ACFs showed excellent and durable antibacterial activities, and the developed method may provide a potential strategy for preparing metal nanowire-grown ACFs. [ABSTRACT FROM AUTHOR]

Transparent conducting oxide films with optimized dopant molar ratio have been prepared with limited pre- and postdeposition annealing duration of 10 min. Multiple aluminum zinc oxide (AZO) layers were spin-coated on ordinary glass substrates. The predeposition consolidation temperature and dopant molar ratio were optimized for electrical conductivity and optical transparency. Next, a group of films were deposited on Corning glass substrates from precursor solutions with the optimized dopant ratio, followed by postdeposition rapid thermal annealing (RTA) at different temperatures and in controlled environments. The lowest resistivity of 10.1 × 10 Ω cm was obtained for films receiving RTA at 600°C for 10 min each in vacuum then in N-5%H environment, while resistivity of 20.3 × 10 Ω cm was obtained for films subjected to RTA directly in N-5%H. Optical measurements revealed average total transmittance of about 85% in the visible region. A direct allowed transition bandgap was determined based on the absorption edge with a value slightly above 3.0 eV, within the typical range for semiconductors. RTA resulted in desorption of oxygen with enhanced carrier concentration and crystallinity, which increased the carrier mobility with decreased bulk resistivity while maintaining the required optical transparency. [ABSTRACT FROM AUTHOR]

The yttrium iron garnet (YIG) thin films prepared by the sol-gel method and rapid thermal annealing (RTA) process for integrated inductor are investigated. The X-ray diffraction (XRD) results indicate that the YIG film annealed above 650 °C is poly-crystalline with single-phase garnet structure. Moreover, it can be found that the initial permeability μ , saturation magnetization M and coercivity H of these YIG films increase with increasing RTA temperature. Low temperature annealing after crystallization can further improve the magnetic properties of YIG film. Thereby, a planar integrated inductor in the presence of Si substrate/SiO layer/YBiFeO thin film/Cu spiral coil structure is fabricated successfully by the standard IC processes. Due to the magnetic enhancement originated from YIG film, the inductance L and quality factor Q of the inductor with YIG film are improved in a certain frequency range. [ABSTRACT FROM AUTHOR]

Recently, colored H-doped TiO (H-TiO) has demonstrated enhanced photoelectrochemical (PEC) performance due to its unique crystalline core-disordered shell nanostructures and consequent enhanced conduction behaviors between the core-shell homo-interfaces. Although various hydrogenation approaches to obtain H-TiO have been developed, such as high temperature hydrogen furnace tube annealing, high pressure hydrogen annealing, hydrogen-plasma assisted reaction, aluminum reduction and electrochemical reduction etc., there is still a lack of a hydrogenation approach in a controlled manner where all processing parameters (temperature, time and hydrogen flux) were precisely controlled in order to improve the PEC performance of H-TiO and understand the physical insight of enhanced PEC performance. Here, we report for the first time a controlled and local rapid thermal annealing (RTA) approach to prepare hydrogenated core-shell H-TiO nanorods grown on F:SnO (FTO) substrate in order to address the degradation issue of FTO in the typical TiO nanorods/FTO system observed in the conventional non-RTA treated approaches. Without the FTO degradation in the RTA approach, we systematically studied the intrinsic relationship between the annealing temperature, structural, optical, and photoelectrochemical properties in order to understand the role of the disordered shell on the improved photoelectrochemical behavior of H-TiO nanorods. Our investigation shows that the improvement of PEC performance could be attributed to (i) band gap narrowing from 3.0 to 2.9 eV; (ii) improved optical absorption in the visible range induced by the three-dimensional (3D) morphology and rough surface of the disordered shell; (iii) increased proper donor density; (iv) enhanced electron-hole separation and injection efficiency due to the formation of disordered shell after hydrogenation. The RTA approach developed here can be used as a suitable hydrogenation process for TiO nanorods/FTO system for important applications such as photocatalysis, hydrogen generation from water splitting and solar energy conversion. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO) ultrathin films with different thicknesses below 20 nm were grown by atomic layer deposition (ALD) on silicon substrates at 300 °C. Spectroscopic ellipsometry (SE) measurements were operated to investigate the effect of thickness on the optical properties of ultrathin films in the spectra range from 200 to 1000 nm with Forouhi-Bloomer (F-B) dispersion relation. It has been found that the refractive index and extinction coefficient of the investigated TiO ultrathin film increase while the band gap of TiO ultrathin film decreases monotonically with an increase in film thickness. Furthermore, with the purpose of studying the temperature dependence of optical properties of TiO ultrathin film, the samples were annealed at temperature from 400 to 900 °C in N atmosphere. The crystalline structure of deposited and annealed films was deduced by SE and supported by X-ray diffraction (XRD). It was revealed that the anatase TiO film started to transform into rutile phase when the annealing temperature was up to 800 °C. In this paper, a constructive and effective method of monitoring the phase transition in ultrathin films by SE has been proposed when the phase transition is not so obvious analyzed by XRD. [ABSTRACT FROM AUTHOR]

A comparative study of different sequences of two metal precursors [trimethylaluminum (TMA) and Tris(isopropylcyclopentadienyl) lanthanum (La(PrCp))] for atomic layer deposition (ALD) lanthanum aluminum oxide (LaAlO) films is carried out. The percentage compositions of C and N impurity of LaAlO films were investigated using in situ X-ray photoelectron spectroscopy (XPS). The effects of different oxidants on the physical and chemical properties and electrical characteristics of LaAlO films are studied before and after annealing. Preliminary testing results indicate that the impurity level of LaAlO films grown with different oxidants can be well controlled before and after annealing. Analysis indicates the rapid thermal annealing (RTA) and kinds of oxidants have significant effects on the equivalent oxide thickness (EOT), dielectric constant, electrical properties, and stability of LaAlO films. Additionally, the change of chemical bond types of rapid thermal annealing effects on the properties of LaAlO films are grown with different oxidants also investigated by XPS. [ABSTRACT FROM AUTHOR]

The geometry of fracture associated with the propagation of cracks originating at the edges of (001) oriented, 200 mm diameter silicon wafers has been investigated under two regimes of high temperature processing. Under spike annealing, fracture did not occur on low index planes and all except one wafer exhibited crack patterns that started initially to run radially, but after a distance of typically 20-30 mm, turned and ran almost tangentially. Wafers subjected to plateau annealing, with a 60 s dwell time at high temperature, predominantly fractured through radial cracks running along $$\langle 110\rangle $$ directions. X-ray diffraction imaging reveals substantial slip in all wafers subjected to plateau annealing. We demonstrate using finite element (FE) modelling that the change in fracture geometry is associated with this plastic deformation, which changes the stress distribution during the cooling phase of the rapid thermal annealing cycle. FE simulations without plastic relaxation show that the radial component of the thermal stress distribution is compressive in the centre of the wafer, causing the crack to run tangentially. Simulations incorporating temperature dependent plasticity showed that the equivalent stress becomes tensile when the plateau anneal allows time for significant plastic relaxation, permitting the crack to continue propagating linearly. [ABSTRACT FROM AUTHOR]

The strong photoluminescence (PL) signal at wavelengths ranging from 1,300 to 1,500 nm was observed in GaAsBi epitaxial layers grown by migration-enhanced epitaxy and annealed at $$600\,^{\circ }\hbox {C}$$ and higher temperatures. PL measurements at liquid helium temperatures showed two peaks at $$\sim $$ 0.9 and $$\sim $$ 1 eV. It was found that intensity of the higher energy peak decreases with temperature leaving only the lower energy peak at room temperature. Structural investigations demonstrated that annealing reduces Bi content in GaAsBi lattice by precipitating bismuth in nanometer-scale clusters. It is suggested that PL can be caused by the semimetal-semiconductor transition quantum confinement due to the quantum confinement effect in Bi clusters. [ABSTRACT FROM AUTHOR]

We report the characteristics of inkjet-printed transparent Ti-doped InO (ITiO) films directly patterned using an ink containing ITiO nanoparticles (NPs) and used as transparent electrodes for liquid crystal (LC) devices. By optimizing the rapid thermal annealing temperature, we could directly pattern square-shaped ITiO electrodes with a sheet resistance of 37.41 Ω square and optical transmittance of 85.40 %, values that made them suitable for LC cell fabrication. It was found that the degree of interconnectedness of the ITiO NPs critically affected the resistivity, optical transmittance, and surface morphology of the inkjet-printed ITiO electrodes. The successful operation of the twisted nematic LC cells fabricated on the inkjet-printed ITiO electrodes indicates that inkjet printing is a promising direct coating method for fabricating all-solution-processed LC devices. Graphical abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The electrical, structural and surface morphological properties of Yb/p-In P Schottky barrier diode (SBD) have been investigated at different annealing temperatures. The determined Schottky barrier height (SBH) and ideality factor n of the as-deposited Yb/p-In P SBD are 0.68 eV ( I-V)/0.81 eV(( C-V)) and 1.44 respectively. After annealing at 300℃, the SBH of Yb/p-In P SBD increases to 0.72 eV ( I-V)/0.88 eV (( C-V)). When the contact is annealed at 400℃, the SBH slightly decreases to 0.67 eV ( I-V)/0.80 eV (( C-V)). These results reveal that the optimum annealing temperature for Yb/p-In P SBD is 300℃. Cheung's functions are also employed to determine the series resistance of the Yb/p-In P SBD. Using Terman's method, the interface state density is estimated for Yb/p-In P SBD at different annealing temperatures. The XPS results reveal that the existence of phosphorous-rich surface after the annealing. The AES and XRD results showed that the formation of phosphide phases at the Yb/p-In P interface may be the reason for the increase of SBH after annealing at 300℃. The decrease in the BH after annealing at 400℃ may be due to the formation of indium phases at the interface. The overall surface morphology of the Yb Schottky contact is fairly smooth at elevated temperatures. [ABSTRACT FROM AUTHOR]

In this article, a detailed analysis of the wet-etching technique for AlGaN/GaN heterostructure using dry thermal oxidation followed by a wet alkali etching was performed. The experimental results show that the oxidation plays a key role in the wet-etching method and the etching depth is mainly determined by the oxidation temperature and time. The correlation of etching roughness with oxidation time and temperature was investigated. It is found that there exists a critical oxidation temperature in the oxidation process. Finally, a physical explanation of the oxidation procedure for AlGaN layer was given. [ABSTRACT FROM AUTHOR]

A 50-nm thick polycrystalline Si film was fabricated by the crystallization of anamorphous Si film using silicide-enhanced rapid thermal annealing (SERTA). The amorphous Si film was deposited on a 5-nm thick polycrystalline Si seed layer containing nickel silicide precipitates in grain boundary areas. With the help of the silicide precipitates, the RTA temperature decreased from 730 to 680°C and the grain size of the crystallized polycrystalline Si film increased to 1.4 - 2.2 μm. Few defects were found within the grains and the Ni concentration in the polycrystalline film decreased to 1 × 10 cm due to the very-thin seed layer that contained nickel silicide precipitates. As a result, the field-effect hole mobility in the p-channel poly-Si thin film transistors (TFTs), fabricated employing the polycrystalline Si film, was as high as 169 cm/V∙s at a drain voltage of V = −0.1 V; the subthreshold swing was as small as 0.24 V/decade. The minimum leakage current at V= 5V was 1.5 × 10 A with very good diode characteristics. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In this work, heavily doped ZnO thin films with carrier concentrations of 1.7 × 10-1.1 × 10 cm were prepared on glass substrates using direct current magnetron sputtering combined with rapid thermal annealing (RTA). The effects of RTA on the electrical transport properties of the thin films were investigated. Results showed that the resistivities of the thin films deposited at low temperatures were markedly improved due to the increased mobilities and/or carrier concentrations. Temperature-dependent Hall measurements and theoretical calculations suggested that the influence of grain boundary scattering was negligible for all the samples and the mobility was mainly determined by ionized impurity scattering. The influence of crystallographic defects on the mobility could be effectively reduced via RTA when the carrier concentration was above 4.0 × 10 cm, resulting in a mobility and resistivity close to the ionized impurity scattering theoretical estimation. The highest mobility of 46 cmV s at the resistivity of 2.8 × 10Ω cm and the lowest resistivity of 2.6 × 10Ω cm were achieved for the RTA-treated 1 wt.% Al-doped ZnO and 5 wt.% Ga-doped ZnO thin films, respectively. [ABSTRACT FROM AUTHOR]

We deposited SnS thin films on indium-tin-oxide (ITO) coated glass substrates using electrochemical deposition. The effect of rapid thermal annealing (RTA) on the microstructural evolution and optical properties of SnS thin films was investigated. The as-deposited films were composed of orthorhombic SnS and γ-SnS. With an increase in the RTA temperature, the γ-SnS phase disappeared and the uniformity of the SnS films improved. The optical band gap of the as-deposited films was 1.44 eV. Increasing the RTA temperature to 200°C led to an increase in the optical band gap to 1.7 eV. These phenomena might be due to the compositional variations in the SnS films and to the formation of the SnO oxide caused by post-growth thermal annealing. [ABSTRACT FROM AUTHOR]

Annealing conditions of CdTe layers grown on Si substrates by metalorganic vapor-phase epitaxy were studied. Typically, 3- μm-thick n-type (211) CdTe layers were annealed for 60 s in flowing hydrogen at atmospheric pressure by covering their surfaces with bulk CdTe wafers. At annealing temperatures above 700°C, improvement of crystal quality was confirmed from full-width at half-maximum values of double-crystal rocking-curve measurements and x-ray diffraction measurements. Photoluminescence measurements revealed no deterioration of electrical properties in the annealed n-CdTe layers. Furthermore, annealing at 900°C improved the performance of radiation detectors with structure of p-like CdTe/ n-CdTe/ n-Si substrate. [ABSTRACT FROM AUTHOR]

In this study, we demonstrate a high sensitivity of surface acoustic wave (SAW) ultraviolet (UV) sensor based on ZnO nanorods (NRs) grown on an aluminum nitride (AlN)/silicon (Si) layered structure. The one-dimensional ZnO NRs act as a high-UV sensing material due to their large surface-to-volume ratio. The fabrication of SAW UV sensor is entirely compatible with micro/nano electromechanical (M/NEMS) process with conventional lithography and synthesized ZnO NRs by hydrothermal method at low temperature. The rapid thermal annealing (RTA) process effectively improved the optical properties of ZnO NRs and the sensitivity of the SAW UV sensors. The resulting SAW UV sensors responded to various UV light intensities, and the RTA-processed samples showed high sensitivity. The SAW UV sensor after RTA treatment at 600 °C showed the highest sensitivity with a 130 kHz frequency shift at a UV light intensity of at 0.6 mW/cm, a 5-fold increase in sensitivity compare with as-grown sample. [ABSTRACT FROM AUTHOR]

A high-quality CoFeSi (CFS)/SiON/Si tunnel junction was fabricated, in which the SiON barrier layer was formed by radical oxynitridation of an Si(100) substrate and the CFS electrode was formed by silicidation of an Fe/Co/amorphous-Si multilayer deposited on the barrier layer. The ultrathin SiON barrier layer completely blocked diffusion of Co and Fe atoms into the Si substrate during rapid thermal annealing (RTA) for the silicidation. X-ray diffraction investigations clarified that the CFS film on the ultrathin SiON barrier layer exhibited a highly (110)-oriented texture structure and that the film had the L2 structure with a high degree of L2 order. High resolution cross-sectional transmission electron microscopy investigations revealed that the CFS/SiON interface was atomically flat and that the crystal lattice of the CFS film was directly grown on the SiON surface without degradation of the crystallinity at the interface. [ABSTRACT FROM AUTHOR]

An experimental study is reported concerning the formation of defects in nitrogen-doped dislocation-free silicon wafers under a multistage heat treatment to produce an internal getter, the first stage being rapid thermal annealing (RTA) under different conditions. The experiments are conducted on p-Si(100) wafers of diameter 200 mm with an oxygen content of (6−7) × 10 cm and a doping level of 1.6 × 10 cm, the resistivity being 10-12 ω cm. The processed wafers are examined by optical microscopy and transmission electron microscopy. With normal conditions of RTA (argon, 1250°C, 20 s), the process is found to be incapable of creating a defect-free subsurface layer of adequate thickness, though it is able to provide the desired system of defects in the bulk. The aim is achieved by changing to sequential RTA in oxygen and argon as the first stage. The reasons for the results are presented. [ABSTRACT FROM AUTHOR]

We studied the effects of rapid thermal annealing in different ambients on the structural, electrical and optical properties of the sol-gel derived ZnO thin films. All the films after annealing showed highly degree of (002) oriented in the X-ray diffractometry (XRD) patterns. The effects of annealing ambients on electrical properties of the films were studied. Carrier concentration, resistivity and mobility were found to be distinguished after annealed in different ambients. The sample with the lowest resistivity of 0.095 Ω·cm and the largest mobility of 105.1 cm/v·s was achieved after annealing in vacuum. XPS results indicated that more oxygen vacancies existed on the ZnO surface when annealed in vacuum than that in O. [ABSTRACT FROM AUTHOR]

Nanocrystalline ZnO thin films were prepared by the sol–gel method and annealed at 600 °C by conventional (CTA) and rapid thermal annealing (RTA) processes on fluorine-doped tin oxide (FTO)-coated glass substrates for application as the work electrode for a dye-sensitized solar cell (DSSC). ZnO films were crystallized using a conventional furnace and the proposed RTA process at annealing rates of 5 °C/min and 600 °C/min, respectively. The ZnO thin films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM) analyses. Based on the results, the ZnO thin films crystallized by the RTA process presented better crystallization than films crystallized in a conventional furnace. The ZnO films crystallized by RTA showed higher porosity and surface area than those prepared by CTA. The results show that the short-circuit photocurrent ( Jsc) and open-circuit voltage ( Voc) values increased from 4.38 mA/cm2 and 0.55 V for the DSSC with the CTA-derived ZnO films to 5.88 mA/cm2 and 0.61 V, respectively, for the DSSC containing the RTA-derived ZnO films. [ABSTRACT FROM AUTHOR]

Calcium copper titanium oxide (CaCu3Ti4O12, abbreviated to CCTO) films were deposited on Pt/Ti/SiO2/Si substrates at room temperature (RT) by radiofrequency magnetron sputtering. As-deposited CCTO films were treated by rapid thermal annealing (RTA) at various temperatures and in various atmospheres. X-ray diffraction patterns and scanning electron microscope (SEM) images demonstrated that the crystalline structures and surface morphologies of CCTO thin films were sensitive to the annealing temperature and ambient atmosphere. Polycrystalline CCTO films could be obtained when the annealing temperature was 700°C in air, and the grain size increased signifi- cantly with annealing in O2. The 0.8- μm CCTO thin film that was deposited at RT for 2 h and then annealed at 700°C in O2 exhibited a high dielectric constant ( ε′) of 410, a dielectric loss (tan δ) of 0.17 (at 10 kHz), and a leakage current density ( J) of 1.28 × 10−5 A/cm2 (at 25 kV/cm). [ABSTRACT FROM AUTHOR]

Dopant impurities were implanted at high dose and low energy (1015 cm-2, 0.5-2.2 keV) into double-side polished 200 mm diameter silicon wafers and electrically activated to form p-n junctions by 10 s anneals at temperatures of 1,025, 1,050, and 1,075°C by optical heating with tungsten incandescent lamps. Activation was studied for P, As, B, and BF2 species implanted on one wafer side and for P and BF2 implanted on both sides of the wafer. Measurements included electrical sheet resistance (Rs) and oxide film thickness. A heavily boron-doped wafer, which is optically opaque, was used as a hot shield to prevent direct exposure to lamp radiation on the adjacent side of the test wafer. Two wafers with opposing orientations with respect to the shield wafer were annealed for comparison of exposure to, or shielding from, direct lamp illumination. Differences in sheet resistance for the two wafer orientations ranged from 4% to 60%. n-Type dopants implanted in p-type wafers yielded higher Rs when the implanted surface was exposed to the lamps, as though the effective temperature had been reduced. p-Type dopants implanted in n-type wafers yielded lower Rs when the implanted surface was exposed to the lamps, as though the effective temperature had been increased. Effective temperature differences larger than 5°C, which were observed for the P, B, and BF2 implants, exceeded experimental uncertainty in temperature control. [ABSTRACT FROM AUTHOR]

Co synthesis silicides with good properties were prepared using MEVVA ion implantation with flux of 25–125 μA/cm2 to does of 5×1017/cm2. The structure of the silicides was investigated using X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM analysis shows that if the ion dose is greater than 2×1017/cm2, a continuous silicide layer will be formed. The sheet resistance of Co silicide decreases with an increase in ion flux and ion dose. The formation of silicides with CoSi and CoSi2 are identified by XRD analysis. After annealing, the sheet resistance decreases further. A continuous silicide layer with a width of 90–133 nm is formed. The optimal implantation condition is that the ion flux and dose are 50 μA/cm2 and 5×1017/cm2, respectively. The optimal annealing temperature and time are 900°C and 10 s, respectively. The ohmic contact for power microwave transistors is fabricated using Co ion implantation technique for the first time. The emitter contact resistance and noise of the transistors decrease markedly, the microwave property has been improved obviously. [ABSTRACT FROM AUTHOR]

Currently, a two-step anneal is employed for the formation of titanium selfaligned silicide (Salicide). The first rapid thermal anneal (RTA) step is to achieve the C49 TiSi2 phase, and the second step is to form the low resistivity C54 phase. However, as the width of the polysilicon line decreases, conversion of C49 to C54 TiSi2 becomes increasingly difficult. This is because the C49 to C54 phase transformation nucleates only at locations where three C49 grains intersect and the number of such intersection points is reduced as the gate length decreases. In this paper; we have investigated the effect of replacing the first RTA step by a laser anneal step on the formation of C54 TiSi2, with all other steps remaining unchanged. Our results show that the laser annealing process can form a fine-grained metastable C49 TiSi2 precursor layer. Upon subjecting this precursor layer to a second RTA step, C54 titanium disilicide can be obtained. [ABSTRACT FROM AUTHOR]

The effect of rapid thermal annealing (RTA) on Ni/Au contacts on P-type GaN was investigated in terms of surface morphology and diffusion depth of metallic species. Ni/Au contacts were evaporated on the P-type 0.5 µm thick top layer of a GaN P/N homojunction. Optical micrographs revealed that the contact morphology degrades when annealed above 800°C for 1 min. At the same time, both Ni and Au atoms strongly diffuse in the P-type layer and even can reach the junction for a 1 min long annealing at 900°C, therefore making the junction structure unoperable. This behavior was evidenced using the Auger voltage contrast (AVC) technique. [ABSTRACT FROM AUTHOR]

We report on the properties of a ferroelectric stack comprising (La0.5Sr0.5)CoO3 (LSCO)/Pb(Nb,Zr,Ti)O3 (PNZT)/LSCO deposited on 4 inch diameter platinized Si wafers (Pt/Ti/SiO2/Si). The LSCO electrodes were deposited at room temperature by pulsed laser ablation and the ferroelectric layer was deposited by the sol-gel technique. Rutherford backscattering was performed to confirm the uniformity in composition, thickness and stoichiometry of LSCO across the wafers. Conventional furnace or rapid thermal annealing was performed to crystallize the electrodes. The oxidation resistance of the conducting barrier layers, Pt/Ti, was found to be dependent on the annealing procedure adopted for the bottom electrode. In the case where the bottom LSCO was crystallized by rapid thermal annealing, Rutherford backscattering analysis and transmission electron microscopy studies revealed that there was no oxidation of the Pt/Ti conducting barrier composite. This is in contrast to the observations for in-situ deposition or conventional furnace annealing of the bottom electrode. The resistivity, coercive field and polarization of the ferroelectric stack were uniform across the 4-inch wafers. The ferroelectric capacitors showed no fatigue up to 1011 cycles and no imprint at 100°C. The ferroelectric properties were independent of the annealing procedure used for crystallizing the electrodes. [ABSTRACT FROM AUTHOR]

The residual electrically active defects in (4×10 cm (30KeV)+5×10 cm (130 KeV)) Si-implanted LEC undoped Si−GaAs activated by two-step rapid thermal annealing(RTA) LABELED AS 970°C(9S)+750°C(12S) have been investigated with deep level transient spectroscopy (DLTS). Two electron traps ET ( E -0.53eV, σ = 2.3 × 10 cm) and ET ( E − 0.81eV, σ = 9.7 × 10 cm) are detected. Furthermore the noticeable variations of trap's concentration and energy level in the forbidden gap with the depth profile of defects induced by ion implantation and RTA process have also been observed. The [As·V·As] and [V·As·V·As] are proposed to be the possible atomic configurations of ET and ET , respectively to explain their RTA behaviors. [ABSTRACT FROM AUTHOR]

The physical and electrical properties of BF implanted polysilicon films subjected to rapid thermal annealing (RTA) are presented. It is found that the out diffusion of F and its segregation at polysilicon/silicon oxide interface during RTA are the major causes of F anomalous migration. Fluorine bubbles were observed in BF implanted samples at doses of 1×10 and 5×10 cm after RTA. [ABSTRACT FROM AUTHOR]

The effect of rapid thermally nitrided titanium films contacting silicided (titanium disilicided) and nonsilicided junctions has been studied in the temperature range of 800 to 900°C. The rapid thermal nitridation of titanium films used as diffusion barriers between aluminum and silicon, has a major impact on shallow junction complementary metal oxide semiconductor technologies. During the process of rapid thermal nitridation, the dopants in the junctions undergo a redistribution and affect the electrical properties of shallow junction structures. This work focuses on using novel contact resistance structures to measure the variation in electrical parameters for rapid thermally nitrided titanium films annealed at different temperatures. The self-aligned silicide (salicide) junctions in this study were formed using rapid thermally annealed titanium films. Electrical contact resistance testers were used to measure the interface contact resistance between the salicide and silicon, as well as between the metal and the salicide. The results show that the interface contact resistance to the p diffused salicided junctions increases with rapid thermal nitridation of the additional titanium film, whereas the interface contact resistance to the n diffused salicided junction shows a decrease. Further, as a function of the rapid thermal annealing temperature (for fixed titanium thickness), the nonsalicided diffusions show an increase in the interface contact resistance. The boron profiles at the TiSi/Si interface obtained using secondary ion mass spectroscopy show an excellent qualitative agreement with the electrical results for each of the conditions discussed. The films were also characterized using Rutherford back-scattering spectrometry and transmission electron microscopy and the results show good agreement with the measured variation in electrical parameters. These results also show that as the anneal temperature is increased, the TiN thickness increases, further the change in the silicide/silicon interface position with the nitridation of the additional titanium layer was verified. [ABSTRACT FROM AUTHOR]

The properties of TiN/TiSi bilayer formed by rapid thermal annealing (RTA) in an NH ambient after the titanium film is deposited on the silicon substrate is investigated. It is found that the formation of TiN/TiSi bilayer depends on the RTA temperature and a competitive reaction for the TiN/TiSi bilayer occurs at 600°C. Both the TiN and TiSi layers represent titanium-rich films at 600°C anneal. The TiN layer has a stable structure at 700°C anneal while the TiSi layer has C and C phase. Both the TiN and TiSi layers have stable structures and stoichiometries at 800°C anneal. When the TiN/TiSi bilayer is formed, the redistribution of boron atoms within the TiSi layer gets active as the anneal temperature is increased. According to secondary ion mass spectroscopy analysis, boron atoms pile up within the TiN layer and at the TiSi−Si interface. The electrical properties for n and p contacts are investigated. The n contact resistance increases slightly with increasing annealing temperature but the p contact resistance decreases. The leakage current indicates degradation of the contact at high annealing temperature for both n and p junctions. [ABSTRACT FROM AUTHOR]

Temperature control and wafer-to-wafer reproducibility during momentary annealing via rapid thermal annealing is critical for TiSi Self-Aligned si LICIDE (SALICIDE) processing for deep submicron complementary metal oxide semiconductor. TiSi must undergo a transformation from the high resistivity C49 phase to the low resistivity C54 phase for applications where it is used as a gate conductor. A process modification to achieve improved wafer-to-wafer and within wafer temperature reproducibility is demonstrated. It has the additional benefit to the TiSi salicide process of enabling anneals of reduced duration, enhancing suicide transformation to the desired phase without leading to agglomeration. [ABSTRACT FROM AUTHOR]

The codiffusion of implanted boron and arsenic during rapid thermal annealing in a polysilicon/monocrystalline silicon system used for high speed bipolar integrated circuit technology has been investigated. Such a process allows a uniformly high concentration in the emitter regions. It induces a very shallow emitter-base junction depth for an n-p-n transistor. On the contrary, in p-n-p configuration, when the arsenic dose is lower than the boron dose, boron deeply penetrates the single-crystal silicon, causing problems for fabricating shallow junctions. The rapid thermal annealing-induced redistribution of arsenic and boron implanted at various implant doses in a 380 nm low-pressure chemical vapor deposition (LPCVD) polysilicon layer has been studied by secondary ion mass spectroscopy measurements. A strong lowering of the minority dopant diffusion in the polysilicon film is observed due to the high concentration of the other dopant. This effect is mainly related to grain boundary trap saturation while the electric field issued from dopant activation in the fastly recrystallized amorphous layer due to arsenic implantation in the upper region of the LPCVD film has a lesser effect. Transmission electron microscopy measurements show that recrystallization extends deeper than the amorphous layer, which is responsible for the increase of grain size. Sheet resistance measurements have been performed as an approach to the electrical behavior for these structures. [ABSTRACT FROM AUTHOR]

Superconducting Bi(Pb)-Sr-Ca-Cu-O thin films were successfully fabricated on MgO substrates by dc sputtering and rapid thermal annealing. No furnace annealing was used in the process. The superconducting thin films, deposited by dc sputtering for 8 hr and rapid thermally annealed at 845°C for 60 sec, showed a superconducting transition onset temperature of 110 K and a zero resistance transition temperature of 86 K. Highly oriented films with the c-axis normal to the substrate surface were obtained. To our knowledge, this is the first time that Bi(Pb)-Sr-Ca-Cu-O superconducting thin films have been fabricated using rapid thermal annealing. [ABSTRACT FROM AUTHOR]

Deep level traps are observed in silicon that has been implanted with high doses of arsenic and subsequently annealed by rapid thermal annealing. The doses studied create enough damage to form a surface amorphous layer. Annealing temperatures, implant fluence, and the presence of a surface amorphous layer contribute to the type of trap observed. These results show evidence for a clustering/declustering mechanism of arsenic in silicon during rapid thermal annealing. [ABSTRACT FROM AUTHOR]