Influence Of Rapid Thermal Annealing Research Articles

Rapid thermal annealing treatment on WO3 thin films for energy efficient smart windows

Electrochromic devices (ECDs) based on tungsten trioxide (WO3) have garnered significant attention in the areas of smart windows, dynamic display, low-power displays, and in other advanced sectors. The electrochromic property of WO3 is primarily influenced by both electron conduction and ion diffusion processes. This research investigates on the influence of rapid thermal annealing (RTA) on the electrochromic performance of RF sputtered tungsten oxide thin films, which relies on ion diffusion process. RTA treated film showed a mixture of amorphous and crystalline (monoclinic), heterostructure phase. Structural, compositional, electrical, optical, morphological, and electrochromic studies were carried out using various techniques. Based on the electrochromic analysis, WO3 thin films, RTA treated at 300°C showed higher diffusion coefficient with larger optical modulation (ΔT) of 80 % due the formation of heterostructure with more oxygen vacancies. We hope that this research could propose the possibility for developing high-performance electrochromic smart windows.

Influence of Rapid Thermal Annealing on the Distribution of Nitrogen Atoms in GaAsN/GaAs

Influence of Rapid Thermal Annealing on the Distribution of Nitrogen Atoms in GaAsN/GaAs

Impact of rapid thermal annealing on structural and sensing properties of Ni–Ti sensitive films for extended-gate field-effect transistor pH sensors

In the present work, a facile Ni–Ti film deposited on n+-type Si substrate is introduced as a sensitive film for the development of a solid-state extended-gate field-effect transistor (EGFET) pH sensor. Influence of rapid thermal annealing (RTA) treatment (500–700 °C) on structural properties of the Ni–Ti sensitive films was extensively investigated. The film structures, surface morphologies, element profiles, film microstructures, and chemical compositions of the Ni–Ti sensitive films were characterized by a combination of X-ray diffraction, atomic force microscopy, secondary ion mass spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy, respectively. The structural features of the Ni–Ti sensitive films are most closely related to their sensing characteristics. The experimental results indicated that the Ni–Ti sensitive film annealed at the RTA temperature of 600 °C exhibited better sensing performances (a higher pH sensitivity of 71.01 mV/pH, a lower hysteresis voltage of 1 mV and a smaller drift rate of 0.15 mV/h) than other RTA temperatures. The proposed Ni–Ti sensitive film is expected to be effectively useful for various long-term pH sensor and biosensor applications, since it satisfies the typically required sensing performances such as sensitivity and stability.

Influence of Rapid Thermal Annealing on the Characteristics of Sn-Doped Ga2O3 Films Fabricated Using Plasma-Enhanced Atomic Layer Deposition

In this work, Sn-doped Ga2O3 films fabricated using plasma-enhanced atomic layer deposition were treated by rapid thermal annealing (RTA). The RTA influence on the chemical state, surface morphology, energy band alignment, and electrical properties of Sn-doped Ga2O3 films were thoroughly investigated. The results of X-ray photoelectron spectroscopy (XPS) demonstrated that Sn atoms were successfully doped into these films. Moreover, energy band alignments were obtained by the energy-loss peak of the O 1s spectrum and valence band spectra and thoroughly discussed. X-ray reflectivity (XRR) and atomic force microscope (AFM) measurements indicated that the Sn-doping level affects the interfacial microstructure and surface morphology. As the Sn content increases, the film thickness decreases while the roughness increases. Finally, the leakage current-voltage (I-V) characteristics proved that the Sn-doped Ga2O3 films have a large breakdown field. In I-V tests, all metal oxide semiconductor (MOS) capacitors exhibited a hard breakdown. This research demonstrates a method for manufacturing high-performance optoelectronic devices with desired properties.

Enhancing the sensing behavior of a reduced graphene magnetite-based plasmonic optical fiber sensor.

The D-shaped optical fiber is a base for the magnetite-based graphene nanocomposite (rGO/Fe3O4) for a Pb heavy metal sensing layer. The designed sensor was studied under the effects of rapid annealing, water circulation, and plasmonic tuning. Various annealing temperatures (100°C, 200°C, 300°C, and 400°C) were investigated. The effect of rapid thermal annealing (RTA) temperature on the transmission results were found at a short wavelength of 300 nm and a minimum point of ∼380nm. The bandgap energy was verified between 2.3 and 3.17 eV for 100°C and 400°C, respectively. The sensor results show modification toward a short wavelength by increasing the rapid annealing temperature. Compared with furnace methods, the transmittance shift of the plasmonic effect showed the best performance under the influence of RTA. RTA at 300°C and 400°C offered an acceptable degree of stability at the beginning (1-50 min). The best performance of the proposed sensor was improved by introducing a circulating liquid chamber into the initial design. The resonance shifts due to Pb ion concentration (5, 10, and 15 ppm) were studied for transmission and wavelength shifts. The sensor shift was enhanced by using a free space polarizer controller attached to the second design. The results give detection and sensing potential in the visible range at a possible remarkable response time. The figure of merit was 62.5 a.u., and the maximum sensitivity was 1 a.u./ppm by using a polarizer controller. This article presents the optical characterizations of plasmonic sensor-based rGO/Fe3O4 for detecting Pb ions and enhancing the resonance shift. RTA for composite material and water circulation associated with D-shaped optical fiber enhances response time and stability designed using a polarizer controller.

Improvement of Surface Defects in CdZnTe Crystals by Rapid Thermal Annealing

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.

Influence of annealing on luminescence and energy transfer in ZnO multilayer structure co-doped with Tb and Eu

The influence of rapid thermal annealing (RTA) on structural and optical properties of ZnO multilayer structures co-doped with Tb and Eu ions has been investigated by X-ray diffraction, Time-of-Fligth Secondary Ion Mass Spectrometry, Specular Infrared reflection, micro-Raman and photoluminescence (PL) methods. It is shown that incorporation of rare earth (RE) ions in ZnO host is accompanied by the formation of intrinsic defects in oxygen and zinc sub-lattices of ZnO. The appearance of intense Raman mode at 275 cm−1 is ascribed mainly to Eu ion incorporation on Zn site in ZnO matrix. The PL of RE ions localized in ZnO and other crystal phases is revealed. The effect of energy transfer from Tb3+ to Eu3+ ions in ZnO is identified. It is shown that the RTA improves crystal structure of ZnO host, i.e. stimulates the increase of coherent domain sizes and strain relaxation, as well as promotes the redistribution of RE ions across the structure. The effect of RTA on RE ion PL depends strongly on the annealing temperature. It is found that RTA at 500 °C promotes Eu incorporation into ZnO and the enhancement of Eu3+ PL due to energy transfer from Tb3+ to Eu3+, while RTA at 800 °C stimulates segregation of RE ions and the decrease of their PL.

Influence of Annealing on the Properties of Ge:Sb/Si(001) Layers with an Antimony Concentration Above Its Equilibrium Solubility in Germanium

The influence of rapid thermal annealing on the electrical and radiative properties of Ge:Sb/Si(001) epitaxial layers with an antimony concentration substantially higher than its equilibrium solubility in germanium is investigated. Local variations in the electrical and luminescence properties of n-Ge/Si(001) throughout the structure depth are investigated by means of the precise chemical etching of Ge. It is shown that a variation in the properties of such layers at relatively low (≤500°C) annealing temperatures (decrease in the electron concentration and photoluminescence intensity) occur in the absence of the noticeable diffusion-related redistribution of dopant atoms. Variations in the electrical and luminescence properties of Ge:Sb layers at relatively high (≥700°C) annealing temperatures are caused by the substantial redistribution of Sb due to its bulk diffusion and desorption from the surface. In particular, Sb diffusion leads to the formation of doped layers in initially undoped parts of the studied structures, which start to give a substantial contribution to the resulting conductivity of the structure and its photoluminescence signal.

Influence of rapid thermal annealing at varied temperatures on conductivity activation energy and structural properties of Si-doped β-Ga2O3 film grown by pulsed laser deposition

Si-doped β-Ga2O3 was generally activated by high-temperature annealing (over 600 °C) due to its strong bonding energy. Considering the electronic applications using β-Ga2O3 such as various power devices with low power consumption, it is strongly required to decrease the device process temperature including the impurity activation process. In this article, in order to decrease the impurity activation process temperature, we proposed the rapid thermal annealing (RTA) treatment to activate the Si atoms in the β-Ga2O3 films since RTA treatment can give the high thermal energy to specimen in a short time and investigated the influence of RTA treatment with various temperatures on conductivity activation energy, and structural properties of Si-doped β-Ga2O3 film. Si-doped β-Ga2O3 films were hetero-epitaxially grown on c-plane sapphire substrate by pulsed laser deposition method. Crystallinity, surface roughness, and electrical properties of specimens were investigated by changing the RTA temperatures. Crystallinity and surface roughness of Si-doped β-Ga2O3 films were not significantly influenced by RTA treatment at temperatures range of 100–700 °C. Conductivity activation energy of specimens with RTA treatment was about 50–100 meV and did not depend on RTA temperatures. As a result, even Si-doped β-Ga2O3 film with RTA treatment at 100 °C showed a relatively good conductivity. Based on the experimental results in this study, it can be said that RTA treatment is useful method to decrease the temperature of activation process for Si-doped β-Ga2O3 thin films without serious structural degradations.

Boosting highly transparent and conducting indium zinc oxide thin films through solution combustion synthesis: influence of rapid thermal annealing

IZO thin films with In:Zn ratio of 7:3 and 3:7 were prepared by solution combustion synthesis of metal oxide nitrates and influence of post-deposition rapid thermal annealing (RTA) was studied. Individual 0.5 M indium and zinc oxide precursor solutions were mixed in 7:3 and 3:7 compositions. XRD analysis showed IZO 7:3 composition has only cubic bixbyite In2O3 structure while IZO 3:7 composition showed both hexagonal wurtzite ZnO and cubic bixbyite In2O3 phases. SEM and AFM analysis showed low roughness for IZO 7:3, rms < 2 nm whereas for IZO 3:7 composition surface roughness was >22 nm due to phase segregation. UV/ViS/NIR analysis showed transparency range desirable of transparent conductors for both compositions. Post-deposition RTA treatment resulted in high conductivity single phase IZO 7:3 films. Segregation of phases enhanced carrier scattering resulting in decreased mobility for IZO 3:7 films. Best performing IZO films demonstrated low resistivity 7.66 × 10−3 Ohm cm and high carrier concentration 5.09 × 1019/cm3 after 10 min RTA at 600 °C. These results demonstrate combustion synthesis and RTA are successful for development of films with enhanced conductivity and transparency through low cost vacuum-free synthesis reducing indium content for applications in photovoltaic devices, flat panel displays and transparent electronics.

Sensing and Impedance Characteristics of YbTaO4 Sensing Membranes

In this study we developed ytterbium tantalum oxide (YbTaO4) sensing membranes for use in electrolyte–insulator–semiconductor (EIS) pH sensors. The influence of rapid thermal annealing (RTA) treatment on the sensing and impedance properties of the YbTaO4 sensing membranes deposited through reactive co-sputtering onto Si substrates was explored. X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy revealed the structural, morphological, and chemical features, respectively, of these YbTaO4 films annealed at 700, 800 and 900 °C. The YbTaO4 EIS device annealed at the 800 °C exhibited a super-Nernstian response of 71.17 mV/pH within the pH range of 2–12. It also showed the lowest hysteresis voltage ( < 1 mV) and the lowest drift rate (0.22 mV/h) among the tested systems. Presumably, the optimal annealing temperature improved the stoichiometry of YbTaO4 film and increased its (−131)-oriented nanograin size. Moreover, the impedance properties of YbTaO4 EIS sensors were investigated by using the capacitance–voltage method. The resistance and capacitance of YbTaO4 sensing films annealed at three various temperatures were evaluated by using different frequency ranges in accumulation, depletion, and inversion regions. The semicircle diameter of the YbTaO4 EIS sensor became smaller, due to a gradual decrease in the bulk resistance of the EIS device, as the RTA temperature was increased.

The striking influence of rapid thermal annealing on InGaAsP grown by MBE: material and photovoltaic device

Rapid thermal annealing (RTA) has been performed on InGaAsP solar cells with the bandgap energy of 1eV grown by molecular beam epitaxy. With the employment of RTA under an optimized condition, the open voltage was increased from 0.45 to 0.5V and the photoelectric conversion efficiency was increased from 11.87–13.2%, respectively, which was attributed to the crystal quality improvement of p-type InGaAsP and therefore a reduced recombination current inside depletion region. The integral photoluminescence (PL) intensity of p-type InGaAsP increased to 166 times after annealing at 800°C and its PL decay time increased by one order of magnitude. While the changes of nominally undoped and n-doped InGaAsP were negligible. The different behaviors of the effect of RTA on InGaAsP of different doping types were attributed to the highly mobile “activator” – beryllium (Be) atom in p-type InGaAsP.

Improved Silicon Surface Passivation of APCVD Al2O3 by Rapid Thermal Annealing

Short-duration post-deposition thermal treatments at temperatures above those normally used for annealing activation have the potential to further improve the already excellent passivation of crystalline silicon (c-Si) achieved by Al2O3, but have so far received little attention. In this work we investigate the influence of rapid thermal annealing (RTA) on the surface passivation of c-Si by Al2O3 deposited by atmospheric pressure chemical vapour deposition (APCVD) as a function of RTA peak temperature between 500 and 900°C, and for Al2O3 deposition temperatures between 325 and 440°C. The saturation current density J0 of undiffused p-type surfaces is observed either to increase or decrease following RTA depending on the Al2O3 deposition temperature and the RTA peak temperature. The optimum deposition temperature depends on the post-deposition thermal processing to be applied. Films deposited at lower temperatures provide worse passivation after low temperature heat treatment, but maintain this passivation better at higher RTA temperatures. An exceptionally low J0 of 7 fA cm−2, due to the combination of a very low interface state density Dit and unusually high negative fixed charge density Qf, is achieved by the use of a short 500–550°C RTA combined with optimised deposition conditions.

Effect of Rapid Thermal Annealing on the Photoluminescence from Si Nanocrystal Decorated Si Nanowires Array Grown by a Metal Assisted Chemical Etching Method

In this report, the micron-long Si nanowires (NWs) array is grown by a metal assisted chemical etching (MACE) process using Ag as the noble metal catalyst in HF/H2O2 solution. These Si NWs are decorated with arbitrary shaped ultrasmall Si nanocrystals (NCs) due to the side wall etching of the Si NWs. The MACE grown samples exhibit strong PL emission in the visible region and quantum confinement (QC) effect of photon in the Si NCs is believed to be the dominant mechanism behind PL. We have investigated the influence of rapid thermal annealing with different annealing environments on the optical properties (such as PL, Raman and reflectivity) of the Si NCs decorated Si NWs samples to gain better insight into the QC effect. The effect of laser excitation power on the PL properties of the as-grown Si NCs/NWs sample are also inspected in this report for further confirmation of QC effect behind the PL emission profile.

Influence of annealing temperature on the electrical, structural and surface morphology properties of Au/Cr Schottky contacts on n-type InP

The influence of rapid thermal annealing on the electrical and structural properties of Au/Cr/n-InP Schottky diode havebeen investigated by the current-voltage (I-V), capacitance-voltage (C-V), auger electron spectroscopy (AES) and X-raydiffraction (XRD) measurements. The Schottky barrier height (SBH) and ideality factor (n) of the as-deposited Au/Cr/n-InPSchottky diode are 0.51 eV (I-V)/0.64 eV (C-V) and 1.81, respectively. When the contact is annealed at 200 oC in N2atmosphere for 1min, a maximum SBH (0.71 eV (I-V)/0.81 eV (C-V)) and low ideality factor (1.15) are achieved for theAu/Cr/n-InP Schottky diode. However, after annealing at 300 oC, the SBH slightly decreases to 0.58 eV (I-V)/0.69 eV (CV),and ideality factor increases to 1.45, respectively. The SBHs obtained from the Norde and Cheung’s methods areclosely matched with those obtained from the I-V method. Results show that the optimum annealing temperature for theAu/Cr/n-InP Schottky diode is 200 °C. Further, the discrepancy between SBHs calculated from I-V and C-V methods isalso discussed. Moreover, the energy distribution of interface state density is estimated from forward bias I-Vcharacteristics at different annealing temperatures. AES and XRD studies reveal that the formation of indium (In) phasesat Au/Cr and InP interface may be the cause for the increase in SBH after annealing at 200 oC. The AFM results show thatthe overall surface morphology of Au/Cr Schottky contacts is considerably smooth at elevated tempratures.

In-situ heavily p-type doping of over 1020 cm−3 in semiconducting BaSi2 thin films for solar cells applications

B-doped p-BaSi2 layer growth by molecular beam epitaxy and the influence of rapid thermal annealing (RTA) on hole concentrations were presented. The hole concentration was controlled in the range between 1017 and 1020 cm−3 at room temperature by changing the temperature of the B Knudsen cell crucible. The acceptor level of the B atoms was estimated to be approximately 23 meV. High hole concentrations exceeding 1 × 1020 cm−3 were achieved via dopant activation using RTA at 800 °C in Ar. The activation efficiency was increased up to 10%.

Influence of rapid thermal annealing on the process of aluminum induced crystallization of amorphous Si

The effects of annealing methods on the crystallization process and microstructure of polycrystalline silicon (poly-Si) films obtained by aluminum-induced crystallization (AIC) of amorphous Si (a-Si) films were comparatively investigated. Glass/Al/a-Si structures were annealed by rapid thermal annealing (RTA) and conventional furnace at 500 °C for different times in Ar. As compared to furnace annealing, AIC of a-Si films annealed by RTA possesses a shorter period of nucleation time, a higher nucleation density and reduces the process time to form continuous poly-Si films. It is revealed that the continuous Si films obtained by both RTA and conventional furnace annealing are polycrystalline in nature, exhibiting good microstructures with Raman peaks at 518 cm−1 and full-width at half-maximums of 6.43–6.48 cm−1.

Influence of Rapid Thermal Annealing on the Structure and Magnetic Properties of CoFe2O4 Films Prepared by Sol-Gel Method

CoFe2O4 thin films were prepared on the Si (001) substrates using the sol-gel method. In this study, the effects of annealing temperature, annealing time and annealing atmosphere on the structure and magnetic properties of CoFe2O4 films have been examined. X-ray diffraction analysis revealed that the films formed single spinel structures when the annealing temperature was above 450°C. The crystallization of the CFO thin films increased as the annealing temperature increased. Atomic force microscopy analysis showed that the film grain size increased with annealing temperature and that there was a single domain structure of critical size at 650°C. Vibrating sample magnetometer measurements showed that the saturation magnetization (Ms) reached a maximum and that the coercivity (Hc) varied with annealing conditions. When the CFO film was annealed at 650°C and 40 seconds, the ratio of O2:Ar was 1:1. The values for Ms and Hc had a maximum of 47.6 Am2.Kg−1 and a minimum of 86.8 KA.m−1, respectively.

Influence of rapid thermal annealing on structure and interfacial characteristic of ZnO thin films

Highly C‐axis oriented ZnO thin film was manufactured by radio‐frequency magnetron sputtering technique on Si (111) substrate. The main objective was to study the influence of rapid thermal annealing (RTA) temperature on the structure and interfacial characteristic of ZnO thin films. X‐ray diffraction results showed that the ZnO thin films annealed at 600 °C by RTA technique had a perfect C‐axis preferred orientation compared to the other ZnO thin films, and the full width at half maximum of ZnO (002) rocking curve measurements indicted that the RTA‐annealed ZnO thin films possessed better crystal structure. Atom force microscopy displayed that the grain size of RTA‐annealed ZnO thin films was fine and uniform compared with the as‐deposited ZnO thin films, although the grains grew in RTA process and the root meant square roughness was smaller than that of as‐deposited films. High‐resolution transmission electron microscopy showed that there was an obvious amorphous layer between ZnO thin films and Si substrate, but the RTA‐annealed ZnO thin films exhibited larger and denser columnar structure and a preferred orientation with highly c axis perpendicular to the amorphous layer. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Effects of Rapid Thermal Annealing on Structural, Luminescent, and Electrical Properties of Al-Doped ZnO Films Grown by Atomic Layer Deposition

The influence of rapid thermal annealing on structural, luminescent, and electrical properties of Al-doped ZnO film grown by atomic layer deposition is investigated. The (100) diffraction peaks show a systematic shift to higher 2θ values for the samples annealed in the temperatures of 400–700°C. The photoluminescence spectra reveal that the UV emission intensity slightly decreases as the annealing temperature increases up to 600°C and then increases significantly after the film is annealed in the temperature range of 700 ∼ 800°C. In addition, the resistivity of the film increases gradually with elevated annealing temperature, which is attributed to the decrease of the carrier concentration and mobility.