Effect Of Rapid Thermal Annealing Research Articles

Effect of rapid thermal annealing on nanocrystalline TiO2 thin films synthesized by swift heavy ion irradiation

Irradiation by swift heavy ions (SHI) is unique tool to synthesize nanocrystalline thin films. We have reported transformation of 100nm thick amorphous films into nanocrystalline film due to irradiation by 100MeV Ag ion beam. Oblate shaped nanoparticles having anatase phase of TiO2 were formed on the surface of the irradiated films. In the present investigation, these films are annealed at 350°C for 2min in oxygen atmosphere by Rapid Thermal Annealing (RTA) method. During RTA processing, the temperature rises abruptly and this thermal instability is expected to alter surface morphology, structural and optical properties of nanocrystalline TiO2 thin films. Thus in the present work, effect of RTA on SHI induced nanocrystalline thin films of TiO2 is studied. The effect of RTA processing on the shape and size of TiO2 nanoparticles is studied by Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Glancing Angle X-ray Diffraction (GAXRD) studies are carried to investigate structural changes induced by RTA processing. Optical characterization is carried out by UV–vis spectroscopy and photoluminescence (PL) spectroscopy. The changes observed in structural and optical properties of nanocrystalline TiO2 thin films after RTA processing are attributed to the annihilation of SHI induced defects.

Effects of thermal annealing treatment on the optical and the electrical properties of GaN films grown on Si substrates

The effects of rapid thermal annealing on the optical and the electrical properties in GaN epilayers grown on Si substrates were investigated by using cathodoluminescence (CL) and Hall effect measurements. From the two-dimensional CL image measurements, the distribution of defects embedded in the films was investigated before and after rapid thermal annealing. The penetration depth dependence of the CL spectrum demonstrated that the defect density become large in the deeper region away from the GaN surface.

The effects of annealing temperature on characteristics of UBMS sputtered CNx films for protective coatings

The carbon nitride (CNx) films have been prepared by unbalanced magnetron sputtering (UBMS) at room temperature. The deposited CNx films have been post-annealed at temperatures ranging from 300°C to 700°C in increments of 200°C using rapid thermal annealing (RTA) equipment in vacuum ambient. We investigated the effects of rapid thermal annealing on the structural, surface, and physical properties of CNx films for application of protective coatings. As the result, the increasing annealing temperature led to a decline in physical properties of CNx films such as hardness, elastic modulus, adhesion, frication coefficient, and surface roughness, however it is attributed to the improvement of the residual stress in the film. These results are related to the ordering of sp2 bonded clustering and the increase of disordered graphite domain by the desorption of N contents in the films, Specially, high annealing temperature over 700°C is attributed to the graphitization of film.

Rapid thermal annealing treatment of ZnO: Al films for photovoltaic applications

We investigated the effect of rapid thermal annealing (RTA) on ZnO: Al (AZO) films prepared at different substrate temperature, the results revealed that the resistivity decreased while crystallinity drastically improved after post annealing treatment. In addition, the amorphous/crystalline silicon heterojunction solar cell was fabricated with AZO films as transparent conductive oxide films. The conversion efficiency of solar cell enhanced significantly after post RTA treatment at 500°C for 5min, which due to the improvements of crystallinity, conductivity and transmission of AZO films. The results suggested that RTA treatment was an effective approach to improve the conversion efficiency of heterojunction solar cell.

Effect of Rapid Thermal Annealing on the Electrical, Optical and Structural Properties of ZnO-Doped In<SUB>2</SUB>O<SUB>3</SUB> Films Grown by Linear Facing Target Sputtering

We investigated the effect of rapid thermal annealing on the electrical, optical, and structural properties of ZnO-doped In2O3 (ZIO) films grown at different Ar/O2 flow ratios (15/0 and 15/1 sccm) by using linear facing target sputtering. It was found that the ZIO films grown at different Ar/O2, flow ratios showed different electrical and optical behavior with increasing rapid thermal annealing temperature. Synchrotron X-ray scattering examination showed that the different electrical and optical properties of the ZIO films could be attributed to the difference in preferred orientation with an increase in rapid thermal annealing temperature.

Inhibition of emission wavelength blueshift in annealed InAs/GaAs quantum dot stacks: an important observation for their potential application in photovoltaic devices

We have investigated the effect of post growth rapid thermal annealing on self-assembled InAs/GaAs multilayer QDs (MQD) overgrown with a combination barrier of InAlGaAs and GaAs for their possible use in photovoltaic device application. The samples were characterized by transmission electron microscopy and photoluminescence measurements. We noticed a thermally induced material interdiffusion between the QDs and the wetting layer in the MQD sample up to a certain annealing temperature. The QD heterostructure exhibited a thermal stability in the emission peak wavelength on annealing up to 700 ∘C temperature. A phenomenological model has been proposed for this stability of the emission peak. The model considers the effect of the strain field, propagating from the underlying QD layer to the upper layers of the multilayer QD and the effect of indium atom gradient in the combination barrier layer due to the presence of a quaternary InAlGaAs layer.

Schottky Barrier Parameters and Interfacial Reactions of Rapidly Annealed Au/Cu Bilayer Metal Scheme on N-type InP

The influence of rapid thermal annealing effect on the electrical and structural properties of Au/Cu Schottky contacts on n-InP has been investigated by the current-voltage (I-V), capacitance-voltage (C-V), auger electron spectroscopy (AES) and the X-ray diffraction (XRD) techniques. As-deposited sample has a barrier height of 0.64 eV (I- V), 0.76 eV (C-V) which increases to 0.82 eV (I-V), 1.04 eV (C-V) after annealing at 400°C for 1min in nitrogen ambient. However, the barrier height decreases to 0.75 eV (I-V), 0.88 eV (C-V) after annealing at 600°C for 1min. Norde method is also employed to calculate the barrier heights of Au/Cu Schottky rectifiers and the values are 0.66 eV for as-deposited, 0.83 eV for 400°C and 0.76 eV for 600°C annealed contacts. These values are in good agreement with the values obtained from I-V method. From the above observations, it is clear that the Schottky barrier height increases with annealing temperatures up to 400°C. Thus, the optimum annealing temperature for the Au/Cu Schottky contact is 400 o C. Based on the AES and XRD results, the formation of indium phases at the Au/Cu/n-InP interface may be responsible for the increase in the barrier height for the contact annealed at 400°C and a corresponding decrease in leakage current. The decrease in the barrier height after annealing at 500 o C may be due to the formation of Cu-P and Au-P interfacial compounds at the interface. The AFM results showed that the surface morphology of Au/Cu Schottky contact is fairly smooth even after annealing at 500°C.

Effect of Rapid Thermal Annealing Ambient on Photoluminescence of ZnO Films

The effects of rapid thermal annealing (RTA) ambient on photoluminescence (PL) of sputtered ZnO films are investigated. The RTA at 800°C under either oxygen (O2) or argon (Ar) ambient can remarkably enhance the PL of the ZnO films due to the improved crystallinities of the ZnO films. It is somewhat unexpected that the ZnO film which received the RTA under O2 ambient exhibits weaker near-band-edge (NBE) PL than that which received the RTA under Ar ambient. It is supposed that a certain amount of negatively charged oxygen species exist on the surface of the ZnO film that received the RTA under O2 ambient, leading to a build-in electric field. This in turn reduces the recombination probability of photo-generated electrons and holes, resulting in the suppressed NBE PL.

Inkjet-Printing of Antimony-Doped Tin Oxide (ATO) Films for Transparent Conducting Electrodes

Antimony-doped Tin oxide (ATO) films have been prepared by inkjet-printing method using ATO nanoparticle inks. The electrical and optical properties of the ATO films were investigated in order to understand the effects of rapid thermal annealing (RTA) temperatures. The decrease in the sheet resistance and resistivity of the inkjet-printed ATO films was observed as the annealing temperature increased. The film annealed at 700 degrees C showed the sheet resistance of 1.7 x 10(3) Omega/sq with the film thickness of 350 nm. The optical transmittance of the films remained constant regardless of their annealing temperatures. In order to further reduce the sheet resistance of the films as well as the annealing temperature, Ag-grid was printed in between two layers of inkjet-printed ATO. With 1.5 mm Ag line spacing, the Ag-grid embedded ATO film showed the sheet resistance of 25.6 Omega/sq after RTA at 300 degrees C.

Effect of the annealing treatments on the electroluminescence efficiency of SiO2 layers doped with Si and Er

We studied the effect of rapid thermal processing and furnace annealing on the transport properties and electroluminescence (EL) of SiO2 layers doped with Si and Er ions. The results show that for the same annealing temperature, furnace annealing decreases the electrical conductivity and increases the probability of impact excitation, which leads to an improved external quantum efficiency. Correlations between predictions from phenomenological transport models, annealing regimes and erbium EL are observed and discussed.

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.

Crystal structure, microstructure and magnetic properties of SmCo-based films treated by different annealing methods

Effect of conventional thermal annealing (CTA) and rapid recurrent thermal annealing (RRTA) processes on crystal structure, microstructure, and magnetic properties of the SmCo-based films were investigated. The results indicated that the CTA-treated films exhibited poor permanent magnetic properties, and a low intrinsic coercivity of 72.8 kA/m was observed. Wide hysteresis loop was obtained for the RRTA-treated films, providing better permanent magnetic properties. The intrinsic coercivity reached 312.0 kA/m. According to the X-ray diffraction (XRD) and atomic force microscopy (AFM) results, the magnetic properties of the CTA-treated films and RRTA-treated films were found to be correlated with the crystal structure and microstructure, which were strongly determined by the annealing treatment. CTA treatment led to poor crystallization effects for the films, and a rough surface (RMS=3.47 nm and P-V=35.42 nm) and large grain size of 92.7 nm were observed correspondingly. However, the RRTA treatment exhibited great contributions on the crystallization of the films, which is accountable for the smooth surface (RMS=2.047 nm and P-V=16.43 nm) and fine grain size of 60.8 nm.

Effects of Growth Conditions on Structure and Dielectric Properties of Bismuth-Magnesium Niobate Thin Films

The Bi1.5MgNb1.5O7 (BMN) thin films were prepared on platinum coated sapphire by rf magnetron sputtering deposition. Effects of substrate temperature, sputtering ambient and post rapid thermal annealing on structure, morphologies, and dielectric properties of films were investigated. Thin films have cubic pyrochlore structure when substrate temperature at 650°C or higher. Corresponding to tunable dielectric properties of bismuth based cubic pyrochlore thin films, voltage tunability of Bi1.5MgNb1.5O7 thin films increases with substrate temperature. Bi1.5MgNb1.5O7 thin films exhibit low dielectric loss of ∼ 0.0018–0.004. A brief discussion is given on the enhanced tunability of Bi1.5MgNb1.5O7 thin films. The relatively high tunability and low dielectric loss suggest that Bi1.5MgNb1.5O7 thin films have potential application for tunable capacitor applications.

Effect of rapid thermal annealing on the luminescence of self-assembled InAs quantum dots embedded in GaAs-based photonic crystal nanocavities

Postgrowth rapid thermal annealing (RTA) was used to modify the optical properties of self-assembled InAs quantum dots (QDs) embedded in a photonic crystal nanocavity. Compared with the reference QDs in the unpatterned regions, it was found that the effect of RTA on the luminescence blueshift of QDs embedded in the nanocavities is similar to that from the unpatterned regions. However, InAs QDs in nanocavities exhibit an anomalous variation of luminescent linewidth during the course of RTA. This could be attributed to the deterioration of InAs QDs at the edge of photonic crystal air holes at high annealing temperatures. The stable position of cavity modes during the RTA temperatures shows the RTA technique could be applied to tune the spectral coupling of QDs/cavities when the QD spectra are on the red side of a cavity mode.

Effects of rapid thermal annealing on structural, magnetic and optical properties of Ni-doped ZnO thin films

XPS depth profiles were used to investigate the effects of rapid thermal annealing under varying conditions on the structural, magnetic and optical properties of Ni-doped ZnO thin films. Oxidization of metallic Ni from its metallic state to two-valence oxidation state occurred in the film annealed in air at 600°C, while reduction of Ni2+ from its two-valence oxidation state to metallic state occurred in the film annealed in Ar at 600 and 800°C. In addition, there appeared to be significant diffusion of Ni from the bottom to the top surface of the film during annealing in Ar at 800°C. Both as-deposited and annealed thin films displayed obvious room temperature ferromagnetism (RTFM) which was from metallic Ni, Ni2+ or both with two distinct mechanisms. Furthermore, a significant improvement in saturation magnetization (Ms) in the films was observed after annealing in air (Ms=0.036μB/Ni) or Ar (Ms=0.033μB/Ni) at 600°C compared to that in as-deposited film (Ms=0.017μB/Ni). An even higher Ms value was observed in the film annealed in Ar at 800°C (Ms=0.055μB/Ni) compared to that at 600°C mainly due to the diffusion of Ni. The ultraviolet emission of the Ni-doped ZnO thin film was restored during annealing in Ar at 800°C, which was also attributed to the diffusion of Ni.

Effect of rapid thermal annealing on properties of thermally evaporated nanostructured CdTe thin film treated with CdCl2

The effects of rapid thermal annealing on properties of crystalline nanostructured CdTe films treated with CdCl2 and prepared by vacuum evaporation are described. X-ray diffraction confirmed the crystalline nature of post-treated films with high preferential orientation around 23.7°, corresponding to a (111) diffracted plane of cubic phase. Optical band gap of CdTe films increased from 1.4eV to 1.48eV after annealing at 500°C for 90s. Atomic force microscopy of annealed films revealed an increase in root mean square roughness and grain size with increased annealing time. Electrical measurements of as-grown and annealed films are consistent with p-type; film resistivity has decreased significantly with increased annealing time.

Influence of annealing on structural and electrical properties of double metal structure Ru/Cu contacts on n‐type InP

AbstractIn this article, we have investigated the effects of rapid thermal annealing on the electrical and structural properties of Ru/Cu Schottky contacts on n‐InP by current density–voltage (J–V), capacitance–voltage (C–V), Secondary ion mass spectrometer (SIMS) and X‐ray diffraction (XRD) measurements. The Schottky barrier height (SBH) of the as‐deposited Ru/Cu Schottky contact is found to be 0.65 eV (I–V) and 0.84 eV (C–V), respectively. The obtained barrier height values 0.81 eV (I–V), 0.95 eV (C–V) at 100 °C, 0.85 eV (I–V), 1.02 eV (C–V) at 200 °C, 0.80 eV (I–V), 0.90 eV (C–V) at 300 °C and 0.75 eV (I–V), 0.88 eV (C–V) at 400 °C. It is observed that the SBH increases with annealing temperature up to 200 °C. Further, increase in the annealing temperature up to 400 °C, SBH decreases compared to the one at 200 °C annealed samples. Norde method is also used to calculate the barrier height of Ru/Cu Schottky contact. Based on the above results, the optimum annealing temperature for the Ru/Cu Schottky contact is 200 °C. According to SIMS and XRD results, the formation of indium phases at the interface may be the reason for the increase of barrier height after annealing at 200 °C. The AFM results showed that the overall surface morphology of Ru/Cu Schottky contact is fairly smooth even after annealing at 400 °C.

Effects of Thickness Effect and Rapid Thermal Annealing on pH Sensing Characteristics of Thin HfO2Films Formed by Atomic Layer Deposition

Effects of Thickness Effect and Rapid Thermal Annealing on pH Sensing Characteristics of Thin HfO₂Films Formed by Atomic Layer Deposition

Effects of Thickness Effect and Rapid Thermal Annealing on pH Sensing Characteristics of Thin HfO2 Films Formed by Atomic Layer Deposition

In this article, thin hafnium oxide (HfO2) films deposited by atomic layer deposition (ALD) were investigated as a sensing layer on an electrolyte–insulator–semiconductor (EIS) structure for pH sensor applications. Compared with sputtering, ALD provides the possibility of shrinking the thickness of the HfO2 sensing layer down to 3.5 nm with a low drift coefficient (<0.2 mV/h). To increase the pH response, an additional rapid thermal annealing was performed on a 3.5-nm-thick ALD-HfO2 film. After annealing at 900 °C, the pH sensitivity could be effectively increased to that near the Nernstian response (59.6 mV/pH), and the drift coefficient (<1 mV/h) and hysteresis width (4.26 mV) are still sufficient. On the basis of the results of atomic force microscopy (AFM) analysis, the increase in surface roughness is possibly the reason for the increase in pH response after annealing. For compatibility with advanced complementary metal–oxide–semiconductor (CMOS) technology, the thin ALD-HfO2 film is a promising candidate for pH sensor fabrications.

Interfacial Reaction and Electrical Properties of HfO2 Film Gate Dielectric Prepared by Pulsed Laser Deposition in Nitrogen: Role of Rapid Thermal Annealing and Gate Electrode

The high-k dielectric HfO(2) thin films were deposited by pulsed laser deposition in nitrogen atmosphere. Rapid thermal annealing effect on film surface roughness, structure and electrical properties of HfO(2) film was investigated. The mechanism of interfacial reaction and the annealing atmosphere effect on the interfacial layer thickness were discussed. The sample annealed in nitrogen shows an amorphous dominated structure and the lowest leakage current density. Capacitors with high-k HfO(2) film as gate dielectric were fabricated, using Pt, Au, and Ti as the top gate electrode whereas Pt constitutes the bottom side electrode. At the gate injection case, the Pt- and Au-gated metal oxide semiconductor devices present a lower leakage current than that of the Ti-gated device, as well as similar leakage current conduction mechanism and interfacial properties at the metal/HfO(2) interface, because of their close work function and chemical properties.