Papers by Keyword: Substrate Temperature

Abstract: Aluminum oxide films were grown on (100) silicon wafers and glass substrates by pulsed dc reactive magnetron sputtering deposition. In this experiment, substrate temperatures were varied from room temperature to 500°C. Grazing-incidence X-ray diffraction (GIXRD) analysis revealed that the resulting films have amorphous structures. Field-emission scanning electron microscope (FESEM) was used to characterize the morphology of the films. The films’ optical properties were determined by UV-Vis spectroscopy. The results demonstrated that the deposition rate, the surface roughness and the transmittance spectra of the aluminum oxide films were strongly influenced by the substrate temperature. The deposition rate and the surface roughness of the films were higher at higher substrate temperatures. In the range between 100°C and 200°C, the transmittance spectra were found to be lower than those of the films deposited at other substrate temperatures. This was due to the sub-aluminum oxide condition in the films. The dependence of films’ optical properties on the substrate temperature might result from the change in chemical compositions during the sputtering process.

Abstract: La_0.9Sr_0.1Ga_0.8Mg_0.2O_3-δ (LSGM) electrolyte thin films were fabricated on La_0.7Sr_0.3Cr_0.5Mn_0.5O_2.75 (LSCM) porous anode substrates by Radio Frequency (RF) magnetron sputtering method. The compatibility between LSGM and LSCM was examined. Microstructures of LSGM thin films fabricated were observed by scanning electron microscope (SEM). The effect of substrate temperature on LSGM thin films was clarified by X-ray Diffraction (XRD). Deposition rate increases firstly at the range of 50°C~150°C, and then decreases at the range of 150°C ~300°C. After annealing, perovskite structure with the same growth orientation forms at different substrate temperature. Crystallite size decreases at first, to the minimum point at 150°C, then increases as substrate temperature rises.

Abstract: In this work the effect of substrate and vaporization temperatures on the structural parameters (sizes of coherent scattering region, values of strain), phase and chemical composition, surface morphology of Co films is revealed. Co films were deposited on Si (100) substrates by Metal-organic chemical vapor deposition using the diiminate complex Co (N’acN’ac)₂ as a precursor. The sizes of coherent scattering region, values of strain and phase composition of Co films were determined by the X-ray diffraction analysis. The chemical composition was identified by the Energy-dispersive X-ray spectroscopy. The surface morphology of Co films was investigated by scanning electron microscope. It is found that the variation of deposition conditions allows us widely to change structural parameters and chemical composition of Co films.

Abstract: Cu (In,Ga)Se₂ (CIGS) thin films were prepared by direct magnetron sputtering CIGS quaternary target at the substrate temperature varying from room temperature (RT) to 300 °C. The effects of substrate temperature on the structural and electrical properties of CIGS films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and Hall effect measurement. The CIGS thin films with a chalcopyrite structure were obtained between 100 and 300 °C and the crystallinity of films were enhanced with the increase of the substrate temperature from 100 to 300 °C. The film compositions were consisted with the target when the substrate temperatures were between RT and 200 °C, however, it deviated from the stoichiometry of the target when the substrate temperature was 300 °C. The CIGS films deposited at 200 °C had the higher carrier mobility of 3.522 cm²/Vs.

Abstract: HfO₂ films were sputter deposited under varying substrate temperatures (T_s) and their structural and morphological characteristics, optical properties were systematically studied by means of X-ray diffraction (XRD), atomic force microscope (AFM), and UV/VIS spectrophotometry. A statistical analysis based on multifractal formalism shows the uniformity of the height distribution increases as T_s is increased and the widths Δα of multifractal spetra are related to the average grain size D _(-111) as Δα ∼ [D_(-111)]^-0.83. The monoclinic HfO₂ is highly oriented along (-111) direction with increasing T_s. The Lattice expansion increases with diminishing HfO₂ crystalline size below 7 nm while maximum lattice expansion occurs with highly oriented monoclinic HfO₂ of crystalline size about 14.8 nm. The film growth process at T_s ≥ 200°C with surface diffusion energy of ∼ 0.29 eV is evident from the structural analysis of HfO₂ films.

Abstract: The uniform temperature flied of substrates is a key factor to deposit high-quality diamond films on milling tools by the hot filament chemical vapor deposition (HFCVD). In this study, a 3-D computational model is established to simulate the temperature distribution on the substrates. Thereafter, the influence of the rotational speed of worktable n and the water flux of water-cooled worktable Q are investigated. The simulation results show that the increasing of the rotational speed of worktable is suitable to grow homogeneous diamond films and gently decrease the even temperature of seals. What’s more, the deceasing of the water flux will significantly increase the overall temperature of seals.

Abstract: Indium tin oxide (ITO) films were deposited on glass substrates by magnetron sputtering. Properties of ITO films showed a dependence on substrate temperature. With an increasing in substrate temperature, the intensity of XRD peak increased and the grain size showed an evident increasing. The results show that increasing substrate temperature remarkably improves the characteristics of the films. The sheet resistance of 10 Ω/sq and the maximum optical transmittance of 90% in the visible range with optimized conditions can be achicved. The results of experiment demonstrate that high-quality films have been achieved by this technique.

Abstract: Zinc oxide (ZnO) films are prepared on n-Si substrates by means of radio frequency (RF) magnetron sputtering method. The influences of substrate temperature on the crystal orientation and crystalline structure of ZnO films are investigated by X-ray diffraction (XRD) and Raman spectroscopy. The surface morphologies are studied by scanning electron microscope (SEM). It is indicated that ZnO films with wurtzite structure were successfully prepared. When the substrate temperature reduced to 100°C, the wurtzite structure with highly preferred orientation along the (002) plane of the ZnO film is prepared and the elliptical shape particles distributed uniformly on the ZnO film surface. The higher substrate temperature can offer more kinetic energy for mobility of particle on the surface to achieve other crystalline growth, resulting in the highly c-axis-oriented crystalline structure is destroyed.

Abstract: Amorphous InAs films are deposited on substrates of quartz glass by RF magnetron sputtering technique in different gas ambient. We present a systematic study of the affects of the sputtering parameters on the chemical composition. Amorphous InAs (a-InAs) films have been achieved at higher working pressure when the substrate temperature and RF power are increased respectively. The films composition is controlled by transport phenomena of sputtered atoms from the target to the substrate and by substrate surface dynamics. We study how to improve the sputtering parameters in order to obtain stoichiometric a-InAs films.

Abstract: Different substrate temperature of CdZnTe films and one with Al-induced crystallization have been investigated by XRD, AFM and UV-spectrophotometry. It was shown that, as the substrate temperature varied from room temperature to 400 °C, improving the substrate temperature helps to enhance the grain size of CdZnTe film, and favours the preferential orientation (111). Moreover, Al-induced crystallization method can effectively reduce the crystallization temperature of the CdZnTe film so that the film can be for high-quality oriented crystallization in a lower temperature. In addition, Al-induced crystallization can make the surface roughness of the film at a small value that facilitates the later application of the film.