Influence of substrate temperature on the materials properties of reactive DC magnetron sputtered Ti/TiN multilayered thin films

Ti/TiN multilayers were deposited by DC reactive magnetron sputtering method using a titanium target and an Ar-N₂ mixture discharge gas. XRD technique was employed to study the structure of the coatings and to observe the variations of structural parameters with substrate temperatures. An increase in grain size with increase of substrate temperature was observed. The components of Ti 2p doublet, related to TiN, TiON and TiO₂, were observed in the core-level spectra of the deposited multilayer films from XPS analysis. A microhardness value of 25.5 GPa was observed for Ti/TiN multilayers prepared at 400 °C. Electrical properties were found to depend on substrate temperature.     

Effect of tantalum addition on microstructure and optical properties of TiN thin films

Titanium nitride thin films were deposited by direct current magnetron sputtering with various tantalum (Ta) concentrations (2, 4 and 8 at.%). The films were characterized using UV/VIS spectrophotometer. Atomic force microscopy (AFM), high resolution transmission electron microscope (HRTEM) were used to observe the microstructure and X-ray photoelectron spectroscopy was used to investigate the core level and the valence band of the films. It was found that the film with 2 at.% Ta is more reflective in the infrared range and more transparent in the visible region (selective behavior). The AFM showed smooth nanostructured surface for the film without Ta addition. It was found that the films with 2 at.% Ta presented relatively coarser grains with larger roughness and the reflectance are not controlled by the surface morphology. Also, this film presented higher electrical conductivity. HRTEM analysis showed that 2 at.% Ta addition gave rise to well crystallized films with elongated nanocrystallites in comparison with the films having 0, 4 and 8 at.% Ta contents.     

Influence of nitrogen gas flow rate on the structural, morphological and electrical properties of sputtered TiN films

In this work, nanocrystalline titanium nitride (TiN) films have been deposited by reactive DC magnetron sputtering technique on the Si/SiO₂ (100) substrates. The influence of nitrogen gas flow rate [0, 3, 5, 7 and 9 sccm (standard cubic centimeter per minute)] on the structural, morphological and electrical properties of the nanocrystalline TiN films has been studied. As-deposited TiN films have been characterized by using X-ray diffraction (XRD), XPS (X-ray photoelectron spectroscopy), FESEM (field emission scanning electron microscopy) and four point probe resistivity measurement, respectively. The XRD patterns revealed the HCP symmetry for pure Ti (N₂ = 0 sccm) with (002) preferred orientations, and the FCC symmetry for TiN (N₂ = 3, 5, 7 and 9 sccm) films having (111) preferred orientations. The lattice parameters were found to be a = 2.950 ?, c = 4.681? for the Ti (N₂ = 0 sccm) film and a = 4.250Å for the TiN films. The presence of different phases such as TiN and TiO₂ were confirmed by XPS analysis. The FESEM images showed a smooth morphology of the film with columnar grain structures. The grain size of the TiN films was found to decrease from 22 to 15 nm as the nitrogen flow rate is increased from 0 to 9 sccm. The electrical resistivity measurement showed that the resistivity of the film increased from 11 × 10^?6 to 17 × 10^?6 Ohm cm on increasing nitrogen flow rate from 3 to 9 sccm, having the lowest resistivity of 11 × 10^?6 Ohm cm for the film deposited at 3 sccm nitrogen flow.     

Structure-composition-property dependence in reactive magnetron sputtered ZnO thin films

Thin films of zinc oxide (ZnO) were prepared by dc reactive magnetron sputtering on glass substrates at various oxygen partial pressures in the range 1×10⁻⁴–6×10⁻³ mbar and substrate temperatures in the range 548–723 K. The variation of cathode potential of zinc target on the oxygen partial pressure was explained in terms of target poisoning effects. The stoichiometry of the films has improved with the increase in the oxygen partial pressure. The films were polycrystalline with wurtzite structure. The films formed at higher substrate temperatures were (0 0 2) oriented. The temperature dependence of Hall mobility of the films formed at various substrate temperatures indicated that the grain boundary scattering of charge carriers was predominant electrical conduction mechanism in these films. The optical band gap of the films increased with the increase of substrate temperature. The ZnO films formed under optimized oxygen partial pressure of 1×10⁻³ mbar and substrate temperature of 663 K exhibited low electrical resistivity of 6.9×10⁻² Ω cm, high visible optical transmittance of 83%, optical band gap of 3.28 eV and a figure of merit of 78 Ω⁻¹ cm⁻¹.     

氮气流量对电弧离子镀TiN薄膜性能的影响

氮化钛是一种应用较广泛的硬质薄膜,其性能受许多因素的影响,本文只改变氮气流量,固定其它工艺参数,对镀覆的氮化钛薄膜性能进行了分析和研究,得出了获得较好氮化钛薄膜综合性能的氮气流量.     

Effect of deposition time on sputtered ZnO thin films and their gas sensing application

Nowadays, advanced industrialization and population growth have led to increasing the environmental related issues. This paper reports the effect of deposition time on ZnO films deposited on to the glass substrate by using rf magnetron sputtering technique and their further use for gas sensing applications. Herein, deposition time is considered to be changed from 300 s, 800 s (S1, S2). The thickness of deposited films lies in the range of 130–180 nm. The synthesized films were characterized by various techniques in terms of structural, morphological, optical and gas sensing properties. The typical crystal size of ZnO films was found to be in the range of 15–27 nm. FESEM analysis revealed the growth of nanospheres was lies in the range of 80–120 nm. Fourier transform infrared spectroscopy confirmed the ZnO bonding located at a wavelength of 430 cm^?1. The average optical transmittance of the film was about 90–95% in the visible range. The optical band gap of ZnO films was decreased from 3.31 to 3.29 eV. The detailed characterization study showed 800 s is an optimum deposition time for good optoelectronic properties. For gas sensing application, highest sensitivity was obtained at operating temperature of 205 °C. Prepared films have a quick response and fast recovery time in the range of 128 s and 163 s respectively. These response and recovery time characteristics were explained by valence ion mechanism.     

Effect of substrate bias voltage on the physical properties of dc reactive magnetron sputtered NiO thin films

Nickel oxide (NiO) thin films were prepared on glass substrates at various bias voltages using dc reactive magnetron sputtering technique. The influence of substrate bias voltage on structural, optical and electrical properties was systematically investigated using X-ray diffraction (XRD), SEM, EDS, spectrophotometer and Hall effect studies. The NiO films are crystalline with preferential growth along (2 0 0) plane. The NiO films exhibit optical transmittance of 55% and direct band gap of 3.78 eV at the substrate bias voltage of −75 V. The electrical resistivity decreases as substrate bias voltage increases from 0 to −75 V thereafter it was slightly increased.     

Effect of Nd3+ incorporation on the microstructure and chemical structure of RF sputtered ZnO thin films

The present work aims at investigating the effects that different levels of Nd atoms incorporation can have on the microstructure and chemical structure of ZnO thin films. Undoped and Nd-doped ZnO films were deposited by RF co-sputtering from pure ZnO and metallic Nd targets in Ar plasma onto Si, quartz and glass substrates. The Nd concentration in the ZnO host matrix was varied in the range 0–26 at.% by varying the bias applied to the Nd target. A comprehensive characterization of the films properties was performed by X-ray photoelectron and Auger electron spectroscopies, X-ray fluorescence analysis, X-ray diffraction and scanning electron microscopy. At low Nd atomic concentration (Nd/Zn < 0.07) Nd atoms were successfully incorporated into the ZnO matrix, whose crystalline structure was preserved. A deterioration of the ZnO würtzite phase was observed on the contrary with increasing Nd content in the films together with the precipitation of a second phase, identified as Nd₂O₃.     

Effect of reactive gases flow ratios on the microstructure and electrical resistivity of Ta-N-O thin films by reactive co-sputtering

A combination of the beneficial properties of tantalum oxide and tantalum nitride may result in a new and functional tantalum oxynitride (Ta-O-N). In this paper, Ta-O-N thin films were fabricated by using reactive magnetron sputtering at different reactive gas ratios. The ratio of reactive gases to total flow gases was controlled from 6% to 30%. The microstructure, composition, chemical bonding, morphology and resistivity of the Ta-O-N thin films were characterized. Increasing reactive gas flow ratio will result in the increase of the O/(O + N) ratio in Ta-O-N from 0.22 to 0.79. All films were quasi-amorphous structures in this study. The higher reactive gas flow ratio led to more disorder or amorphous microstructure with a broader diffraction peak. The position of the highest intensity peak about 36° shifts downward with increasing O/(O + N) ratio because of the sufficient Ta-O phase formation. The FTIR absorption bands at 500-800 cm^− 1 corresponding to Ta-O-Ta and Ta-O stretching vibration modes were observed_. A weak absorption band at 800-1000 cm^− 1 was the tantalum suboxides. The resistivity increased from 288 μΩcm (conducting) to 11,540 Ωcm (semiconducting-insulating) with increasing O/(O + N) ratio. The oxygen content dominates the microstructure formation and resistivity of the Ta-O-N system compared to nitrogen.     

Effect of background gas environment on oxygen incorporation in TiN films deposited using UHV reactive magnetron sputtering

The effect of the base pressure on the incorporation of oxygen into reactively magnetron-sputtered metal-nitride films has been investigated. A UHV sputtering system with a base pressure of less than 10⁻⁶ Pa was used to examine the relationship between a deliberately introduced background pressure of oxygen and a measured oxygen content in the sputter-deposited TiN films. The results showed that with an oxygen partial pressure of 10⁻⁴ Pa, the deposited TiN was found to include 10-20 at.% of oxygen when measured by the technique of X-ray photoelectron spectroscopy (XPS). When no oxygen was admitted into the system, no trace of oxygen could be detected in the deposited TiN films. The incorporation mechanism is discussed in terms of the coverage-dependent sticking probabilities of O₂ and N₂ on a Ti metal surface.     

射频反应溅射中N2分量对TiN薄膜性质的影响

用射频反应溅射的方法制备了TiN薄膜，其晶体结构与电阻率都与溅射气氛中N2分量有直接关系。随着N2分量由5％增加到50％，薄膜先是呈现（111）的择优取向，后是呈现（200）的取向，最后没有衍射峰出现，结构趋于无定型，于此同时，电阻率也由接近金属的良好导电性变为半导体的导电性。     

Effect of bias voltage on microstructure and mechanical properties of nanocrystalline TiN films deposited by reactive magnetron sputtering

Nanocrystalline TiN films deposited under various bias voltages have been prepared by a reactive magnetron sputtering. The effect of bias voltage on the microstructural morphologies of the TiN films was characterized by FE-SEM and AFM. The texture of the TiN films was characterized by XRD. It is also observed that the crystallite size decreases with increasing bias voltages. However, rms roughness increases with increasing bias voltages. The changes in roughness and crystallite size in the TiN thin films are due to one or a combination of factors such as resputtering, ion bombardment, surface diffusivity and adatom mobility; the influence of each factor depends on the processing conditions.     

Effects of nitrogen partial pressure on microstructure,morphology and N/Ti ratio of TiN films deposited by reactive magnetron sputtering

Abstract

TiN films were deposited on Si(111) substrates at different nitrogen partial pressures with reactive magnetron sputtering. The crystal structure and preferred growth orientation of the films were determined using X-ray diffraction (XRD) analysis. Their morphology and composition were analysed using field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). It is found that with the increase in nitrogen partial pressure, the growth of TiN films varies from the {111} preferred orientation to the {100} preferred orientation and the deposition rate of TiN films decreases. When the {111} preferred orientation is presented, TiN films reveal a kind of surface morphology of triangular pyramid with right angles; while the {100} orientation is dominant, TiN films characterise another kind of domelike surface morphology. Furthermore, the N/Ti ratio of the TiN films first increases, then decreases and increases again as nitrogen partial pressure enlarges.     

Bias effect on microstructure and mechanical properties of magnetron sputtered nanocrystalline titanium carbide thin films

Nanocrystalline titanium carbide (TiC) thin films were prepared by magnetron sputtering deposition at 473 K. The effect of substrate bias on microstructure and mechanical properties was studied in details using X-ray photoelectron spectroscopy, X-ray diffraction, field emission scanning electron microscopy, indentation and scanning microscratch. The TiC films exhibit a (111) preferential orientation. Substrate bias decreases grain size and deposition rate of the TiC films. The TiC films have columnar structure which becomes finer at high substrate bias. Nanoindentation hardness, Young's modulus, and toughness of the films are increased as the substrate bias goes up. However, the adhesion peaks at substrate bias of − 100 V and drops when bias is increased further.     

二极溅射沉积Fe-N-O薄膜的形貌与结构分析

利用二极溅射的方法在不同衬底上沉积了Fe N O薄膜。通过扫描电子显微镜(SEM)、光电子能谱(XPS)和透射电子显微镜(TEM)等先进实验分析手段对二极溅射沉积Fe N O薄膜的形貌与结构进行了分析。XPS和TEM的结果表明,薄膜的主要成分为FeO和少量的Fe16N2多晶体组成,生长上存在择优取向;表面均匀、致密、平整,晶粒大小在50nm左右。     

Diffusion of copper in thin TiN films

The diffusivity of copper in thin TiN layers was determined in specimens prepared by r.f. sputtering a copper (80 nm) layer onto a TiN (200 nm) layer on sapphire and silicon substrates. Specimens were isothermally heat treated at 608, 635 and 700 °C at pressures lower than 2 × 10^?6 Pa; they were compositionally analyzed by Rutherford backscattering spectroscopy and Auger sputter profiling; and they were microstructurally characterized by transmission electron microscopy and electron diffraction. The diffusivity D = 9 × 10⁷cm²s^?1exp(?427 kJmol^?1/RT) from 608 to 700 °C. The mechanisms of copper diffusion were not bulk processes, but they were probably processes involving primarily grain boundaries in the TiN. This very low diffusivity at these temperatures makes TiN/Cu an excellent candidate for a high temperature metallization for silicon solar concentrator cells.     

Studies on the RF sputtered amorphous SiGe thin films

In this study, rf sputtered hydrogenated amorphous silicon-germanium thin films deposited at room temperature have been investigated by spectroscopic ellipsometry and Rutherford backscattering. Technological parameters were determined for good layer quality of amorphous material. The layer thicknesses were first evaluated from the Rutherford backscattering and spectroscopic ellipsometry measurements, then measured directly by step-profiler, and compared to each other. The inherence of technological parameters and composition of the layers is discussed. The text was submitted by the authors in English.