Effect of tantalum doping on the structural and optical properties of RF magnetron sputtered indium oxide thin films

Tantalum doped indium oxide films are prepared by RF magnetron sputtering technique and the films are annealed in air at 300 °C. The effect of Ta doping on the structural, morphological, and optical properties of the annealed films are studied using techniques like X-ray diffraction (XRD), atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), EDX analysis, micro-Raman, UV–visible and photoluminescence spectroscopy and electrical measurements. The XRD patterns present a cubic bixbyite structure for all the films with preferred orientation along the (222) plane. The lattice constant estimation presents a reduction in lattice size with Ta doping. The W–H plot shows a tensile strain for all the films and also indicates the presence of strain induced broadening of the XRD peaks. The Raman spectra present all the characteristic modes of In₂O₃ cubic bixbyite phase. FESEM and AFM images show the uniform and dense distribution of smaller grains in the films. All the films show high transmittance (above 85%) in the 400–900 nm region. Electrical measurement shows a systematic increase of carrier concentration and electrical conductivity with increase in Ta doping concentration. Band gap energy increases with increase in Ta doping concentration. All the films show intense PL emission in the UV region.     

原位退火对磁控溅射制备的ZnS薄膜微结构和发光性能的影响

采用射频磁控溅射技术在玻璃衬底上制备了系列ZnS薄膜,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)和荧光分光光度计研究了Ar气氛中300～500℃原位退火对薄膜微结构和发光性能的影响.结果表明,退火温度对ZnS薄膜的结晶性能和晶粒大小的影响不大,但会显著影响其发光特性.低温退火处理的薄膜的PL谱具有多个发光峰,...     

Microstructure and corrosion resistance of room-temperature RF sputtered Ta2O5 thin films

The connection between the chemical corrosion resistance and the microstructure of the Ta₂O₅ thin films prepared at room temperature by a RF magnetron sputtering technique on Si substrates has been investigated. We find that the microstructure of the films changes with different RF sputtering power, and is responsible for the degradation of the corrosion resistance in HF solutions. The deposited films are amorphous and porous when the RF power is low. A preferred orientation toward (200) β-Ta₂O₅ can be observed when the RF power is increased to 150 W. In addition, the films deposited under this condition are dense and are consequently more resistant to the attack of chemicals. AT an RF power of 300 W the corrosion resistance of the films declines due to an increase of the exposed pore surface to the HF solution.     

Properties of V–Ce mixed-oxide thin films deposited by RF magnetron sputtering

Thin films of vanadium cerium mixed oxides are good counter-electrodes for electrochromic devices because of their passive optical behavior and very good charge capacity. We deposited thin films of V–Ce mixed oxides on glass substrates by RF magnetron sputtering under argon at room temperature using different power settings. The targets were pressed into pellets of a powder mixture of V₂O₅ and CeO₂ at molar ratios of 2:1, 1:1, and 1:2. For a molar ratio of 2:1, the resulting crystalline film comprised an orthorhombic CeVO₃ phase and the average grain size was 89 nm. For molar ratios of 1:1 and 1:2, the resulting films were completely amorphous in nature. Scanning electron microscopy images and energy-dispersive X-ray spectroscopy data confirmed these results. The optical properties of the films were studied using UV-Vis-NIR spectrophotometry. The transmittance and indirect allowed bandgap for the films increased with the RF power, corresponding to a blue shift of the UV cutoff. The average transmittance increased from 60.9% to 85.3% as the amount of CeO₂ in the target material increased. The optical bandgap also increased from 1.94 to 2.34 eV with increasing CeO₂ content for films prepared at 200 W. Photoacoustic amplitude (PA) spectra were recorded in the range 300–1000 nm. The optical bandgap was calculated from wavelength-dependent normalized PA data and values were in good agreement with those obtained from UV-Vis-NIR data. The thermal diffusivity calculated for the films increased with deposition power. For thin films deposited at 200 W, values of 53.556×10⁻⁸, 1.069×10⁻⁸, and 0.2198×10⁻⁸ m²/s were obtained for 2:1, 1:1, and 1:2 V₂O₅/CeO₂, respectively.     

制备工艺对ITO薄膜的电阻率及沉积速率的影响

采用射频磁控溅射法制备了氧化铟锡[ITO,In2O3:SnO2=90:10(质量比)]薄膜,详细探讨了溅射气氛氧氩体积比、溅射功率及溅射气压对ITO薄膜电阻率和沉积速率的影响。结果表明:溅射工艺参数对ITO薄膜电阻率和沉积速率的影响十分明显。随着氧氩体积比的增大,样品的电阻率显著增大,沉积速率下降;随着溅射功率的增加,ITO薄膜的电阻率先减小后略微增大,沉积速率上升;随着溅射气压升高,ITO薄膜的电阻率先减小后增大,当溅射气压增大到较大值时,ITO薄膜的电阻率又开始减小,而沉积速率则先上升后下降。     

退火温度对AZO薄膜场发射性能的影响

以纯度为99.95%、Al₂O₃为2wt.%的 ZnO-Al₂O₃金属氧化物为溅射靶材,采用射频(RF)磁控溅射的方法,在玻璃衬 底上制备Al掺杂ZnO(AZO)薄膜,研究其场发射特性和导电性能,并分析了不同的退火温度 对AZO薄膜的形貌、导 电及场发射性能的影响。采用原子力显微镜(AFM)及X射线衍射(XRD)对AZO薄膜表面 形貌与结晶特性 进行测试的结果表明,随着退火温度的升高,AZO薄膜的表面粗糙度随之增大,AZO薄膜的结 晶度变好;场发射 性能研究的结果表明,AZO薄膜的开启电场随着退火温度增加呈先减小后增大的趋势,当 退火温度为300℃时, AZO薄膜样品粗糙度最大,场发射性能最好,开启场强为2.8V/μm, 发光均匀性较好,亮度达到650cd/m²,导电 性能最好,电阻率为5.42×10－4 Ω·cm。     

（英）沉积参数对射频磁控溅射制备的碲锌镉薄膜的影响

采用Cd096Zn0.04Te靶,利用射频磁控溅射制备碲锌镉薄膜,通过改变基片温度、溅射功率和工作气压,制得不同的碲锌镉薄膜.将制备的碲锌镉薄膜放置在高纯空气气氛中,在473 K温度下退火.利用台阶仪、分光光度计、XRD和SEM测试设备表征,结果表明,通过退火和改变沉积参数,可以制备出禁带宽度在1.45～2.02eV之间调节的碲锌镉薄膜.     

Effects of substrate temperature on the degradation of RF sputtered NiO properties

Nickel oxide (NiO) film was grown on Si (100) substrate through RF sputtering of NiO target in Ar plasma at various temperatures ranging from room temperature (RT) to 300 °C. The structural study revealed (200) oriented NiO diffraction peak at RT and at 100 °C, however, by increasing the substrate temperature to 200 °C, intensity of (200) NiO diffraction peak was decreased. At higher temperature (300 °C), crystalline quality of NiO was significantly degraded and the film was decomposed into Ni. The EDS results confirmed an increase of Ni atomic percentage with increase of the substrate temperature. The surface morphology of NiO film at RT and at 100 °C displayed cubical like grains that were changed into elongated grains with further increase of the substrate temperature. The UV–vis reflectance measurements of NiO revealed a small decrease in its band gap by increasing the substrate temperature to 200 °C.     

Characteristics of RF sputtered barium titanate thin films

Results of a study on the deposition of thin-film barium titanate (BaTiO3) by RF sputtering are discussed. BaTiO3was deposited onto Pt foil and onto thin-film electrodes on various substrates, and counterelectroded to form metal-dielectrio-metal structures. Dielectrics were deposited at substrate temperatures from 23° to 1000°C, some of the dielectrics fired in air at temperatures up to 1400°C after deposition. On bulk Pt, the BaTiO3film matrix indicated an average grain size of 2000 Å after heat treatment Constant Ba/Ti ratios were measured for the films deposited over the entire substrate temperature range. Dielectric constants ranged from 16- 1900, the tan δ of the capacitors varying from 0.005 for amorphous films to 0.065 for polycrystalline films with highest dielectric constants. Effects of temperature and frequency on the capacitors and the charge-voltage and field dependence of the dielectric constant are described. Current-voltage relationships, breakdown strengths, and processing conditions indicate the potential of the capacitor structures for practical applications.     

射频磁控溅射法制备Cu_2ZnSnS_4薄膜

利用射频磁控溅射法在玻璃基片上制备了Cu2ZnSnS4(CZTS)薄膜,薄膜在室温下生长,再在Ar气氛中快速退火。通过X射线衍射、X射线电子能谱、原子力显微镜和吸收谱研究了退火温度对薄膜结构、组分、形貌和禁带宽度的影响。结果表明,所制备样品为Cu2ZnSnS4多晶薄膜,具有较强的沿(112)晶面择优取向生长的特点,薄膜组分均为富S贫Cu,样品表面形貌比较均匀。退火温度为350,400,450和500℃的薄膜样品的禁带宽度分别是1.49,1.53,1.51和1.46 eV。     

Magnetic properties of ZnO:Cu thin films prepared by RF magnetron sputtering

ZnO films and ZnO:Cu diluted magnetic semiconductor films were prepared by radio frequency magnetron sputtering on Si (111) substrates, with targets of ZnO and Zn0.99Cu0.01 O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.     

射频磁控溅射法制备ZnO:Cu薄膜的磁性研究

ZnO films and ZnO：Cu diluted magnetic semiconductor films were prepared by radio frequency mag-netron sputtering on Si （111） substrates, with targets of ZnO and Zn0.99Cu0.01O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1＋. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.     

Properties of CdTe nanocrystalline thin films grown on different substrates by low temperature sputtering

CdTe nanocrystalline thin films have been prepared on glass, Si and Al2O3 substrates by radio-frequency magnetron sputtering at liquid nitrogen temperature. The crystal structure and morphology of the films were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The XRD examinations revealed that CdTe films on glass and Si had a better crystal quality and higher preferential orientation along the (111) plane than the Al2O3. FESEM observations revealed a continuous and dense morphology of CdTe films on glass and Si substrates. Optical properties of nanocrystalline CdTe films deposited on glass substrates for different deposited times were studied.     

磁控溅射法在有机衬底上制备SnO2掺Sb透明导电膜

采用射频磁控溅射法在有机柔性衬底上制备出了SnO2:Sb透明导电膜,讨论了薄膜的结构和光电性质对制备条件的依赖关系.制备的样品为多晶薄膜,并且保持了氧化锡的金红石结构.对衬底适当地加热,当衬底温度为200℃时,在PI(聚酰亚胺)胶片上制备出了性能良好的薄膜,薄膜相应自由载流子霍耳迁移率的最大值为1 3.9cm2/V@s,载流子浓度为15.5×1019cm-3,薄膜电阻率的最小值为3.7×103Ω@cm.在可见光范围内,样品的相对透过率为85%左右.     

不同衬底上纳米晶CdTe薄膜的低温制备及光性能研究

CdTe nanocrystalline thin films have been prepared on glass, Si and Al2O3 substrates by radio-frequency magnetron sputtering at liquid nitrogen temperature. The crystal structure and morphology of the films were charac-terized by X-ray diffraction （XRD） and field-emission scanning electron microscopy （FESEM）. The XRD examinations revealed that CdTe films on glass and Si had a better crystal quality and higher preferential orientation along the （111） plane than the Al2O3. FESEM observations revealed a continuous and dense morphology of CdTe films on glass and Si substrates. Optical properties of nanocrystalline CdTe films deposited on glass substrates for different deposited times were studied.     

Preparation,characterization and application of RF sputter deposited boron doped silicon dioxide thin films

We report the preparation of thin film boron doped silicon dioxide (also called borosilicate–glass or BSG) by RF magnetron and its use as a boron diffusion source, especially for shallow junctions. For this purpose, a sputtering target of BSG was prepared through conventional solid state reaction route. Deposition rates of sputter deposited BSG film at different sputtering parameters were studied. The presence of boron in the deposited film was confirmed by hot probe and sheet resistance techniques on silicon wafer following a diffusion step. The structural evaluation of BSG thin film was performed using Fourier Transform Infrared Spectroscopy (FTIR). Secondary Ion Mass Spectroscopy (SIMS) was used to measure the concentration profile of boron in the BSG film. The effect of sputtering parameters on boron concentration in the deposited BSG film was also studied. A p–n junction diode was fabricated using BSG thin film as diffusion source of boron. The junction depth was measured to be in the range of 0.06–1.0 µm for different sputtering and diffusion parameters.     

RF功率对非晶铟镓锌氧薄膜和器件电学特性的影响

The influence of radio frequency(RF) power on the properties of magnetron sputtered amorphous indium gallium zinc oxide(a-IGZO) thin films and the related thin-film transistor(TFT) devices is investigated comprehensively.A series of a-IGZO thin films prepared with magnetron sputtering at various RF powers are examined.The results prove that the deposition rate sensitively depends on RF power.In addition,the carrier concentration increases from 0.91 x 1019 to 2.15 x 1019 cm-3 with the RF power rising from 40 to 80 W,which may account for the corresponding decrease in the resistivity of the a-IGZO thin films.No evident impacts of RF power are observed on the surface roughness,crystalline nature and stoichiometry of the a-IGZO samples.On the other hand,optical transmittance is apparently influenced by RF power where the extracted optical band-gap value increases from 3.48 to 3.56 eV with RF power varying from 40 to 80 W,as is supposed to result from the carrierinduced band-filling effect.The rise in RF power can also affect the performance of a-IGZO TFTs,in particular by increasing the field-effect mobility clearly,which is assumed to be due to the alteration of the extended states in a-IGZO thin films.     

Bias voltage dependence properties of Nb-doped indium tin oxide thin films by RF magnetron sputtering at room temperature

Niobium doped indium tin oxide (ITO:Nb) thin films were fabricated on glass substrates by RF magnetron sputtering from one piece of ceramic target material at room temperature. The bias voltage dependence of properties of the ITO:Nb films were investigated by adjusting the bias voltage. Structural, electrical and optical properties of the films were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), UV–visible spectroscopy, and electrical measurements. XRD patterns showed a change in the preferential orientations of polycrystalline crystalline structure from (222) to (400) crystal plane with the increase of negative bias voltage. AFM analysis revealed that the smooth film was obtained at a negative bias voltage of -120 V. The root mean square (RMS) roughness and the average roughness are 1.37 nm and 1.77 nm, respectively. The films with the lowest resistivity as low as 1.45×10⁻⁴ Ω cm and transmittance over 88% have been obtained at a negative bias voltage of −120 V. Band gap energy of the films, depends on substrate temperature, varied from 3.56 eV to 3.62 eV.     

ZnO薄膜的射频磁控溅射制备及性能研究

采用射频磁控溅射法在玻璃衬底上制备出高质量的ZnO薄膜.对薄膜的结构和性能进行了研究.所制备的ZnO是具有六角纤锌矿结构的多晶薄膜,最佳择优取向为(002)方向.ZnO薄膜的霍尔迁移率和载流子浓度分别为8×104m2/(V·s)和11.3×1020 cm-3.     

射频磁控溅射制备钛酸锶钡薄膜的研究进展

综述了射频磁控溅射制备钛酸锶钡(BST)薄膜的国内外研究动态,详细阐述了溅射工艺参数(电极、溅射气压、氧分压、温度)对BST薄膜微结构和电性能的影响,提出了射频磁控溅射制备BST薄膜中亟待解决的问题。