射频功率对微晶硅薄膜微结构和光电性能的影响

采用射频等离子体增强化学气相沉积(rf-PECVD)技术,在玻璃和硅衬底上沉积微晶硅(μc-Si:H)薄膜。利用拉曼光谱、AFM和电导率测试对不同射频功率下沉积的薄膜的结构特性及光电性能进行分析。研究表明:随着射频功率的增加,薄膜的晶化率和沉积速率也随之增加,而当射频功率增加到一定的程度,晶化率和沉积速率反而减小。薄膜的暗电导率与晶化率的变化情况相对应。     

溅射功率对ZnO:Al薄膜光电性能的影响

采用射频磁控溅射工艺,以Al掺杂ZnO(ZAO)陶瓷靶为靶材在石英玻璃基片上制备出具有优良光电性能的ZAO透明导电薄膜,研究了溅射功率对薄膜光电性能的影响。在不同溅射功率条件下制备的ZAO薄膜具有很好的c轴择优取向。较大功率溅射有利于薄膜晶粒尺寸的增大、电阻率降低。ZAO薄膜在可见光区的透过率平均值高达90%以上,受溅射功率影响不大。在340nm-420nm波长附近ZAO薄膜透过率急剧下降,呈现明显的紫外吸收边;高的溅射功率提高了ZAO薄膜的光学带隙宽度。     

硼掺杂对非晶硅薄膜微结构和光电性能的影响

以硅烷 (SiH4 )和硼烷 (B2 H6)为气相反应先驱体 ,采用等离子体增强化学气相沉积法 (PECVD)制备出轻掺硼非晶氢硅薄膜。X射线衍射、原子力显微镜和光、暗电导测试表明 ,一定程度的硼掺杂提高了非晶氢硅薄膜的电导率 ,降低了非晶氢硅薄膜的光、暗电导比 ,并促进了非晶氢硅薄膜中硅微晶粒的生长。红外吸收谱研究预示了大量的硼原子与硅、氢原子之间能形成某些形式的复合体 ,仅有少量硼元素对P型掺杂有贡献。     

乙烯掺杂APCVD法沉积非晶硅薄膜的光学特性

通过硅烷、乙烯和氮气的混合气体在620下采用常压化学气相沉积(APCVD)法沉积了非晶硅薄膜,讨论了乙烯/硅烷的体积比(R=VC2H4/VsiH4)对薄膜的光学性质的影响.用Raman光谱、红外光谱和紫外-可见光光谱仪对薄膜进行表征.结果表明通过乙烯掺杂制备的薄膜样品中存在着Si-C键,在R值变化的开始阶段薄膜的光学带隙随着R值增大而增大,在R=0.1时达到最大值,然后随着R值的增大而减小.     

硼掺杂对非晶硅薄膜微结构和光电性能的影响

以硅烷（SiH4)和硼烷（B2H6）为气相应反应先驱体，采用等离子体增强化学气相沉积法（PECVD）制备出轻掺硼非昌氢硅薄膜，X射线衍射，原子力显微镜和光，暗电导测试表明，一定程度的硼掺杂提高了非晶氢硅薄膜的电导率，降低了非晶氢硅薄膜的光，暗电导比，并促进了非晶氢硅薄膜中硅微晶粒的生长，红外吸为研究预示了大量的硼原子与硅，氢原子之间能形成某些形式的复合体，仅有少量硼元素对P型掺杂有贡献。     

PECVD法制备非晶硅薄膜及光电性能研究

采用等离子体增强化学气相沉积（PECVD）方法在玻璃衬底上制备出非晶硅薄膜,利用正交试验法对射频功率、气体总压、硅烷比例、沉积时间、退火温度、退火时间因素进行了研究,对透过率和电阻率进行了分析,结果表明,采用PECVD法成功制备出非晶硅薄膜。正交实验表的分析得知,气体总压对透过率影响最大;硅烷比例对电阻率影响最大。制备非晶硅薄膜的优化条件为：射频功率30W、气体总压100Pa,硅烷5％、沉积时间5min、退火温度300℃、退火时间45min。非晶硅薄膜的光透过率93．18％,电阻率为13．238kΩ·cm。     

V2O5薄膜的结构和光电性能研究

在O2／Ar混合气氛中，用脉冲磁控溅射金属V靶沉积出非晶的V2O5薄膜。对所沉积的薄膜进行450℃退火。利用X射线衍射、原子力显微镜、分光光度计和电阻测量等手段对薄膜的结构和性能进行了分析，从200nm-2500nm光谱的透射和反射测量结果，计算出薄膜的吸收系数。结果表明，V2O5薄膜纯度高，结晶好，高低温电阻变化2个量级。光学能隙为2．46eV。     

MW-ECR制备的氢化非晶硅光电特性研究

通过对热丝辅助微波电子回旋共振(HW-MW-ECRCVD)法制备的氢化非晶硅(a-SiH)薄膜进行暗电导与温度关系的测试,可得到暗电导激活能(Ea),并研究了Ea与a-SiH薄膜光敏性(σph/σ d)的关系;发现随着Ea的增大,费米能级位置下移,缺陷态密度减少,薄膜的光敏性变好.     

溅射气压对HfO_2薄膜结构和光学性能的影响

HfO2薄膜的结构和光学性能与反应溅射时使用的气压有很强的依赖关系。薄膜的晶粒生长取向、生长速率和折射率明显受溅射气压的影响。所有的薄膜均为单斜相,晶粒尺寸在纳米量级。薄膜的折射率在1.92～2.08范围内变化,透过率大于85%。结果表明,这些HfO2薄膜很适宜用作增透膜或者高反膜。此外,通过Tauc公式推出光学带隙在5.150～5.433eV范围内变化,表明样品是良好的绝缘体。     

Optical properties of CeO<Subscript>2</Subscript> thin films

Cerium oxide (CeO₂) thin films have been prepared by electron beam evaporation technique onto glass substrate at a pressure of about 6 × 10⁻⁶ Torr. The thickness of CeO₂ films ranges from 140–180 nm. The optical properties of cerium oxide films are studied in the wavelength range of 200–850 nm. The film is highly transparent in the visible region. It is also observed that the film has low reflectance in the ultra-violet region. The optical band gap of the film is determined and is found to decrease with the increase of film thickness. The values of absorption coefficient, extinction coefficient, refractive index, dielectric constant, phase angle and loss angle have been calculated from the optical measurements. The X-ray diffraction of the film showed that the film is crystalline in nature. The crystallite size of CeO₂ films have been evaluated and found to be small. The experimental d-values of the film agreed closely with the standard values.     

热丝CVD制备微晶硅薄膜的研究

采用热丝化学气相沉积技术制备微晶硅薄膜,利用X射线衍射谱、Raman散射谱、透射光谱和扫描电子显微镜等检测手段,系统地研究沉积过程中沉积气压对微晶硅薄膜晶粒尺寸、晶态比和光学带隙的影响,运用Tacu法则对薄膜的透射率和厚度进行计算分析,得到薄膜光学带隙与沉积气压之间的关系,结果表明薄膜的光学带隙随着沉积气压的升高而单调下降。     

Determination of optical and electrical properties of ZnSe thin films

A thin film of zinc selenide (ZnSe) was deposited onto a clean glass substrate using a vacuum evaporation technique. This thin film was characterized through X-ray diffraction, which indicated that the film was polycrystalline in nature. Absorption and transmission spectra of this thin film were recorded using a spectrophotometer. The energy band gap, refractive index and extinction coefficient were determined using these spectra. It was found that the energy band gap of ZnSe film was 2.55 eV. It was also observed that the refractive index and extinction coefficient of the film decreased with the increase of wavelength. The conductivity of this thin film was determined by current–voltage measurement using an electrometer over the temperature range from room temperature to 413 K. It was observed that conductivity increased with increase in temperature. This is explained on the basis of structural changes occurring due to the change in grain size and the increase in carrier density.     

准分子激光引起的非晶硅薄膜晶化行为的研究

利用KrF准分子激光对非晶硅薄膜的表层进行了晶化.研究了激光能量密度和照射脉冲数对薄膜结晶度的影响,并对晶化后薄膜的形貌和结构进行了表征.结果表明:该非晶硅薄膜晶化阈值约为110 mJ/cm2,且不受照射脉冲数的影响;激光能量密度是影响薄膜结晶度的首要因素,但在较低的能量密度时,增加照射脉冲数也会显著的提高薄膜结晶度;结构及形貌表征发现,薄膜晶化层厚度约为400～500 nm,平均晶粒尺寸为30～50 nm.     

双离子束溅射制备非晶SiOxNy薄膜的强黄光发射

用双离子束溅射法制备了SiOxNy薄膜,并对薄膜的结构和光致发光(PL)性质进行了研究.XRD和TEM的实验结果表明薄膜是非晶结构;用XPS对样品进行了表征,在397.8eV位置处出现一个对应于N1s的对称峰,表明样品中的N原子主要与Si原子结合,FTIR的实验结果也说明了这一点.光吸收测量结果显示SiOxNy薄膜的光学带隙比Si-SiO2薄膜宽.在225nm波长的激发下,测得在590nm处有强的黄光发射,并利用能带模型讨论了可能的发光机制.     

Study of annealing effects in Al-Sb bilayer thin films

In this paper, we present preparation and characterization of Al-Sb bilayer thin films. Thin films of thicknesses, 3000/1000 Å and 3000/1500 Å, were obtained by the thermal evaporation (resistive heating) method. Vacuum annealing and rapid thermal annealing methods were used to mix bilayer thin film structure. Results obtained from optical band gap data and Rutherford back scattering spectrometry showed mixing of Al-Sb bilayer system.     

Optical constants in the ultraviolet region of evaporated high index thin films

A suitable method to determine the optical constants of high index thin films is essential for developing high efficiency dielectric thin film devices in theuv region from 240 nm to 400 nm. A quick and accurate method is established to determine these constants. Using this method the optical losses, refractive index, absorption coefficient and extinction coefficient of ZrO₂ films prepared by the method of reactive evaporation were evaluated in theuv region.     

Influence of RF power on the electrical and mechanical properties of nano-structured carbon nitride thin films deposited by RF magnetron sputtering

Nano structured carbon nitride thin films were deposited at different RF powers in the range of 50 W to 225 W and constant gas ratio of (argon: nitrogen) Ar:N₂ by RF magnetron sputtering. The atomic percentage of Nitrogen: Carbon (N/C) content and impedance of the films increased from 14.36% to 22.31% and 9 × 10⁻¹ Ω to 7 × 10⁵ Ω respectively with increase in RF power. The hardness of the deposited films increased from 3.12 GPa to 13.12 GPa. The increase in sp³ hybridized C-N sites and decrease of grain size with increase in RF power is responsible for such variation of observed mechanical and electrical properties.