红外微测辐射热计用纳米氧化钒薄膜的制备和性能研究

具有优异热敏性能的氧化钒薄膜材料是红外测辐射热计的首选热敏电阻材料，合适的薄膜电阻及高温度电阻系数的氧化钒薄膜的制备是实现高探测率红外测辐射热计的保证．利用新型对靶反应磁控溅射工艺制备了具有纳米颗粒的氧化钒薄膜材料，确定了最佳工艺参数．对其组成、结构和性能进行了分析，原子力显微镜AFM形貌分析表明薄膜具有均匀致密的表面，X射线光电子能谱分析XPS确定了其组成成分主要为V2O5,VO2和少量的V2O3.在常用作微测辐射热计结构层材料的氮化硅基底上，该薄膜材料在室温附近具有合适的薄膜电阻（大约为每方14kΩ）以及高的温度电阻系数（-3．17％／℃），有望适用于非致冷红外测辐射热计探测器．     

用于微测辐射热计的氧化钒薄膜制备

采用射频(RF)反应溅射法,在微结构衬底上制备氧化钒薄膜,研究了氧气压、衬底温度、退火条件及薄膜厚度对薄膜电阻及电阻温度系数(TCR)的影响.在氮气保护下,采用常规退火和快速升降温退火对薄膜进行热处理.结果表明:氧分压、退火条件和薄膜厚度对电阻温度系数影响较大,需综合考虑;衬底温度对薄膜电阻的影响较大,但对电阻温度系数的影响较小;与常规退火方法相比,采用快速升降温退火有利于薄膜电阻温度系数的提高;通过优化工艺参数,制得的薄膜电阻温度系数可达(-4%/℃)左右,满足微测辐射热计的要求.     

用于微测辐射热探测器的纳米VO2薄膜

用离子束溅射和后退火工艺制备了一种适用于微测辐射热探测器热敏材料的新型纳米结构二氧化钒(VO2)薄膜材料,薄膜具有平均粒度8 nm,在半导体相区具有电阻温度系数(TCR)为-7%/K,性能高于传统的VO2材料(平均粒度为1-2μm,在半导体相区具有TCR约为-2%/K).基于纳米结构的VO2薄膜材料的器件比基于传统的VO2薄膜材料具有更高的性能,而两者的噪声基本相当.     

氧化钒薄膜热敏特性的研究

为研究氧化钒薄膜在非致冷红外微测辐射热计中的应用,综述了制备工艺等诸多因素对氧化钒热敏特性的影响,对其机理进行了探究,结果表明掺杂和新的制备工艺是调整氧化钒热敏特性较为有效的方法.     

用于微测辐射热计的氧化钒薄膜的光电性能研究

采用磁控溅射方法在p-Si(100)衬底上制备了VO2和择优取向的V6O13混合相成分的薄膜.利用X射线衍射(XRD)分析、原子力显微镜(AFM)、傅立叶红外光谱(FT-IR)分析及四探针测试方法,研究了薄膜的相成分和红外吸收特性,并测试分析了薄膜的电学热稳定性.研究结果表明,通过这种方法制备的氧化钒薄膜具有较低的电阻率和较高的电阻温度系数(TCR),并且具有良好的热稳定性,可以作为微测辐射热计的热敏材料.     

二氧化钒微测辐射热计的制备及工艺

针对二氧化钒微测辐射热计在红外吸收型气体检测方面的应用,采用微电子机械系统(MEMS)体硅工艺制备了二氧化钒微测辐射热计,重点对关键工艺进行了研究;通过优化工艺参数及步骤,制得的微测辐射热计结构稳定,成品率高;对单元器件的性能参数进行测试,结果表明,在光源调制频率为1Hz时,单元器件的响应率为18.1kV/W;探测率为1.37×108cmHz1/2/W;热时间常数为72.4ms。     

硅CCD和红外CCD研制中的HWLPCVD技术

着重介绍热壁ＬＰＣＶＤ（ＨＷＬＰＣＶＤ）的特点、改善薄膜均匀性的措施,对ＣＣＤ转移效率的影响以及在非致冷微测辐射热计中的应用。     

CTIA读出方式的微测辐射热计

在微测辐射热计热敏元的热平衡模型基础上,分析了CTIA读出方式的微测辐射热计在不同背景和衬底温度下的输出响应率,仿真了探测器面阵在偏移-增益两点校正法校正后的输出。为衡量不同衬底温度下校正后残余非均匀性噪声的大小,考虑到响应率随背景温度和衬底温度变化的因素,提出了非均匀性噪声等效功率(NNEP)指标。研究结果表明,在采用20μs积分时间和5pF积分电容时,探测元响应率可以达到106V/W到107V/W;衬底温度的变化在约0.01K以内时,采用两点校正法可以对该读出方式的微测辐射热计输出进行良好的校正。     

铜薄膜微结构的X射线衍射线形分析

首先采用真空蒸镀法制备了不同厚度的铜薄膜,并对薄膜进行了退火处理;然后用X射线衍射仪测定铜薄膜的衍射谱,最后采用线形分析法对衍射谱进行计算,得到了不同厚度铜薄膜退火前后的晶粒尺寸和微应变。结果表明:真空蒸镀铜薄膜晶粒尺寸随薄膜厚度的增加而增大,微应变随薄膜厚度的增加而减小;退火处理后薄膜晶粒明显长大,薄膜微应变在退火处理后明显减小。     

两步退火形成钛硅化物和氮化物的研究

模拟自对准硅化物技术的两步退火工艺，对超高真空（UHV）下制备的Ti／Si样品依次进行低温退火、腐蚀和高温退火。利用俄歇微探针（AES）和X射线衍射（XRD）分析样品的组分及晶相。发现高温退火后，薄膜内同时生成了Ti的硅化物及氮化物，这对发展MOS器件工艺中自对准硅、氮化物技术很有意义。另外，还利用扫描电镜（SEM）观察了薄膜形貌，用VandePauw法测量了薄膜电阻。     

基于溶胶凝胶法的二氧化锡复合薄膜的制备及表征

以金属无机盐SnCl2.2H2O、CuCl2.2H2O和无水乙醇为原料,用溶胶凝胶法制备了SnO2和CuO掺杂的CuO-SnO2薄膜,并用X射线衍射、扫描电镜、透射电镜和电化学工作站对样品进行了表征。结果表明:随着退火温度的增加,薄膜结晶性变好,晶粒长大,电学特性增强,最佳退火温度确定为450℃。掺杂CuO的SnO2薄膜导电性好于同等条件下未掺杂的SnO2薄膜。SnO2呈四方相金红石结构,衍射峰显示薄膜中存在部分SnO。聚乙二醇的添加增强了SnO2的衍射峰,当超过一定添加量后将抑制晶粒的生长,并使得CuO-SnO2薄膜的导电性呈先减小后增大的趋势。丙三醇的添加可极大改善薄膜的表面形貌,增强了SnO2的衍射峰,且导电性明显变好。     

Room temperature deposited vanadium oxide thin films for uncooled infrared detectors

We demonstrate the room temperature deposition of vanadium oxide thin films by pulsed laser deposition (PLD) technique for application as the thermal sensing layer in uncooled infrared (IR) detectors. The films exhibit temperature coefficient of resistance (TCR) of 2.8%/K implies promising application in uncooled IR detectors. A 2-D array of 10-element test microbolometer is fabricated without thermal isolation structure. The IR response of the microbolometer is measured in the spectral range 8-13 μm. The detectivity and the responsivity are determined as ∼6×10⁵ cm Hz^1/2/W and 36 V/W, respectively, at 10 Hz of the chopper frequency with 50 μA bias current for a thermal conductance G∼10-3 W/K between the thermal sensing layer and the substrate. By extrapolating with the data of a typical thermally isolated microbolometer (G∼10⁻⁷ W/K), the projected responsivity is found to be around 10⁴ V/W, which well compares with the reported values.     

Growth and stability of Ga2O3 nanospheres

Gallium oxide thin films were prepared by thermal evaporation and deposition of Ga₂O₃ on NaCl(001) cleavage planes at varying substrate temperatures, oxygen pressures and deposition rates. The structure of the so-prepared thin films was checked by Transmission Electron Microscopy and Selected Area Diffraction and also characterized by X-ray Photoelectron Spectroscopy and Atomic Force Microscopy, both in the as-deposited state and after different oxidative and reductive treatments. The substrate temperature proved to be most crucial for the structure of the gallium oxide films, ranging from low-contrast amorphous structures at low substrate temperatures (298 K) to nanosphere structures at higher temperatures (580 K). The stability of the films was found to be mainly determined by the interaction of substrate temperature and deposition rate. Crystalline β-Ga₂O₃ structures were obtained after oxidative, reductive and annealing treatments at and beyond 773 K suggesting that the crystallization is mainly a thermal annealing effect.     

Effect of annealing temperature on the tribological behavior of ZnO films prepared by sol-gel method

The tribological behavior of zinc oxide (ZnO) films grown on glass and silicon (100) substrates by sol-gel method was investigated. Particularly, the as-coated films were post-annealed at different temperatures in air to investigate the effect of annealing temperature. Crystal structural and surface morphology of the films were measured by X-ray diffraction (XRD) and Atomic Force Microscopy (AFM). XRD patterns and AFM images indicated that the crystallinity and grain size of the films were enhanced and increased, respectively, with temperature. The tribological behavior of films was evaluated by sliding the ZnO films against a Si₃N₄ ball under 0.5 gf normal load using a reciprocating pin-on-plate tribo-tester. The wear tracks of the films were measured by AFM to quantify the wear resistance of the films. The results showed that the wear resistance of the films could be improved by the annealing process. The wear resistance of the films generally increased with annealing temperature. Specifically, the wear resistance of the films was significantly improved when the annealing temperature was higher than 550° C. The increase in the wear resistance is attributed to the increase in hardness and modulus of the film with annealing temperature.     

VOx/TiOx/Ti多层薄膜的制备工艺与内耗研究

用磁控反应溅射法在玻璃和镅片衬底上制备Vox/TiOx/Ti多层薄膜.用X射线衍射(XRD)、QJ31单臂电桥、薄膜内耗仪等测试了薄膜的晶体结构、电阻、内耗.分别进行了薄膜的制备工艺与内耗研究.测试分析结果表明:试样的晶体结构、电阻-温度曲线、杨氏模量的突变均表明多层薄膜在66℃左右发生相变.样品的电阻温度系数为-4.35%/℃.并且真空退火有利于二氧化钒相生成.     

Size control and magnetic properties of single layer monodisperse Ni nanoparticles prepared by magnetron sputtering

Single layer monodisperse Ni nanoparticles were successfully prepared by reductive annealing of NiO films formed by magnetron sputtering. The spherical Ni nanoparticles had a monodisperse distribution on the substrate. The formation process of Ni nanoparticles was investigated, and the Ni nanoparticle size can be precisely controlled by the magnetron sputtering time. Morphology of these nanoparticles was observed with scanning electron microscopes and transmission electron microscopes. Magnetic properties of Ni nanoparticles have been confirmed by using a vibration sample magnetometer. The blocking temperature, particle size, and effective anisotropy constant were calculated by fitting the relationship between coercivity and temperature.     

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.     

Role of oxygen in enhancing N-type conductivity of CuInS2 thin films

Post-growth treatments in air atmosphere were performed on CuInS₂ films prepared by the single-source thermal evaporation method. Their effect on the structural, optical and electrical properties of the films was studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), optical reflection and transmission and resistance measurements. The films were annealed from 100 to 350 °C in air. The stability of the observed N-type conductivity after annealing depends strongly on the annealing temperature. Indeed it is shown that for annealing temperatures above 200 °C the N-type conductivity is stable. The resistance of the N-CuInS₂ thin films correlates well with the corresponding annealing temperature. The samples after annealing have direct bandgap energies of 1.45-1.50 eV.     

PECVD法制备的SnOx气敏膜的色变机理

有用ＰＥＶＣＤ法制备了非晶掺Ｓｎ有机膜，经过退火处理得到ＳｎＯｘ气敏膜，考察了退火过程和气敏响应过程的阻温特性和颜色变化的关系，研究了表面掺Ａｇ对ＳｎＯｘ元件电阻、