高透过率红外窗口保护薄膜的研制

在Si、Ge红外窗口上利用离子辅助电子束蒸发技术和RF-PECVD技术制备了具有高透过率的AR／DLC保护薄膜,并与单层DLC保护薄膜的光学性能进行了对比。所制备的高透过率保护薄膜达到如下性能：在3～5μm波段,Si基底上一面镀高效红外增透膜一面镀AR／DLC增强型保护薄膜的平均透过率达到约96％,较之镀DLC膜平均透过率提高了约4％。在8～12μm波段,Ge基底上一面镀高效红外增透膜一面镀AR／DLC增强型保护薄膜的平均透过率达到约95％,较之镀DLC膜平均透过率提高了约5％。有关薄膜样品都通过了相应的环境试验。     

退火对Ge诱导晶化多晶Si薄膜结晶特性的影响

本文采用磁控溅射法, 衬底温度500 ℃下在硅衬底上分别制备具有Ge填埋层的a-Si/Ge 薄膜和a-Si薄膜, 并进行后续退火, 采用Raman光谱、X射线衍射、原子力显微镜及场发射扫描电镜等对所制薄膜样品进行结构表征. 结果表明, Ge有诱导非晶硅晶化的作用, 并得出以下重要结论: 衬底温度为500 ℃时生长的a-Si/Ge薄膜, 经600 ℃退火5 h Ge诱导非晶硅薄膜的晶化率为44%, 在相同的退火时间下退火温度提高到700 ℃, 晶化率达54%. 相同条件下, 无Ge填埋层的a-Si薄膜经800 ℃退火5 h薄膜实现晶化, 晶化率为46%. 通过Ge填埋层诱导晶化可使在相同的条件下生长的非晶硅晶薄膜的晶化温度降低约200 ℃. Ge诱导晶化多晶Si薄膜在Si(200)方向具有高度择优取向, 且在此方向对应的晶粒尺寸约为76 nm. 通过Ge诱导晶化制备多晶Si薄膜有望成为制备高质量多晶Si薄膜的一条有效途径.     

化学溶液法制备的Pb(Mg1/3 Nb2/3)O3-PbTiO3薄膜的光学性能

用化学溶液方法在宝石衬底及有LaNiO3缓冲层的Pt/TiO2/SiO2/Si衬底上制备了92%Pb(Mg1/3 Nb2/3)O3-8%PbTiO3(PMNT)薄膜,X射线衍射测试结果表明:在有LaNiO3缓冲层的Pt/TiO2/SiO2/Si衬底上制备的PMNT薄膜几乎是纯钙钛矿相,且薄膜呈现(110)择优取向.通过对Pt/TiO2/SiO2/Si衬底上的PMNT薄膜在2.5-12.6μm波长范围内的红外椭圆偏振光谱测试,并拟合得到了PMNT薄膜在2.5-12.6μm波长范围内的光学常数(n和k),通过对宝石衬底上的PMNT薄膜在200-1100nm波长范围内的可见-紫外透过率测试,并拟合得到了PMNT薄膜在200-1100nm波段的光学常数(n和k)和吸收系数α,进而推导出PMNT薄膜的禁带宽度为4.03eV.     

Au诱导形成有序Si纳米孔阵列及其应用

以自组装聚苯乙烯小球(PS)单层膜为掩膜,利用Au对Si表面的催化氧化作用以及KOH溶液对单晶Si的各向异性腐蚀特性,在Si(100)面上制备了一系列尺寸小于100 nm有序可控的Si纳米孔阵列.扫描电镜(SEM)和原子力显微镜(AFM)等的测试结果显示:当PS小球溶液与甲醇溶液的体积比为9:11时,可形成大面积无缺陷的单层膜;但当体积比过大时,会导致类似双层膜结构的形成;而当体积比过小时,会诱导形成点缺陷和线缺陷.对PS小球及溅射Au处理过的Si晶片进行KOH溶液腐蚀,随着腐蚀时间变长,纳米孔的横向尺寸和深度增大,其形貌由圆形逐渐变为倒金字塔型,当腐蚀时间超过10 min,纳米孔阵列的有序性遭到破坏.采用离子束溅射技术在倒金字塔型纳米孔衬底上获得了有序Ge/Si纳米岛,而在圆形纳米孔衬底上获得了有序Ge/Si纳米环.进一步对有序Ge/Si纳米岛及纳米环的形成机理进行了解释.     

自支撑Zr膜制备及软X射线透过性能研究

软X射线波段滤光膜材料大都为自支撑金属薄膜,实验室环境下自支撑薄膜长期与空气接触表面易氧化,空气中的杂质原子进入自支撑薄膜内部,致使自支撑膜光学性能大幅下降.5 nm至20 nm软X射线波段Zr具有较低的质量吸收系数和较小的密度,在该波段Zr滤光膜透过率较高.采用脱模剂法制备自支撑Zr膜,在洁净的浮法玻璃上蒸镀一层NaCl做为脱膜剂,直流磁控溅射沉积Zr膜,脱膜后的到自支撑Zr膜.为防止薄膜表面氧化及空气中杂质原子进入薄膜内部,在Zr膜两面各直流磁控溅射沉积一层10 nm厚的C或Si膜作为保护膜,得到C/Zr/C、Si/Zr/Si复合膜,测试结果显示C或Si膜的引入对于自支撑Zr膜光学性能基本无影响.     

离子源辅助电子枪蒸发制备Ge1－xCx薄膜

应用电子枪蒸发纯Ge,考夫曼离子源辅助的方法在Ge基底上沉积了Ge1－xCx薄膜.制备过程中,Ge作为蒸发材料,CH4作为反应气体.通过改变CH4/(CH4+Ar)的气体流量比（G）,制备了G从40％到85％的Ge1－xCx薄膜.应用X射线衍射仪（XRD）测量了Ge1－xCx薄膜的晶体结构,使用傅里叶红外光谱仪（FTIR）测量了2～22 μm的光学透过率,X射线光电子能谱测试（XPS）计算得到C的含量随G的变化关系,用纳米压痕硬度测试计测量了Ge1－xCx薄膜的硬度,原子力显微镜（AFM）测量了G为60％,85％时Ge1－xCx薄膜的表面粗糙度.测试结果表明：制备的Ge1－xCx薄膜在不同的G值下均为无定形结构.折射率随着G值的增加而减小,在3.14～3.89之间可变,并具有良好的均匀性以及极高的硬度.     

多层膜界面结构探测技术

分别以丙醇锆和正硅酸乙酯为原料,采用溶胶-凝胶工艺制备了性能稳定的ZrO2和Si O2溶胶。用旋转镀膜法在K9玻璃上分别制备了Si O2单层膜、ZrO2单层膜和ZrO2/Si O2/ZrO2三层膜。采用椭偏仪测量薄膜的厚度与折射率,用紫外-可见分光光度计测量了薄膜的透过率,利用TFCalc_Demo模系设计软件,采用三层理论模型对薄膜的透过率进行模拟,用扫描电镜(SEM)观察了三层膜的断面结构,用X射线光电子能谱仪(XPS)测量了薄膜的成分随深度方向的变化,进一步验证了ZrO2/Si O2/ZrO2三层膜之间的渗透关系,同时对多层膜的界面结构探测方法起到了借鉴作用。     

硫化锌基底硬质红外保护薄膜技术研究

硫化锌在3~5μm和7.7~9.3μm两个波段具有较高透过率,但其脆性大、耐摩擦性能较差,在其表面镀制类金刚石膜保护膜可显著提高其使用性能。直接在硫化锌基底沉积类金刚石膜难以实现,采用匹配层与过渡层的设计思想,制备出类金刚石膜与硫化锌基底之间相互牢固结合的过渡层。通过等离子体化学气相增强法在过渡层上成功制备类金刚石膜。研究了射频功率、气压等对保护膜系力学性能的影响。结果表明,镀制了硬质保护薄膜的硫化锌窗口在3~5μm和7.7~9.3μm双波段的平均透过率均高于90%,膜层硬度为硫化锌窗口近5倍。经环境试验之后,膜层光学性能与机械性能均无变化。     

RF-PECVD法制备大面积类金刚石薄膜性能的研究

采用RF-PECVD法在锗、硅红外光学窗口上制备了大面积(基底直径φ=150～250mm)类金刚石薄膜.采用拉曼光谱分析了大面积DLC膜的结构组成,对RF-PECVD法制备的大面积DLC膜的均匀性、红外光学性能、机械力学性能以及其抗恶劣环境的能力进行了检测和分析.膜层厚度均匀性在3%以内.锗、硅红外窗口双面镀制DLC膜后,极值透过率分别达92%和96%以上,可显著提高红外光学窗口的显微硬度.膜层具有极强的抗盐雾、耐海水腐蚀和抗摩擦的能力.     

衬底温度对HfO_2薄膜结构和光学性能的影响

采用直流磁控反应溅射法,分别在室温,200,300,400和500℃下制备了HfO2薄膜。利用X射线衍射(XRD)、椭圆偏振光谱(SE)和紫外可见光谱(UVvis)研究了衬底温度对HfO2薄膜的晶体结构和光学性能的影响。XRD研究结果显示:不同衬底温度下制备的HfO2薄膜均为单斜多晶结构;随衬底温度的升高,(-111)面择优生长更加明显,薄膜中晶粒尺寸增大。SE和UVvis研究结果表明:随衬底温度升高,薄膜折射率增加,光学带隙变小;制备的HfO2薄膜在250～850nm范围内有良好的透过性能,透过率在80%以上。     

激光制备类金刚石膜技术研究

现有技术制备的类金刚石(DLC)膜由于含氢、硬度低、内应力大、附着力差等特点,严重限制了其光学工程应用.激光法是近年发展的一种制备DLC膜的新方法,相比其他制备方法具有诸多优点.综合分析了激光制备DLC膜过程中,激光波长、脉宽、功率密度、衬底温度和偏压等因素对薄膜质量的影响规律.采用氧气氛辅助沉积、元素掺杂和双波长激光...     

衬底材料对制备立方氮化硼薄膜的影响

较系统地研究了不同衬底材料对制备氮化硼薄膜的影响。用热丝增强射频等离子体CVD法,以NH3,B2H6和H2为反应气体,在Si,Ni,Co和不锈钢等衬底材料上,成功生长出高质量的立方氮化硼薄膜,还用13.56MHz的射频溅射系统将c-BN薄膜沉积在Si衬底上,靶材为h-BN(纯度为99.99％）,溅射气体为氩气和氮气的混合气体,所得到的氮化硼薄膜中立方相含量高于90%,用X射线衍射谱和傅里叶变换红谱对样品进行了分析表明,衬底材料与c-BN的晶格匹配情况,对于CVD生长立方氮化硼薄膜影响很大,而对溅射生长立方氮化硼薄膜影响不大。     

A study of the optical properties and adhesion of zinc sulfide anti-reflection thin film coated on a germanium substrate

To conduct this study, zinc sulfide (ZnS) thin films deposited on germanium (Ge) substrates were prepared by an evaporation method. The effects of deposition rate and annealing on the optical properties and adhesion of the ZnS thin films were investigated. The transmission intensity and the X-ray diffraction (XRD) pattern of the samples showed that the transmittance of the samples decreases by increasing the evaporation rates. However, with the increase of the annealing temperature, crystallinity of the thin films improves which, in turn, results in the enhancement of the transmission intensity in a far infrared region. The maximum grain size was obtained at the annealing temperature of 225 °C. Our experimental results also show that evaporation rate and annealing influences the adhesion of ZnS thin films to Ge substrates.     

The comparison between CdS thin films grown on Si(111) substrate and quartz substrate by femtosecond pulsed laser deposition

Two kinds of cadmium sulfate (CdS) thin films have been grown at 600 °C onto Si(111) and quartz substrates using femtosecond pulsed laser deposition (PLD). The influence of substrates on the structural and optical properties of the CdS thin films grown by femtosecond pulsed laser deposition have been studied. The CdS thin films were characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), photoluminescence (PL) and Raman spectroscopy. Although CdS thin films deposited both on Si(111) and quartz substrates were polycrystalline and hexagonal as shown by the XRD , SEM and AFM results, the crystalline quality and optical properties were found to be different. The size of the grains for the CdS thin film grown on Si(111) substrate were observed to be larger than that of the CdS thin film grown on quartz substrate, and there is more microcrystalline perpendicularity of c-axis for the film deposited on the quartz substrate than that for the films deposited on the Si substrate. In addition, in the PL spectra, the excitonic peak is more intense and resolved for CdS film deposited on quartz than that for the CdS film deposited on Si(111) substrate. The LO and TO Raman peaks in the CdS films grown on Si(111) substrate and quartz substrate are different, which is due to higher stress and bigger grain size in the CdS film grown on Si(111) substrate, than that of the CdS film grown on the amorphous quartz substrate. All this suggests that the substrates have a significant effect on the structural and optical properties of thin CdS films. PACS 81.15.Fg; 81.05.Ea; 78.20.-e; 78.67.-n; 42.62.-b     

立方氮化硼薄膜的生长特性与粘附性研究

用X射线衍射技术、红外吸收光谱、扫描电子显微镜、X射线光电子能谱对热丝辅助射频等离子体化学汽相沉积法制备的立方氮化硼(c-BN)薄膜的生长特性和粘附性进行了研究.改变生长条件，在Si、不锈钢和Ni衬底上沉积c-BN薄膜，进而研究了c-BN薄膜的质量和生长条件与衬底之间的关系.实验发现，Ni衬底上生长的薄膜c-BN含量较高，且粘附性好.当Si衬底上溅射一层Ni过渡层，再生长c-BN薄膜，薄膜中c-BN含量提高，与Si衬底的粘附性也显著增强. 关键词：     

Room temperature oxidation of Cu(3)Ge films grown on Si and Si(1-x)Ge(x) substrates

Room temperature oxidation of Cu3Ge films grown on Si, Si(0.85)Ge(0.15) and Si(0.52)Ge(0.48) substrates, respectively, at a temperature of 200-300 degrees C was studied using transmission electron microscopy (TEM) in conjunction with energy dispersive spectrometry (EDS) and scanning electron microscopy (SEM). For Cu(3)Ge films grown at 200 degrees C and subsequently exposed in air for 1 week oxide protrusions and oxide networks appeared in the film surface and grain boundaries of Cu(3)Ge, respectively. At room temperature O from air and Si from the substrate, diffused along the grain boundaries of Cu(3)Ge to react with Cu(3)Ge grains, initiating the Cu(3)Si-catalyzed oxidation. Cu(3)Ge films are superior to Cu(3)(Si(1-x)Gex) films in retarding Cu(3)Si-catalyzed oxidation. Annealing at 300 degrees C allowed Si diffusion from the substrate into the Cu(3)Ge overlayer to form Cu(3)(Si(1-x)Gex), enhancing the Cu(3)Si-catalyzed oxidation rate. In the present study, Cu(3)Ge films grown on Si(0.52)Ge(0.48) at 200 degrees C show the best resistance to room temperature oxidation because higher Ge concentration in the substrate and lower temperature annealing can more effectively retard Si diffusion from the substrate into the Cu(3)Ge overlayer, and hence reduce the Cu(3)Si-catalyzed oxidation rate.     

Pulsed laser deposition of hexagonal and cubic boron nitride films

Hexagonal and cubic boron nitride films are deposited by pulsed laser ablation from a boron nitride and a boron target using a KrF excimer laser. Hexagonal films are deposited in nitrogen as background gas or with nitrogen/argon ion bombardment at ion-to-arriving-target-atom (I/A) ratios at the substrate below 0.5. Nucleation of the cubic phase takes place exclusively with ion bombardment at I/A ratios above 1.0, which may be reduced down to 0.6 after the completion of the nucleation process. The influence of the parameters of the laser and ion beams on the properties of the hexagonal films are presented. The Vickers microhardness and the intrinsic stress of those films vary in wide ranges of 5 to 25 GPa and 1 to 16 GPa, respectively. Pulsed laser deposited hexagonal boron nitride films show good adhesion to silicon and stainless steel if they are deposited at I/A ratios below 0.5, and can be used as intermediate layers for improving the adhesion of cubic boron nitride films. So far, 0.5 7m thick, nearly phase-pure cubic boron nitride films with good adhesion have been deposited. The microstructural, mechanical, and optical properties of those layer systems are presented and discussed.     

GeC薄膜的射频磁控反应溅射制备及性质

用射频磁控反应溅射法在ZnS衬底上制备了GeC薄膜,研究了工艺参数对Ge靶溅射及GeC薄膜红外透射性能的影响.衬底温度较低时GeC薄膜中含有H,形成了CH₂,CH₃,Ge-CH₃等,使薄膜产生红外吸收;随衬底温度升高,薄膜红外吸收明显减小.靶基距、射频功率、Ar:CH₄气体流量比、总气压对靶面中毒及溅射影响较大,但对GeC薄膜红外吸收影响较小.靶面中毒严重时,所制备无氢GeC薄膜附着性能差,随靶中毒减弱薄膜附着性能变好.优化工艺后,在ZnS衬底上制备了附着性能良好的无氢GeC薄膜,其折射率约为1.78,薄膜中C的含量比Ge的大,二者主要形成了C—Ge键.所制备的GeC/GaP红外增透保护膜系对ZnS衬底有良好的增透效果. 关键词： GeC薄膜 红外透射光谱 射频磁控溅射 XPS     

Study of the optical properties of germanium films in the mid-IR spectral range

The optical properties of Si-doped germanium films have been investigated. It is shown that Ge films with 1.5 wt % Si have a minimum optical loss. The optical constants of Ge films have been measured at different substrate temperatures. The optimal conditions for producing films with minimum loss are determined.     

Reflective thin-film device for generating spatial binary patterns of orthogonal circular polarization states

A novel device is described that generates, by reflection, polarized optical wavefronts of juxtaposed fields of alternating orthogonal circular polarization states. It consists of a dielectric substrate coated by a transparent thin film of certain refractive index and of thickness that alternates between two discrete values over adjacent areas of the substrate, in a pattern that corresponds to the desired binary polarization pattern of the reflected wave. Devices that use Ge and Si substrates at wavelengths of 10.6 and 0.6328 μm, respectively, are presented as examples.