热丝化学气相沉积金刚石薄膜空间场的数值分析

根据热丝化学气相沉积(HFCVD)金刚石薄膜的几何特点和工艺参数,建立了该系统的二维温度场、速度场和密度场 的耦合模型.利用该模型对沉积大面积金刚石薄膜的空间场进行了模拟计算,研究了沉积参数对空间场的影响.结果表明,衬底处 的温度分布和质量流密度的计算值与实测值相吻合.只有气体进口速度对质量流密度的均匀性影响最大,其它沉积参数对衬底温度 的均匀性、质量流密度的均匀性影响不大.从热丝阵列的最低温度出发,优选出沉积100 mm×100 mm、高质量金刚石薄膜比 较适宜的热丝几何参数.     

脉冲激光沉积技术制备IrO2薄膜的研究

利用脉冲激光沉积(PLD)技术,在Si(100)衬底上制得了导电氧化铱(IrO2)薄膜.讨论了沉积参数(O2分压、衬底温度)对IrO2薄膜的结构、表面形貌和导电性的影响.结果表明20 Pa为最佳O2分压、400℃～500℃为适宜的沉积温度,此条件下制得的IrO2薄膜结晶完整,组织均匀、形状一致,排列致密,其最低电阻率约为42μΩ·cm.     

碳化硼薄膜的电子束蒸发制备及表面分析

采用电子束蒸发技术制备碳化硼薄膜,利用X射线衍射(XRD)分析了薄膜的结构,测量了薄膜的X射线光电子能谱(XPS),并利用原子力显微镜(AFM)对薄膜进行表面分析.XRD结果表明:薄膜的结晶性随着衬底温度的升高逐渐转好,在较低的衬底温度下制备出多晶碳化硼薄膜.XPS分析得到了碳化硼薄膜表面的化学成分和结构特性,其主要成分为B_4C.AFM结果表明,薄膜表面光滑平整、均匀致密,随着衬底温度的升高薄膜均方根(RMS)粗糙度逐渐增大.     

衬底温度对Fe-N薄膜结构、形貌及磁性能的影响

采用直流磁控溅射方法,以Ar和N2作为放电气体,在单晶Si(100)衬底上沉积了Fe-N薄膜.采用X射线衍射仪(XRD)、X射线光电子能谱分析仪(XPS)、原子力显微镜(AFM)和超导量子干涉仪(SQUIDS)对所制备的样品进行了结构、成分、形貌和磁性能分析,研究了衬底温度对薄膜的结构、形貌和磁性能的影响.结果表明:衬底温度对Fe-N薄膜的结构有重要的影响,通过控制衬底温度可以获得单相γ′-Fe4N化合物薄膜;γ′-Fe4N具有较高的饱和磁化强度,是非常有应用前景的磁记录介质及磁头功能材料.     

等离子增强化学气相沉积制备氮化硅薄膜的工艺优化与性能

采用等离子增强化学气相沉积方法在p型<100>硅片沉积氮化硅薄膜，通过椭偏仪和缓冲氧化物刻蚀液(BOE)溶解实验来表征薄膜的均匀性与致密度，研究了射频功率、腔室气压、气体流量比和衬底温度4个工艺参数对氮化硅薄膜性能的影响。结果表明：在60～100 W范围内，射频功率越大，氮化硅薄膜生长速率越快；腔室气压在130 Pa时有利于形成均匀性好、结构致密的氮化硅薄膜。硅烷/氨气气体流量比例较低时，提高流量比可以提高薄膜的致密度，但比例超过1.4后致密度几乎不再变化；衬底温度在200～300℃时，衬底温度越高，薄膜的生长速率越低，致密度越高。最优的工艺参数为：射频功率100 W、腔室气压130 Pa、硅烷流量280 mL/min、氨气流量10 mL/min、衬底温度300℃,此时氮化硅薄膜的生长速率为16.3 nm/min,均匀性为0.07%,折射率为2.1,溶解速率为0.42 nm/s。     

衬底温度对脉冲激光沉积氧化锌薄膜性能的影响

采用脉冲激光沉积(PLD)技术,在Si(100)衬底上制备出高度c轴取向的ZnO薄膜。运用X射线衍射(XRD)、光致发光谱(PL)、拉曼光谱(Raman)对衬底温度在300⁷00℃条件下沉积的氧化锌薄膜进行表征,研究了衬底温度对氧化锌薄膜结构和发光特性的影响。实验表明,700℃条件下沉积的薄膜具有相对较好的结晶质量,其X射线衍射峰半高宽(FWHM)最窄,晶粒最大,近带边紫外发光峰与深能级发光峰的比值显著增强。     

衬底温度对CuCrO_2薄膜结构及光电性能的影响

采用射频磁控溅射方法,在石英衬底上制备CuCrO_2薄膜。通过X射线衍射(XRD)、X射线光电子能谱(XPS)、紫外吸收光谱以及电导率的测定,表征不同衬底温度沉积薄膜样品的结构与光电性能。结果表明:薄膜的结晶度、可见光透过率与室温电导率均随衬底温度的升高而增大。衬底温度升高至923 K后,薄膜由非晶转变为具有铜铁矿结构的单相CuCrO_2。1023 K沉积的薄膜光电性能最佳,其平均可见光透过率为50%,室温电导率为0.33 S/cm。在近室温区(150～300 K),1023 K沉积薄膜导电规律符合半导体热激活模式,激活能为0.04 eV。     

衬底温度对FeCrCoNiMn高熵合金氮化物薄膜组织结构和电性能的影响

采用射频反应磁控溅射法在Si(100)衬底上制备出纳米晶高熵合金FeCrCoNiMn氮化物薄膜,结合场发射扫描电子显微镜(FESEM)、电子显微探针(EPMA)、X射线光电子能谱分析仪(XPS)、原子力显微镜(AFM)及四点探针(FPP)研究了衬底温度(40、300、500℃)对沉积薄膜的表面形貌、化学组成、微观结构和导电性能的影响。结果表明,衬底温度对高熵合金FeCrCoNiMn-N薄膜的形貌、组织结构和导电性能有显著影响。随衬底温度的升高,薄膜的表面粗糙度和颗粒/晶粒尺寸增大;与氮反应沉积后,含氮高熵合金薄膜中形成了Mn3N2、MnN、Cr2N和CrN金属氮化物,而Fe、Ni和Co元素则以Fe-Ni-Co合金相形式存在。不含氮合金薄膜其电阻率高达131.78mΩ·cm,加入氮沉积后,随衬底温度的增加,含氮薄膜的电阻率逐渐减小(6.14~0.43mΩ·cm),含氮合金薄膜的电阻率明显小于合金靶材的沉积膜,衬底温度500℃时薄膜的电阻率达到最小值0.43mΩ·cm。     

TiO_2薄膜成分和结构分析及其对折射率的影响

在硅衬底上利用电子束蒸发沉积了TiO_2薄膜,利用椭圆偏振仪测量了不同沉积温度下的TiO_2薄膜的折射率,发现其折射率随着沉积温度的升高而升高.利用X射线衍射(XRD)仪对这些薄膜的结构进行表征,发现折射率高的样品其结晶化程度也高.利用X射线光电子能谱(XPS)和傅立叶红外吸收谱(FT-IR)相结合的方法对薄膜的成分进行分析,发现内部存在低价态的钛氧化物,使薄膜的折射率明显低于固体块材料的折射率.     

不同基底温度FeNiCoCrMn高熵合金薄膜的制备及耐腐蚀性能的研究

用射频磁控溅射的方法分别在单晶Si(100)和304不锈钢基底上制备了FeNiCoCrMn高熵合金薄膜,利用EPMA、XRD、SEM和动电位极化测试,确定薄膜的成分并探讨不同基底温度下沉积的薄膜的相结构、膜厚、形貌以及耐腐蚀性能规律。研究表明:高熵合金薄膜的成分与高熵合金靶材的成分一致,组成元素接近等摩尔比,且薄膜成分均匀;基底温度为100、200、300℃沉积的薄膜为非晶结构,基底温度为400、500℃沉积的薄膜为晶体结构;随着基底温度的升高,薄膜的厚度变薄,薄膜表面颗粒越来越大,横截面柱状组织越来越明显;由动电位极化测试的结果得出不同衬底温度沉积的高熵合金薄膜在1mol/L H2SO4溶液中的耐腐蚀性都优于304不锈钢,且随着衬底温度的升高,薄膜的耐腐蚀性能降低,其中100℃沉积的薄膜的耐腐蚀性能最优。     

Investigation on carbon dioxide corrosion behaviour of HP13Cr110 stainless steel in simulated stratum water

The carbon dioxide corrosion behaviour of HP13Cr110 stainless steel in simulated stratum water is studied by potentiodynamic curve and electrochemical impedance spectroscopy (EIS); the micro-structure and composition of the corrosion scale formed at high-temperature and high-pressure are analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results show that 13Cr stainless steel is in passive state in the stratum water, the passive current density increases and the passive potential region decreases with increasing temperature. The corrosion scale formed at high-temperature and high-pressure is mainly composed of iron/chromium oxides and a little amount of FeCO₃.     

Sputter deposition and XPS analysis of nickel silicide thin films

Binary component Ni-Si films of different compositions are fabricated on AISI 304L stainless steels by means of ion-beam sputter (IBS) deposition. The compositions of the thin films and the chemical states of elements are analysed by means of X-ray photoelectron spectroscopy (XPS). The phase formation is studied and discussed in view of Pretorius' effective heat of formation (EHF) model. The proportions of the resulting phases can then be deduced. The electronic structure for the various compositions is also qualitatively investigated from the XPS valence band spectra, suggesting the bonding changes from predominating metallic to covalent bonding in Ni-Si systems when Si content increases.     

Effect of laser fluences on the structure of carbon nitride films deposited by direct current plasma assisted pulsed laser ablation

Carbon nitride films were deposited by direct current plasma assisted pulsed laser ablation of a graphite target under a nitrogen atmosphere at room temperature. The surface morphology, composition and bonding structure of the deposited films were characterized by atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, Raman, and X-ray photoelectron spectroscopy (XPS). The effect of laser fluences in the range 0.5–3 J/cm² on the surface morphology, composition and bonding structure of the carbon nitride films were systematically studied. As laser fluence is increased, AFM results show a great decrease in the surface roughness of carbon nitride films. FTIR and XPS results indicate an increase in the N/C ratio and the content of N atoms bonded to sp³ C, as well as a decrease in the content of H atoms and the content of N atoms boned to sp² C in the deposited films, and Raman spectra indicate an increase in the content of disordered sp² C atoms and the sp² cluster size. The increase in the film density and the decrease in the particle fraction contribute to the decrease of surface roughness with increasing laser fluence.     

PECVD OF HARD AND ELASTIC BCN COATINGS

Compounds of the B-C-N system are very promising to produce superhard coatings with good tribological, chemical and thermal properties. Consequently, BCN films were prepared by plasma enhanced chemical vapor deposition (PECVD). The films were deposited from gaseous mixtures of BCl3-C2H4-N2-H2-Ar in different unipolar and bipolar pulsed glow discharges at 550℃ and analyzed with respect to composition, electronic structure and mechanical properties. The micro structure and composition of the BCN films were determined by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS). Mechanical properties were characterized using both the traditional Vickers method and nanoindentation. The films, that were deposited using a bipolar pulsed generator, were weak and had a sponge-like structure, whereas the films prepared using an unipolar generator were well adherent, had a hardness of more than 11GPa and very high e     

氨化Si基Ga2O3／Al2O3制备GaN薄膜

研究了Ga2O3／Al2O3膜反应自组装制备GaN薄膜。首先利用磁控溅射法在硅衬底上制备Ga2O3／Al2O3膜，再将Ga2O3／Al2O3膜在高纯氨气气氛中氨化反应得到了GaN薄膜。用X射线衍射(XRD)，X光光电子能谱(XPS)、扫描电镜(SEM)、透射电镜(TEM)和荧光光谱(PL)对样品进行结构、组分、形貌和发光特性的分析。测试结果表明：用此方法得到了六方纤锌矿结构的GaN晶体膜。     

防X射线稀土/聚丙烯复合纤维的制备及性能研究

通过密炼机将纳米稀土和聚丙烯(PP)共混,然后对共混物进行熔融纺丝,采用红外、差示扫描量热、X射线衍射、扫描电子显微镜测试等手段对所得纤维进行结构性能表征,并将短纤维层压作防辐射测试。实验结果表明,氧化镧质量分数在60%以内,其在聚丙烯基体中呈纳米级不均匀分散;随着氧化镧加入量的增加,铅当量也相应增加,稀土/聚丙烯复合防护纤维具有较好的X射线防护功能。     

Oxidation of copper by fast atomic oxygen

The surface composition of the oxide formed on thin-film and solid OFHC copper samples exposed to a fast-atomic-oxygen environment in a low-earth orbit on NASA's Long Duration Exposure Facility (LDEF) was investigated using X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), thin-film X-ray diffraction (TF-XRD), high-resolution profilometry, and reflectance measurements. The results confirm that it is easier to form thick copper oxide layers in the atomic oxygen ambient than is normally possible with other laboratory-based techniques.     

Corrosion properties of thermally annealed and co-sputtered nickel silicide thin films

The corrosion properties of nickel silicide thin films are addressed by means of polarisation experiments in combination with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) characterisation before and after the polarisation runs. The thin films studied included two pairs of nickel silicide of different compositions fabricated on Si wafer by means of ion-beam sputter deposition technique. For one pair, thin films were prepared by co-sputtering Si and Ni targets. To achieve higher crystallinity, the other pair was prepared by Ni sputter deposition followed by subsequent thermal annealing at 280 °C and 480 °C to develop single silicide phase of Ni₂Si and NiSi in individual film, respectively. The variation of the binding energy (BE) of Ni 2p_3/2 core-level peak in the XPS measurement in accordance with the Si content for this binary system follows a Boltzmann's relationship. The electrochemical polarisation tests conducted in 1.00 M HCl solution showed almost the same behaviour for the tested specimens irrespective of structure or film composition, still, the SEM and XPS studies together with optical microscopy showed that the Ni₂Si, leaner in Si, experienced thin film corrosion, whilst the NiSi appeared to be more resistant. Clearly, composition is found to be a more important design factor to tailor the corrosion properties than the structure for this binary silicide system.