共查询到16条相似文献,搜索用时 140 毫秒
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采用脉冲激光沉积(PLA)法,在单晶Si试样表面沉积制备了一系列TiN/AlN硬质多层膜,并采用基于免疫算法的免疫径向基函数(IRBF)神经网络对AlN厚度建立预测模型,设计出具有可控调制周期和调制比的TiN/AlN多层膜。X射线衍射(XRD)结果表明,小调制层周期下,过高或过低的工艺条件下薄膜通常为非晶态,适当的工艺条件下TiN、AlN形成具有强烈织构的超晶格柱状晶多层膜;与此相应,纳米多层膜产生了硬度和弹性模量异常增高;随着调制比增加,使纳米多层膜形成非晶AlN层和纳米晶TiN层的多层结构,多层膜的硬度和弹性模量逐渐下降。XPS结果表明,薄膜界面由Ti+4、Ti+3离子组成,N的负二价、三价亚谱结构预示着非当量TiN、AlN的形成。AFM研究显示,薄膜的调制周期均在10~200 nm范围内,且薄膜表面较均匀;当多层薄膜调制周期在50 nm以下时,薄膜的纳米硬度值明显高于TiN和AlN的混合硬度值,达30 Gpa。 相似文献
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脉冲激光沉积TiN/AlN多层膜的微结构与力学性能 总被引:1,自引:1,他引:0
采用脉冲激光沉积(LPA)法,在单晶Si表面制备了调制周期为50nm的不同调制比的TiN/AlN多层膜,并研究了调制比对多层膜微结构和力学性能的影响。扫描电镜(SEM)和原子力显微镜(AFM)显示,薄膜的调制比在1~4之间。并且小调制比下薄膜表面的岛密度小,岛面积过大,分布不均匀,相邻岛之间的起伏较大。X射线衍射(XRD)结果表明,小调制比下,AlN相为明显的(002)择优取向,TiN相主要以(200)、(220)形式存在;调制比增大后,AlN相的择优取向减弱,同时伴随着薄膜晶粒的细化及硬度增强,这一研究结果说明,调制比对多层膜的性质有一定的影响,大调制比会导致Al元素在界面处聚集,并与TiN进行合金化后的形成TiAlN结构,进而对薄膜的硬度产生影响。 相似文献
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本文采用纳秒脉冲激光沉积法在单晶硅试样表面制备了调制周期为20nm和200nm的TiN/AlN硬质多层膜,通过有限元模拟和纳米压痕方法研究了调制周期对多层膜的开裂机理的影响。结果表明:调制周期200nm时,载荷致使能量表层积累形成应力集中,一定程度后界面应变梯度劣化促使界面裂纹萌生、扩展。载荷继续增加后,主裂纹沿纵向扩展,其两侧也形成新的应力集中区,原有应力释放。薄膜应力近表层的应力集中超过多层膜的强度极限时,多层膜表层发生开裂。调制周期20nm时,加载诱导应力沿着AlN软膜向多层薄膜内部传递,能量在纵深方向累积储存,直至超过薄膜的屈服极限时,多层膜内部损伤失效。 相似文献
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由于存在超模量和超硬度效应,纳米多层膜的力学性能成为近年来薄膜研究的热点之一。金属/金属、金属/陶瓷、和陶瓷/陶瓷组成的纳米多层膜都得到了研究。陶瓷/陶瓷体系因表现出更高的硬度值而受到重视,并发现了一些具有超硬效应的多层膜体系[1,2]。本文制备了NbN/TiN纳米多层膜,并研究了其界面微结构与超硬度效应。TiN/NbN纳米多层膜在日本ANELVA公司生产的SPC-350多靶磁控溅射仪上采用反应溅射法制备。溅射气体为氩气和氮气的混和气体。硅基片在Ti靶和Nb靶前交替停留不同时间,得到具有一定调制比(lNbN∶lTiN=1.5∶1)和调制周期(Λ… 相似文献
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宽禁带半导体TiN作为扩散阻挡层以及场效应管的门电极在集成电路中发挥重要作用。通过原子层沉积(atomic layer deposition,ALD)技术沉积不同循环次数TiN薄膜,采用四探针测试仪、台阶仪、扫描电子显微镜(SEM)、原子力显微镜(AFM)对薄膜进行了表征,确定了薄膜电阻率、生长速率、表面粗糙度与工艺条件的依赖关系。实验结果表明,ALD可实现膜厚精确控制、大面积均匀性优异、电阻率较小的薄膜制造,沉积薄膜的最小粗糙度为0.101nm,电阻率为5μΩ·cm,薄膜稳定生长速率为0.025nm/cycle。 相似文献
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采用射频(RF)反应磁控溅射法,以氩气和氮气为反应气体,在不同的RF偏置功率下,在Si(100)和Si(111)衬底上制备了具有六方纤锌矿结构的AlN薄膜。使用扫描电子显微镜(SEM)表征了薄膜的截面形貌和厚度;利用原子力显微镜(AFM)和X射线衍射仪(XRD)研究了RF偏置功率对Si(111)和Si(100)衬底上沉积的AlN薄膜微观结构和表面粗糙度的影响。结果表明,在RF偏置功率为5~15 W时,两种衬底均可生长(002)择优取向AlN薄膜。RF偏置功率为20 W时,AlN薄膜(002)择优取向变弱,薄膜质量变差。当RF偏置功率为10 W时,Si(111)和Si(100)两种衬底沉积的AlN薄膜的半高宽(FWHM)值和表面均方根粗糙度均最小,其表面均方根粗糙度的最小值分别为2.427和2.836 nm。 相似文献
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Pulsed laser deposition and processing of wide band gap semiconductors and related materials 总被引:1,自引:0,他引:1
R. D. Vispute S. Choopun R. Enck A. Patel V. Talyansky R. P. Sharma T. Venkatesan W. L. Sarney L. Salamancariba S. N. Andronescu A. A. Iliadis K. A. Jones 《Journal of Electronic Materials》1999,28(3):275-286
The present work describes the novel, relatively simple, and efficient technique of pulsed laser deposition for rapid prototyping
of thin films and multi-layer heterostructures of wide band gap semiconductors and related materials. In this method, a KrF
pulsed excimer laser is used for ablation of polycrystalline, stoichiometric targets of wide band gap materials. Upon laser
absorption by the target surface, a strong plasm a plume is produced which then condenses onto the substrate, kept at a suitable
distance from the target surface. We have optimized the processing parameters such as laser fluence, substrate temperature,
background gas pressure, target to substrate distance, and pulse repetition rate for the growth of high quality crstalline
thin films and heterostructures. The films have been characterized by x-ray diffraction, Rutherford backscattering and ion
channeling spectrometry, high resolution transmission electron microscopy, atomic force microscopy, ultraviolet (UV)-visible
spectroscopy, cathodoluminescence, and electrical transport measurements. We show that high quality AlN and GaN thin films
can be grown by pulsed laser deposition at relatively lower substrate temperatures (750–800°C) than those employed in metal
organic chemical vapor deposition (MOCVD), (1000–1100°C), an alternative growth method. The pulsed laser deposited GaN films
(∼0.5 μm thick), grown on AlN buffered sapphire (0001), shows an x-ray diffraction rocking curve full width at half maximum
(FWHM) of 5–7 arc-min. The ion channeling minimum yield in the surface region for AlN and GaN is ∼3%, indicating a high degree
of crystallinity. The optical band gap for AlN and GaN is found to be 6.2 and 3.4 eV, respectively. These epitaxial films
are shiny, and the surface root mean square roughness is ∼5–15 nm. The electrical resistivity of the GaN films is in the range
of 10−2–102 Θ-cm with a mobility in excess of 80 cm2V−1s−1 and a carrier concentration of 1017–1019 cm−3, depending upon the buffer layers and growth conditions. We have also demonstrated the application of the pulsed laser deposition
technique for integration of technologically important materials with the III–V nitrides. The examples include pulsed laser
deposition of ZnO/GaN heterostructures for UV-blue lasers and epitaxial growth of TiN on GaN and SiC for low resistance ohmic
contact metallization. Employing the pulsed laser, we also demonstrate a dry etching process for GaN and AlN films. 相似文献
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We have investigated the deposition of titanium nitride (TiN) and diamond-like carbon (DLC ) films on polymethylmethacrylate (PMMA) substrates using pulsed laser deposition (PLD) technique. The TiN and diamond-like films were deposited by laser ablation (KrF excimer laser λ = 248 nm, pulse duration τ~25 × 10?9 s, energy density ~2?15J/cm2) of TiN and graphite targets, respectively, at room temperature. These films were characterized by transmission electron microscopy, scanning electron microscopy, x-ray diffraction, Auger electron spectroscopy, UV-visible absorption spectroscopy, and Raman spectroscopy. The TiN films were smooth and found to be polycrystalline with average grain size of 120Å. The diamond-like carbon films were amorphous with a characteristic Raman peak at 1550 cm?1. The TiN films are highly adherent to the polymer substrates as compare to DLC films. The adhesion strength of DLC films on polymers was increased by interposing thin TiN layer (200Å) on polymers byin-situ pulsed laser deposition. The DLC films were found to be amorphous with good adhesion to TiN/PMMA substrates. 相似文献
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G. S. Sudhir H. Fujii W. S. Wong C. Kisielowski N. Newman C. Dieker Z. Liliental-Weber M. D. Rubin E. R. Weber 《Journal of Electronic Materials》1998,27(4):215-221
Thin films of AlN and GaN were grown by pulsed laser deposition on c-plane sapphire substrates. It is demonstrated that the
structure and surface morphology of layers can actively be controlled by adjusting the nitrogen partial pressure during the
growth. The observed trends in the structural quality of the thin films can be attributed to the changes in the surface diffusion
of adatoms. It is argued that the surface diffusion of adatoms can be influenced by the collisions between the nitrogen gas
molecules and the activated atoms which can reduce the kinetic energy of activated atoms and increase the rate of formation
of immobile surface dimers. Through these nitrogen pressure related effects, thin films with microstructure ranging from crystalline
to amorphous can be produced. The observed similar impact of nitrogen pressure on the growth of GaN and AlN thin films indicates
that a pressure assisted growth procedure is generally applicable to design the surface morphology of group III-nitride thin
films. A minimal surface root mean square roughness of 0.7 nm for amorphous AlN is obtained which compares well with the substrate
roughness of 0.5 nm. Rutherford backscattering spectroscopy of thin films of GaN and AlN showed a large incorporation of oxygen
which was found to reduce the lattice constants of GaN and AlN. 相似文献
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利用ZnO缓冲层制备AlN薄膜 总被引:2,自引:1,他引:2
采用脉冲激光淀积 (PL D)技术 ,利用 Zn O作为缓冲层 ,在 Si(10 0 )衬底上生长出 Al N薄膜。X-射线衍射图谱表明 ,该 Al N薄膜具有 c轴取向特性。X-光电子能谱测试表明 ,要获得接近理想化学配比的 Al N薄膜 ,需要高真空淀积气氛或合适的 N2 气氛 ;同时还表明 ,Al N薄膜表面容易形成保护性氧化层。剖面透射电子显微镜显微照相显示该 Al N/ Zn O/ Si(10 0 )多层结构清晰可辨 ,层与层之间的界面非常平整。原子力显微镜分析表明 ,采用 Zn O缓冲层可改善 Al N薄膜的表面粗糙度 (RMS=1nm) 相似文献
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金刚石基底上制备(002)AlN薄膜的研究 总被引:1,自引:1,他引:0
首先采用微波等离子体化学气相沉积(MPCVD)方法,在O2/H2/CH4混合气体气氛下利用大功率微波在(100)Si片上生长出了异质外延金刚石膜,X-射线衍射(XRD)、拉曼光谱和场发射扫描电子显微镜(FESEM)对薄膜的表征分析结果表明,制备的金刚石膜具有很高的金刚石相纯度,且晶粒排列紧密;继而采用射频磁控反应溅射法,在抛光的金刚石基底上成功制备了高C轴择优取向的氮化铝(AlN)薄膜,研究了不同的溅射气压、靶基距对AlN薄膜制备的影响,XRD检测结果表明,溅射气压低,靶基距短,有利于AlN(002)面择优取向,相反则更有利于AlN薄膜的(103)面和(102)面择优取向;研究了AlN薄膜在以N终止的金刚石基底和纯净金刚石基底两种表面状态上的生长机制,结果发现,以N终止的金刚石基底非常有利于AlN(002)面择优取向生长;从Al-N化学键的形成以及溅射粒子平均自由程的角度,探讨了其对AlN薄膜择优取向的影响。 相似文献