掺氮氧化铪的光学特性研究

掺氮氧化铪是半导体工业非常重要的材料。在本论文中,我们利用Hf[N(C₂H₅)(CH₃)]₄ 和 H₂O₂作为原子层淀积的前驱体,制备了二氧化铪材料。然后,我们使用快速热退火的办法,在不同温度下,对二氧化铪进行了氮掺杂工艺。我们对掺氮二氧化铪的组分,跟硅界面的稳定性以及薄膜材料的光学特性随退火温度的变化进行了细致的研究。研究发现,随着退火温度的提高,二氧化铪薄膜材料的氮组分从1.41% 上升至 7.45%,相应的,薄膜材料的禁带宽度从5.82 eV 降低为 4.94 eV。     

富硅氮化硅薄膜的制备及其发光特性

采用射频磁控反应溅射法制备了氮化硅薄膜.利用X射线衍射谱(XRD)、红外光谱(IR)、能谱(EDS)和光致发光谱(PL),通过与氮气中和空气中退火薄膜比较,对原沉积薄膜进行了成分与结构和发光特性研究.研究发现原沉积薄膜是部分晶化的富硅氮化硅薄膜,薄膜中晶态氮化硅颗粒的平均粒径为33 nm;在氮气中退火后,纳米颗粒增大;在空气中退火后,薄膜被氧化,晶态颗粒消失.在4.67 eV的光激发下,原沉积薄膜中观测到7个强的PL峰,其峰位分别为3.39,3.24,3.05,2.82,2.61,2.37和2.11 eV.在氮气和空气中退火后, PL峰位和强度有变化.对其光致发光机制进行了探讨, 认为硅悬挂键≡Si,氮悬挂键=N,硅错键≡Si-Si≡以及与氧有关的缺陷在富硅氮化硅薄膜高强度荧光发射中起主导作用.     

氧分压对HfOxNy薄膜结构和光学性能的影响

用磁控反应溅射法在不同氧分压下制备了氮氧化铪薄膜.沉积过程在氧气、氮气和氩气的气氛中进行,衬底为多光谱ZnS,沉积温度为室温.用X射线衍射、扫描电镜、原子力显微镜、傅里叶变换红外光谱仪、紫外-可见分光光度计等分别研究了不同氧分压下HfOxNy薄膜的晶体结构、显微结构、光学性能等.XRD分析表明随着氧分压的降低,薄膜的晶体结构由氧化铪转变为氮氧化铪相;SEM和AFM分析表明不同氧分压下沉积的薄膜都为柱状结构,氧分压较低时薄膜表面粗糙度较大;镀膜之后,在0.35～2μm范围内,薄膜的透过率变化有显著差异,在2～12μm波段,薄膜透过率和未镀膜衬底透过率相当,变化不明显.     

氧离子束辅助沉积氧化铪薄膜的激光损伤阈值研究

电子枪蒸发制备了氧化铪薄膜,对氧离子束辅助和未辅助两种情况下的样品进行了折射率、吸收、激光损伤阈值等属性的测试,结果表明,氧离子束辅助沉积的样品与未辅助沉积的样品相比具有高的折射率和高的吸收,以及稍低的激光损伤阈值.经过分析发现,薄膜的激光损伤阈值是影响薄膜抗激光特性的不利因素和有利因素竞争的结果,离子束辅助沉积技术在引入结构致密等有利因素的同时,也引入了吸收增加等不利因素.     

钽掺杂对二氧化钒多晶薄膜相变特性的影响

将Ta_2O_5与V_2O_5均匀混合,压制成溅射靶,用离子束增强沉积方法在二氧化硅衬底上沉积掺Ta氧化钒薄膜.在氮气中适当退火,形成掺杂二氧化钒多晶薄膜.X射线衍射结果显示,薄膜具有单一的(002)取向.XPS测试表明,膜中V为+4价,Ta以替位方式存在.温度-电阻率测试表明,薄膜具有明显的相变行为,原子比为3%的Ta掺杂后,二氧化钒多晶薄膜相变温度降低到约48℃.Ta原子的半径大于V原子的半径,Ta的掺入在薄膜中引入了张应力;5价Ta 替代4价V,在d轨道中引入多余电子,产生施主能级,这些是掺钽二氧化钒多晶薄膜相变温度降低的原因.     

真空蒸发、淀积、溅射、氧化与金属化工艺

IELDVD060:9322:29630-29 0600574 关于应变在锗硅层上ALD二氧化铪薄膜置信度的快速沉淀退火效应=Post deposition annealing effects on the reliability of ALD HfO／sub 2／films on strained-Si／ sub 0．8／Ge／sub 0．2／Jayers[会,英]／Tzeng,P．J．／／ Physical and Failure Analysis of Integrated Circuits, 2004．IPFA 2004．Proceedings of the 11th International Symposium on the．-29-32(A)     

金刚石光发射装置

日本佳能公司最近研制成功一种金刚石光发射装置,能发出蓝光或紫光。这种装置由以下各层组成(从底部到顶部):(1)n~+硅茎片,相当于电极的作用;(2)02μm厚的二氧化铪;(3) 0.2μm厚的氧化铝;(4)     

脉冲激光沉积法制备二氧化钒薄膜的研究进展

主要阐述了脉冲激光沉积(PLD)技术在制备金属氧化物方面的物理过程和技术特点,详细介绍了脉冲激光沉积制备二氧化钒(VO2)薄膜的工艺参数和同内外研究进展,并与几种常规制备方法进行了对比,给出了脉冲激光沉积掺杂对VO2溥膜特性的影响,以及脉冲激光沉积制备VO2纳米材料,讨论了脉冲激光沉积制备VO2薄膜存在的问题和发展方向.     

氧离子束辅助沉积氧化铪薄膜光学属性的研究

电子枪蒸发制备了氧化铪薄膜,对氧离子束辅助和未辅助两种情况下的样品进行了折射率、吸收、激光损伤阈值等属性的测试,结果表明,氧离子束辅助沉积的样品与未辅助沉积的样品相比具有高的折射率和高的吸收,以及稍低的激光损伤阈值。经过分析发现,薄膜的激光损伤阈值是影响薄膜抗激光特性的不利因素和有利因素竞争的结果,离子束辅助沉积技术在引入结构致密等有利因素的同时,也引入了吸收增加等不利因素。     

含无机硅薄膜的等离子体沉积

含硅双氮、氧、碳、氢的非晶态膜构成了一大批对制作微电子电路极为有用的材料.与其他较常用的化学和物理沉积法相比,辉光放电感应沉积是一种更好的方法.硅烷(SiH_4)在辉光放电中与不同比率的氮化剂或氧化剂作用生成具有多种成份和性能都不同的薄膜.当放电功率较低时,薄膜密度基本上只与表面温度有共.在低温和低功率密度下生成的氮化物薄膜含有大量的硅-氢和氮-氢键,其中有些可通过高温退火来消除.薄膜的许多性能都可以测定,其中有些性能与退火的关系为确定材料的质量因数提供了简单的模型.     

钯膜上CVD法制备碳纳米管薄膜的研究

采用化学气相沉积法,以乙炔为碳源,在各种钯膜上制备了碳纳米管薄膜。通过电子显微镜观察了碳管薄膜和钯膜的表面形貌。结果表明,在真空气氛下磁控溅射的钯膜上无法生长碳纳米管。对溅射的钯膜进行大气气氛下的退火处理,则可生长出稀疏的碳纳米管团聚颗粒。采用在氧气气氛下磁控溅射的钯膜作为催化剂,则可显著提高碳管的生长密度和纯度,从而获得致密均匀的碳纳米管薄膜。     

Growth of AgGaTe2 Layers by a Closed-Space Sublimation Method

AgGaTe₂ layers were deposited on Si substrates by the closed-space sublimation method. Multiple samples were deposited with various source temperatures and holding times, and constant temperature differential. Variation of the source temperature was used primarily to improve the stoichiometry of the film. Deposited films were evaluated by the θ–2θ method of x-ray diffraction (XRD) and transmission electron microscopy. These results confirmed that the deposited films were stoichiometric (after optimizing the above parameters). From XRD, it was also clear that films deposited on Si (111) have strong preference for (112) orientation.     

Effect of deposition temperature on electric conduction and microstructure of Au films

Electric conduction was studied on thin gold films deposited at room (RT = 300 K) and liquid nitrogen temperature (LT = 77 K). Microstructure properties, and surface morphology of metal films were investigated by transmission electron spectroscopy (TEM) and atomic force microscope (AFM). The film thickness was chosen less than several hundred angstroms. Electrical measurement found that the LT film showed several orders lower resistance compared to the film obtained at room temperature at very low (about 100 Å) thickness. TEM study found that the LT films showed much smaller density of grain boundaries than that of the RT samples. In AFM observation, for film thickness of 100 Å, LT film showed smoother and continuous surface while the RT film consisted of discrete islands. When the thickness increased to be 200 Å, the LT film showed much larger-sized grains compared to that of the RT film. It is possible that for LT deposition, two-dimensional larger-sized grains were first formed at low temperature deposition which later extended to be three-dimensional.     

Synthesis of the PZT films deposited on pt-coated (100) Si substrates for nonvolatile memory applications

Ferroelectric lead-zirconate-titanate (PZT) thin films were deposited by the pulsed laser deposition technique on Pt-coated (100) Si substrates. This study was focused on the investigation of the PZT film growth on (100) Si substrate at varying deposition parameters and electrical characterization of the films including hysteresis loop and fatigue properties by RT66A Standardized Ferroelectric Test System. PZT deposited at higher temperature (575°C in 450 mTorr O₂ partial pressure) showed the best crystalline structure. The remnant polarization and the retained polarization of the ferroelectric capacitors were 13 μC/cm² and 20 μC/cm², respectively. The crystallographic properties of the films were determined using the x-ray diffractometer method. The cross-sectional transmission electron microscope results showed very smooth interfaces among different layers of films.     

LP同质过渡层对ZnO薄膜结构性能的影响

采用磁控溅射法低功率在玻璃衬底上制备低功率(LP)过渡层,再在其上高功率生长ZnO薄膜,研究了LP过渡层对薄膜结构性能的影响。XRD和SEM结果表明,引入LP过渡层后,高射频(RF)功率溅射的ZnO薄膜(002)定向性显著改善。随溅射功率的提高,薄膜(002)定向性有所下降,但致密性明显好转。与无过渡层薄膜相比,在溅射功率分别为30 W和50 W过渡层上生长的薄膜晶粒变大。研究表明,在30 W的LP过渡层上用200 W功率制备的薄膜性能最佳。     

Polysilicon transistors fabricated on plasma-deposited amorphoussilicon

P-channel MOS transistors were fabricated on plasma-enhanced chemical-vapor deposited (PECVD) amorphous silicon films. The films were deposited at temperatures of 425, 450, and 475°C and crystallized at 600°C. Film thicknesses were between 50 and 250 nm. Transistors were also fabricated on 150-nm-thick low-pressure chemical-vapor-deposited (LPCVD) amorphous silicon films deposited at 560°C. A comparison of device characteristics using 150-nm-thick PECVD and LPCVD films shows that the PECVD films deposited at 425°C produced devices with a factor-of-two-higher hole mobility, a factor-of-1.5-lower subthreshold slope, and a factor-of-3.5-higher on-off current ratio. For all film thicknesses tested there was an increase in the hole mobility and on-off current ratio as the PECVD film temperature was decreased     

Fifteen-Nanometer Ru Diffusion Barrier on NiSi/Si for a sub-45 nm Cu Contact Plug

A ruthenium film on a NiSi/Si substrate was evaluated for barrier performance in Cu contact metallization. The films were deposited by magnetron sputtering using Ni, Ru, and Cu targets. The low-resistivity NiSi film was initially produced from an Ni/Si substrate, and Ru and Cu films were sequentially deposited on the NiSi/Si substrate so that barrier performance could be studied. Barrier properties were elucidated by four-point probe measurement, x-ray diffractometry, scanning electron microscopy, Auger electron spectroscopy, and transmission electron microscopy. The stability temperatures of 600°C (Cu/NiSi/Si) and 650°C (Cu/Ru/NiSi/Si) were systematically verified and are discussed. Structural analysis indicated that the failure mechanism involved penetration of the Cu through the Ru/NiSi stacked film at a specific temperature, which induced the accelerated dissociation of the NiSi. Interposition of an Ru layer between the Cu and the NiSi/Si effectively prevented intermixing and substantially improved the thermal stability in the Cu/NiSi/Si stack films.     

VO2(B)薄膜的制备及特性优化研究

采用直流磁控溅射法,在纯氩气氛中溅射V2O5靶材,在覆盖有氮化硅薄膜的P(100)硅基片表面沉积氧化钒薄膜.对沉积的薄膜进行了后续高真空高温退火处理.利用XRD对薄膜的晶相进行了分析,结果表明退火处理前和退火处理后的薄膜都具有VO2各晶面的取向,XPS分析证明了XRD的物相分析结果.对薄膜的方阻特性的测试表明生成的薄膜是典型的VO2(B)薄膜,退火后的薄膜方阻减小,方阻温度系数也降低.在此基础上,利用薄膜晶界散射理论,通过改变薄膜沉积时间和沉积温度使薄膜的方阻和方阻温度系数随薄膜厚度和晶粒大小而变化,从而使薄膜的电性能达到优化.     

Characterization of polysilicon oxides thermally grown anddeposited on the polished polysilicon films

This work examines the characteristics of polyoxides thermally grown and deposited on polished polysilicon films. A well-controlled chemical mechanical polishing (CMP) process is also presented to achieve a planar surface morphology for polysilicon films. The thermally-grown and deposited polyoxides on the polished polysilicon films exhibit a lower leakage current, higher dielectric breakdown field, higher electron barrier height, lower electron trapping rate, lower density of trapped charges, and markedly higher charge to breakdown (Q_bd) than the conventional polyoxide. In particular, the deposited polyoxide on the polished polysilicon film has the highest dielectric breakdown field, lowest electron trapping rate, and highest charge to breakdown due to the planar polyoxide/polysilicon interface. In addition, experimental results indicate that the trapped charges of the polished samples are located in the polyoxides' upper portion, which differs from conventional polyoxides. Undoubtedly, the deposited polyoxide on the polished polysilicon film considered herein is the most promising candidate to yield optimum characteristics of polyoxide     

垂直型MoS2/C60范德华异质结的研究

研究了采用垂直堆垛方式构筑的MoS2/C60范德华异质结的特性。利用直流磁控溅射法制备Mo薄膜,对Mo薄膜进行硫化退火处理得到MoS2薄膜,采用真空蒸镀法在MoS2薄膜上沉积C60进而形成MoS2/C60范德华异质结,并制备了Au/MoS2/C60/Al结构的器件。对MoS2薄膜的晶体结构进行了分析,对MoS2,C60及MoS2/C60薄膜的喇曼光谱及光吸收特性进行了测试和表征。结果表明:经过750℃退火后的MoS2晶型为2H型;由于在MoS2和C60薄膜之间范德华力的存在,相对于生长在Si/SiO2衬底上,沉积在MoS2上的C60薄膜喇曼特征峰发生红移;MoS2/C60薄膜在可见光范围内具有明显的光吸收特性;异质结表现出良好的整流特性,通过电子导电模型分析得出电子的传输机制包含热电子发射,空间电荷限制电流传导(SCLC)和隧穿现象。