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1.
Electron field emission characteristics of nano-catkin carbon films deposited by electron cyclotron resonance microwave plasma chemical vapour deposition
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This paper reported that the nano-catkin carbon films were prepared on Si substrates by means of electron cyclotron resonance microwave plasma chemical vapour deposition in a hydrogen and methane mixture. The surface morphology and the structure of the fabricated films were characterized by using scanning electron microscopes and Raman spectroscopy, respectively. The stable field emission properties with a low threshold field of 5V/μm corresponding to a current density of about 1μA/cm^2 and a current density of 3.2mA/cm^2 at an electric field of 10V/μm were obtained from the carbon film deposited at CH4 concentration of 8%. The mechanism that the threshold field decreased with the increase of the CH4 concentration and the high emission current appeared at the high CH4 concentration was explained by using the Fowler-Nordheim theory. 相似文献
2.
利用微波ECR全方位离子注入技术,在单晶硅(100)衬底上制备类金刚石薄膜.分析结果表明,所制备的类金刚石碳膜具有典型的类金刚石结构特征,薄膜均匀、致密,表面粗糙度小,摩擦系数小.其中,薄膜的结构和性能与氢流量比关系密切,随氢流量比的增加,薄膜的沉积速率减小,表面粗糙度降低,且生成sp3键更加趋向于金刚石结构,表面能 更低,从而使摩擦系数大幅降低.
关键词:
全方位离子注入
类金刚石碳膜
拉曼光谱
摩擦磨损 相似文献
3.
Field emission characteristics of nano-sheet carbon films deposited by quartz-tube microwave plasma chemical vapour deposition
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Nano-sheet carbon films are prepared on Si wafers by means of quartz-tube microwave plasma chemical vapour deposition (MPCVD) in a gas mixture of hydrogen and methane. The structure of the fabricated films is investigated by using field emission scanning electron microscope (FESEM) and Raman spectroscopy. These nano~carbon films are possessed of good field emission (FE) characteristics with a low threshold field of 2.6 V/μm and a high current density of 12.6 mA/cm^2 at an electric field of 9 V/μm. As the FE currents tend to be saturated in a high E region, no simple Fowler-Nordheim (F-N) model is applicable. A modified F N model considering statistic effects of FE tip structures and a space-charge-limited-current (SCLC) effect is applied successfully to explaining the FE data observed at low and high electric fields, respectively. 相似文献
4.
为了刻蚀出图形完整、侧壁陡直、失真度小的α:CH薄膜微器件,研究了有铝和无铝掩膜、气体流量比、工作气压对刻蚀速率的影响,并对纯氧等离子体刻蚀稳定性进行了研究。研究结果表明:在相同条件下,刻蚀速率随刻蚀时间变化不大;a:CH薄膜上有铝和无铝掩膜时,刻蚀速率相同;流量一定时,刻蚀速率随氩气和氧气体积比的增大而降低,当用纯氩气时,几乎没刻蚀作用;刻蚀速率随工作气压的增大而降低。实验中,得到最佳刻蚀条件是:纯氧气,流量4 mL·s-1,工作气压9.9×10-2 Pa,微波源电流80 mA,偏压-90 V。 相似文献
5.
采用电子回旋共振等离子体化学气相淀积(ECR-CVD)法,以C4F8和CH4为源气体制备了非晶氟化碳(a-C:F)薄膜.X射线电子能谱(XPS)和傅里叶变换红外光谱(FTIR)分析表明,a-C:F薄膜退火后厚度减小是由于位于a-C:F薄膜交联结构末端的C—C和CF3结合态的热稳定性较差,导致退火时容易生成气态挥发物造成的.a-C:F膜介电常数在300℃氮气气氛中退火后由于电子极化增大和薄膜密度增加而上升,界面态陷阱密度从(5—9)×1011eV-1·cm-2降至(4—6)×1011eV-1·cm-2.a-C:F薄膜导电行为在低场强区域呈现欧姆特性,在高场强区域符合 Poole-Frankel机理.非定域π电子在带尾形成陷阱且陷阱能量在退火后降低,从而使更多陷阱电子在场增强热激发作用下进入导带并引起电流增大.
关键词:
a-C:F
ECR-CVD
键结构
电学性质 相似文献
6.
V. K. Goncharov D. R. Ismailov O. R. Lyudchik S. A. Petrov M. V. Puzyrev 《Journal of Applied Spectroscopy》2007,74(5):704-709
We have obtained and analyzed the optical transmission spectra of diamond-like carbon films deposited on quartz substrates
by pulsed laser deposition (λ = 1064 nm, τ = 20 nsec, q = 4.9·108 W/cm2) under vacuum (p = 2.6·10−3 Pa). Based on the spectra obtained, we have estimated the size of the bandgap by the Tauc method, and also have studied the
growth dynamics of the coatings formed.
__________
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 637–641, September–October, 2007. 相似文献
7.
利用螺旋波等离子体增强化学气相沉积(HWP-CVD)技术,以SiH4和N2为反应气体进行了氮化硅(SiN)薄膜沉积,并研究了实验参量对薄膜特性的影响.利用傅里叶变换红外光谱、紫外—可见光谱和椭偏光检测等技术对薄膜的结构、厚度和折射率等参量进行了测量.结果表明,采用HWP-CVD技术能在低衬底温度条件下以较高的沉积速率制备低H含量的SiN薄膜,所沉积的薄膜主要表现为Si—N键合结构.采用较低的反应气体压强将提高薄膜沉积速率,并使薄膜的致密性增加.适当提高N2/SiH4比例有利于薄膜中H含量的降低.
关键词:
螺旋波等离子体
化学气相沉积
氮化硅薄膜 相似文献
8.
A series of hydrogenated amorphous carbon (a-C:H) films were deposited on silicon substrates by microwave plasma chemical vapor deposition technique with a mixture of hydrogen and acetylene. The effects of flow ratio of hydrogen to acetylene on surface morphology and structure of a-C:H films were investigated using surface-enhanced Raman spectroscopy and scanning probe microscope (SPM) in the tapping AFM mode. Raman data imply a transition from graphite-like phase to diamond-like bonding configurations when the flow ratio increases. AFM measurements show that the increase in hydrogen content, to some extent, can smoothen the surface morphology and decrease the RMS roughness. Excessive hydrogen is found to cause the formation of polymeric hydrocarbon clusters in the films and reduce deposition rate. 相似文献
9.
以高纯石墨做靶,CHF3和Ar气为源气体,采用射频反应磁控溅射法在不同流量比条件下制备了氟化类金刚石(F-DLC)薄膜.利用原子力显微镜、纳米压痕仪、拉曼光谱和红外光谱、摩擦磨损测试仪对薄膜的表面形貌、硬度、键结构以及摩擦性能做了具体分析.表面形貌测试结果表明,制备的薄膜整体均匀致密,表现出了良好的减摩性能.当CHF3与Ar气流量比r为1:6时,所得薄膜的摩擦系数减小至0.42,而纳米压痕结果显示,此时薄膜的硬度也最高.拉曼和红外光谱显示,随着r的增加,薄膜中的F浓度呈上升趋势,薄膜中的芳香环比例减小.研究表明,F原子的键入方式是影响F-DLC薄膜摩擦系数的一个重要因素,CF2反对称伸缩振动强度的减弱和CC中适量碳氢氟键的形成都能导致薄膜具有相对较低的摩擦系数. 相似文献
10.
11.
Diamond-like carbon (DLC) films have been deposited using three different
techniques: (a) electron cyclotron resonance---plasma source ion
implantation, (b) low-pressure dielectric barrier discharge, (c)
filtered---pulsed cathodic arc discharge. The surface and mechanical properties of
these films are compared using atomic force microscope-based tests. The experimental results
show that hydrogenated DLC films are covered with soft surface layers
enriched with hydrogen and sp$^{3}$ hybridized carbon while the soft surface
layers of tetrahedral amorphous carbon (ta-C) films have graphite-like
structure. The formation of soft surface layers can be associated with the
surface diffusion and growth induced by the low-energy deposition process.
For typical CVD methods, the atomic hydrogen in the plasmas can contribute
to the formation of hydrogen and sp$^{3}$ hybridized carbon enriched
surface layers. The high-energy ion implantation causes the
rearrangement of atoms beneath the surface layer and leads to an increase in film
density. The ta-C films can be deposited using the medium energy carbon ions
in the highly-ionized plasma. 相似文献
12.
Fabrication of ZnO nanoparticles-embedded hydrogenated diamond-like carbon films by electrochemical deposition technique
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ZnO nanoparticles-embedded hydrogenated diamond-like carbon (ZnO-DLC) films have been prepared by electrochemical deposition in ambient conditions. The morphology, composition, and microstructure of the films have been investigated. The results show that the resultant films are hydrogenated diamond-like carbon films embedded with ZnO nanoparticles in wurtzite structure, and the content and size of the ZnO nanoparticles increase with increasing deposition voltage, which are confirmed by X-ray photoelectron spectroscopy (XPS), Raman, and transmission electron microscope (TEM). Furthermore, a possible mechanism used to describe the growth process of ZnO-DLC films by electrochemical deposition is also discussed. 相似文献
13.
研究了十甲基环五硅氧烷(D5)的电子回旋共振等离子体沉积的SiCOH薄膜中Si—OH基团对介电性能和漏电流的影响.结果表明Si—OH含量的增大会导致介电常数k的增大、漏电流的降低和介电色散的增强.由于Si—OH结构的强极化补偿了薄膜密度减小带来的介电常数降低,导致总的介电常数k增大.高Si—OH含量下漏电流的降低是由于封端的Si—OH基团降低了薄膜中Si—O网络的连通概率p而导致网络电导下降的缘故.介电色散的增强与Si—OH封端结构的快极化过程有关.改变放电参数以提高电子能量,从而提高源的电离程度,使更多的Si—OH基团断裂并通过缩合反应形成Si—O—Si网络,可以进一步降低薄膜的介电常数.
关键词:
SiCOH薄膜
Si—OH结构
介电性能
ECR放电等离子体 相似文献
14.
强激光辐照红外热像系统时,可造成系统的干扰和破坏,激光的波长不同,对系统的破坏效果也不同.为了保护红外系统窗口以及提高窗口的透过率,红外窗口广泛沉淀类金刚石(DLC)薄膜.当入射的激光波长位于红外系统响应波段外时,激光对系统的破坏首先是激光对DLC薄膜的破坏.以波长为1.06μm的激光为例,研究了脉冲激光对DLC薄膜的损伤机理,建立了DLC薄膜的热冲击效应模型,并通过求解热传导和应力平衡方程,得出了薄膜的温度场和应力场分布.理论分析表明,热应力破坏在脉冲强激光对DLC膜的损伤机理中占主导地位.当 辐照能量密度为E0=100mJ·cm-2时,在薄膜表面距光斑中心约 40μm区域内的压应 力明显超出其断裂强度,将造成膜层的剥离、脱落.理论分析与实验结果基本相符,表明建 立热冲击效应模型的正确性.
关键词:
激光辐照
类金刚石(DLC)薄膜
热冲击效应 相似文献
15.
16.
Characterization of doped hydrogenated nanocrystalline silicon films prepared by plasma enhanced chemical vapour deposition
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The B- and P-doped hydrogenated nanocrystalline silicon films
(nc-Si\jz{0.2ex}{:}H) are prepared by plasma-enhanced chemical
vapour deposition (PECVD). The microstructures of doped
nc-Si\jz{0.2ex}{:}H films are carefully and systematically
characterized by using high resolution electron microscopy
(HREM), Raman scattering, x-ray diffraction (XRD), Auger
electron spectroscopy (AES), and resonant nucleus reaction
(RNR). The results show that as the doping concentration of
PH3 increases, the average grain size (d) tends to
decrease and the crystalline volume percentage (Xc)
increases simultaneously. For the B-doped samples, as the doping
concentration of B2H\xj{6} increases, no obvious change in
the value of d is observed, but the value of Xc is
found to decrease. This is especially apparent in the case of
heavy B2H2 doped samples, where the films change from
nanocrystalline to amorphous. 相似文献
17.
Tribological properties of diamond-like carbon films deposited by pulsed laser arc deposition 总被引:1,自引:0,他引:1
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A novel method, pulsed laser arc deposition combining the advantages
of pulsed laser deposition and cathode vacuum arc techniques, was
used to deposit the diamond-like carbon (DLC) nanofilms with
different thicknesses. Spectroscopic ellipsometer, Auger electron
spectroscopy, x-ray photoelectron spectroscopy, Raman spectroscopy,
atomic force microscopy, scanning electron microscopy and
multi-functional friction and wear tester were employed to
investigate the physical and tribological properties of the deposited
films. The results show that the deposited films are amorphous and
the sp$^{2}$, sp$^{3}$ and C--O bonds at the top surface of the films
are identified. The Raman peak intensity and surface roughness
increase with increasing film thickness. Friction coefficients are
about 0.1, 0.15, 0.18, when the film thicknesses are in the range of
17--21~nm, 30--57~nm, 67--123~nm, respectively. This is attributed to
the united effects of substrate and surface roughness. The wear
mechanism of DLC films is mainly abrasive wear when film thickness
is in the range of 17--41~nm, while it transforms to abrasive
and adhesive wear, when the film thickness lies between 72 and 123~nm. 相似文献
18.
采用分子动力学(MD)模拟研究了离子束辅助沉积(1BAD)生长类金刚石(DLC)膜的物理过程.分 别选C2分子和Ar离子作为沉积源和辅助沉积粒子.改变Ar的入射能量和到达比(A r/C),研 究了它对DLC膜结构的影响.重点讨论了Ar辅助沉积引起表面原子的瞬间活性变化对薄膜结构 产生的影响.分析表明,由于Ar离子的轰击引起的能量和动量的传递,大大地增强了C原子在 表面的反冲动能及迁移概率,增加了合成薄膜的SP3键含量.研究结果和实验 观察一致,并从合成机理上给出了一些定量解释.
关键词:
类金刚石膜
离子束辅助沉积
分子动力学模拟 相似文献
19.
20.
掺硅类金刚石(Si-DLC) 薄膜表现出优异的摩擦学性能, 在潮湿空气和高温中显示出极低的摩擦系数和很好的耐磨性, 但是许多实验表明Si-DLC膜的摩擦性能受其硅含量的影响很大. 因此, 本文采用分子动力学模拟的方法分别研究干摩擦和油润滑两种情况下不同硅含量的Si-DLC膜的摩擦过程. 滑移结果表明干摩擦时DLC膜和掺硅DLC膜之间生成了一层转移膜, 而油润滑时则为边界膜. 因此干摩擦时的摩擦力明显大于油润滑时的摩擦力. 少量添加硅确实能降低DLC膜的摩擦力, 但是硅含量大于20%后对DLC膜的摩擦行为几乎无影响. 干摩擦时硅含量对转移膜内键的数量影响很大, 转移膜内CC键和CSi键都先增加后减少, 滑移结束时几乎不含CSi键. 相似文献