掺N类金刚石薄膜的制备及微观结构分析

采用直流磁控溅射法,在光学玻璃衬底上沉积类金刚石(DLC)和掺N类金刚石薄膜(DLC:N)。用喇曼光谱、X射线光电子能谱(XPS)、傅里叶红外光谱(FTIR)等研究分析了所制备薄膜的微观结构。喇曼光谱的结果表明,掺N类金刚石膜仍具有典型的类金刚石膜结构,在类金刚石薄膜中掺N不仅有助于提高膜中sp3/sp2的比例,而且还能阻止sp2键向石墨相的转化,稳定并优化薄膜的类金刚石属性。FTIR表明,薄膜中N与C原子形成了C—N、CN及C≡N等键合方式。XPS谱表明,掺N类金刚石膜中除了C和N元素外,还出现了少量的O元素,而C1s和N1s的解谱显示,掺N后的类金刚石膜中的C、N结合能发生了明显的移动,由计算得出薄膜中N的含量为13.5%。薄膜的表面形貌图(AFM)表明,在类金刚石薄膜中掺N能够改善其表面形貌。     

PECVD法制备类金刚石薄膜结构和表面形貌分析

以CH4为碳源,Ar气为载气,采用等离子体增强化学气相沉积法(PECVD)在硅(100)衬底上制备了类金刚石(DLC)薄膜。利用拉曼(Raman)光谱仪与原子力显微镜(AFM)对其结构与表面形貌进行了表征。结果表明:所制备的DLC薄膜是含sp3和sp2混合键的非晶态碳膜,其表面均匀、光滑、致密;且随着射频功率的提高,薄膜的平均晶粒直径由8.0nm降为4.2nm,粗糙度由2.2nm减为0.9nm。     

氮气压强对脉冲激光沉积类金刚石薄膜和红外光学特性的影响

为了研究氮气压强对脉冲激光沉积(PLD)类金刚石(DLC)薄膜和红外光学特性的影响,在脉冲激光沉积类金刚石薄膜的实验过程中,把沉积腔抽真空到10-5Pa,再在沉积腔中分别充入10-3、10-2和10-1Pa的氮气来沉积类金刚石薄膜。用拉曼光谱仪和X射线光电子能谱仪(XPS)对类金刚石薄膜的微结构与组成进行检测分析;用原子力显微镜(AFM)对薄膜的表面形貌进行检测分析;用傅里叶变换红外光谱仪(FTIR)对类金刚石薄膜的红外光透射谱进行检测分析。实验结果表明,沉积腔中的氮气压强从10-3Pa增加到10-1Pa时,类金刚石薄膜中sp3键含量增加;C-O和C=O含量减少;石墨晶粒尺寸减小;薄膜表面粗糙度显著增大。与此同时,氮气压强增加还导致类金刚石薄膜对红外光的增透作用减弱、增透范围变窄。     

磁激励RF-PECVD法低温制备类金刚石薄膜及其特性

采用磁激励射频等离子体增强化学气相沉积(M-RF-PECVD)方法,室温下分别在玻璃和Si(100)衬底上制备类金刚石(DLC)薄膜,通过扫描电镜(SEM)、傅里叶红外光谱(FTIR)和Raman光谱对不同沉积条件下制备的薄膜进行表征。结果表明,在反应压强为30 Pa、入射功率为50 W、CH4/Ar=5/90、衬底温度为40℃的实验条件下,制备的含氢DLC薄膜表面平整、结构致密,膜基结合度良好,薄膜中以sp3键为主。     

脉冲激光沉积类金刚石膜和细胞相容性研究

为了解决机械瓣膜的凝血问题,在相同的实验条件下,用脉冲激光沉积(PLD)法在机械瓣膜,Al2O3,316 L不锈钢和Si衬底上沉积类金刚石(DLC)膜.结果表明类金刚石膜与机械瓣膜之间的黏附性最好,用拉曼光谱仪(Raman),X射线光电子能谱仪(XPS)和原子力显微镜(AFM)对机械瓣膜上的类金刚石膜进行检测,然后把人脐带静脉血管内皮细胞(HUVEC)种植在类金刚石膜的表面并进行体外培养.结果表明,Raman光谱的D峰出现在1341.66 cm-1处.G峰出现在1528.17 cm-1处.薄膜中sp3的含量达到21.45%.平均粗糙度为26.4 nm.血管内皮细胞能够正常生长、增殖并融合成片,因此可以实现机械瓣膜表面的血管内皮化,达到抗凝的目的.     

激光脉冲能量对类金刚石薄膜及其红外光学特性的影响

为了研究在氮气中激光的脉冲能量对类金刚石薄膜的微结构组成、表面形貌和红外光学特性的影响,在KrF准分子脉冲激光沉积(PLD)类金刚石薄膜的实验中,在沉积腔中充入10-1Pa氮气并保持其他实验参数不变,脉冲能量分别取120 mJ和150 mJ来沉积类金刚石薄膜。用拉曼光谱仪和X射线光电子能谱仪(XPS)对类金刚石薄膜的微结构与组成进行检测分析;用原子力显微镜(AFM)对薄膜的表面形貌进行检测分析;用傅里叶变换红外光谱仪对类金刚石薄膜和硅衬底的红外光透射谱进行检测分析。实验结果表明,脉冲能量从120 mJ增加到150 mJ导致类金刚石薄膜中的氮含量和sp3键含量增加,C-O,C=O和O的含量减少,石墨晶粒的数量减少、尺寸变小,薄膜表面的粗糙度显著降低。同时,脉冲能量增加导致类金刚石薄膜对红外光的增透作用减弱,增透范围变窄。     

超快脉冲激光沉积类金刚石膜的研究进展

综述了脉冲沉积(PLD)类金刚石膜(DLC)的优势和局限,对其局限的补偿和突破,以及脉冲沉积法的重要发展方向——超快脉冲激光沉积(Ultra-fast PLD)类金刚石膜(DLC)的研究进展。     

脉冲激光沉积法沉积类金刚石薄膜的实验研究

为了研究脉冲激光沉积法中衬底温度和距离对类金刚石薄膜的影响,首先温度保持在200℃,靶和衬底间的距离分别取25.0mm和30.0mm来沉积类金刚石膜。其次温度保持在400℃,距离分别取25.0mm和30.0mm来沉积类金刚石膜。用Raman光谱仪对薄膜的微观结构进行检测,用原子力显微镜对薄膜的表面形貌进行检测。实验结果表明：距离增加或者温度升高都会导致类金刚石薄膜的密度和sp3/ sp2的比值减小,薄膜中石墨晶粒的数量增多和体积增大。近距离时温度的变化和低温时距离的变化对薄膜微观结构产生的影响更明显。距离和温度的变化对类金刚石薄膜的表面形貌也产生显著的影响。     

碲镉汞衬底上沉积类金刚石薄膜的界面分析

采用等离子增强化学气相法 (PECVD)在碲镉汞 (MCT)衬底上沉积纳米颗粒的类金刚石薄膜 (DLC) ,对DLC MCT界面进行了俄歇电子能谱 (AES)分析 ,并与离子溅射法 (IS)沉积的ZnS MCT界面比较 ,结果表明DLC和ZnS薄膜都能较好地抑制MCT中HgTe的分解 ,在一定程度上阻挡了MCT中Hg的外扩散 .相对于ZnS中的S而言 ,DLC的C在MCT中的内扩散深度较小 (前者为 4 0 0 ,而后者仅为 2 0 0 ) .红外透射光谱结果表明DLC膜比ZnS膜具有更好的抗反射效果     

射频功率对红外光学用类金刚石膜结构和性能的影响

利用射频等离子体增强化学气相沉积技术,以CH4为气源,在单晶锗基底上制备了具有红外增透效果的薄膜。Raman光谱分析表明,D峰和G峰分别位于1200~1450 cm-1和1500~1700 cm-1之间,说明薄膜具有典型的类金刚石的特征峰,可知镀制的薄膜是类金刚石膜。通过研究射频功率对类金刚石膜红外透过率以及硬度等性能的影响,分析了类金刚石膜的红外透过率和纳米硬度随着薄膜中sp3含量的增加而增大的原因,从而找出一种利用PECVD方法制备DLC膜的最佳工艺参数。     

The influence of rf induced bias on the properties of diamond-like carbon films prepared using ECR-CVD

The deposition of diamond-like carbon (DLC) films from a mixture of hydrogen and methane using the electron resonance chemical vapor deposition (ECR-CVD) method with radio-frequency (rf) bias is reported. The structural characteristics of the DLC films were characterized using Raman spectroscopy. The effects of the self-generated dc bias resulting from the rf power on the optical gap, Raman spectra, infrared (IR) absorption, and film hardness in depositions carried out at 7 and 15 mTorr process pressures were investigated. Under conditions of 100 W microwave power and for dc bias variation ranging from −10 to −200 V, there is evidence from Raman scattering analysis to show an increase in the DLC-like characteristic in films deposited at low dc bias at both process pressures. The variation of the D and G line peak position and intergrated intensity ratio (I_D/I_G) in the Raman spectra correlates well with the film hardness profile. There does not seem to be a relationship between the variation of the C-H absorption peak intensity in the IR spectra (bonded hydrogen content) and the optical gap, although films with the highest optical gap tend to show a relatively higher C-H absorption peak intensity in the IR spectra. Films deposited at high dc bias showed a reduction in the C-H infrared absorption, suggesting a reduction in the bonded hydrogen content.     

衬底温度对机械瓣膜上沉积的类金刚石薄膜的影响

为掌握机械瓣膜衬底温度对类金刚石薄膜的影响规律,在实验中保持其它实验参数不变,机械瓣膜衬底温度分别取室温和150℃时,用脉冲激光沉积法在机械瓣膜上制备类金刚石薄膜。用Raman光谱仪对薄膜的微观结构进行检测;用原子力显微镜对薄膜的表面形貌和粗糙度进行检测。结果表明：当其它实验参数不变时,机械瓣膜衬底温度从室温升高到150℃时,薄膜的微观结构没有发生明显改变;薄膜表面的粗糙度减小。类金刚石薄膜和机械瓣膜衬底之间具有很好的黏附性。     

Pulsed laser deposition of titanium nitride and diamond-like carbon films on polymers

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.     

Characterization of DLC films by EELS and electron holography

Thickness measurements of diamond-like carbon (DLC) films by electron energy-loss spectroscopy (EELS) and electron holography are discussed. In order to evaluate the thickness by EELS and electron holography, the mean free path for inelastic scattering and mean inner potential of DLC films were determined precisely, respectively. It is found that both the mean free path for inelastic electron scattering and the mean inner potential are sensitive to the preparation methods, namely the density of DLC films. The present work has demonstrated that thickness measurement by EELS is available to DLC films thicker than 20 nm, while electron holography can be applied to thinner films ( approximately 5 nm). Furthermore, close relations are observed between the density of DLC films and the energy-loss spectra.     

Effects of nitrogen trifluoride on the growth and properties of plasma-enhanced chemical-vapor-deposited diamond-like carbon films

The effects of nitrogen trifluoride (NF₃) on the growth and properties of plasma-enhanced chemical-vapor-deposited diamond-like carbon (DLC) films were investigated. The addition of NF₃ increases the deposition rate of DLC film due presumably to the removal of activated hydrogen species by the fluorine radical (F⁻). Diamond-like carbon films deposited in a methane/NF₃ mixture have a higher refractive index, a lower bulk resistivity, and a lower optical bandgap compared to films deposited in pure methane due to a lower hydrogen content in the films. Moreover, the bulk resistivity of methane/NF₃ DLC films remains constant for annealing temperatures below 400°C. Thus, DLC films deposited with NF₃ are more stable than DLC films deposited without NF₃.     

激光沉积红外窗口高性能类金刚石膜技术

类金刚石(DLC)膜具有宽光谱高透射率、高硬度、高热传导及高稳定性等优点,是红外窗口增透保护膜的优选,但现有方法制备的类金刚石膜难以满足高马赫数或海上盐雾等恶劣条件下的应用。激光法相比其他制备方法具有诸多优点,介绍了激光法制备DLC膜的原理及特点,并分析了实现工程应用的难题及关键技术。采用激光沉积法制备出综合性能优异的类金刚石膜,纳米硬度高达44 GPa、内应力仅0.8 GPa、临界刮擦载荷附着力为59.1 mN。正面镀DLC膜,背面镀普通增透膜的硫化锌、硅、锗等红外窗口的平均透射率达82%~91%。实现了150 mm基片的激光法大尺寸均匀薄膜,膜厚不均匀性≤±2%。制备的DLC膜红外窗口通过军标环境适应性试验,并已实现工程化应用。