氢、氧等离子体处理对氮化硼薄膜场发射特性的影响

用RF磁控溅射的方法在Si(100)基底上沉积了纳米氮化硼薄膜,然后分别用氢、氧等离子体对薄膜表面进行了处理,用红外光谱、原子力显微镜、光电子能谱以及场发射试验对薄膜进行了研究,结果表明氢等离子体使BN薄膜表面NEA增加,阈值电场降低,发射电流明显增大.氧等离子体处理对BN薄膜的场发射特性影响不大,只是发射电流略有降低,这只能是由于氧化层存在的原因.     

PECVD法淀积氮化硼薄膜场发射特性研究

用 Ｂ２Ｈ６和 ＳｉＨ４作反应气体,通过射频等离子体增强化学气相淀积（ＲＦ－ＰＥＣＶＤ）方法,在 Ｓｉ（１００）面上沉积生长ＢＮ薄膜,用Ｓ－５２０扫描电子显微镜对所得薄膜进行观测,并用红外透射光谱测试分析了膜的成分。在室温、压力为 ８ × １０－４ Ｐａ条件下,对 ＢＮ薄膜的电流一电压特性进行测量,并得到了 Ｆｏｗｌｅｒ－Ｎｏｒｄｈｅｉｍ特性曲线,ＢＮ膜的场发射开启电场为９ Ｖ／μｍ,在电场３７．５ Ｖ／μｍ时,电流密度达到２４．８ ｍＡ／ｃｍ２。     

热处理对氧化锌纳米线场发射特性的影响

用场发射显微镜研究了在钨针尖上生长的氧化锌纳米线的场发射性能,得到了氧化锌纳米线的场发射像及场发射电流与电压关系,并讨论了氧化锌纳米线场发射像的形成原因和不同热处理条件对其场发射性能的影响,给出了氧化锌纳米线比较合适的热处理温度.     

表面镀钛对金刚石薄膜场发射特性的影响

利用等离子体化学气相（MWPCVD）沉积法在Si（100）面上沉积了金刚石薄膜,采用SEM、AFM、XRD、Raman、XPS等方法对薄膜的结构及表面形貌进行了分析。为提高薄膜的场发射性能,在金刚石表面溅射了金属Ti,对比金刚石薄膜、金刚石／金属Ti复合薄膜的场发射性能,结果表明,金刚石／金属Ti薄膜的发射电流密度更大,且随着电场的增加电流密度急剧增加,开启电场低,约为3V／μm,当电场为25V／μm时发射电流密度可达到1400mA／cm2,并在机理上进行了一些探索,对金刚石／金属复合结构薄膜的场发射性能研究有重要意义。     

热处理对单壁碳纳米管场发射的影响

将单壁碳纳米管组装于W针尖，对它进行热处理，得到单壁碳纳米管在不同温度去气时的残气质谱图和热处理后的场发射特性曲线。通过对不同温度去气后的I－U特性曲线的Fowler-Nordheim直线斜率的变化，结合残气质谱图的分析，研究热处理对单壁碳纳米管场发射特性的影响，并对其机理进行了初步讨论。     

立方氮化硼薄膜表面的XPS研究

研究立方氮化硼薄膜表面的性质对于研究立方氮化硼薄膜的成核机理和应用,具有重要的价值.本文用XPS对立方氮化硼薄膜表面进行研究,并对有关问题进行了讨论.XPS分析表明,立方氮化硼薄膜表面除了B、N外,还含有C和O.从XPS谱图计算得到含有立方相的氮化硼薄膜的N/B为0.90,较接近于氮化硼的理想化学配比11;不含立方相的氮化硼薄膜的N/B为0.86,离氮化硼的理想化学配比11较远.计算表明立方氮化硼薄膜的顶层六角相的厚度约为0.8nm.     

碳纳米管的薄膜场发射

薄膜场发射特性是碳纳米管(CNT)研究的重要课题之一，它直接关系到CNT场发射阴极在将来的实际应用。本就CNT的场发射做一综合评述，主要涉及性能指标、结构模型、图形化方法和工艺等。     

碳纳米管的薄膜场发射

薄膜场发射特性是碳纳米管 (CNT)研究的重要课题之一 ,它直接关系到CNT场发射阴极在将来的实际应用。本文就CNT的场发射做一综合评述 ,主要涉及性能指标、结构模型、图形化方法和工艺等     

碳纳米管薄膜场发射器件中栅极的调制特性研究

三极结构的场发射器件的研究备受关注,栅极的调制特性是三极结构的主要研究对象.本文通过计算机模拟分析碳纳米管薄膜层表面的电场分布,结合在二极结构中碳纳米管薄膜发射的实验结果,将两者代入Fowler-Nordheim公式中求得三极结构中阴极发射电流,得到不同栅极电压对发射电流的调制关系.     

Deposition and electrical characteristics of S-doped boron nitride thin films

cBN/Si n-p heterojunctions have been fabricated and characterized. n-type cBN films were grown on p-type Si wafers using RF reactive sputter, and the n-type cBN films were obtained by adding S (sulfur) into working gas. The I-V (current-voltage) characteristics have obvious rectification. The fitting results show that the current transporting model for the cBN/Si n-p heterojunctions is the same as Anderson’s transporting model. The C-V (capacitance-voltage) characteristics are close to that of ideal heterojunctions. The built-in potential in the cBN/Si n-p heterojunctions was determined from C-V measurements at 4.71 V. The dopant concentration in the n-type cBN films was also determined from the C-V measurements at 6.50 × 10¹⁴/cm³.     

Deposition and electrical characteristics of S-doped boron nitride thin films

cBN/Si n–p heterojunctions have been fabricated and characterized. n-type cBN films were grown on p-type Si wafers using RF reactive sputter, and the n-type cBN films were obtained by adding S (sulfur) into working gas. The I–V (current–voltage) characteristics have obvious rectification. The fitting results show that the current transporting model for the cBN/Si n–p heterojunctions is the same as Anderson’s transporting model. The C–V (capacitance–voltage) characteristics are close to that of ideal heterojunctions. The built-in potential in the cBN/Si n–p heterojunctions was determined from C–V measurements at 4.71 V. The dopant concentration in the n-type cBN films was also determined from the C–V measurements at 6.50 × 10¹⁴/cm³.     

沉积参量对硼碳氮薄膜光透过性质的影响

采用射频磁控溅射技术,用六角氮化硼和石墨为溅射靶,以氩气(Ar)和氮气(N2)为工作气体,在玻璃衬底上制备出硼碳氮(BCN)薄膜.通过改变氮气分压比、衬底温度及沉积时间,研究了沉积参量对薄膜光透过性质的影响.利用X射线光电子能谱(XPS)、原子力显微镜(AFM)及可见-近红外透过光谱对薄膜进行了表征.实验结果表明,所制备薄膜在400～1000nm波段具有较高透过率.并且沉积参量对BCN薄膜的透过性能有很大影响,适当改变沉积参量能获得透过率高于90%的BCN薄膜.在固定其它条件只改变一个沉积参量的情况下,得到制备具有较高透过率的BCN薄膜的最佳沉积条件:氮气分压比为1/3、沉积温度为300℃、沉积时间为1h.     

Laser physico-chemical vapour deposition of cubic boron nitride thin films

A laser physico-chemical vapour deposition (LPCVD) technique was developed based on the interaction of an ultraviolet laser beam with a boron nitride target and borazine gas to synthesize cubic boron nitride (CBN) thin films on silicon substrates. The process involved a hybrid of pulsed laser ablation (PLA) of a solid HBN target and chemical vapour deposition (CVD) using borazine as a feed stock. The films were characterized with scanning electron microscopy, X-ray diffraction and infrared spectroscopy. Results indicate that the thin films consisted of almost single-crystalline CBN structures and that the film quality in terms of adherence, particulate density and smoothness was excellent. The purity and crystal structure of target material, laser beam wavelength and energy fluence were the key variables that controlled the film characteristics. In contrast to LPCVD, the conventional PLA method did not generate CBN films.     

Mechanism of nucleation and growth of cubic boron nitride thin films

The mechanism and the crystallography of the nucleation and growth of cubic boron nitride (c-BN) films deposited on 〈100〉-oriented silicon substrate by RF bias sputtering have been studied by means of cross-sectional high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. Both methods provide experimental information showing no sp²-bonded BN layer formation in the subsurface region of c-BN phase. This is clear evidence for layer-by-layer homoepitaxial growth of cubic boron nitride without graphitic monolayers in the near-surface region of the film. The turbostratic boron nitride (t-BN) consists of thin sub-layers, 0.5–2 nm thick, growing in such a way that a sub-layer normal is almost parallel to the growth direction. t-BN also comprises a large volume fraction of the grain boundaries with high interface energies. The present result and the finding by Shtansky et al. [Acta Mater. 48, 3745 (2000)], who showed that an individual sub-layer consists of parallel lamellae in both the hexagonal +h-BN) and rhombohedral (r-BN) configurations, demonstrate that high intrinsic stress in the films is due to the complex structure of sp²-bonded BN. The crystallography of c-BN films indicates heteroepitaxial nucleation of cubic phase on the graphitic BN structural precursor. The present results are consistent with stress-induced c-BN formation.     

射频磁控溅射制备硼碳氮薄膜

采用射频磁控溅射技术,用六角氮化硼和石墨为溅射靶,以氩气(Ar)和氮气(N2)为工作气体,在Si (100)衬底上制备出硼碳氮薄膜.通过X射线衍射(XRD)、傅里叶红外吸收光谱(FTIR)和X射线光电子能谱(XPS)等分析手段对样品结构、组分进行了分析.结果表明,样品的组成原子之间实现了原子级化合,且薄膜为乱层石墨结构.样品中B、C、N的原子比近似为1:1:1.     

Mechanism of nucleation and growth of cubic boron nitride thin films

The mechanism and the crystallography of the nucleation and growth of cubic boron nitride (c-BN) films deposited on 100-oriented silicon substrate by RF bias sputtering have been studied by means of cross-sectional high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. Both methods provide experimental information showing no sp²-bonded BN layer formation in the subsurface region of c-BN phase. This is clear evidence for layer-by-layer homoepitaxial growth of cubic boron nitride without graphitic monolayers in the near-surface region of the film. The turbostratic boron nitride (t-BN) consists of thin sub-layers, 0.5–2 nm thick, growing in such a way that a sub-layer normal is almost parallel to the growth direction. t-BN also comprises a large volume fraction of the grain boundaries with high interface energies. The present result and the finding by Shtansky et al. [Acta Mater. 48, 3745 (2000)], who showed that an individual sub-layer consists of parallel lamellae in both the hexagonal (h-BN) and rhombohedral (r-BN) configurations, demonstrate that high intrinsic stress in the films is due to the complex structure of sp²-bonded BN. The crystallography of c-BN films indicates heteroepitaxial nucleation of cubic phase on the graphitic BN structural precursor. The present results are consistent with stress-induced c-BN formation.