等离子体源离子渗氮合成硼碳氮薄膜的研究

采用等离子体源离子渗氮,即低能,超大剂量氮离子注入－同步热扩散技术,在３００－５００℃处理碳化硼薄膜,合成了硼碳酸三元薄膜。俄歇电子能谱和漫反射富氏变换红外光谱分析表明,合成的硼碳氮薄膜是碳硼比固定,氮含量可控的非晶态薄膜。     

非晶碳膜及掺氮非晶碳膜的制备及光学性质的比较

用射频磁控溅射法成功地制备了非晶碳薄膜薄膜。拉曼光谱表征表明所沉积的非晶碳薄膜是非晶结构,具有类金刚石特性。对所制备的掺氮非晶碳薄膜用光电子能谱和红外光谱进行了表征。同时还研究了两种薄膜的光学性质,为该类薄膜的实际应用提供了可靠的实验依据     

采用MCECR等离子体溅射方法制备硬碳膜

采用封闭式电子回旋共振(MCECR)等离子体溅射的方法在硅(100)基片上沉积了高质量的硬碳纳米微晶薄膜,膜层厚度约40 nm,采用氩等离子体溅射碳靶.薄膜的键结构采用X射线光电子能谱仪(XPS)分析,纳米结构采用高分辨率透射电子显微镜(HRTEM)分析.本文研究了基片偏压对薄膜的纳米结构、摩擦特性(摩擦系数及磨损率)以及薄膜的纳米硬度的影响.摩擦特性采用POD摩擦磨损仪测试,纳米硬度采用纳米压入仪测试.     

钛合金表面等离子体电解氮碳共渗的研究

在含有硝酸铵、甘油、乙醇的水溶液中,利用等离子体电解渗入技术在Ti6Al4V钛合金表面制备了氮碳共渗层.利用SEM、XRD、GDS以及显微硬度计分析了渗层的形貌、成分、组织和显微硬度,探讨了渗层形成的机理和过程.结果表明:(1)以300V的电压经45min处理制备的渗层总厚度约为100μm,其中化合物层约为20μm,主要由Ti(C,N)相组成;(2)渗层最高显微硬度超过2000HK0.0025.等离子体电解渗入技术可以较快地在钛合金表面制备出厚度大、硬度高的氮碳共渗层.     

液相法制备掺氮碳膜的实验研究

在低温和常压下,通过电解甲醇和氨水混合溶液,在硅基片上进行沉积掺氮碳膜的尝试,得到了含氮８％的类金刚石薄膜。通过拉曼光谱和Ｘ光电子能谱对样品的测试表明：碳和氮在薄膜中是以ｓｐ＾２和ｓｐ＾３进行化学成键,本文还提出了液相掺氮碳膜生长的化学机制。     

合成硼碳氮体系薄膜的XPS研究

采用Ｘ射线光电子谱（ＸＰＳ）分析３００～５００℃等离子体源离子渗氮硼和碳化硼薄膜合成的氮化硼和硼碳氮薄膜。利用合成薄膜成分可控的特点,研究Ｂ、Ｃ、Ｎ对薄膜的ＸＰＳ影响。结果表明,ＸＰＳ分析合成氮化硼薄膜能够确定其化学组成,但不能确定ｓｐ＾２和ｓｐ＾３型键合结构特性;ＸＰＳ分析硼碳氮薄膜能够确定其成分和结构特性。在较高的工艺温度下,等离子体源离子渗氮合成的硼硕氮薄膜具有ｓｐ＾２和ｓｐ＾３型复合的键合     

磁控溅射制备染料敏化太阳能电池氮掺杂碳膜对电极

采用双极脉冲磁控溅射法制备氮掺杂碳膜并作为对电极应用在染料敏化太阳能电池(DSSC)中。研究了氮掺杂对碳膜的结构与性能的影响。用X射线光电子能谱(XPS)对氮掺杂碳膜进行薄膜表面元素分析,用四探针测试仪对氮掺杂碳膜的方块电阻进行测试,用扫描电镜对氮掺杂碳膜表面形貌进行分析。组装电池,用太阳光模拟器测试电池的光电转化率。研究结果表明,经过氮掺杂的碳膜,表面形貌致密,当N2的体积分数为30%时,薄膜中N元素含量为15.21%,薄膜的方块电阻为9.4Ω/□,电池的光电转化率为1.16%。     

用微波等离子体CVD制备C3N4薄膜

采用微波等离子体化学气相沉积法（ＭＰＣＶＤ）,使用高纯Ｎ２（９９．９９９％）和ＣＨ４（９９．９％）作反应气体,在多晶Ｐｔ（９９．９９％）基片上沉积Ｃ３Ｎ４薄膜。Ｘ射线能谱（ＥＤＸ）分析结果表明Ｎ／Ｃ原子比为１．０～１．４,接近Ｃ３Ｎ４的化学比;Ｘ射线衍射谱（ＸＲＤ）说明薄膜主要由β－和α－Ｃ３Ｎ４组成;Ｘ射线光电子谱（ＸＰＳ）、傅立叶变换红外谱（ＦＴ－ＩＲ）和喇曼（Ｒａｍａｎ）谱说明在Ｃ３Ｎ４薄膜     

等离子体法制备类金刚石膜的研究

等离子体法制备超微材料是比较理想的方法之一，采用等离子体法制备类金刚石膜，近年来有了很大的进展，通过比较可知；等离子体法可以在低温下进行化学合成反应，实现了低温化学气相反应过程。     

Crystalline carbon nitride films prepared by microwave plasma chemical vapour deposition

Crystalline carbon nitride films have been synthesized on Si (100) substrates by a microwave plasma chemical vapour deposition technique, using mixture of N₂, CH₄ and H₂ as precursor. Scanning electron microscopy shows that the films consisted of hexagonal bars, tetragonal bars, rhombohedral bars, in which the bigger bar is about 20 μm long and 6 μm wide. The X-ray photoelectron spectroscopy suggests that nitrogen and carbon in the films are bonded through hybridized sp² and sp³ configurations. The x-ray diffraction pattern indicates that the films are composed of α-, β-, pseudocubic and cubic C₃N₄ phase and an unidentified phase. Raman spectra also support the existence of α- and β-C₃N₄ phases. Vickers microhardness of about 41.9 GPa measured for the films.     

Hydrogenated amorphous carbon and carbon nitride films deposited at low pressure by plasma enhanced chemical vapor deposition

Hydrogenated amorphous carbon (a-C:H) films were deposited by plasma enhanced chemical vapor deposition from methane, argon diluted methane, and nitrogen diluted methane at 26.7 Pa with a 13.56 MHz RF power supply. In this pressure regime, multiple-scattering of carbon species within the plasma phase is expected during the transport to the substrates placed on both the driven and the earthed electrodes. These films were analyzed using UV-VIS optical transmittance, monochromatic ellipsometry, Raman spectroscopy and current-voltage measurements. From these results, the effect of the plasma conditions and the effective flux of the carbon species controlled by the input power through the negative self bias are found to be important in the deposition process. The growth conditions at the higher pressure regime are important to synthesize a-C:H films from low energetic carbon species, since it reduces the defect density and improves the quality of the films. Furthermore, the effect of nitrogen on the growth conditions of a-C:H:N films is observed.     

Laser deposition of gallium nitride films

Insulating c-oriented hexagonal epitaxial gallium nitride (GaN) films have been obtained by means of pulsed laser sputtering of a gallium target in nonactivated nitrogen atmosphere. The GaN films were deposited onto (0001)-oriented sapphire substrates either directly or above a ZnO buffer layer. The laser-deposited films exhibit edge photoluminescence at 370 nm.     

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.     

XPS study of carbon nitride films deposited by hot filament chemical vapor deposition using carbon filament

Amorphous carbon nitride, a-CN_x, thin films were deposited by hot filament CVD using a carbon filament with dc negative bias voltage on the substrate. The effects of the negative bias and the filament components on the binding structure of the films are investigated by XPS. The composition ratio of graphite to amorphous carbon in the filaments affects the bonding structure of carbon and nitrogen in the films, although the nitrogen content in the films is almost same as 0.1. The nitrogen content in the films changes from 0.1 to 0.3 as the negative bias changes from 0 to − 300 V.     

Effects of rf power on the structural properties of carbon nitride thin films prepared by plasma enhanced chemical vapour deposition

Carbon nitride (CN_x) thin films were deposited by radio frequency plasma enhanced chemical vapour deposition (rf PECVD) technique from a gas mixture of methane (CH₄), hydrogen (H₂) and nitrogen (N₂). The effects of rf power on the structural properties of CN_x thin films were discussed in this paper. It was found that rf power had significant effects on the growth rate, structural and morphological properties of the deposited films. The point of transition of the growth rate trend marked the equilibrium condition for primary and secondary reactions in growth kinetics of the film with respect to rf power. The films grown at this optimum rf power were most ordered in structure with high surface roughness and had the lowest N incorporation. This work showed that H etching effects and ion bombardment effects increase with increase in rf power and strongly influenced the structure of the CN_x films.     

Multi-phase structured silicon carbon nitride thin films prepared by hot-wire chemical vapour deposition

In this work, Silicon Carbon Nitride (Si-C-N) thin films were deposited by Hot Wire Chemical Vapour Deposition (HWCVD) technique from a gas mixture of silane (SiH₄), methane (CH₄) and nitrogen (N₂). Six sets of Si-C-N thin films were produced and studied. The component gas flow rate ratio (SiH₄:CH₄:N₂) was kept constant for all film samples. The total gas flow-rate (SiH₄ + CH₄ + N₂) was changed for each set of films resulting in different total gas pressure which represented the deposition pressure for each of these films ranging from 40 to 100 Pa. The effects of deposition pressure on the chemical bonding, elemental composition and optical properties of the Si-C-N were studied using Fourier transform infrared (FTIR) spectroscopy, Auger Electron Spectroscopy (AES) and optical transmission spectroscopy respectively. This work shows that the films are silicon rich and multi-phase in structure showing significant presence of hydrogenated amorphous silicon (a-Si:H) phase, amorphous silicon carbide (a-SiC), and amorphous silicon nitride (a-SiN) phases with Si-C being the most dominant. Below 85 Pa, carbon content is low, and the films are more a-Si:H like. At 85 Pa and above, the films become more Si-C like as carbon content is much higher and carbon incorporation influences the optical properties of the films. The properties clearly indicated that the films underwent a transition between two dominant phases and were dependent on pressure.     

Chemical stability of hydrogen-containing boron nitride films obtained by plasma enhanced chemical vapour deposition

The purpose of this paper is the investigation of the dehydrogenation kinetics of boron nitride films during thermal annealing. BN_x:H films on silicon substrates were prepared by remote plasma enhanced chemical vapour deposition at 473 K using a mixture of borazine and helium. IR spectroscopy and ellipsometry were used to characterize the film properties and composition. The films contain a certain amount of hydrogen in B---H and N---H bonds. The breakage kinetics of these bonds is different. The breakage of N---H bonds determines the hydrogen annealing kinetics at 973–1073 K. The low-temperature annealing (673–873 K) of B---H bonds is sensitive to the generation of hydrogen from N---H bonds. Heat treatment leads to ordering of the films.     

Silicon carbon nitride cones prepared from an ellipsoid microwave plasma chemical vapor deposition reactor

Silicon carbon nitride (SiCN) cones were synthesized on Si wafers using an ellipsoid microwave plasma chemical vapor deposition (MPCVD) reactor with gas mixtures of CH₄, SiH₄, Ar, H₂ and N₂ as precursors. It was shown that the cones have nanometer-sized tips and their roots vary from nanometers to micrometers in sizes. The films are atomic-level hybrids composed of Si, C and N atoms. A lowest turn-on field of 0.6 V/μm as well as field emission current densities of 4.7 mA/cm² at an applied field of 2.8 V/μm was obtained from these SiCN cones.     

Hot-wire growth of multi-phase carbon nitride films

This paper describes the growth of multi-phase carbon nitride films using hot-wire chemical vapor deposition (HWCVD) on (100)-oriented crystalline Si substrates. A mixture of either CH₄/NH₃ or CH₄/N₂ was activated over a hot tungsten filament under varying deposition conditions. The samples were characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). AFM micrographs show the presence of facetted crystallites. The XRD peaks observed were compared with theoretical predictions for -C₃N₄ and β-C₃N₄—the two ultra-hard phases of carbon nitride. The results suggest the presence of -C₃N₄ and β-C₃N₄, as well as other unidentified phases in our films. We also calculated the equilibrium concentration of the various gas species as a function of temperature and pressure. Our results indicate that CN and C₂N₂ radicals are possible precursors to carbon nitride growth.