Characteristics and applications of plasma enhanced-atomic layer deposition

Atomic layer deposition (ALD) is expected to play an important role in future device fabrication due to various benefits, such as atomic level thickness control and excellent conformality. Plasma enhanced ALD (PE-ALD) allows deposition at significantly lower temperatures with better film properties compared to that of conventional thermal ALD. In addition, since ALD is a surface-sensitive deposition technique, surface modification through plasma exposure can be used to alter nucleation and adhesion. In this paper, characteristics of PE-ALD for various applications in semiconductor fabrication are presented through comparison to thermal ALD. The results indicate that the PE-ALD processes are versatile methods to enable nanoscale manufacturing in emerging applications.     

BCl3-NH3-H2-N2前驱体化学气相沉积法制备氮化硼涂层

以BCl₃-NH₃-H₂-N₂为前驱体系统, 在垂直放置的热壁反应器中利用化学气相沉积工艺制备氮化硼(BN)涂层, 分析了工艺参数对沉积速率的影响, 通过扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和X射线衍射技术(XRD)分析了碳化硅纤维表面BN涂层的形貌和微观结构, 提出了BN沉积过程中主要的气相和表面反应, 以及关键气相组分。研究结果显示：在600~850℃的范围内, 随着沉积温度的升高, BN沉积速率逐渐加快, 同一温度下, 沉积区域内BN沉积速率沿气流方向逐渐减缓, 表明气相组分在气流方向逐渐消耗; 随着系统压力的提高, BN沉积速率先加快后减缓, 表明沉积过程由表面反应控制转变为质量传输控制; 随滞留时间延长, 距气体入口1~3 cm处, BN的沉积速率逐渐增大, 而距气体入口4~5 cm处, 沉积速率先增大后逐渐变小。SEM照片显示碳化硅纤维表面BN涂层光滑致密, XPS结果表明主要成分为BN及氧化产物B₂O₃, XRD图谱表明热处理前BN为无定形态, 1200℃热处理后BN的结晶度提高, 并向六方形态转变。BN的沉积是由BCl₃和NH₃反应所生成的中间气相组分Cl₂BNH₂、ClB(NH₂)₂和B(NH₂)₃来实现的。     

用射流电沉积进行局部快速电镀的工艺研究

射流电沉积是近年来发展起来的一种电沉积新工艺,具有普通电镀所不具备的一些优点.利用二维移动平台系统进行射流电沉积,研究了瓦特镍镀液的喷射速度、温度以及阴阳极间距等因素对射流电沉积的影响.研究结果表明,当镀液喷射速度为0.3 m/s,槽电压为20 V,阴阳极之间距离为17 mm时,采用该系统可在金属试样上快速获得预先设定的图形镀层,镀层分布均匀,与基体的结合力良好.     

多层喷射沉积技术的研究及进展

详细阐述了多层喷射沉积技术的产生及发展现状。多层喷射沉积技术与传统喷射沉积技术相比,在制备大型预成形坯件时冷却速度更大,工艺操作更简单,坯件表面精度更高。     

High-rate deposition of amorphous silicon films using hot-wire CVD with a coil-shaped filament

To reduce the manufacturing cost of amorphous silicon (a-Si:H)-based photovoltaic devices, it is important to deposit high-quality a-Si:H and related materials at a high deposition rate. To this end, we designed and constructed a hot-wire deposition chamber with a coiled filament design and with multiple gas inlets. The process gas could be directed into the chamber through the filament coil and have maximum exposure to the high-temperature filament surface. Using such a chamber design, we deposited a-Si:H films at high deposition rates up to 800 Å s⁻¹ and dense, low-void a-Si:H at rates up to 240 Å s⁻¹.     

基于文献数据可视化的真空镀膜技术研究与应用分析

一项技术应用的热度和广度,与其本身的技术优势、成熟度、适用性等密切相关。本文以文献数据可视化为手段对真空镀膜技术在世界范围内的研究及应用情况进行分析,以探究该技术的应用广度和热度特征,为真空镀膜技术装备的行业发展提供有益参考。研究发现离子束溅射、离子束辅助沉积、等离子体辅助物理气相沉积和原子层沉积技术是当前及以后一个时期内应重点关注的方向。     

Characterization of a large area scanning PECVD deposition system with small size RF electrodes

We have conducted characterization of a scanning plasma enhanced chemical vapor deposition (PECVD) system for producing controlled non-uniform deposition or etching profiles. Both self-bias and plasma potential showed that the plasma conditions were disturbed significantly when the source was very close to the chamber wall but electron temperature and ion density were not affected significantly. It was found that a very thin but long tail of parasitic deposition was present over the entire large substrate. To eliminate the parasitic deposition an aperture (plasma guarding house) was constructed and was found to eliminate the parasitic plasma deposition. Deposited silicon nitride and silicon oxide thin films using the plasma guarding house in the scanning PECVD system showed very good optical properties similar to those obtained in conventional deposition methods. No multilayer structure was observed in TEM analysis on these films.     

多层喷射沉积工艺的研究现状

多层喷射沉积技术是在传统喷射沉积的基础上发展而来的 ,克服了喷射沉积技术的局限性 ,具有独特的优越性。介绍了多层喷射沉积技术的原理 ,发展过程及在耐磨材料、耐热材料和复合材料等材料的制备上的应用情况。     

甲烷浓度对金刚石薄膜质量的影响

纳米金刚石薄膜具有优异的性能,已在多个领域获得广泛应用.但微波等离子体化学气相沉积制备的金刚石薄膜质量却严重受沉积工艺的影响,为了深入了解沉积工艺对制备的金刚石薄膜质量的影响,本文详细研究了甲烷浓度对微波等离子体化学气相沉积( MPCVD)金刚石薄膜质量的影响,利用扫描电镜、X射线衍射、拉曼光谱以及原子力显微镜对其进行...     

High-speed preparation of c-axis-oriented YBa2Cu3O7-δ film by laser chemical vapor deposition

YBa₂Cu₃O_7-δ (YBCO) films were prepared by laser chemical vapor deposition using Y(DPM)₃, Ba(DPM)₂/Ba(TMOD)₂ and Cu(DPM)₂ as precursors with enhancement by a continuous wave Nd:YAG laser. A c-axis-oriented YBCO film almost entirely in a single phase was obtained. The YBCO film consisted of rectangular grains about 30 μm in size. The highest deposition rate was about 100 μm h^− 1, which was 10-1000 times higher than that of conventional MOCVD.     

温度对化学水浴法制备ZnS薄膜的影响

采用化学水浴法在玻璃上制备了太阳能电池中的ZnS缓冲层。采用SEM、EDS、XRD和nkd-分光光度计等手段研究了水浴温度对ZnS薄膜的表面形貌、结构和光学性能的影响。结果表明,升高温度不能明显改变薄膜的结晶性、形貌和沉积生长方式,能否成膜与温度的关系也不大,但成膜速率对温度的依赖性较大。随温度的升高,薄膜的透过率先减小后增大,反射率则先增大后减小。对同一试样而言,透过率和反射率对应较好。当温度为70℃时,可制得禁带宽度为3.83eV、符合化学计量比、平整的非晶ZnS薄膜。     

Physical and tribological properties of diamond films grown in argoncarbon plasmas

Nanocrystalline diamond films have been deposited using a microwave plasma consisting of argon, 2–10% hydrogen and a carbon precursor such as C₆₀ or CH₄. It was found that it is possible to grow the diamond phase with both carbon precursors, although the hydrogen concentration in the plasma was 1–2 orders of magnitude lower than normally required in the absence of the argon. Auger electron spectroscopy, X-ray diffraction measurements and transmission electron microscopy indicate the films are predominantly composed of diamond. Surface roughness, as determined by atomic force microscopy and scanning electron microscopy indicate the nanocrystalline films grown in low hydrogen content plasmas are exceptionally smooth (30–50 nm rms) to thicknesses of 10 m. The smooth nanocrystalline films result in low friction coefficients (μ = 0.04–0.06) and low average wear rates as determined by ball-on-disk measurements.     

Reactive sputter deposition of titanium dioxide

The microstructural, optical and electrical properties of reactively sputtered TiO_x films have been examined at points along the reactive deposition hysteresis curve. The deposition process utilizes feedback control loops of the current and oxygen/argon flowrates for operation in the internal region of the hysteresis curve. The variations in the optical properties are well correlated to the process conditions and the microstructure. For thicknesses of 60–100 nm, the films are polycrystalline for low deposition/high oxygen flow rates, and become amorphous for high deposition/low oxygen flow rates. Electron diffraction ring patterns of the polycrystalline phase are best fit to the d-spacings of the rutile structure. The index of refraction at 550 nm for the rutile phase polycrystalline films (10 nm grain size) is 2.6, this falls to 2.4 as the films become amorphous, and rises to 2.5 as the films become oxygen substoichiometric. We find the variation of the optical band gap of TiO_x to be less than 1%, and is less indicative of chemical and/or microstructural changes than the extinction coefficient at higher energies in the visible. The index of extinction at 350 nm shows a minimum at the same point as the index of refraction at 550 nm. We find the indirect fit of Tauc to the index of extinction gives the most linear fit. Variations in the complex index of refraction are consistent with the processing of r.f. sputtered films from titania targets.     

Radical species involved in hotwire (catalytic) deposition of hydrogenated amorphous silicon

Threshold ionization mass spectroscopy is used to measure the radicals that cause deposition of hydrogenated amorphous silicon by “hotwire” (HW), or “catalytic,” chemical vapor deposition. We provide the probability of silane (SiH₄) decomposition on the HW, and of Si and H release from the HW. The depositing radicals, and H atoms, are measured versus conditions to obtain their radical-silane reaction rates and contributions to film growth. A 0.01-3 Pa range of silane pressures and 1400-2400 K range of HW temperatures were studied, encompassing optimum device production conditions. Si₂H₂ is the primary depositing radical under optimum conditions, accompanied by a few percent of Si atoms and a lot of H-atom reactions. Negligible SiH_n radical production is observed and only a small flux of disilane is produced, but at the higher pressures some Si₃H_n is observed. A Si-SiH₄ reaction rate coefficient of 1.65 ^? 10^{− 11} cm³/s and a H + SiH₄ reaction rate coefficient of 5 ^? 10^{− 14} cm³/s are measured.     

CVD法与PCVD法TiN薄膜研究

用等离子增强化学气相沉积（ＰＣＶＤ）法和化学气相沉积（ＣＶＤ）法分别制备ＴiV系薄膜。采用扫描电镜、Ｘ射线衍射仪和连续加载压入仪研究分析薄膜的微观结构、相结构和薄膜的力学性能,并采用电极电位法测定了薄膜的耐腐蚀性能,研究表明,PCVD法ＴiN系薄膜的微观组织形态明显优于同类的ＣＶＤ法薄膜,ＰＣＶＤ法薄膜晶粒尺寸细小,均匀,形态圆整,组织致密;ＣＶＤ法薄膜晶粒形态为多边形,尺寸较粗大、不均匀,组织致密性差,ＰＣＶＤ法ＴiN系薄膜的声望生和结合力等力学性能可达或优于同类ＣＶＤ法薄膜,虽然ＰＣＶＤ法薄膜的氯含量（约为２％）远主ＣＶＤ法薄膜（约为０．５％）,但ＰＣＶＤ法薄膜的耐蚀性能却明显优于ＣＶＤ法薄膜,还研究分析了ＰＣＶＤ法和ＣＶＤ法成膜模式对薄膜微观结构和性能的影响机理。     

沉积条件对CVD-SiC沉积热力学与形貌的影响

以CH3SiCl3为源物质，H2为载气，Ar气为稀释气体，研究了沉积温度和沉积气氛压力对SiC沉积形貌的影响。应用晶体成核－长大理论和SiC沉积热力学理论，解释了SiC沉积的各种形貌。研究表明：降低系统压力和提高沉积温度，能减小SiC在气相中形核所需的最大能量，促进形核。SiC沉积热力学随沉积条件的改变决定了SiC沉积形貌的改变。     

单分子膜诱导化学/电化学沉积纳米复合薄膜的研究进展

介绍了以单分子膜为基底，化学／电化学沉积纳米复合薄膜的发展现状，并对该方法的制备原理、工艺条件、膜结构、及其表征方法进行了阐述，还对发展方向进行了展望。     

Epitaxial growth of CoSi2 on Si(001) by reactive deposition epitaxy: Island growth and coalescence

Epitaxial CoSi₂ layers, which are phase pure but contain {111} twins, are grown on Si(001) at 700 °C by reactive deposition epitaxy. Transmission electron microscopy analyses show that the initial formation of CoSi₂(001) follows the Volmer-Weber mode characterized by the independent nucleation and growth of three-dimensional islands whose evolution we follow as a function of deposited Co thickness t_Co in order to understand the origin of the observed twin density. We find that there are two families of island shapes: inverse pyramids and platelets. The rectangular-based pyramidal islands extend along orthogonal 〈110〉 directions, bounded by four {111} CoSi₂/Si interfaces, and grow with a cube-on-cube orientation with respect to the substrate: (001)_CoSi2||(001)_Si and [100]_CoSi2||[100]_Si. Platelet-shaped CoSi₂ islands are bounded across their long 〈110〉 directions by {111} twin planes (i.e. {111}(001)_CoSi2||{111}_Si) and their narrow 〈110〉 directions by {511}_CoSi2||{111}_Si interfaces. The top and bottom surfaces are {22¯1}, with {22¯1}_CoSi2||(001)_Si, and {1¯1¯1}, with {1¯1¯1}_CoSi2||{11¯1}_Si, respectively. The early stages of film growth (t_Co ≤ 13 Å) are dominated by the twinned platelets due to a combination of higher nucleation rates resulting from a larger number of favorable adsorption sites in the Si(001)2 × 1 surface unit cell and rapid elongation of the platelets along preferred 〈110〉 directions. However, at t_Co ≥ 13 Å island coalescence becomes significant as orthogonal platelets intersect and block elongation along fast growth directions. In this regime, where both twinned and untwinned island number densities have saturated, further island growth becomes dominated by the untwinned islands. A continuous epitaxial CoSi₂(001) layer, with a twin density of 2.8 × 10¹⁰ cm^− 2, is obtained at t_Co = 50 Å.