纳米硅薄膜制备新技术——逐层生长法

介绍了利用逐层生长法（ｌａｙｅｒ ｂｙ ｌａｙｅｒ）在等离子体化学气相沉积系统中制备纳米硅薄膜，着重介绍了制备纳米硅薄膜的沉积过程和生长机制。指了氢基团为制备新技术发展的关键，并且将在今后纳米硅薄膜制备技术发展中起重要作用。     

氢稀释对纳米晶硅薄膜微结构的影响

采用电感耦合等离子体化学气相沉积技术制备了氮化纳米硅薄膜,利用Raman散射、x射线衍射、红外吸收等技术对不同氮稀释条件下薄膜的微观结构和键合特性变化进行了研究.结果表明,较高的氢稀释比导致薄膜从非晶硅到纳米晶硅的结构转化,随着氮稀释比的增加,所沉积薄膜的晶化度及纳米晶硅的晶粒尺寸单调增加,纳米硅颗粒呈现在(110)方...     

三洋开发出有助太阳能电池量产的新技术

日本三洋电机公司成功开发出了高速生产硅薄膜的技术，并用新技术生产出了双重构造的薄膜型太阳能电池，使以较低成本生产光电转换效率较高的实用太阳能电池成为可能。太阳能电池的硅薄膜一般用等离子化学气相沉积法生成。等离子化学气相沉积法的要点是将气态硅喷涂到基板上，但是如果需要面积大的薄膜，喷涂的气体压力就容易下降，     

掺硼非晶硅薄膜的微结构和电学性能研究

以硅烷(SiH4)和硼烷(B2H6)为气相反应先驱体，采用等离子体增强化学气相沉积法，(PECVD)制备出能应用于液晶光阀光导层的硼掺杂非晶氢硅薄膜。X射线衍射、原子力显微镜和光、暗电导测试表明，一定程度的硼掺杂提高了非晶氢硅薄膜的电导率、降低了非晶氢硅薄膜的光、暗电导比；硼掺杂促进薄膜晶态率的增加和硅晶粒尺寸的增大，薄膜的结晶状态将逐渐从非晶硅过渡到纳米硅，最后发展为多晶硅。红外吸收谱研究表明了大量的硼原子与硅、氢原子之间能形成某些形式的复合体，仅有少量硼元素对受主掺杂有贡献。     

DBDCVD法制备a-Si:H的性能研究

本文用介质阻挡放电化学气相沉积(DBDCVD)在室温下进行了非晶氢硅薄膜制备.通过硅烷氢气流量比、DBD放电电压等工艺条件的调整,在玻璃上沉积了系列样品.研究表明,DBDCVD法可以在室温下快速制备非晶氢硅薄膜,最大沉积速率可达0.34nm/s,由于DBDCVD的高能量和室温沉积的特点,薄膜中硅-氢键以SiH2为主.随硅烷反应气体浓度的变化,薄膜的光学带隙可在1.92eV～2.18eV之间调整.     

低温制备高质量多晶硅薄膜技术及其应用

多晶硅薄膜是集晶体硅材料和非晶硅氢合金薄膜优点于一体,在能源科学、信息科学的微电子技术中有广泛应用的一种新型功能材料。本文综述低温（＜600℃）制备高质量多晶硅薄膜技术的研究进展及其应用,着重讨论用等离子体化学气相沉积（PECVD）硅基薄膜固相晶化制备多晶硅技术及其在薄膜硅太阳能电池上的应用。     

硅膜制备

介绍了两大类硅膜的制备方法:物理方法与化学方法,其中包括物理方法中的电子束物理气相沉积技术(EB-PVD),目前该技术在国内应用比较少,所以对其工作原理、薄膜质量的影响因素等作了重点介绍.此外还介绍了磁控溅射法、化学气相沉积法、等离子体增强化学气相沉积、热丝化学气相沉积法等硅膜制备方法的基本原理及特点,并对它们的优缺点进行了比较.     

PCVD法制备硅系纳米复合薄膜材料

纳米复合薄膜材料由于具有传统复合材料和现代纳米材料两者的优点,成为重要的前沿研究领域之一.其中半导体纳米复合材料,尤其是硅系纳米复合薄膜,由于具有独特的光电性能,加之与集成电路相兼容的制备技术,有着广泛的应用前景.近年来关于纳米复合薄膜的研究不断深入,但仍有许多问题没有完全解决.本文围绕硅系纳米复合薄膜的材料特点,说明了等离子体化学气相沉积(PCVD)技术的工作原理和装置结构,以及该技术在硅系纳米复合薄膜制备中的独特优点.并以氮化硅薄膜为重点,介绍纳米复合薄膜材料的PCVD制备技术.文章最后对硅系纳米复合薄膜的在光电技术等各个领域的应用前景做了一些展望.     

硼掺杂对非晶硅薄膜微结构和光电性能的影响

以硅烷（SiH4)和硼烷（B2H6）为气相应反应先驱体，采用等离子体增强化学气相沉积法（PECVD）制备出轻掺硼非昌氢硅薄膜，X射线衍射，原子力显微镜和光，暗电导测试表明，一定程度的硼掺杂提高了非晶氢硅薄膜的电导率，降低了非晶氢硅薄膜的光，暗电导比，并促进了非晶氢硅薄膜中硅微晶粒的生长，红外吸为研究预示了大量的硼原子与硅，氢原子之间能形成某些形式的复合体，仅有少量硼元素对P型掺杂有贡献。     

脉冲激光薄膜制备技术

脉冲激光薄膜沉积是近年来受到普遍关注的制膜新技术。简要介绍了脉冲激光薄膜沉积技术的物理原理、独具的特点和研究发展动态,并介绍了采用脉冲激光薄膜沉积技术制备硅基纳米PtSi薄膜的结果     

Role of argon in hot wire chemical vapor deposition of hydrogenated nanocrystalline silicon thin films

Structural, optical and electrical properties of hydrogenated nanocrystalline silicon (nc-Si:H) films, deposited from silane (SiH₄) and argon (Ar) gas mixture without hydrogen by hot wire chemical vapor deposition (HW-CVD) method were investigated. Film properties are carefully and systematically studied as a function of argon dilution of silane (R_Ar). We observed that the deposition rate is much higher (4-23 Å/s) compared to conventional plasma enhanced chemical vapor deposited nc-Si:H films using Ar dilution of silane (0.5-0.83 Å/s). Characterization of these films with Raman spectroscopy revealed that Ar dilution of silane in HW-CVD endorses the growth of crystallinity and structural order in the nc-Si:H films. The Fourier transform infrared spectroscopic analysis showed that with increasing Ar dilution, the hydrogen bonding in the films shifts from di-hydrogen (Si-H₂) and (Si-H₂)_n complexes to mono-hydrogen (Si-H) bounded species. The hydrogen content in the films increases with increasing Ar dilution and was found to be < 4 at.% over the entire range of Ar dilutions of silane studied. However, the band gap shows decreasing trend with increase in Ar dilution of silane and it has been attributed to the decrease in the percentage of the amorphous phase in the film. The microstructure parameter was found to be > 0.4 for the films deposited at low Ar dilution of silane and ~ 0.1 or even less for the films deposited at higher Ar dilution, suggesting that there is an enhancement of structural order and homogeneity in the film. From the present study it has been concluded that the Ar dilution of silane is a key process parameter to induce the crystallinity and to improve the structural ordering in the nc-Si:H films deposited by the HW-CVD method.     

双纳米硅p层优化非晶硅太阳能电池

采用等离子体增强化学气相沉积(Plasma Enhanced Chemical Vapor Deposition,PECVD)技术在高功率密度、高反应气压和低衬底温度下制备出不同氢稀释比RH的硅薄膜.高分辨透射电镜(High-Resolution Transmission Electron Microscopy,HRT...     

Size modulation of nanocrystalline silicon embedded in amorphous silicon oxide by Cat-CVD

Different issues related to controlling size of nanocrystalline silicon (nc-Si) embedded in hydrogenated amorphous silicon oxide (a-SiO_x:H) deposited by catalytic chemical vapor deposition (Cat-CVD) have been reported. Films were deposited using tantalum (Ta) and tungsten (W) filaments and it is observed that films deposited using tantalum filament resulted in good control on the properties. The parameters which can affect the size of nc-Si domains have been studied which include hydrogen flow rate, catalyst and substrate temperatures. The deposited samples are characterized by X-ray diffraction, HRTEM and micro-Raman spectroscopy, for determining the size of the deposited nc-Si. The crystallite formation starts for Ta-catalyst around the temperature of 1700 °C.     

纳米Si薄膜的结构及压阻效应

使用ＨＲＥＭ及ＳＴＭ技术检测了纳米Ｓｉ薄膜的微结构，纳米Ｓｉ薄膜由大量的细微Ｓｉ晶粒以及大量的晶粒间界面区组成，这一特殊的结构造成纳米Ｓｉ薄膜具有较大的压阻效应及较高氢含量，本文分析讨论了薄膜微结构对其压阻效应的作用，并认为纳米Ｓｉ薄膜材料将是一种理想的传感器材料。     

Preferred growth of nanocrystalline silicon in boron-doped nc-Si:H Films

Preferred growth of nanocrystalline silicon (nc-Si) was first found in boron-doped hydrogenated nanocrystalline (nc-Si:H) films prepared using plasma-enhanced chemical vapor deposition system. The films were characterized by high-resolution transmission electron microscope, X-ray diffraction (XRD) spectrum and Raman Scattering spectrum. The results showed that the diffraction peaks in XRD spectrum were at 2θ≈47° and the exponent of crystalline plane of nc-Si in the film was (2 2 0). A considerable reason was electric field derived from dc bias made the bonds of Si-Si array according to a certain orient. The size and crystalline volume fraction of nc-Si in boron-doped films were intensively depended on the deposited parameters: diborane (B₂H₆) doping ratio in silane (SiH₄), silane dilution ratio in hydrogen (H₂), rf power density, substrate's temperature and reactive pressure, respectively. But preferred growth of nc-Si in the boron-doped nc-Si:H films cannot be obtained by changing these parameters.     

Structural effect on intrinsic stress in nanocrystalline Si:H films

Intrinsic stress in nanocrystalline Si:H films which prepared by the plasma enhanced chemical vapor deposition (PECVD) technique, was illustrated as a compressive stress by means of Raman scattering and radius of curvature measurement. The Raman signals can be well fitted by a model of strain-calibrated phonon confinement, where the sole effect of phonon confinement and Fano interference on Raman scattering was excluded, respectively. The ion bombardment effect on the origination of intrinsic stress in the PECVD films was discussed. The formation of nc-Si:H was explained by etching model in present experimental parameters’ range. The results infer that the intrinsic compressive stress shows intensive correlation to amorphous Si:H, grain boundaries and hydrogen incorporation in the as-deposited materials.     

Structural effect on intrinsic stress in nanocrystalline Si:H films

Intrinsic stress in nanocrystalline Si:H films which prepared by the plasma enhanced chemical vapor deposition (PECVD) technique, was illustrated as a compressive stress by means of Raman scattering and radius of curvature measurement. The Raman signals can be well fitted by a model of strain-calibrated phonon confinement, where the sole effect of phonon confinement and Fano interference on Raman scattering was excluded, respectively. The ion bombardment effect on the origination of intrinsic stress in the PECVD films was discussed. The formation of nc-Si:H was explained by etching model in present experimental parameters’ range. The results infer that the intrinsic compressive stress shows intensive correlation to amorphous Si:H, grain boundaries and hydrogen incorporation in the as-deposited materials.     

Hot wire configuration for depositing device grade nano-crystalline silicon at high deposition rate

The University of Barcelona is developing a pilot-scale hot wire chemical vapor deposition (HW-CVD) set up for the deposition of nano-crystalline silicon (nc-Si:H) on 10 cm × 10 cm glass substrate at high deposition rate. The system manages 12 thin wires of 0.15-0.2 mm diameter in a very dense configuration. This permits depositing very uniform films, with inhomogeneities lower than 2.5%, at high deposition rate (1.5-3 nm/s), and maintaining the substrate temperature relatively low (250 °C). The wire configuration design, based on radicals’ diffusion simulation, is exposed and the predicted homogeneity is validated with optical transmission scanning measurements of the deposited samples. Different deposition series were carried out by varying the substrate temperature, the silane to hydrogen dilution and the deposition pressure. By means of Fourier transform infrared spectroscopy (FTIR), the evolution in time of the nc-Si:H vibrational modes was monitored. Particular importance has been given to the study of the material stability against post-deposition oxidation.     

Microstructures of microcrystalline silicon thin films prepared by hot wire chemical vapor deposition

Undoped hydrogenated microcrystalline silicon (μc-Si:H) thin films were prepared at low temperature by hot wire chemical vapor deposition (HWCVD). Microstructures of the μc-Si:H films with different H₂/SiH₄ ratios and deposition pressures have been characterized by infrared spectroscopy X-ray diffraction (XRD), Raman scattering, Fourier transform (FTIR), cross-sectional transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS). The crystallization of silicon thin film was enhanced by hydrogen dilution and deposition pressure. The TEM result shows the columnar growth of μc-Si:H thin films. An initial microcrystalline Si layer on the glass substrate, instead of the amorphous layer commonly observed in plasma enhanced chemical vapor deposition (PECVD), was observed from TEM and backside incident Raman spectra. The SAXS data indicate an enhancement of the mass density of μc-Si:H films by hydrogen dilution. Finally, combining the FTIR data with the SAXS experiment suggests that the Si---H bonds in μc-Si:H and in polycrystalline Si thin films are located at the grain boundaries.     

氢化碳化硅(SixC1-x∶H)薄膜发光特性和纳米线发光增强研究

氢化碳化硅薄膜作为一种宽带隙的半导体材料,具有优越的物理特性,其在光电子器件上的潜在应用引起了人们的兴趣。利用等离子增强化学气相沉积(PECVD)系统制备了一系列氢化碳化硅薄膜,通过改变反应前驱物及流量比调节薄膜的室温光致发光性质。实验发现在一定范围内随着流量比R(CH_4/SiH_4)的提高,氢化碳化硅薄膜的光致发光峰位蓝移且发光强度增强;同时反应前驱物中的氢会极大影响氢化碳化硅薄膜的发光强度。通过椭偏仪(Ellipsometer)测量了薄膜的光学常数,发现薄膜沉积速率随着流量比R的增加而降低;傅里叶红外光谱仪(FTIR)测试表明Si-C有序度随着流量比的增加而增大。同时研究了三维纳米线结构对多态碳化硅薄膜发光性质的影响。光致发光测试结果表明三维纳米线结构可以有效提高薄膜的光致发光强度。