共查询到18条相似文献,搜索用时 62 毫秒
1.
2.
532nm连续激光晶化非晶硅薄膜的原位拉曼光谱研究 总被引:1,自引:0,他引:1
用磁控溅射制备了非晶硅薄膜,用波长为532 nm的连续激光退火和显微Raman光谱原位测试技术和场发射扫描电子显微镜研究了非晶硅薄膜在不同激光功率密度和不同扫描速度下的晶化状态。结果表明,激光照射时间10 s,激光功率密度大于2.929×105W/cm2时,能实现非晶硅薄膜晶化。在激光功率密度为5.093×105W/cm2,扫描速度为10 mm/s时非晶硅开始向多晶硅转化。在5.093×105W/cm2的功率密度下,以1.0 mm/s的扫描速度退火非晶硅薄膜,得到的晶粒直径为740 nm。 相似文献
3.
利用共焦显微喇曼光谱仪,对采用PECVD方法制备的非晶硅薄膜进行了退火晶化。晶化后薄膜的喇曼光谱表明。薄膜由非晶硅结构转变为微晶硅结构,同时根据微晶硅结构的喇曼光谱的晶化峰位的移动。可以计算出晶化后微晶硅晶粒尺寸为5nm左右。在对晶化后的薄膜进行深度剖析喇曼光谱研究中,对光谱进行分峰拟合,根据晶化峰的积分强度和非晶峰的积分强度的深度剖析曲线。可以看出晶化程度最高的部分位于薄膜中央,也就是在薄膜上层和接近衬底底部材料结构仍是非晶硅结构。而位于薄膜中间的材料结构转变为微晶硅结构。 相似文献
4.
利用等离子增强化学气相沉积系统制备了本征非晶硅薄膜,并选用488 nm波长的连续激光进行晶化.采用喇曼测试技术对本征非晶硅薄膜在不同激光功率密度和扫描时间下的晶化状态进行了表征,并用514 nm波长与488 nm波长对样品的晶化效果进行了比较.测试结果显示:激光照射时间60 s, 激光功率密度在1.57×105 W/cm2时,能实现非晶硅向多晶硅的转变,在功率密度达到2.7 56×105 W/cm2时,有非晶开始向单晶转变,随着激光功率密度的继续增加,晶化结果仍为单晶;在功率密度为2.362×105 W/cm2下,60 s照射时间晶化效果较好;在功率密度为2.756×105 W/cm2和照射时间为60 s的条件下,用488 nm波长比514 nm波长的激光晶化本征非晶硅薄膜效果较好,并均为单晶态. 相似文献
5.
6.
7.
采用分子动力学方法模拟研究了激光诱导金属薄膜的电离过程,对激光等离子体形成早期原子的运动轨迹、薄膜表面的温度变化以及原子的电离特性进行了详细分析,并探究了脉冲激光参数对原子电离过程的影响.结果表明,在激光照射过程中,薄膜表面先熔化而后又气化,气化的原子继续吸收激光能量继而电离.激光的峰值功率密度越大,原子电离速率越快,电离数目越多,薄膜表面的温度越高.脉冲宽度越小,原子电离速率越快,薄膜表面的温度越高,但原子的电离数目先增加后减小. 相似文献
8.
9.
采用分子动力学方法和镶嵌原子势,模拟了500个Cu原子(简称Cu500) 组成的纳米颗粒的等温晶化过程.利用修正的均方位移、键对分析技术和内在结构(IS) 等方法对该过程中的结构和动力学行为进行分析研究.结果显示:与块体金属不同的是, Cu500纳米颗粒在某一温度保温时,其晶化时间并不是一个定值, 而是存在一个统计分布,并且保温温度越低其晶化时间的分布范围越广, 最长晶化时间越长.在低温晶化时, Cu500经历了一系列中间构型的转变才达到晶态, 表现出多步晶化的特征.文章作者研究了颗粒的初始构型对晶化进程的影响, 发现颗粒的初始结构特征和能量状态对其随后的晶化过程有着重要的影响, 同一温度下,颗粒初始构型的IS能量越低其晶化时间越长,这一点在低温时尤其明显. 相似文献
10.
采用XeCl准分子激光对非晶碳化硅(a-SiC)薄膜的脉冲激光晶化特性进行了研究.通过原子力显微镜(AFM)和Raman光谱技术对退火前后薄膜样品的形貌、结构及物相特性进行了分析.结果表明,选用合适的激光能量采用激光退火技术能够实现a-SiC薄膜的纳米晶化.退火薄膜中的纳米颗粒大小随着激光能量密度的增加而增大;Raman谱分析结果显示了退火后的薄膜的晶态结构特性并给出了伴随退火过程存在的物相分凝现象.根据以上结果并结合激光退火特性,对a-SiC的脉冲激光晶化机理进行了讨论.
关键词:
激光退火
晶化
碳化硅 相似文献
11.
12.
Polycrystalline silicon (poly-Si) thin film has been prepared by means of
nickel-disilicide (NiSi多晶硅 受激准分子激光器结晶 结晶化 界面晶粒生长 polycrystalline silicon, excimer laser crystallization,Ni-disilicide, Ni-metal-induced lateral crystallization, two-interface grain growth Project supported by the National High Technology Development Program of China (Grant No 2002AA303250) and by the National Natural Science Foundation of China (Grant No 60576056). 9/7/2005 12:00:00 AM 3/6/2006 12:00:00 AM Polycrystalline silicon (poly-Si) thin film has been prepared by means of nickel-disilicide (NiSi2) assisted excimer laser crystallization (ELC). The process to prepare a sample includes two steps. One step consists of the formation of NiSi2 precipitates by heat-treating the dehydrogenated amorphous silicon (a-Si) coated with a thin layer of Ni. And the other step consists of the formation of poly-Si grains by means of ELC. According to the test results of scanning electron microscopy (SEM), another grain growth model named two-interface grain growth has been proposed to contrast with the conventional Ni-metal-induced lateral crystallization (Ni-MILC) model and the ELC model. That is, an additional grain growth interface other than that in conventional ELC is formed, which consists of NiSi2 precipitates and a-Si. The processes for grain growth according to various excimer laser energy densities delivered to the a-Si film have been discussed. It is discovered that grains with needle shape and most of a uniform orientation are formed which grow up with NiSi2 precipitates as seeds. The reason for the formation of such grains which are different from that of Ni-MILC without migration of Ni atoms is not clear. Our model and analysis point out a method to prepare grains with needle shape and mostly of a uniform orientation. If such grains are utilized to make thin-film transistor, its characteristics may be improved. 相似文献
13.
利用激光干涉结晶方法,采用周期为400 nm的一维(1D)移相光栅掩模调制KrF准分子激光器的脉冲激光束斑的能量分布,在不同厚度的超薄氢化非晶硅(a-Si:H)膜内直接制备1D有序纳米硅(nc-Si)阵列.拉曼散射谱表明,样品上呈条状分布的受辐照区域发生晶化.原子力显微镜和透射电子显微镜测试结果表明:1D的nc-Si阵列的周期和移相光栅掩模一样.随着a-Si:H膜厚度从10nm降至4nm,通过控制激光的能量密度,每个周期中nc-Si条状分布区宽度可达到30nm.nc-Si条状分布区的高分辨电子显微镜照片显
关键词:
纳米硅
激光干涉结晶
移相光栅
定域晶化 相似文献
14.
The excimer laser-induced crystallization technique has been
used to investigate the preparation of nanocrystalline silicon (nc-Si)
from amorphous silicon ($\al$-Si) thin films on silicon or glass
substrates. The $\al$-Si films without hydrogen grown by pulsed-laser
deposition are chosen as precursor to avoid the
problem of hydrogen effluence during annealing. Analyses
have been performed by scanning electron microscopy, atomic
force microscopy, Raman scattering spectroscopy and high-resolution
transmission--electron microscopy. Experimental results show
that silicon nanocrystals can be formed through laser annealing.
The growth characters of nc-Si are strongly dependent on the laser
energy density. It is shown that the volume of the molten silicon
predominates essentially the grain size of nc-Si, and the surface
tension of the crystallized silicon is responsible for the mechanism of nc-Si growth. 相似文献
15.
16.
17.
S. H. Park H. J. Kim D. B. Lee J. S. Lee Y. K. Choi O. M. Kwon 《Superlattices and Microstructures》2004,35(3-6):205
Applying a molecular dynamics simulation technique with the Tersoff potential, we investigate the isothermal crystallization processes of amorphous silicon (a-Si). To obtain a realistic amorphous structure, a rapid quenching process from liquid-phase at 3500 K to solid-phase at 500 K is simulated at a rate of 1012 K/s and the Voronoi analysis is conducted to observe atomic structural changes during this cooling process. This amorphous structure is utilized to simulate the crystallization processes at various process temperatures with and without external force fields. While homogeneous crystallization of a-Si could not be achieved readily, it is shown that the heterogeneous crystallization can be significantly accelerated by external force fields. This enhancement is owing to increased molecular jumping frequencies associated with the molecular potential energies being increased by external excitations, rather than due to thermal mechanisms normally found in conventional solid-phase crystallization processes. 相似文献
18.
为提高电池的光电转换效率,通过改善激光刻蚀工艺,采用355 nm紫外纳秒激光分别进行了ZnO:Al薄膜(AZO)刻蚀(P1)、非晶硅薄膜(-Si)刻蚀(P2)和背电极刻蚀(P3)研究。采用万用表测量P1隔离电阻,采用电子扫描显微镜(SEM)和三维激光扫描仪测量刻槽的微结构和三维成像,激光拉曼散射光谱检测非晶硅薄膜刻蚀边缘的晶化。实验结果表明,当刻蚀速度600 mm/s,重复频率40 kHz,功率1.74 W的紫外激光刻蚀ZnO:Al薄膜时,刻槽的隔离效果最佳,达20 M; 紫外激光刻蚀能够有效地减小激光热效应引起的热影响和刻槽边缘的晶化范围,提高非晶硅薄膜电池的性能。 相似文献