Fractal Pattern Formation In Anodic Bonding Of Pyrex Glass/Al/Si

Anodic bonding of Pyrex glass/Al/Si is an important bonding technique in micro/nanoelectromechanical systems (MEMS/NEMS) industry. The anodic bonding of Pyrex 7740 glass/Aluminum film/Silicon is completed at the temperature from 300 degrees C to 375 degrees C with a bonding voltage between 150 V and 450 V. The fractal patterns are formed in the intermediate Al thin film. This pattern has the fractal dimension of the typical two-dimensional diffusion-limited aggregation (2D DLA) process, and the fractal dimension is around 1.7. The fractal patterns consist of Al and Si crystalline grains, and their occurrences are due to the limited diffusion, aggregation, and crystallization of Si and Al atoms in the intermediate Al layers. The formation of the fractal pattern is helpful to enhance the bonding strength between the Pyrex 7740 glass and the aluminum thin film coated on the crystal silicon substrates.

Comparative Study Of The Influence Of Natural Convection On Directional Solidification Of Al-3.5 Wt% Ni And Al-7 Wt% Si Alloys

We present numerical simulations of thermosolutal convection for directional solidification of Al-3.5 wt% Ni and Al-7 wt% Si. Numerical results predict that fragmentation of dendrite arms resulting from dissolution could be favored in Al-7 wt% Si, but not in Al-3.5 wt% Ni. Corresponding experiments are in qualitative agreement with the numerical predictions. Distinguishing the two fragmentation mechanisms, namely dissolution and remelting, is critical during experiments on earth, when fluid flow is dominant. (C) 2007 COSPAR. Published by Elsevier Ltd. All rights reserved.

Laudato Si' : uma abordagem teológica

Resumen: Mario de França Miranda nos propone en su artículo tomar cuenta de la importancia teológica del cuidado de nuestra casa común. Olvidar la importancia de tratar a la naturaleza con respeto brota de una crisis que arraiga en una pérdida de sentido en el designio salvífico que ha sido pronunciado sobre el hombre. Designio que abraza a todo el cosmos.

Properties of high k gate dielectric gadolinium oxide deposited on Si(100) by dual ion beam deposition (DIBD)

Gadolinium oxide thin films have been prepared on silicon (100) substrates with a low-energy dual ion-beam epitaxial technique. Substrate temperature was an important factor to affect the crystal structures and textures in an ion energy range of 100-500 eV. The films had a monoclinic Gd2O3 structure with preferred orientation ((4) over bar 02) at low substrate temperatures. When the substrate temperature was increased, the orientation turned to (202), and finally, the cubic structure appeared at the substrate temperature of 700 degreesC, which disagreed with the previous report because of the ion energy. The AES studies found that Gadolinium oxide shared Gd2O3 structures, although there were a lot of oxygen deficiencies in the films, and the XPS results confirmed this. AFM was also used to investigate the surface images of the samples. Finally, the electrical properties were presented. (C) 2004 Elsevier B.V. All rights reserved.

强CO_2激光退火时离子注入Si的光学性质

本文测量了砷离子(As~+)注入的Si在连续CO_2激光辐照下光的椭圆偏振参数、反射率、表面薄层电阻率随时间的变化。从(?)、△、R、ρ的变化看出Si注入层的激光退火是在一定的时间、温度条件下迅速完成的。

扩硼Si在连续CO_2激光辐照后的特性

本文研究了高温高浓度扩硼Si在连续CO_2激光辐照后表面薄层电阻随激光功率密度和扫描速度的变化.实验发现,一定功率密度和扫描速度的CO_2激光辐照可使扩硼Si的载流子面密度提高到原来的一倍半到三倍左右.

强激光辐照下集成电路Si片的椭圆偏振光研究

<正> 用强激光辐照的方法对集成电路用的离子注入Si进行退火是近几年大力研究的一个问题。至今为止绝大多数的激光退火都是采用红宝石、YAG、氩离子等波长较短的激光器。实验虽已证实CO_2激光的退火效果完全可与其他激光比美,然而研究者甚少,且基本上限于最后结果的观测。激光作为电磁波,其趋肤深度

强CO_2激光辐照下离子注入Si反射率的动态干涉效应

本文从理论和实验研究了连续CO_2激光辐照下磷离子注入Si对He-Ne激光束反射率呈现的动态干涉效应。从反射强度随时间的变化看出,Si片离子注入层固相外延的速率在整个再结晶过程中是不均匀的。

离子注入Si在连续CO_2激光退火时的动态反射特性

本文用红外探测器测量了注磷Si在高功率连续CO_2激光辐照下反射率随时间的变化,发现在激光加热和随后冷却的过程中均出现不可逆的反射率跃升现象,这说明Si的表面载流子浓度也有着类似的变化。

力学量与国际单位制(SI)

<正> 过去我国采用的基本计量单位是米制(即公制),而今后我国将逐步推行国际单位制.采用国际单位制,牵涉较多的部门主要是工业技术、生产和教学等方面,牵涉较多的学科主要是力学专业.为此,在这里介绍国际单位制和有关的力学量单位.国际单位制(Système International d'Unités,简称SI)是一九六○年第十一届国际计量大会(CGPM)通