Electrical characterization of homoepitaxial diamond p–n junction

Electrical properties of homoepitaxial diamond p–n⁺ junction of boron (B)-doped p-type layer and phosphorus-doped n-type layer on Ib (111) diamond single crystal have been characterized. Current–voltage characteristics show a clear rectifying property with rectification ratio of over 10⁵ at ± 10 V. From capacitance–voltage characteristics, it is found that a spatial distribution of space-charge density N_i of the p–n⁺ junction is not uniform and N_i at a middle region of the space-charge layer formed at zero bias voltage is higher than that of other region of the space-charge layer. This peculiar characteristic can be explained by superposition of two effects; one is the deep dopant effect due to B atoms in the p-type layer, which makes to reduce N_i at around the edge of the space-charge layer formed at zero bias voltage. The other is the compensation of B acceptors by impurity atoms diffusing during the p–n⁺ interface and incorporating during the growth of p-type layer, which makes to reduce N_i at the vicinity of the p–n⁺ interface.     

化学气相沉积铜薄膜研究进展

本文综术了集成电路工艺的Cu布线中Cu薄膜化学气相沉积(CVD)的研究背景,详细介绍了CVD生长Cu金属薄膜的国内外研究进展及CVD对前趋物的要求,并对前趋物的一些物理、化学性质进行了总结,最后,对薄膜沉积的计算机摸拟作了简要介绍。     

Pool boiling on a superhydrophilic surface

Titanium Dioxide, TiO₂, is a photocatalyst with a unique characteristic. A surface coated with TiO₂ exhibits an extremely high affinity for water when exposed to UV light and the contact angle decreases nearly to zero. Inversely, the contact angle increases when the surface is shielded from UV. This superhydrophilic nature gives a self-cleaning effect to the coated surface and has already been applied to some construction materials, car coatings and so on. We applied this property to the enhancement of boiling heat transfer. An experiment involving the pool boiling of pure water has been performed to make clear the effect of high wettability on heat transfer characteristics. The heat transfer surface is a vertical copper cylinder of 17 mm in diameter and the measurement has been done at saturated temperature and in a steady state. Both TiO₂-coated and non-coated surfaces were used for comparison. In the case of the TiO₂-coated surface, it is exposed to UV light for a few hours before experiment and it is found that the maximum heat flux (CHF) is about two times larger than that of the uncoated surface. The temperature at minimum heat flux (MHF) for the superhydrophilic surface is higher by 100 K than that for the normal one. The superhydrophilic surface can be an ideal heat transfer surface. Copyright © 2002 John Wiley & Sons, Ltd.     

Evolution of grain structure in thin film reactions

In this paper, we examine, both experimentally and theoretically, the kinetics of formation and microstructure of product phases in thin film reactions, using the Nb/Al and Ti/Al systems as our prototypes. The results of calorimetry and microscopy studies are interpreted using simple kinetic and morphology models. In particular, the kinetic models employed here focus on the nucleation and growth components of the phase formation process and the morphology models provide a starting point for the classification of product grain structures. An erratum to this article is available at .     

溅射——气体——聚集共沉积法制备金属／金属（介质）复合团簇镶嵌薄膜

提出了溅射－气体－聚集共沉积制备金属／金属（介质）复合团簇镶嵌薄膜的新方法，并利用该方法成功地在方华膜衬底上制备了系列Ｆｅ／Ａｇ及ＣａＦ２复合团簇镶嵌薄膜样品。透射电镜分析结果表明，样品中Ｆｅ（Ｃｕ）团簇都较好地镶嵌于Ａｇ（ＣａＦ２）基质中，其结构为两种材料的多晶共存形态。进一步分析发现，与块材相比，Ｆｅ／Ａｇ样品中Ｆｅ团簇晶格常数呈现出不同程度的收缩，而Ｃｕ／ＣａＦ２样品中Ｃｕ团簇晶格常数则呈现出不同程度的膨胀。运用附加压力的模型对该现象进行了解释。     

粉尘薄膜爆轰

与普通爆轰不同，粉尘薄膜爆轰波前氧化剂与燃料处于分离状态．由于激波作用下壁面燃料的注入才于壁面附近形成燃烧的粉尘云，燃烧释放的热使激波自持形成粉尘薄膜爆轰。本文在长2、8m，横截面20mm×20mm的方型水平激波管中对此类爆轰进行了实验研究．并根据作者建立的模型对其二维结构进行了数值模拟。     

薄Si膜对基底表面粗糙度的影响

利用ＺＹＧＯ光学干涉测量仪，散射积分测量法观测了光学元件表面均方根粗糙度．详细分析了薄Ｓｉ膜对基底均方根粗糙度的影响，由此认为薄膜并不总是复制基底表面的粗糙度，结果出现了薄膜降低表面粗糙度的现象．提出了一定厚度范围的薄Ｓｉ膜的表面粗糙度存在着一个稳定值的新设想．     

薄膜干涉型光学全通滤波器的设计与分析

设计并分析了用于多信道色谱补偿的薄膜Gires-Tournois干涉仪（GTI）型光学全通滤波（OAPF），讨论了反射镜的膜层结构对器件 的群延迟谱和反射谱的影响，。以及大角度入射引起的偏分离现象和幅度畸变现象，给出了单级和多级串拉OAPF的初步设计结果。     

Mathematical modeling of falling liquid film evaporation process

A mathematical model of evaporation process from a laminar falling liquid film on a vertical plate of constant temperature is presented. The model is developed with and without interfacial shear stress due to the vapor flow at the liquid film surface. The vapor pressure drop, vapor exit velocity and cooling rate are calculated for different liquid mass flow values. It is shown that lower liquid mass flow produces higher cooling rate. The results also show that the interfacial shear stress has a considerable negative effect on the cooling rate. It is proved that there exists an optimum distance between the plates, which gives the maximum volumetric cooling rate.     

薄膜生长的计算机模拟

薄膜技术在现代科技领域中有着广泛的应用。人们对薄膜的生长过程通过理论和实验进行了深入的研究，其中计算机模拟是重要的方法，本文概述了对薄膜生长过程的实验观察结果及其理论分析，主要讨论了薄膜生长的计算机模拟中经常采用的方法-蒙特卡罗法和分子动力学方法、描述衬底上成膜粒子运动的一些模型以及在计算机模拟中需注意的一些问题，其中主要包括粒子间的相互作用，入射粒子的能量和粒子上的衬底上的扩散运动。