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Electronic Structures and the Mechanical Stability of Ultra-thin Metal Films on the Semiconductor Surface and the Effect of Internal Stress on Them

半导体表面超薄金属薄膜的电子结构和机械稳定性以及内应力对其的影响

基本信息

批准号：
62460057
负责人：
KINBARA Akira
金额：
$ 3.46万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1987
资助国家：
日本
起止时间：
1987 至 1989
项目状态：
已结题

项目摘要

Thin films of indium (In), lead (Pb) and silver (Ag) whose thickness ranges from 1 to 10 nanometers, have been deposited on crystalline surface of Si(111), amorphous surfaces of carbon and glass by using molecular beam methods and sputtering.Reflection high energy electron diffraction (RHEED) and electron energy loss spectroscopy (ELS) were employed to study the two-dimensional crystalline structure and the electron states. On the crystalline surface phase diagrams of In and Pb have been established concerning the thickness and the temperature.In the loss spectrum, definite transitions from valence or core electrons could be observed in films growing epitaxially but they became ambiguous as crystallinity decreased. Metal films have a tendency to grow in island form on the semiconductor surface, the size and interisland distributions were analyzed on the electron microphotographs. The kinetic effects and the effect of charge up were observed clearly in the sputter deposited thin films.The durability of thin films under the practical condition was measured from the internal stress and the scratch test.Various combinations of films/substrate and the effect of the preparation conditions were examined. Internal stress does not effect directly on the adhesion strength but the scatter of observed strength becomes great due to surface contamination and roughness. Applying positive bias to the substrate results in a temperature rise and the island structure is close to those obtained by vacuum deposition. When negative bias is applied, island structure becomes small but uniform. A technique to control the orientation of the craystallite structure by applying a proper voltage to substrate has been established.

采用分子束法和溅射法制备了厚度为1 ~ 10纳米的铟（In）、铅（Pb）和银（Ag）薄膜在硅（111）的结晶表面、碳（111）的非晶表面和玻璃（111）的非晶表面上。利用反射高能电子衍射（RHEED）和电子能量损失谱（ELS）研究了二维晶体结构和电子态。在In和Pb的结晶表面建立了随厚度和温度变化的相图。在损耗谱中，可以观察到外延生长的薄膜中价电子或核心电子的明确跃迁，但随着结晶度的降低，它们变得模糊。金属薄膜在半导体表面呈岛状生长，在电子显微照片上分析了金属薄膜的大小和岛间分布。在溅射沉积薄膜中观察到明显的动力学效应和电荷上升效应。通过内应力和划痕试验对薄膜在实际条件下的耐久性进行了测试。考察了薄膜/衬底的不同组合以及制备条件的影响。内应力对粘接强度没有直接影响，但由于表面污染和粗糙度的影响，观察到的强度散射很大。在衬底上施加正偏压会导致温度升高，并且岛状结构接近于真空沉积得到的岛状结构。当施加负偏压时，岛屿结构变得小而均匀。建立了一种通过在衬底上施加适当的电压来控制小龙虾结构取向的技术。