Dissertation Enhancement in Japan: Investigation of Metal Impurities in Ultra Thin Oxide on Silicon

该奖项将使哈佛大学的博士研究生Alison Shull与Hirofumi Shimizu博士在日本东京日立公司的半导体器件开发中心进行为期三个半月的合作研究。通过表征金属沉积前后硅和硅衬底的表面，该团队将分析硅晶圆中的表面缺陷，金属污染和氧化引起的缺陷。今天，电子工业需要干净的硅晶圆表面来生产超大规模的集成电路。金属杂质会降低硅集成电路元件的各种特性，并且随着器件几何形状的减小，它们对污染物和缺陷变得更加敏感。在金属气相沉积之前，该团队将利用Shimizu博士在金属污染物无损诊断方面的专业知识，使用扫描光子显微镜（SPM）以及日立的其他仪器来表征硅片表面。然后，该团队将利用Shull女士的技术，用激光扫描曲率测量设备测量界面应力，研究污染物和缺陷对铜和银多层膜气相沉积的影响。同样，该团队还将研究氧化硅层在防止金属和硅的非晶薄膜结晶方面的作用。Shull将提供薄膜无定形二氧化硅样品，包括有和没有氧化物覆盖层的样品，这些样品已经过各种高真空热退火。该团队将利用SPM分析硅/金属界面和硅/氧化硅薄膜/金属薄膜层状结构。Shimizu和Shull的努力将进一步从根本上了解金属杂质在超薄膜中的行为，从而促进薄膜、多层膜和表面涂层技术的研究和发展。＊＊＊

9407043 Spaepen This award will enable Alison Shull, a Ph.D. graduate student at Harvard University, to conduct collaborative research with Dr. Hirofumi Shimizu for three and a half months at the Semiconductor Device Development Center, Hitachi, Ltd., in Tokyo, Japan. By characterizing the surfaces of silicon and silicon substrates before and after metal deposition, the team will analyze the surface flaws, metal contamination, and oxidation induced defects in silicon wafers. Today, the electronic industry is demanding clean silicon wafer surfaces to produce ultra large scale integrated circuits. Metal impurities can degrade various characteristics of the silicon integrated circuit components, and as the device geometries are reduced, they become more sensitive to contaminants and defects. Prior to the vapor deposition of metal, the team will utilize Dr. Shimizu's expertise in non-destructive diagnostics of metal contaminants using a scanning photon microscope (SPM) as well as other instruments at Hitachi to characterize the surface of silicon wafers. The team will then utilize Ms. Shull's technique of measuring interfacial stress with a laser scanning curvature measurement device to study the effect the contaminants and defects have on the vapor deposition of copper and silver multilayers. Similarly, the team will also study the effect of a silicon oxide layer in preventing crystallization of amorphous thin films of metals and silicon. Shull will provide samples of thin film amorphous silica, both with and without an oxide capping layer, which have been subjected to various high vacuum thermal anneals. The team will utilize the SPM to analyze the silicon/metal interfaces and the silicon/silicon oxide thin film/metal thin film layered structure. The efforts of Shimizu and Shull will further the fundamental understanding of the behavior of metal impurities in ultra thin films enhancing the research and development of thin film, multilaye r and surface coating technologies. ***