在四族半導體表面上的超薄離子固體自我組裝與其薄膜、介面性質

Abstract

現今的尖端材料研究課題常須要各種互補的專門技術合作研究，而這種合作越來越多是由跨國界的團隊完成。美國國家科學基金會今年宣佈了新的跨國界材料研究獎助計劃，國科會也由國際合作處宣佈提供對等的合作計劃申請。在這個獎助計劃模式下，我們提議和享譽國際的美國伊利諾大學物理系江台章教授實驗室合作研究在四族半導體表面上的超薄離子固體自我組裝與其薄膜、介面性質。江台章教授同時也是該大學在國際上極有名的材料研究中心資深副主任。 四族半導體是基體電路的最重要基板材料，和此有關的薄膜生長與特性當然提供了微電子元件尖端製造技術的重要進步推動力。雖然過去二十年中，許多的研究工作已經提供了四族半導體表面與各種金屬、半導體體、介電質薄膜的重要薄膜的生長知識與其物理特性，但和離子固體薄膜有關的研究則很少。 我們計劃利用我們實驗室專長的掃瞄探針顯微技術、同步輻射核心層光電子能譜術，結合美國合作組的角分析光電子能譜術、x-光繞射技術對超薄離子固體薄膜在四族半導體表面上的自我組裝與其薄膜、介面性質作深入研究。具體研究題目包括：１、矽鍺表面上超薄離子固體薄膜生長模式；２、鹼金屬滷化鹽晶體的原子層生長控制研發；３、鹼金屬滷化鹽薄膜的晶體結構參數；４、介面間電子轉移與鍵結特性；５、二維離子固體電子價電子結構。

The Division of Materials Research, Directorate for Mathematical and Physical Sciences, National Science Foundation (NSF), USA announced the Program entitled “Materials World Network: Cooperative Activity in Materials Research between US Investigators and their Counterparts Abroad (MWN)” . The Department of International Programs, National Science Council (NSC) has called for counterproposals for this program. This proposal is organized in response to these new programs aiming to enhance opportunities for collaborative activities in materials research. Under the joint funding support from both NSC and NSF, this project is to investigate in depth the fundament science of ultra thin ionic crystals on group IV semiconductor surfaces by establishing a close collaboration between our research group and a renowned team led by Professor T.C. Chiang at the University of Illinois at Urbana-Champaign. The ability to understand, manipulate and control ultra-thin films of various kinds at the atomic and molecular level is one of the great challenges of modern research. On metal and semiconductor surfaces, much work has been carried out in the last decades for their fundament properties and for various overlaying thin-film systems such as metal, semiconductor, organic and amorphous dielectric thin films in the last decade. However, the growth behavior, growth control and interfacial properties of the crystalline ionic solids on the covalently bonded semiconductor substrates is relatively less studied and poorly understood to date. This project proposes to investigate the fundamental properties and ultimate control of ultra thin films of the ionic solids, in particular, the ultra-thin alkali halide (AH) on group IV semiconductors. The key approach is to combine the technical strength of the two groups. By employing high resolution microscopic and spectroscopic techniques, we are to observe the interface between the AH atomic layers and the semiconductor substrates. The work will include investigations and development of (1) the growth mode of various ultra-thin films of ionic crystals on the Si, Ge surfaces, (2) the atomic-layer-epitaxy (ALE) technique for alkali halides (AH) films, (3) atomic structure of the thin AH films, (4) charge transfer between the Si and Ge substrates and the AH layers, and (5) the band structure of 2D ionic solid films. The experimental techniques to be employed include synchrotron photoemission core-level (TAIWAN and US teams), angled resolved photoemission spectroscopy (US team), variable-temperature ultra-high-vacuum scanning probe microscopy (TAIWAN team), and synchrotron x-ray diffraction (US team). Other US and TAIWAN theoretical groups will also be involved in less formal settings.