Ionization-Assisted Deposition of Large Molecular Weight Organic Materials and its Mass Analysis

有机薄膜功能器件的发展需要一种新的沉积高质量大分子量有机材料薄膜的技术。在真空的清洁环境中形成薄膜的干法工艺特别有利于微器件的未来发展。然而，通过常规的真空蒸发技术难以制备具有高分子量的有机材料的薄膜。本计画旨在借由开发一种新的制程技术--离子化辅助沉积来解决此问题。重点是从工艺技术的角度研究高分子量有机薄膜。其战略主要分为两类：1。有机分子的直接沉积，以及2.在沉积过程中伴随聚合过程的成膜。后一类根据聚合反应的类型又分为两种方法：逐步反应法和分步反应法。 ...更多信息 在第一类反应中，我们沉积了几种单体材料，包括二萘嵌苯四甲酸二酐和8-羟基喹啉铝。已经发现，离子化辅助沉积方法在控制这些材料的半导体和发光性质方面是有效的。该技术可应用于有机发光二极管等薄膜器件的开发。作为一种高分子材料，聚四氟乙烯的直接沉积是通过电离辅助的方法沉积。第二类是单体源材料通过蒸发在基底表面反应形成聚合物薄膜。通过二异氰酸酯和联哌啶两种共沉积单体的分步反应得到聚脲薄膜。结果表明，离子辅助沉积可以通过施加在衬底上的偏压和沉积在薄膜表面的离子电荷来控制薄膜的电偶极取向。结果表明，所制备的薄膜在不进行极化处理的情况下，就表现出了光学非线性和电光效应。一些乙烯基化合物通过链反应在基材表面聚合。虽然简单的蒸发技术不能产生聚合物膜，但是电离辅助沉积可以在沉积期间激发分子，并且可以通过离子电流和离子加速电压来控制聚合反应。对沉积束的质量分析表明，可聚合分子在电离过程中容易形成碎片。少

A new technique of depositing high-quality thin films of large-molecular weight organic materials is required for the development of functional organic thin film devices. A dry process, that forms thin films in the clean environment of vacuum, is especially favorable for the future development of micro devices. However, it has been difficult by the conventional vacuum evaporation technique to produce thin films of organic materials that have high molecular weight. This project aims to solve this problem by developing a new process technique, ionization-assisted deposition. The emphasis is to study the high molecular weight organic thin films from the standpoint of process technology. Its strategy is largely classified in two categories ; 1. Direct deposition of organic molecules, and 2. Film formation that accompanies polymerization process in the course of deposition. The latter category is subdivided into two methods according to the type of polymerization reaction ; stepwise reactio … More n and chain reaction.In the first sategory, we have deposited several monomer materials, including perylenetetracarboxylicdianhidride and 8-hydroxyquinoline aluminum. It has been found that the ionization-assisted deposition method was effective in controlling the semiconducting and light emitting properties of these materials. The technique can be applied for the development of thin film devices such as organic light-emitting diode. As a polymeric material, direct deposition of polytetrafluoroethylene was deposited by the ionization-assisted method. Thin polymeric films that have controlled molecular orientation and improved electrical insulation capability were obtained.In the second category, monomer source materials were evaporated to form polymeric thin film by the reaction on the substrate surface. Polyurea thin films were obtained by stepwise reaction of two codeposited monomers ; diisocyanate and dipiperidine. It was found that the ionization-assisted deposition can control the dipole orientation during the film formation by means of the bias voltage on the substrate and the ionic charge accumulated on the film surface. As a consequence, the as-deposited films showed optical nonlinearity and electro-optic effect without additional poling process. Some vinyl compounds were polymerized by chain reaction on the substrate surface. Although the simple evaporation technique does not yield polymeric films, the ionization-assisted deposition can excite the molecules during the deposition and can control the polymerization reaction by the ion current and ion acceleration voltage. Mass analysis of the deposition beam showed that the polymerizable molecules easily form fragments upon the ionization process. Less