New Liquid Precursors for Chemical Vapor Deposition

该项目由化学和运输系统以及化学司共同资助。该项目的目标是为选定的金属开发新的化学气相沉积(CVD)工艺。实际的化学气相沉积工艺通常基于将液体前体转化为水蒸气，然后反应形成涂层。使用液体，而不是溶解的固体，在化学兼容性、混合、处理和汽化方面可能是有利的。该方法是合成含有随机取代烷基的新型前体混合物，使材料在室温下保持液态。这些新的液体前体材料将作为CVD反应物进行提纯、表征和汽化。将对沉积材料的成分、结构、厚度、电阻、表面形态和台阶覆盖率进行全面表征。这一方法将在选定的金属及其化合物上进行测试和应用。用这种方法对含有几种不同金属的材料进行化学气相沉积可能更实用，因为前体液体在化学上是相容的，可以安全地混合。开发和表征的液体前体将促进混合金属氧化物的沉积，如钛酸锶钡，这种材料有可能增加计算机芯片上的信息存储。对前驱体反应机理的研究将有助于设计有效的CVD反应器，并为过程提供合理的控制。对这些新型化学前体的反应机理的洞察将增加化学的基础知识。

This project is co-funded by Chemical and Transport Systems and the Chemistry Division. The goal of this project is to develop new chemical vapor deposition (CVD) processes for selected metals. Practical CVD processes are generally based on turning liquid precursors into vapors that react to form the coatings. The use of liquids, rather than dissolved solids, may be advantageous in terms of chemical compatibility, mixing, handling, and vaporization. The approach is to synthesize novel precursor mixtures containing randomly substituted alkyl groups that keep the material in liquid form at room temperature. These new liquid precursor materials will be purified, characterized, and vaporized as CVD reactants. The deposited materials will be fully characterized for composition, structure, thickness, electrical resistance, surface morphology, and step coverage. This approach will be tested and applied to selected metals and their compounds. The CVD of materials containing several different metals may be more practical with this approach because the precursor liquids are chemically compatible and can be safely mixed. The liquid precursors developed and characterized will facilitate the deposition of mixed metal oxides such as barium strontium titanate, a material with the potential to increase information storage on computer chips. Studies of the mechanisms of precursor reactions will be useful in designing effective CVD reactors and providing rational control for the processes. The insights gained into the reaction mechanisms of these novel chemical precursors will add to the fundamental knowledge base of chemistry.