Investigating Novel Reactivities of Transition Metal Complexes and Pathways in the Formation of Microelectronic Materials

美国国家科学基金会化学部化学合成项目支持美国田纳西大学诺克斯维尔分校薛子玲教授对微电子用金属氧化物材料的研究。新材料，如用于替代栅极材料中的氧化硅的金属氧化物，由于它们允许进一步的器件小型化，因此引起了当前的强烈兴趣。金属氧化物材料是利用化学气相沉积（CVD）或原子层沉积（ALD）工艺从早期过渡金属配合物合成的。虽然这些材料非常有用，但通常不清楚它们是如何从前体化合物与水或氧的反应中形成的。该项目的深入研究旨在了解氧和水的反应，从而指出可能的合成途径，以更好地商业化制造微电子器件。这项研究为培养学生成为化学合成和机械研究跨学科领域的未来科学家提供了一个很好的机会。鼓励女性和未被充分代表的少数民族学生，以及来自田纳西州贫困率高地区的高中生参与这项研究。氧是双自由基。它的许多反应本质上是自由基（一个电子），特别是在氧和早期过渡金属配合物的反应中，经常发生配体氧化，这对研究具有挑战性。本研究探索了罕见的锆过氧配合物的形成途径，研究了过氧配合物的反应活性，并研究了其他早期过渡金属配合物与氧的反应。所研究的配合物含有具有不同电子和空间性质的配体。这项研究提高了对金属配合物如何与氧反应的认识。水与配合物反应的研究揭示了配合物转化为金属氧化物的机理途径。该研究还有助于开发用于微电子材料合成的新的CVD/ALD前体和工艺。

The Chemical Synthesis Program of the NSF Division of Chemistry supports the research of Professor Ziling (Ben) Xue of the University of Tennessee Knoxville for the investigation of metal oxide materials that are used in microelectronics. New materials, such as metal oxides which are used in the replacement silicon oxide in gate materials, are of intense current interest as they allow further device miniaturization. Metal oxide materials are synthesized from early transition metal complexes using chemical vapor deposition (CVD) or atomic layer deposition (ALD) processes. While these materials can be very useful, it is often not clear how they are formed from reactions of precursor compounds with water or oxygen. The in-depth studies included in this project seek to understand the reactions of oxygen and water and thus indicate possible synthetic pathways to better commercial manufacturing of microelectronics devices. This research provides a good opportunity to train students to become future scientists in interdisciplinary areas of chemical synthesis and mechanistic studies. Female and underrepresented minority students, as well as high school students from areas of Tennessee with high poverty rates, are encouraged to participate in the research. Oxygen is a diradical. Many of its reactions are radical (one electron) in nature and are challenging to investigate especially with regard to reactions of oxygen and early transition metal complexes where ligand oxidation often occurs. This research probes the pathways for the formation of unusual zirconium peroxo complexes, investigates the reactivities of the peroxo complexes, and studies the reactions of other early transition metal complexes with oxygen. The complexes under study contain ligands with different electronic and steric properties. This research enhances the understanding of how metal complexes react with oxygen. The studies of the reactions between water and the complexes reveal the mechanistic pathways in the conversion of the complexes to metal oxides. The research also aids in the development new CVD/ALD precursors and processes for use in the synthesis of microelectronic materials.