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的化学合成计划支持田纳西大学诺克斯维尔的薛子凌（本）教授的研究，用于微电子学中使用的金属氧化物材料的调查。新材料，例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而受到强烈的关注。金属氧化物材料使用化学气相沉积（CVD）或原子层沉积（ALD）工艺由前过渡金属络合物合成。虽然这些材料可能非常有用，但通常不清楚它们是如何由前体化合物与水或氧气反应形成的。该项目中的深入研究旨在了解氧气和水的反应，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。这项研究提供了一个很好的机会，培养学生成为未来的科学家在化学合成和机理研究的跨学科领域。鼓励女性和代表性不足的少数民族学生，以及来自田纳西州贫困率高的地区的高中生参与研究。氧是双自由基。它的许多反应本质上是自由基（一个电子），并且具有挑战性，特别是对于氧和早期过渡金属络合物的反应，其中经常发生配体氧化。本研究探索了不寻常的锆过氧配合物的形成途径，研究了过氧配合物的反应性，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不同的电子和空间性质的配体。这项研究增强了对金属络合物如何与氧反应的理解。对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新的CVD/ALD前体和工艺，用于合成微电子材料。

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.