Investigation of Factors Affecting the Performance of Electrical Contacts to Gallium Nitride

9504259 Mohney这项研究计划补助金专注于研究基础材料科学方面的问题，以了解与第三类氮化物，主要是氮化镓(GaN)之间的热稳定电接触。我们将使用热力学计算以及X射线衍射和电子探针对大块相平衡样品进行分析，以确定金属-镓-氮系固相图的主要特征。这项研究将有助于选择耐热稳定的触头材料。此外，由于氮气在GaN上的高蒸汽压，以及N空位对GaN中载流子浓度的可能作用，气相平衡对GaN接触的热稳定性和电学性质的影响预计比对其他III-V半导体接触的影响更大。然后，将评估控制GaN点缺陷浓度和接触/GaN势垒高度的新方法和传统方法的潜力，以设计那些从热稳定性角度已经很有吸引力的接触的电学性质。这些方法将包括尝试操纵直接位于触点/GaN界面下方的N空位浓度，以影响n型载流子浓度。还将评估触头材料功函数对阻挡层高度的作用以及触头的后续性能。虽然该项目将主要集中于开发氮化镓的电触点，但它也将有助于未来设计与其他III族氮化物的触点，并有助于更好地了解这些半导体的材料问题。在项目规划期间，将选择至少两个模型系统来测试控制氮化镓触点的电气性能和稳定性的想法。规划期将帮助PI完成足够的前期工作，以显示想法的承诺或根据获得的数据对其进行修改。因此，规划期内的支助将有助于私人投资编写一份更具竞争力的全面提案。***

9504259 Mohney This Research Planning Grant focuses on studies to understand fundamental materials science aspects of thermally stable electrical contacts to group III nitrides, primarily Gallium Nitride (GaN). Thermodynamic calculations will be used, along with x-ray diffraction and electron probe microanalysis of bulk phase equilibria samples, to determine key features of the solid phase diagrams in the Metal-Ga-N systems. This investigation will aid in the selection of thermally stable contact materials. In addition, because of the high vapor pressure of N2 over GaN and the presumed role of N vacancies on the carrier concentration in GaN, the gas phase equilibria are expected to exert a greater influence on the thermal stability and electrical properties of contacts to GaN than they do for contacts to the other III-V semiconductors. Both novel and conventional methods to control the GaN point defect concentration and the contact/GaN barrier height will then be evaluated for their potential to engineer the electrical properties of those contacts that are already attractive from the standpoint of thermal stability. These methods will include attempts to manipulate the N vacancy concentration immediately beneath the contact/GaN interface to influence the n-type carrier concentration. The role of the work function of the contact material on the barrier height and subsequent performance of the contact will also be evaluated. %%% While this project will focus primarily on the development of electrical contacts to Gallium Nitride, it will also be of benefit for future design of contacts to other group III nitrides, and will contribute to a greater understanding of materials issues for these semiconductors. During the planning period of the project, at least two model systems will be selected to test ideas for controlling the electrical properties and stability of contacts to Gallium Nitride. The planning period will aid the PI in accomplishing enough prelimin ary work to show the promise of ideas or to modify them based on the data acquired. Thus, support during the planning period will aid the PI in preparing a more competitive full proposal. ***