Enhancement of Deep Acceptor Activation in Semiconductors by Superlattice Doping

9714047舒伯特对III-V氮化物材料系统的研究在过去几年中使材料质量得到了显著改善，并展示了高温晶体管、高效发光二极管和在紫外区和蓝光区发射的激光。然而，为了制造可靠的GaN基器件，还必须克服几个材料挑战，包括增加这些结构中可获得的p型掺杂浓度。在这项工作中，舒伯特教授和他的研究生提出通过“超晶格掺杂”的方法来克服p掺杂的限制。超晶格掺杂是均匀掺杂半导体的短周期成分调制，它有望降低GaN中受主的有效激活能，从而使自由空穴浓度提高约一个数量级。研究了AlGaN/GaN材料体系中的突变和抛物线梯度成分调制，以及梯度对面内和垂直空穴输运的影响。***

9714047 Schubert Research in III-V nitride material system has resulted in significant improvements in material quality over the last few years, and has resulted in the demonstration of high temperature transistors, efficient light emitting diodes, and lasers emitting in the ultraviolet and blue regions of the optical spectrum. However, in order to produce, reliable GaN-based devices, several materials challenges must yet be overcome, including increasing the p-type dopant concentrations attainable in these structures. In this work, Prof. Schubert and his graduate student propose to overcome this p-doping limitation by means of "superlattice doping". Superlattice doping, the short period compositional modulation of uniformly doped semiconductors, promises to decrease the effective activation energy of acceptors in GaN, thereby enhancing the free hole concentration by approximately one order of magnitude. Abrupt and parabolically graded composition modulation in the AlGaN/GaN material system will be investigated and the influence of the grading on in-plane and perpendicular hole transport will be studied. ***