Di Russo E, Mavel A, Fan Arcara V, Damilano B, Dimkou I, Vézian S, Grenier A, Veillerot M, Rochat N, Feuillet G, Bonef B, Rigutti L, Duboz J-Y, Monroy E, Cooper D
Univ. Grenoble Alpes, CEA, LETI, Grenoble F-38000, France.
Nanotechnology. 2020 Nov 13;31(46):465706. doi: 10.1088/1361-6528/ab996c.
A multi-microscopy investigation of a GaN tunnel junction (TJ) grown on an InGaN-based light emitting diode (LED) has been performed. The TJ consists of a heavily Ge-doped n-type GaN layer grown by ammonia-based molecular-beam epitaxy on a heavily Mg-doped p-type GaN thin layer, grown by metalorganic vapor phase epitaxy. A correlation of atom probe tomography, electron holography and secondary ion mass spectrometry has been performed in order to investigate the nm-scale distribution of both Mg and Ge at the TJ. Experimental results reveal that Mg segregates at the TJ interface, and diffuses into the Ge-doped layer. As a result, the dopant concentration and distribution differ significantly from the nominal values. Despite this, electron holography reveals a TJ depletion width of ∼7 nm, in agreement with band diagram simulations using the experimentally determined dopant distribution.
对生长在基于氮化铟镓的发光二极管（LED）上的氮化镓隧道结（TJ）进行了多显微镜研究。该隧道结由通过氨基金属有机分子束外延生长的重掺杂锗的n型氮化镓层和通过金属有机气相外延生长的重掺杂镁的p型氮化镓薄层组成。为了研究隧道结处镁和锗的纳米级分布，进行了原子探针断层扫描、电子全息术和二次离子质谱的关联研究。实验结果表明，镁在隧道结界面处偏析，并扩散到掺杂锗的层中。结果，掺杂剂浓度和分布与标称值有显著差异。尽管如此，电子全息术显示隧道结耗尽宽度约为7纳米，这与使用实验确定的掺杂剂分布进行的能带图模拟结果一致。
