Enhancement of surface migration by Mg doping in the metalorganic vapor phase epitaxy of N-polar GaN/sapphire
Enhancement of surface migration by Mg doping in the metalorganic vapor phase epitaxy of N-polar GaN/sapphire
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DOI：
10.7567/jjap.53.05fl05
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发表时间：
2014-04
影响因子：
1.5
通讯作者：
T. Tanikawa;K. Shojiki;Takashi Aisaka;Takeshi Kimura;S. Kuboya;T. Hanada;R. Katayama;T. Matsuoka
中科院分区：
文献类型：
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作者：
T. Tanikawa;K. Shojiki;Takashi Aisaka;Takeshi Kimura;S. Kuboya;T. Hanada;R. Katayama;T. Matsuoka
对于在蓝宝石衬底上生长的n极性GaN，精确地研究了Mg掺杂对其表面形貌、光学和电学性能的影响。Mg的掺入抑制了氮化镓表面的丘状现象，而阶跃聚束现象变得严重。原子平台宽度随Mg/Ga前驱体比的增大而增大。在生长过程中，Mg的掺杂可以促进Ga原子在GaN表面的迁移。在重mg掺杂GaN的情况下，原子台阶变成波浪形。从光致发光光谱中发现，主跃迁由近带边跃迁变为供体-受体对跃迁。当Mg/Ga前驱体比为4.5 × 10−3时，霍尔效应测量显示样品在室温下的p型导电。活化能为143 meV，与传统的ga -极性（0001）GaN中Mg的活化能相当。
With respect to N-polar GaN grown on a sapphire substrate, the effects of Mg doping on the surface morphology, and the optical, and electrical properties are precisely investigated. By doping Mg, hillocks observed on the surface of GaN can be suppressed, while step bunching becomes severe. The atomic terrace width is extended with increasing Mg/Ga precursor ratio. Mg doping can promote the surface migration of Ga adatoms on a GaN surface during growth. In the case of heavily Mg-doped GaN, atomic steps become wavy. From photoluminescence spectra, the dominant transition was found to change from near-band-edge transition to donor–acceptor-pair transition. Hall-effect measurement shows p-type conduction at room temperature for a sample grown with the Mg/Ga precursor ratio of 4.5 × 10−3. The activation energy is 143 meV, which is comparable to that of Mg in the conventional Ga-polar (0001) GaN.