Electrical characteristics of a-plane low-Mg-doped p-GaN Schottky contacts
Electrical characteristics of a-plane low-Mg-doped p-GaN Schottky contacts
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a 面低镁掺杂 p-GaN 肖特基接触的电特性
DOI：
10.1002/pssb.201451581
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Hiroshi Amano and Kenji Shiojima
中科院分区：
文献类型：
--
作者：
Moe Naganawa;Toshichika Aoki;Ji-Su Son;Hiroshi Amano and Kenji Shiojima
Electrical characteristics of a variety of Schottky contacts formed with ten metal species on thea‐plane of p‐type low‐Mg‐doped GaN grown onr‐plane sapphire substrates were studied. We found that while current–voltage characteristics obtained under voltage scanning show no memory effect in samples formed ona‐plane samples onc‐plane showed a substantial memory effects. We consider that the absence of memory effect in thea‐plane p‐GaN samples is originating from a smaller density of interfacial defect than that in thec‐plane p‐GaN samples. In internal photoemission spectra, we observed two linearly increasing portions suggesting two different Schottky barriers with different heights coexisting in a contact. A potential barrier corresponding to a linear increase locating at lower photon energy typically ranged between 1.6 and 2.5 eV; and that corresponding to another linear increase locating at higher energy ranged between 0.7 and 1.7. The barrier heights showed no relevance to metal work function. Thea‐plane GaN surface was found to reveal a lamellar structure with stripes along [0001] direction with a randomly oriented roughness. We thus speculate that contact barrier spatially varies according to the different crystal plane.
