Effects of Mg accumulation on chemical and electronic properties of Mg-doped p-type GaN surface
Effects of Mg accumulation on chemical and electronic properties of Mg-doped p-type GaN surface
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DOI：
10.1063/1.1580195
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发表时间：
2003-07-01
影响因子：
3.2
通讯作者：
Hashizume, T
中科院分区：
文献类型：
--
作者：
Hashizume, T
用X射线光电子能谱(XPS)和俄歇电子能谱(AES)系统地研究了掺镁p-GaN表面的化学和电学性质。镁的掺杂浓度为3×10(19)~9×10(19)cm(-3)。XPS和AES分析表明，所有暴露在空气中和经过化学处理的p-GaN表面都积累了镁元素。由XPS积分强度和俄歇能谱强度计算得到的镁的表观密度比二次离子质谱仪测定的体相密度高一个数量级以上。镁的积累以及大量的氧化物组成了p-GaN：Mg表面的无序区。由于高密度表面态的存在，即使在KOH和NH4OH溶液中处理后，p-GaN表面仍存在1.2-1.6 eV的大表面能带弯曲。结果表明，电子回旋共振辅助N-2等离子体在300℃下处理1min，对消除表面无序区和减少表面能带弯曲非常有效。(C)2003年美国物理研究所。
Chemical and electronic properties of Mg-doped p-GaN surfaces were systematically investigated by x-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The doping density of Mg ranged from 3x10(19) to 9x10(19) cm(-3). The XPS and AES analyses revealed the accumulation of Mg for all the air-exposed and chemically treated p-GaN surfaces. The apparent density of Mg calculated from the XPS integrated intensity and the AES intensity was more than one order higher than the value in bulk determined by secondary ion mass spectroscopy. Mg accumulation as well as large amounts of oxides made up the disordered region on the p-GaN:Mg surfaces. Large surface band bending of 1.2-1.6 eV was found at the p-GaN surfaces even after treatment in KOH and NH4OH solutions, due to the existence of high-density surface states. It was found that electron cyclotron resonance assisted N-2 -plasma treatment at 300 degreesC for 1 min is very effective in removing such surface disordered regions and reducing surface band bending. (C) 2003 American Institute of Physics.