Dislocation-governed current-transport mechanism in (Ni/Au)-AlGaN/AlN/GaN heterostructures
Dislocation-governed current-transport mechanism in (Ni/Au)-AlGaN/AlN/GaN heterostructures
复制标题
DOI：
10.1063/1.3068202
复制
发表时间：
2009-01-15
影响因子：
3.2
通讯作者：
Ozbay, Ekmel
中科院分区：
文献类型：
--
作者：
Arslan, Engin;Altindal, Semsettin;Ozbay, Ekmel
在80-410 K温度范围内，利用温度相关的正偏电流-电压（I-V）特性研究了（Ni/Au）-Al 0，22 Ga 0，78 N/AlN/GaN异质结的电流输运机制.为了确定（Ni/Au）-Al 0，22 Ga 0，78 N/AlN/GaN异质结构的电流机制，我们将实验I-V数据拟合到在宽范围的外加偏压和不同温度下给出的电流输运机制的解析表达式。考虑了电子发射、产生复合、隧穿、非均匀性引起的漏电流以及金属-半导体界面电流机制缺陷的贡献。隧道电流机制得到了最佳的拟合结果。另一方面，我们没有观察到足够的协议之间的实验数据和其他目前的机制。从拟合结果中获得了隧道饱和电流（I-t）和隧道参数（E-0）的温度依赖性。我们观察到一个弱的温度依赖性的饱和电流和隧穿参数的温度依赖性的情况下，在这个温度范围内。结果表明，在80-410 K温度范围内，（Ni/Au）-Al 0. 22 Ga 0. 78 N/AlN/GaN异质结构中的电荷输运机制是通过与空间电荷区相交的位错之间的隧穿实现的。根据沿着位错线隧穿的模型，由I-V特性计算的位错密度（D）给出0.24 × 10（7）cm（-2）的值。该值在大小上接近从X射线衍射测量获得的位错密度。
The current-transport mechanisms in (Ni/Au)-Al0,22Ga0,78N/AlN/GaN heterostructures were studied by using temperature dependent forward-bias current-voltage (I-V) characteristics in the temperature range of 80-410 K. In order to determine the current mechanisms for (Ni/Au)-Al0,22Ga0,78N/AlN/GaN heterostructures, we fitted the experimental I-V data to the analytical expressions given for the current-transport mechanisms in a wide range of applied biases and at different temperatures. The contributions of thermionic-emission, generation-recombination, tunneling, leakage currents that are caused by inhomogeneities, and defects at the metal-semiconductor interface current mechanisms were all taken into account. The best fitting results were obtained for the tunneling current mechanism. On the other hand, we did not observe sufficient agreement between the experimental data and the other current mechanisms. The temperature dependencies of the tunneling saturation current (I-t) and tunneling parameters (E-0) were obtained from fitting results. We observed a weak temperature dependence of the saturation current and the absence of the temperature dependence of the tunneling parameters in this temperature range. The results indicate that in the temperature range of 80-410 K, the mechanism of charge transport in the (Ni/Au)-Al0.22Ga0.78N/AlN/GaN heterostructure is performed by tunneling among those dislocations intersecting the space charge region. The dislocation density (D) that was calculated from the I-V characteristics, according to a model of tunneling along the dislocation line, gives the value of 0.24x10(7) cm(-2). This value is close in magnitude to the dislocation density that was obtained from the x-ray diffraction measurements.