Schottky barrier diodes based on room temperature fabricated amorphous zinc tin oxide thin films
Schottky barrier diodes based on room temperature fabricated amorphous zinc tin oxide thin films
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DOI：
10.1002/pssa.201700210
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发表时间：
2017-06
期刊：
影响因子：
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通讯作者：
P. Schlupp;H. von Wenckstern;M. Grundmann
中科院分区：
文献类型：
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作者：
P. Schlupp;H. von Wenckstern;M. Grundmann
报道了非晶态氧化物半导体氧化锌(ZTO)肖特基势垒二极管。采用脉冲激光沉积法在室温下制备了ZTO薄膜。反应溅射金、镍、铂、钯和银层用来实现肖特基接触。为了加强整流，在金属-半导体界面处引入了一层薄的半绝缘锌锡氧化层。用热电子发射理论模拟了铂肖特基势垒二极管的正向电流-电压特性。根据随温度变化的测量结果，二极管的平均势垒高度在没有和有半绝缘层的情况下分别为0.8 eV和1.3 eV。此外，通过电容-电压测量和热导纳谱(TAS)对所制备的铂-ZTO二极管进行了研究。我们发现，得到的净掺杂密度与由霍尔效应测量得到的自由电子密度一致。TAS发现了两个缺陷能级：一个是激活能为220 meV的深缺陷，另一个是与载流子冻结有关的浅缺陷。假定在冻结温度下，导带内势垒的散射是多阳离子半导体的主要散射机制，得到了约15-27 meV的激活能。
We report on Schottky barrier diodes on the amorphous oxide semiconductor zinc tin oxide (ZTO). The ZTO thin films were grown by pulsed laser deposition at room temperature. Reactively sputtered gold, nickel, platinum, palladium, and silver layers were used to realize the Schottky contacts. To enhance rectification, a thin semi‐insulating zinc tin oxide layer was introduced at the metal–semiconductor interface. The forward current–voltage characteristics of the platinum Schottky barrier diodes were modeled using thermionic emission theory. From temperature dependent measurements, the mean barrier heights of the diodes were determined to be 0.8 and 1.3 eV for diodes without and with a semi‐insulating layer, respectively. Further, the Pt–ZTO diodes were investigated by capacitance–voltage measurements and thermal admittance spectroscopy (TAS). We found that the obtained net doping density agrees with the free electron density determined from Hall‐effect measurements. TAS revealed two defect levels: one deep defect with an activation energy of 220 meV and one shallow defect connected to the carrier freeze‐out. Assuming scattering at potential barriers within the conduction band minimum being the dominant scattering mechanism in multi‐cation semiconductors at freeze‐out temperature, an activation energy of about 15–27 meV was derived.