GaN surface sputter damage investigated using deep level transient spectroscopy
GaN surface sputter damage investigated using deep level transient spectroscopy
复制标题
DOI：
10.1016/j.mssp.2020.105654
复制
发表时间：
2021-05
影响因子：
4.1
通讯作者：
Xiaoyan Tang;S. Hammersley;V. Markevich;I. Hawkins;I. Crowe;T. Martin;Tony Peaker;M. Halsall
中科院分区：
文献类型：
--
作者：
Xiaoyan Tang;S. Hammersley;V. Markevich;I. Hawkins;I. Crowe;T. Martin;Tony Peaker;M. Halsall
摘要对于电阻热蒸发和等离子体溅射沉积制备的名义上相同的GaN肖特基二极管，溅射沉积制备的二极管被发现表现出明显的反向漏电流增加，这是大约两个数量级高于使用热蒸发制备的二极管。利用深能级瞬态谱研究了等离子体溅射金制备的n型GaN肖特基二极管中的缺陷，并与电阻热蒸发制备的类似结构中的缺陷进行了比较。从深能级瞬态谱确定了两个缺陷的溅射二极管的激活能为0。26±0。01电子V相对于导带边缘和0。62±0。04电子伏相对于价带边缘。溅射二极管的缺陷浓度分布显示，缺陷密度从表面到结构深处逐渐减小，表明它们是通过溅射引入的。由于溅射沉积技术在器件制造中的广泛应用，因此应注意由于引入额外缺陷而产生的不利影响，例如HEMT中的电荷陷阱和LED中的非辐射复合。
Abstract For nominally identical GaN Schottky diodes prepared by resistive thermal evaporation and plasma sputter deposition, diodes prepared by sputter deposition were found to exhibit a clear increase in the reverse leakage current, which is about two orders of magnitude higher than diodes prepared using thermal evaporation. Defects in n-type GaN Schottky diodes fabricated by plasma sputtering of gold were investigated using deep-level transient spectroscopy and compared with those in similar structures fabricated by resistive thermal evaporation. From deep level transient spectroscopy two defects were identified in the sputtered diode with the activation energies for charge carrier emission of 0. 26±0. 01 e V relative to the conduction band edge and 0. 62±0. 04 e V relative to the valence band edge. Defect concentration profiles of sputtered diodes show the defect density reduces from the surface to deeper in the structure, indicating that they are introduced through sputtering. Since the sputter deposition technique is widely used in device fabrication, attention should be paid to the adverse effects due to the additional defect introduction such as the charge trapping in HEMTs and the non-radiative recombination in LEDs.