中国物理B ›› 2014, Vol. 23 ›› Issue (2): 27102-027102.doi: 10.1088/1674-1056/23/2/027102

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Different influences of Schottky metal on the strain and relative permittivity of barrier layer between AlN/GaN and AlGaN/GaN heterostructure Schottky diodes

吕元杰a, 冯志红a, 顾国栋a, 敦少博a, 尹甲运a, 王元刚a, 徐鹏a, 韩婷婷a, 宋旭波a, 蔡树军a, 栾崇彪b, 林兆军b   

  1. a National Key Laboratory of Application Specific Integrated Circuit, Hebei Semiconductor Research Institute, Shijiazhuang 050051, China;
    b School of Physics, Shandong University, Jinan 250100, China
  • 收稿日期:2013-03-29 修回日期:2013-05-06 出版日期:2013-12-12 发布日期:2013-12-12
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61306113, 60876009, and 11174182).

Different influences of Schottky metal on the strain and relative permittivity of barrier layer between AlN/GaN and AlGaN/GaN heterostructure Schottky diodes

Lü Yuan-Jie (吕元杰)a, Feng Zhi-Hong (冯志红)a, Gu Guo-Dong (顾国栋)a, Dun Shao-Bo (敦少博)a, Yin Jia-Yun (尹甲运)a, Wang Yuan-Gang (王元刚)a, Xu Peng (徐鹏)a, Han Ting-Ting (韩婷婷)a, Song Xu-Bo (宋旭波)a, Cai Shu-Jun (蔡树军)a, Luan Chong-Biao (栾崇彪)b, Lin Zhao-Jun (林兆军)b   

  1. a National Key Laboratory of Application Specific Integrated Circuit, Hebei Semiconductor Research Institute, Shijiazhuang 050051, China;
    b School of Physics, Shandong University, Jinan 250100, China
  • Received:2013-03-29 Revised:2013-05-06 Online:2013-12-12 Published:2013-12-12
  • Contact: Feng Zhi-Hong E-mail:917vv@163.com
  • About author:71.55.Eq; 77.80.bn; 77.22.Ch; 73.30.+y
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61306113, 60876009, and 11174182).

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摘要： Ni/Au Schottky contacts on AlN/GaN and AlGaN/GaN heterostructures are fabricated. Based on the measured current–voltage and capacitance-voltage curves, the polarization sheet charge density and relative permittivity are analyzed and calculated by self-consistently solving Schrödinger’s and Poisson’s equations. It is found that the values of relative permittivity and polarization sheet charge density of AlN/GaN diode are both much smaller than the ones of AlGaN/GaN diode, and also much lower than the theoretical values. Moreover, by fitting the measured forward I–V curves, the extracted dislocations existing in the barrier layer of the AlN/GaN diode are found to be much more than those of the AlGaN/GaN diode. As a result, the conclusion can be made that compared with AlGaN/GaN diode the Schottky metal has an enhanced influence on the strain of the extremely thinner AlN barrier layer, which is attributed to the more dislocations.

关键词: Al(Ga)N/GaN, strain, relative permittivity, Schottky metal

Abstract: Ni/Au Schottky contacts on AlN/GaN and AlGaN/GaN heterostructures are fabricated. Based on the measured current–voltage and capacitance-voltage curves, the polarization sheet charge density and relative permittivity are analyzed and calculated by self-consistently solving Schrödinger’s and Poisson’s equations. It is found that the values of relative permittivity and polarization sheet charge density of AlN/GaN diode are both much smaller than the ones of AlGaN/GaN diode, and also much lower than the theoretical values. Moreover, by fitting the measured forward I–V curves, the extracted dislocations existing in the barrier layer of the AlN/GaN diode are found to be much more than those of the AlGaN/GaN diode. As a result, the conclusion can be made that compared with AlGaN/GaN diode the Schottky metal has an enhanced influence on the strain of the extremely thinner AlN barrier layer, which is attributed to the more dislocations.

Key words: Al(Ga)N/GaN, strain, relative permittivity, Schottky metal

中图分类号:  (III-V semiconductors)

  • 71.55.Eq
77.80.bn (Strain and interface effects) 77.22.Ch (Permittivity (dielectric function)) 73.30.+y (Surface double layers, Schottky barriers, and work functions)