中国物理B ›› 2011, Vol. 20 ›› Issue (12): 127204-127204.doi: 10.1088/1674-1056/20/12/127204

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The electrical characteristics of a 4H–silicon carbide metal–insulator–semiconductor structure with Al2O3 as the gate dielectric

刘莉1, 杨银堂1, 马晓华2   

  1. (1)School of Microelectronics, Xidian University, Xi'an 710071, China;Key Laboratory of Wide Band Gap Semiconductor Materials and Devices of Ministry of Education, Xi'an 710071, China; (2)School of Technical Physics, Xidian University, Xi'an 710071, China
  • 收稿日期:2011-03-28 修回日期:2011-10-12 出版日期:2011-12-15 发布日期:2011-12-15
  • 基金资助:
    Project supported by the 2010 School Fundamental Scientific Research Fund of Xidian University (Grant No. K50510250008).

The electrical characteristics of a 4H–silicon carbide metal–insulator–semiconductor structure with Al2O3 as the gate dielectric

Liu Li(刘莉)a)c)† , Yang Yin-Tang(杨银堂) a)c), and Ma Xiao-Hua(马晓华)b)   

  1. a School of Microelectronics, Xidian University, Xi'an 710071, Chinab School of Technical Physics, Xidian University, Xi'an 710071, China; c Key Laboratory of Wide Band Gap Semiconductor Materials and Devices of Ministry of Education, Xi'an 710071, China
  • Received:2011-03-28 Revised:2011-10-12 Online:2011-12-15 Published:2011-12-15
  • Supported by:
    Project supported by the 2010 School Fundamental Scientific Research Fund of Xidian University (Grant No. K50510250008).

摘要: A 4H-silicon carbide metal-insulator-semiconductor structure with ultra-thin Al2O3 as the gate dielectric, deposited by atomic layer deposition on the epitaxial layer of a 4H-SiC (0001) 80N-/N+ substrate, has been fabricated. The experimental results indicate that the prepared ultra-thin Al2O3 gate dielectric exhibits good physical and electrical characteristics, including a high breakdown electrical field of 25 MV/cm, excellent interface properties (1×1014 cm-2) and low gate-leakage current (IG = 1 × 10-3 A/cm-2@Eox = 8 MV/cm). Analysis of the current conduction mechanism on the deposited Al2O3 gate dielectric was also systematically performed. The confirmed conduction mechanisms consisted of Fowler-Nordheim (FN) tunneling, the Frenkel-Poole mechanism, direct tunneling and Schottky emission, and the dominant current conduction mechanism depends on the applied electrical field. When the gate leakage current mechanism is dominated by FN tunneling, the barrier height of SiC/Al2O3 is 1.4 eV, which can meet the requirements of silicon carbide metal-insulator-semiconductor transistor devices.

关键词: Al2O3, 4H-silicon carbide, metal-insulator-semiconductor capacitor, gate leakage current, C-V characteristics

Abstract: A 4H-silicon carbide metal-insulator-semiconductor structure with ultra-thin Al2O3 as the gate dielectric, deposited by atomic layer deposition on the epitaxial layer of a 4H-SiC (0001) 80N-/N+ substrate, has been fabricated. The experimental results indicate that the prepared ultra-thin Al2O3 gate dielectric exhibits good physical and electrical characteristics, including a high breakdown electrical field of 25 MV/cm, excellent interface properties (1×1014 cm-2) and low gate-leakage current (IG = 1 × 10-3 A/cm-2@Eox = 8 MV/cm). Analysis of the current conduction mechanism on the deposited Al2O3 gate dielectric was also systematically performed. The confirmed conduction mechanisms consisted of Fowler-Nordheim (FN) tunneling, the Frenkel-Poole mechanism, direct tunneling and Schottky emission, and the dominant current conduction mechanism depends on the applied electrical field. When the gate leakage current mechanism is dominated by FN tunneling, the barrier height of SiC/Al2O3 is 1.4 eV, which can meet the requirements of silicon carbide metal-insulator-semiconductor transistor devices.

Key words: Al2O3, 4H-silicon carbide, metal-insulator-semiconductor capacitor, gate leakage current, C-V characteristics

中图分类号:  (Insulators)

  • 72.80.Sk
73.40.Qv (Metal-insulator-semiconductor structures (including semiconductor-to-insulator))