Low Resistivity Ohmic Ni/Si/Ni Contacts to N-Type 4H-SiC

낮은 접촉저항을 갖는 Ni/Si/Ni n형 4H-SiC의 오옴성 접합

  • 김창교 (순천향대학교 정보기술공학부) ;
  • 양성준 (충남전략산업기획단 기획ㆍ평가실) ;
  • 조남인 (선문대학교 전자공학과) ;
  • 유홍진 (순천향대학교 신소재화학공학부)
  • Published : 2004.10.01

Abstract

Characteristics of ohmic Ni/Si/Ni contacts to n-type 4H-SiC are investigated systematically. The ohmic contacts were formed by annealing Ni/Si/Ni sputtered sequentially The annealings were performed at 950℃ using RTP in vacuum ambient and N₂ ambient, respectively. The specific contact resistivity(p/sub c/), sheet resistance(R/sub s/), contact resistance (R/sub c/) transfer length(L/sub T/) were calculated from resistance(R/sub T/) versus contact spacing(d) measurements obtained from TLM(transmission line method) structure. While the resulting measurement values of sample annealed at vacuum ambient were p/sub c/ = 3.8×10/sup -5/Ω㎠, R/sub c/ = 4.9 Ω and R/sub T/ = 9.8 Ω, those of sample annealed at N₂ ambient were p/sub c/ = 2.29×10/sup -4/Ω㎠, R/sub c/ = 12.9 Ω and R/sub T/ = 25.8 Ω. The physical properties of contacts were examined using XRD 3nd AES. The results showed that nickel silicide was formed on SiC and Ni was migrated into SiC. This result indicates that Ni/Si/Ni ohmic contact would be useful in high performance electronic devices.

Keywords

References

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