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Au‐free Si MOS compatible Ni/Ge/Al ohmic contacts to n + ‐InGaAs
Author(s) -
Oh Jungwoo,
Yoon Seonno,
Ki Bugeun,
Song Yunwon,
Lee HiDeok
Publication year - 2015
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201431713
Subject(s) - ohmic contact , materials science , electrical resistivity and conductivity , germanium , contact resistance , oxide , diffusion barrier , layer (electronics) , metal , optoelectronics , indium gallium arsenide , doping , gallium arsenide , silicon , nanotechnology , metallurgy , electrical engineering , engineering
Complementary metal‐oxide semiconductor‐compatible Ni/Ge/Al ohmic contacts to a n + ‐InGaAs layer exhibited a specific contact resistivity of 9.8 × 10 −8 Ωcm 2 at 300 and 5.1 × 10 −8 Ωcm 2 at 500 °C. Only 7 nm of the n + ‐InGaAs layer was consumed during the Ni/Ge/Al ohmic formation. For comparison, Ni/Al and Ge/Ni/Al contacts showed a higher specific contact resistivity with significant consumption of the n + ‐InGaAs layer. The relatively low contact resistivities for Ni/Ge/Al are attributed to the transient increase in the donor concentration of n + ‐InGaAs. Ge metals segregated towards the n + ‐InGaAs surface and redistributed into the Ga and In sites, which increased the doping and acted as a diffusion barrier. These electrical and physical analyses of Ni/Ge/Al ohmic contacts to n + ‐InGaAs advance Au‐free metallization techniques for highly scaled InGaAs channel metal‐oxide field‐effect transistors.