
98 Gallium Nitride (GaN): Physics, Devices, and Technology
TABLE 3.7 Benchmarking Different Gold-Based Ohmic Contacts to InAlN/
GaN HEMTs
Afliation
InAlN/
AlN/GaN
HEMT on
Ohmic
Metal
Treatments
Prior to
Metallization
Anneal
Temperature
(°C)/Time
(seconds) R
c
(Ω-mm)
NTU [78] Si Ti/Al/Ni/
Au
— 825/30 0.33
NIT [79] Si Ti/Al/Ni/
Au
— 800/30 0.60
ETH [83] Si Ti/Al/Au — 800/30 and
850/30
(two-time
annealed)
0.36
UND [77] SiC Ti/Au Regrown
n+-GaN by
MBE
Nonalloyed 0.16
ISSE [84] SiC Ti/Al/Ni/
Au
Ohmic recess
(SiCl
4
plasma)
600/— 0.70
IEMN [85] SiC Ti/Al/Ni/
Au
— 900/30 0.15
UIUC [86] SiC Mo/Al/Mo/
Au
Ohmic recess
(SiCl
4
plasma)
650/30 0.15
MIT [87] SiC Si/Ge/Ti/
Al/Ni/Au
— 820/30 ...