TY - JOUR
T1 - Anatomy-performance correlation in Ti-based contact metallizations on AlGaNGaN heterostructures
AU - Mohammed, Fitih M.
AU - Wang, Liang
AU - Koo, Hyung Joon
AU - Adesida, Ilesanmi
N1 - Funding Information:
The work at the University of Illinois was supported by ONR Grant No. N000140610449 (Program Monitor: Dr. Paul Maki). SEM/EDS measurements were carried out in the Center for Microanalysis of Materials, University of Illinois, which is partially supported by the U.S. Department of Energy under Grant No. DEFG02-91-ER45439. The help of James Mabon in SEM/EDS measurements is acknowledged.
PY - 2007
Y1 - 2007
N2 - A comprehensive study of the electrical and surface microstructural characteristics of TiAu, TiAlAu, TiMoAu, and TiAlmetalAu schemes, where metal is Ir, Mo, Nb, Pt, Ni, Ta, and Ti, has been carried out to determine the role of constituent components of multilayer contact metallizations on Ohmic contact formation on AlGaNGaN heterostructures. Attempts have been made to elucidate the anatomy (composition-structure) performance correlation in these schemes. Evidences have been obtained for the necessity of the Al and metal barrier layer as well as an optimal amount of Ti for achieving low-resistance Ohmic contact formation. A strong dependence of electrical properties and intermetallic interactions on the type of metal barrier layer used was found. Scanning electron microscopy characterization, coupled with energy dispersive x-ray spectroscopy, has shown evidence for alloy aggregation, metal layer fragmentation, Al-Au solid solution formation, and possible Au and/or Al reaction with metal layer. Results from the present study provide insights on the active and the necessary role various components of a multilayer contact metallization play for obtaining excellent Ohmic contact formation in the fabrication of AlGaNGaN high electron mobility transistors.
AB - A comprehensive study of the electrical and surface microstructural characteristics of TiAu, TiAlAu, TiMoAu, and TiAlmetalAu schemes, where metal is Ir, Mo, Nb, Pt, Ni, Ta, and Ti, has been carried out to determine the role of constituent components of multilayer contact metallizations on Ohmic contact formation on AlGaNGaN heterostructures. Attempts have been made to elucidate the anatomy (composition-structure) performance correlation in these schemes. Evidences have been obtained for the necessity of the Al and metal barrier layer as well as an optimal amount of Ti for achieving low-resistance Ohmic contact formation. A strong dependence of electrical properties and intermetallic interactions on the type of metal barrier layer used was found. Scanning electron microscopy characterization, coupled with energy dispersive x-ray spectroscopy, has shown evidence for alloy aggregation, metal layer fragmentation, Al-Au solid solution formation, and possible Au and/or Al reaction with metal layer. Results from the present study provide insights on the active and the necessary role various components of a multilayer contact metallization play for obtaining excellent Ohmic contact formation in the fabrication of AlGaNGaN high electron mobility transistors.
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U2 - 10.1063/1.2433765
DO - 10.1063/1.2433765
M3 - Article
AN - SCOPUS:33847123988
SN - 0021-8979
VL - 101
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 3
M1 - 033708
ER -