Structural and electrical studies on Ti/Al-based Au-free ohmic contact metallization for AlGaN/GaN HEMTs
Marek Guziewicz , Andrzej Taube , Marek Ekielski , Krystyna Gołaszewska , Joanna Zdunek , Piotr Bazarnik , Bogusława Adamczyk-Cieślak , Anna Szerling
AbstractIn order to fabricate the AlGaN/GaN-on-Si HEMTs on existing Si-CMOS production lines, manufacturing processes must meet the rigors of Si-CMOS technology eliminating Au. One of the requirements is formation of Au free, low resistivity ohmic contacts to AlGaN/GaN heterostructures. In this work we report structural and electrical studies of Ti/Al-based ohmic contacts to AlGaN/GaNHEMTs with TiN/Cu cover layers. Ohmic contacts have been observed after annealing of Ti/Al/TiN/Cu or Ti/Al/Ti/TiN/Cu/TiN multilayers on recessed AlGaN/ GaN structure at temperature of 550°C, speciﬁc contact resistance is about 2.3×10−4 Ωcm2, however, lower value was obtained after annealing at 750°C. The XRD and TEM studies reveal formation of additional phases during annealing, namely Al3Ti and Ti2AlN inside the volume of the metallization stack and AlN at metal/GaN interface. Measured dependence of contact resistance on temperature suggests a “metal-like” carrier transport mechanism in partially recessed Ti/Al/Ti/TiN/Cu ohmic contact to 2D electron gas.
|Journal series||Materials Science in Semiconductor Processing, ISSN 1369-8001|
|Publication size in sheets||0.5|
|Keywords in Polish||Kontakt omowy, Metalizacja, Heterostruktura AlGaN/GaN, Transmisyjna mikroskopia eletronowa|
|Keywords in English||Ohmic contacts, Metallization, AlGaN/GaN heterostructure, TEM|
|ASJC Classification||; ; ;|
|Score||= 70.0, 18-12-2019, ArticleFromJournal|
|Publication indicators||= 0; = 0; : 2017 = 0.992; : 2018 = 2.722 (2) - 2018=2.568 (5)|
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