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


In 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.
Author Marek Guziewicz - Institute of Electron Technology (ITE) [Instytut Technologii Elektronowej]
Marek Guziewicz,,
, Andrzej Taube - Institute of Electron Technology (ITE) [Instytut Technologii Elektronowej]
Andrzej Taube,,
, Marek Ekielski - [Institute of Electron Technology (ITE)]
Marek Ekielski,,
- Instytut Technologii Elektronowej
, Krystyna Gołaszewska - Institute of Electron Technology (ITE) [Instytut Technologii Elektronowej]
Krystyna Gołaszewska,,
, Joanna Zdunek (FMSE / DMD)
Joanna Zdunek,,
- Division of Materials Design
, Piotr Bazarnik (FMSE / DMD)
Piotr Bazarnik,,
- Division of Materials Design
, Bogusława Adamczyk-Cieślak (FMSE / DMD)
Bogusława Adamczyk-Cieślak,,
- Division of Materials Design
, Anna Szerling - Institute of Electron Technology (ITE) [Instytut Technologii Elektronowej]
Anna Szerling,,
Journal seriesMaterials Science in Semiconductor Processing, ISSN 1369-8001
Issue year2019
Publication size in sheets0.5
Keywords in PolishKontakt omowy, Metalizacja, Heterostruktura AlGaN/GaN, Transmisyjna mikroskopia eletronowa
Keywords in EnglishOhmic contacts, Metallization, AlGaN/GaN heterostructure, TEM
ASJC Classification2210 Mechanical Engineering; 2211 Mechanics of Materials; 3104 Condensed Matter Physics; 2500 General Materials Science
Languageen angielski
Structural and electrical studies on TiAl-based Au-free ohmic contact for HEMTs _ MSSP 2019.pdf 2.91 MB
Score (nominal)70
Score sourcejournalList
ScoreMinisterial score = 70.0, 09-06-2020, ArticleFromJournal
Publication indicators Scopus Citations = 1; WoS Citations = 0; Scopus SNIP (Source Normalised Impact per Paper): 2017 = 0.992; WoS Impact Factor: 2018 = 2.722 (2) - 2018=2.568 (5)
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