Epitaxial NbN/AlN/NbN tunnel junctions on Si substrates with TiN buffer layers

Journal Article · Wed Jun 15 00:00:00 EDT 2016 · AIP Advances

DOI:https://doi.org/10.1063/1.4954743· OSTI ID:22611539

Sun, Rui ^[1]; Makise, Kazumasa; Terai, Hirotaka ^[2]; Zhang, Lu ^[1]; Wang, Zhen ^[1]

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1. State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences (CAS), Shanghai 200050 (China)
2. Advanced ICT Research Institute, National Institute of Information and Communications Technology (Japan)

We have developed epitaxial NbN/AlN/NbN tunnel junctions on Si (100) substrates with a TiN buffer layer. A 50-nm-thick (200)-oriented TiN thin film was introduced as the buffer layer for epitaxial growth of NbN/AlN/NbN trilayers on Si substrates. The fabricated NbN/AlN/NbN junctions demonstrated excellent tunneling properties with a high gap voltage of 5.5 mV, a large I{sub c}R{sub N} product of 3.8 mV, a sharp quasiparticle current rise with a ΔV{sub g} of 0.4 mV, and a small subgap leakage current. The junction quality factor R{sub sg}/R{sub N} was about 23 for the junction with a J{sub c} of 47 A/cm{sup 2} and was about 6 for the junction with a J{sub c} of 3.0 kA/cm{sup 2}. X-ray diffraction and transmission electron microscopy observations showed that the NbN/AlN/NbN trilayers were grown epitaxially on the (200)-orientated TiN buffer layer and had a highly crystalline structure with the (200) orientation.

• OSTI ID: 22611539
• Journal Information: AIP Advances, Vol. 6, Issue 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM NITRIDES
BUFFERS
CRITICAL CURRENT
CURRENT DENSITY
ELECTRIC CONTACTS
EPITAXY
LAYERS
LEAKAGE CURRENT
NIOBIUM NITRIDES
QUALITY FACTOR
SEMICONDUCTOR JUNCTIONS
SUBSTRATES
SUPERCONDUCTING JUNCTIONS
THIN FILMS
TITANIUM
TITANIUM NITRIDES
TRANSMISSION
TRANSMISSION ELECTRON MICROSCOPY
TUNNEL EFFECT
X-RAY DIFFRACTION