Interfacial reactions in epitaxial Al/Ti[sub 1[minus][ital x]]Al[sub [ital x]]N (0[le][ital x][le]0. 2) model diffusion-barrier structures

Journal Article · Fri Jan 01 00:00:00 EST 1993 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578277· OSTI ID:6906726

Petrov, I; Mojab, E; Adibi, F; Greene, J E ^[1]; Hultman, L; Sundgren, J ^[2]

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1. Coordinated Science Laboratory, Materials Research Laboratory, and Department of Materials Science, University of Illinois, Urbana, Illinois 61801 (United States)
2. Thin Film Division, Physics Department, Linkoeping University, S-581 83 Linkoeping (Sweden)

Transmission electron microscopy (TEM), cross-sectional TEM, scanning TEM with energy dispersive x-ray analysis, and Auger electron spectroscopy were used to investigate the nature of rate-controlling interfacial reactions in epitaxial Al/Ti[sub 1[minus][ital x]]Al[sub [ital x]]N thin-film couples. TiN and NaCl-structure Ti[sub 1[minus][ital x]]Al[sub [ital x]]N layers, 120 nm thick, with compositions [ital x]=0.1 and 0.2 were grown on MgO(001) substrates by ultrahigh vacuum reactive magnetron cosputter deposition in N[sub 2] discharges. Epitaxial Al films, 200-nm-thick, were then grown in Ar on top of the nitride layers during the same vacuum cycle. The reaction paths for Al/TiN and Al/(Ti,Al)N interactions during anneals at [ital T][sub [ital a]]=600 [degree]C for [ital t][sub [ital a]] up to 150 min was similar, but the extent of reaction was dramatically decreased by the substitution of (Ti,Al)N barrier layers for TiN. The primary mobile species during annealing was Ti which penetrated into the Al layers and reacted to form the ordered tetragonal intermetallic phase Al[sub 3]Ti while Al segregation resulted in the formation of a narrow metastable zincblende structure AlN layer at the Al/nitride interface. The room-temperature resistivity of 1-[mu]m-thick nitride layers varied from 15 [mu][Omega] cm for TiN to 60 [mu][Omega] cm for Ti[sub 0.8]Al[sub 0.2]N.

• DOE Contract Number: AC02-76ER01198
• OSTI ID: 6906726
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Vol. 11:1; ISSN 0734-2101
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM
ATOM TRANSPORT
DIFFUSION
ALUMINIUM NITRIDES
TITANIUM
TITANIUM NITRIDES
ANNEALING
AUGER ELECTRON SPECTROSCOPY
ELECTRIC CONDUCTIVITY
INTERFACES
SPUTTERING
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
ALUMINIUM COMPOUNDS
ELECTRICAL PROPERTIES
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
FILMS
HEAT TREATMENTS
METALS
MICROSCOPY
NEUTRAL-PARTICLE TRANSPORT
NITRIDES
NITROGEN COMPOUNDS
PHYSICAL PROPERTIES
PNICTIDES
RADIATION TRANSPORT
SPECTROSCOPY
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
360104* - Metals & Alloys- Physical Properties
360204 - Ceramics
Cermets
& Refractories- Physical Properties