Epitaxial metals for interconnects beyond Cu
Abstract
Experimentally measured resistivity of Co(0001) and Ru(0001) single crystal thin films, grown on c-plane sapphire substrates, as a function of thickness is modeled using the semiclassical model of Fuchs–Sondheimer. The model fits show that the resistivity of Ru would cross below that for Co at a thickness of approximately 20 nm. For Ru films with thicknesses above 20 nm, transmission electron microscopy evidences threading and misfit dislocations, stacking faults, and deformation twins. Exposure of Co films to ambient air and the deposition of oxide layers of SiO2, MgO, Al2O3, and Cr2O3 on Ru degrade the surface specularity of the metallic layer. However, for the Ru films, annealing in a reducing ambient restores the surface specularity. Epitaxial electrochemical deposition of Co on epitaxially deposited Ru layers is used as an example to demonstrate the feasibility of generating epitaxial interconnects for back-end-of-line structures. An electron transport model based on a tight-binding approach is described, with Ru interconnects used as an example. The model allows conductivity to be computed for structures comprising large ensembles of atoms (105–106), scales linearly with system size, and can also incorporate defects.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 13, 2020
- Source ID
- 10.1116/6.0000018
Entities
People
- Alan C West
- Amirali Zangiabadi
- Asim Khaniya
- Atharv Jog
- Daniel Gall
- Eduardo R Mucciolo
- Erik Milosevic
- Kadir Sentosun
- Katayun Barmak
- Kevin R. Coffey
- Patrick K. Schelling
- Ryan Gusley
- Sameer Ezzat
- Sit Kerdsongpanya
- W. E. Richardson
- William E. Kaden
Organizations
- Air Force Office of Scientific Research
- Columbia University
- National Science Foundation
- Rensselaer Polytechnic Institute
- Semiconductor Research Corporation
- University of Central Florida
- University of Mosul