CATANIA, April 30, 2020 — Growth of high-quality substrates for microelectronic applications is one of the key elements that drive society toward a more sustainable green economy. Today, silicon plays a central role within the semiconductor industry for microelectronic and nanoelectronic devices. Silicon wafers of single-crystalline high-purity (99.0% or higher) material can be obtained via a combination of liquid growth methods, such as pulling a seed crystal from the melt and by subsequent epitaxy. The catch is that the former process cannot be used for the growth of silicon carbide (SiC) because it lacks a melting phase.
In the journal Applied Physics Reviews, from AIP Publishing, Giuseppe Fisicaro and an international team of researchers led by Antonino La Magna, describe a theoretical and experimental study of the atomic mechanisms governing extended defect kinetics in cubic SiC (3C-SiC), which has a diamondlike zincblende (ZnS) crystal structure that manifests both stacking and anti-phase instabilities. The investigation is driven by the fact that the development of a technological framework for the control of crystalline imperfections within SiC for wide bandgap applications can be a game-changing strategy.
The researchers’ study pinpoints the atomistic mechanisms responsible for extended defect generation and evolution, where anti-phase boundaries — i.e. planar crystallographic defects representing the contact boundary between two crystal regions with switched bonds (C-Si instead of Si-C) — are found to be a critical source of other extended defects in a plethora of configurations.
Eventual reduction of these anti-phase boundaries is particularly important to achieve good-quality crystals that can be used in electronic devices and enable viable commercial yields.
The study took advantage of an innovative simulation Monte Carlo code based on a superlattice (MulSKIPS, www.github.com/giuseppefisicaro/mulskips), which is a spatial lattice that contains both the perfect SiC crystal and all crystal imperfections. The code helped to shed light on the various mechanisms of defect-defect interactions and their impact on the electronic properties of this material. The manuscript has been selected by the Editorial Board as “one of the journal's best” and promoted as a Featured Article.
This work is part of the European Union’s Horizon 2020 CHALLENGE Program (www.h2020challenge.eu; HORIZON 2020-NMBP-720827).
Genesis and evolution of extended defects: The role of evolving interface instabilities in cubic SiC (https://aip.scitation.org/doi/10.1063/1.5132300)
Giuseppe Fisicaro, Corrado Bongiorno, Ioannis Deretzis, Filippo Giannazzo, Francesco La Via, Fabrizio Roccaforte, Marcin Zielinski, Massimo Zimbone, and Antonino La Magna
Consiglio Nazionale delle Ricerche/Institute for Microelectronics and Microsystems
NOVASiC, Savoie Technolac, Arche Bat 4, BP267, 73375 Le Bourget du Lac, France
AIP press release - https://publishing.aip.org/publications/latest-content/emerging-wide-bandgap-semiconductor-devices-based-on-silicon-carbide-may-revolutionize-power-electronics/
phys.org - https://phys.org/news/2020-04-wide-bandgap-semiconductor-devices-based.html