Remote Epitaxy Application for SiC Wafer Cost Reduction

Professor Jeehwan Kim reported epitaxial growth on 2D material-coated substrates and exfoliation of the remote epitaxial film from the graphene-GaAs substrate in 2017 [1]. Furthermore, SiC production wafers are fabricated by physical vapor transport (PVT) at a temperature over 2200 degree C in inert gas environment. This seeded sublimation growth needs extremely time-consuming. If the wafer production time and costs can be significantly reduced, SiC power devices will be more widely used and greatly contribute to solving environmental issue.<br/>In the present study, we introduce the application of remote epitaxy technology through graphene to SiC alternative substrates with epitaxial membranes. Epitaxial graphene is formed by a graphitization process, where the top layer of silicon (Si) atoms on the (0001) surface of 4H-SiC wafer is sublimated at high temperature and epitaxial growth of 4H-SiC is obtained on graphene-coated SiC substrates with the same crystal orientation direction as the SiC substrates used. Then, the epitaxial membrane is exfoliated with using stressor films and the polycrystalline SiC substrate is formed on the peeled epitaxial film. This remote epitaxy method allows the reuse the SiC substrates for fabrication of SiC epitaxial layer and significantly reduces the cost of crystal growth and material loss for SiC wafer production compared to existing methods.<br/>[1] Y. Kim et al., “Remote epitaxy through graphene enables two-dimensional material-based layer transfer,” Nature 544.7650 (2017): 340-343.