The crystalline Rare Earth Oxides (cREO®) are a family of multi-functional oxides grown epitaxially on Si(111).
Use of the appropriate rare earth (e.g. Er, Sc, Gd) enable the properties of the oxide to be designed to match a specific application. The process is robust and available for wafers up to 200 mm in diameter.
cREO® template summary
To date, IQE has focused on applying cREO® to its enabling RF filter technology (IQepiMoTM). In this application, the cREO® serves as a chemical barrier that supports the high temperature epitaxial growth of Mo. IQE has demonstrated that its epiMo templates offer significant electrical and crystallinity benefits for BAW filter applications.
cREO® opens up other possibilities beyond RF filters. For example, it is an attractive template for c-plane III-N epitaxial growth for multiple applications. For Power Electronics, the high breakdown field of cREO® (4.5 MV/cm) is particularly attractive as it offers a route to accessing higher voltage nodes at reduced III-N epi thickness. This mitigates strain management challenges inherent to the growth of thick III-N films on Si.