Fraunhofer Institute for Electron BeamMagnetron Sputter Epitaxy (MSE) at Fraunhofer FEP represents an innovative technology for resource-efficient deposition of high-purity, crystalline III-nitride semiconductors such as Gallium Nitride (GaN) and Aluminum Nitride (AlN). These semiconductors are crucial for the development of future microelectronic devices. III-nitrides have a variety of applications, including in energy-efficient power converters for renewable energies, in frequency converters for e-mobility, in radar and wireless technologies, as well as in optoelectronic LED and laser systems.
Fraunhofer FEP is developing MSE as a complementary approach to synthesising III-nitride semiconductors more efficiently. Compared to traditional metalorganic chemical vapor deposition (MOCVD), which is the industrial standard for complex III-nitride devices, MSE produces crystalline layers via plasma-assisted deposition. This allows operating at decreased temperatures and helps circumventing the drawbacks of expensive and toxic organometallic precursors. Through the development of MSE technology, resource-efficient deposition of high-purity AlN- and GaN-layers at temperatures below 1000°C has been successfully realized.
The fabrication of AlN templates on silicon substrates with a 200 mm diameter provides a scalable foundation for the subsequent epitaxy of active devices, for example via MOCVD. MSE's lower process temperatures (800°C is targeted, compared to MOCVD at around 1100°C) minimize mechanical stresses and could enable direct integration of the epitaxy into the Si-CMOS frontend. In the mid-term, it is intended to directly deposit active devices using MSE.
So far, only with the Double Ring Magnetron (DRM) technology developed by Fraunhofer FEP it has been possible to directly control polarity of AlN (Al- or N-polar) on 200 mm silicon wafers and on 100 mm sapphire wafers thorugh the epitaxy process itself, enabling new device architectures.
The stable reactive MSE deposition of GaN requires a solid-state gallium target (melting point of Ga ≈ 29°C). Thus, the DRM at Fraunhofer FEP has been further developed and equipped with an innovative evaporative cooling system.
In 2026, Fraunhofer FEP will commission its new epitaxy tool »EpiLab« specifically designed for MSE. It will enable confocal deposition of AlGaN layers as well as AlN/GaN superlattices on 200 mm wafers, and the investigation of novel dopant approaches. This investment in infrastructure (including an ISO-3 cleanroom) provides the foundation for developing active layers for GaN-based devices and positions Fraunhofer FEP as a leading player in sustainable semiconductor technology.
