The promise of GaN on Silicon
The growing demand for high-speed, high-temperature and high-power handling capabilities has made the semiconductor industry rethink the choice of materials. Today’s Silicon semiconductor technologies are approaching their theoretical limits and only incremental performance improvements are still possible. Due to the unique characteristics of Gallium Nitride (GaN) (extremely high current density, breakdown voltage and switching frequency, as well as low noise figure and high linearity), devices can provide a step change in performance for power switching, RF power and sensor systems. At the same time GaN on Si epitaxial wafers enable device manufacturing on automated Si CMOS fabrication lines and leverage Si based economies of scale for lowest production costs.
EpiGaN's unique in-situ SiN passivation
To control the extreme sensitivity of GaN transistors to surface charges, EpiGaN deposits a unique in-situ SiN capping layer, which is grown by MOCVD as part of the epitaxy process on top of the HEMT (high electron mobility tansistor) epiwafers. The interface between this capping layer and the top nitride surface is incredibly smooth and it provides excellent passivation of surface states. In addition, the SiN layer enables the growth of pure AlN barriers with the resulting heterostructures having even lower sheet resistance values. As a consequence engineers can realize more compact and lower cost power switching HEMT designs enabled by EpiGaN's unique SiN/AlN/GaN heterostructures. Moreover, RF power transistors will benefit from high transconductances even at relatively moderate gate lengths.