Welcome

     Energy attainability has forced a great effort towards reserves searching. In fact, more than 10% of all electricity is lost in the form of conversion losses, representing over 10 times higher volume than the world′s supply of renewable energy.
To decrease the conversion losses, highly efficient converters utilizing a new generation of power switching transistor based on SiC or GaN can be employed. Amongst them, GaN offers the highest theoretical figure-of-merits substantially over-performing the state-of-the-art Si switching devices.
Moreover, GaN is a robust and chemically stable material resistive to aggressive surrounding and high temperatures.
However, a wider commercialization of the GaN power switching devices is hampered by the technology immaturity and, in particular, absence of a safe enhancement mode (or normally-off) transistor concept with a highly positive threshold voltage (Vth).
As recently proposed by us, this issue can be addressed by implementing a metal-oxide-semiconductor (MOS) gate structure with a sufficiently low density of surface donors (SD) at the oxide/heterostructure interface. However, technological control of charges in GaN based MOS structures remains an open question.
We intend to analyze the feasibility of controlling charges in processed MOS-HEMT structures using comprehensive electrical and structural characterization.
Great effort will be devoted towards suppression of the trapping effects, often degrading threshold voltage stability in GaN MOS-HEMTs.
Alternative MOS-HEMT designs will be also implemented and analyzed.