To develop next generation epitaxial wafers, with state of art performance, to enable manufacture of improved efficiency GaN RF devices capable of operating up to W-band

Thanks to previous activities, GREAT2, GaN devices have been successfully developed enabling use of the devices into applications up to Ka-Band. However the efficiency is less than is required to meet future planned missions, in particular for the High Power Amplifier (HPA), which is a critical element for the deployment of active array/phase array antennas.  To achieve higher frequency transistor operation in the mm-wave range, design modifications of the device are required : it is necessary to shrink both the active device lateral (gate length) and vertical (channel barrier) dimensions. However, this modification has a negative effect on performances. As the channel barrier thickness is reduced, there is a pro-rata reduction in electron population leading to lower current and hence poor output power / efficiency capability. 

To overcome this problem and to maintain device performances in the mm-wave frequency range, two approaches have to be considered : 

- use of new materials (e.g. InAlN, AlN, ScAIN) in the transistor channel to increase the electron density capability

- introduce new design concepts (e.g. multiple conducting channels) in order to maintain transistor current capability, and minimise short channel effects. 

This activity is the first phase of a two phases work program that aims to achieve disruptive performances of GaN integrated circuits operating in the mm-wave frequency range, with a particular emphasis on efficiency improvement. 

This activity focuses on material improvement according industrial production quality standard and encompasses the following tasks :

- literature review to identify materials and transistor structures

- modeling and simulation of material composition

- exploratory expitaxial manufacturing trials

- design and process optimisation

- manufacturing and characterization of best concepts within European foundries

- definition of future work 

During the second phase, subject to a follow-on activity, more in depth analysis of best design concepts and best materials would be carried out to design, manufacture  and characterise the new GaN devices.