Gallium Nitride (GaN) devices are foreseen to play a major role in next generation of power electronic applications. This is due to its outstanding material properties and cost-effective manufacturing when grown on silicon substrate. Thus, GaN-based power switches have the potential to enable high efficiency connection of renewable energy sources to the electricity grid. The new technology would enable higher efficiency and less complexity as well as being light-weight with greater functionality, robustness and the ability to operate in a wide ambient temperature range. The ultimate goal for renewable energy companies is to supply/interface their energy to the national grid with minimal loss. This will ultimately mean there will be less demand for energy derived from fossil-fuel sources, and so this way will protect the environment from CO2 emissions. GaN devices are expected to reliably operate at elevated junction temperatures up to at least 225°C (presently used Si-based devices cease to function at ~150°C), easing the constraints on current cooling requirements. Similarly, GaN-based power conversion circuits can operate at higher efficiencies and high frequencies enabling compact converter and inverter designs, up to a 10? reduction in size, cost and weight. This will translate into significant energy saving (~10%), overall cost reduction, increased adoption of renewable energy sources, and improvements in profit for the renewable energy companies. In this frame, we have developed a new concept enabling to boost significantly the GaN-on-silicon device breakdown voltage above 3000 V. The key feature of this concept lies in a backside local removal of the silicon substrate around the drain electrode. One of the main challenges of power devices is the thermal management. This project aims at developing an innovative thermal management solution integrated within the backside trenches, which should generate unique substrate grounded GaN power devices operating at voltages far beyond existing GaN-based devices. Four public institutions IEMN, ESIEE, CRHEA and LAAS will combine their skills to reach this ambitious goal that would lead to a real technological breakthrough for power applications. The DESTINEE research effort addresses key critical components based on the emerging GaN material for next generation of power electronics. It will benefit from existing collaborations with partners that have leadership in their respective domain. The project covers a large added value chain from epitaxy, integrated device technology developments, to prototype device characterisation and preliminary reliability.