Gallium Nitride Smart Power Integrated Circuit Technology (GaN SPICe)

Undeniably, there are numerous crystal materials that surpass Silicon based devices (such as Gallium Nitride, Silicon Carbide and Diamond), but the high cost of their manufacturing has always been the roadblock for their implementation in applications therefore nowadays Silicon dominates the semiconductor industry. Gallium nitride (GaN) is a more superior semiconductor to Silicon for RF and Power applications. The advantage of GaN is that it can be grown as a thin layer on top of a standard low-cost Silicon wafer (i.e. substrate) enabling a new power device family, Power High Electron Mobility Transistors (HEMTs) on Silicon. Power HEMTs are faster, compact in size, more efficient and comparable in price for converter applications to their aging Silicon counterparts. Similarly to Silicon power technology development (from discrete devices to smart power integrated circuits), the arrival of GaN-based integrated circuits, GaN power transistors monolithically integrated with Hall-effect and temperature sensors, GaN gate drivers and ASICs, will facilitate widespread use of gallium nitride technology for high-volume applications.

The GaN Smart Power Integrated Circuit Technology (GaN SPICe) project brings together the Universities of Coventry and Glasgow to investigate, develop and provide functional verification of the game-changing GaN smart power integrated technology; the group will be the 1st in the World to integrate a normally-off power GaN HEMT with advanced galvanic Hall-effect and temperature sensors. HEMT is a voltage controlled device and on-chip monitoring of its output current is critical for safe and long operation of an electronic system, similar to monitoring one's heart rate. The galvanic sensor is a GaN Hall-effect device accompanied by signal conditioning circuitry (with Coventry's filed patent application number 1913936.9), to minimise drift in sensor characteristics at elevated temperatures. This will increase functionality, enable a reduction of system volume, reduce cost of assembly, and as chip temperature can be actively compensated, improve reliability and efficiency of the power device. These are fundamental requirements for complex power electronics systems, in particular when installed in limited volume, hostile (high temperature/vibration) environments, such as battery electric and hybrid vehicles for example.

Coventry and Glasgow are uniquely positioned to make this project success, thanks to the track record and expertise of its academic and research staff, GaN power HEMT at Glasgow and GaN Hall-effect sensors at Coventry, and the investment in their laboratory facilities (clean room, design, and test and characterisation laboratories), making it one of very few research consortiums, in the UK and overseas, capable of providing innovation at every stage of this development.