Integrated Computational Materials, Process and Product Engineering – IC-MPPE 2022

Power transistors based on wide band gap semiconductors have become commercially available in recent years. In the case of power conversion for e-mobility, silicon carbide (SiC) power transistors are a serious competitor to established silicon technology due to their low on-state resistance at high breakdown voltage. However, raw SiC wafer cost is a key cost driver and currently limits its widespread adoption. Gallium nitride (GaN), on the other hand, can be grown epitaxially on affordable foreign substrates such as silicon or sapphire and has been successfully commercialized for lower voltage applications using a lateral transistor architecture.
This talk will introduce the concept of vertical GaN membrane power transistors, a new class of power transistors which is currently developed by the European ECSEL project YESvGaN. It combines the cost advantages of GaN heteroepitaxy on affordable substrates with the current handling capabilities of a vertical transistor architecture which is needed for, e.g., the traction inverter of an EV. Besides an introduction to the concept itself and the current state of development, the talk will highlight the challenges from epitaxial growth, over chip processing to the interconnection technology which have to be mastered for vertical GaN membrane transistors to become the next generation of power semiconductors.