Sunday, 14 May, 2017, 1:30–3:30 pm

Lateral GaN power devices, circuits and technologies

 

Dr. Patrick Waltereit
Fraunhofer Institute for Applied Solid State Physics
Tullastrasse 72, 79108 Freiburg, Germany
+49 761 5159 620, patrick.waltereit@iaf.fraunhofer.de

 

During the last 20 years GaN has become one of the most important semiconductor materials next to Si. Optoelectronic devices for efficient lighting based on white LEDs made from GaN have already replaced conventional light sources such as incandescent lamps. But GaN has more advantages than just being the most important light source. Thanks to its superior materials properties compared to Si it also offers a variety of advantages for electronic applications such as high breakdown fields, low conduction and switching losses, the ability to operate at high frequencies as well as high temperatures. As a result GaN offers the ability to reduce weight, volume and cost of electronic systems. These remarkable benefits are already exploited for radio-frequency devices with GaN replacing Si LDMOS devices for base stations for mobile communication and GaAs for radar applications. The next step is forecasted to be the use of GaN devices for power switching devices in order to further improve the efficiency for power conversion applications.

The overall electrical performance of GaN transistors exceeds those of conventional Si counterparts such that one is tempted to simply use this technology as plug-and-play. However, GaN-HEMTs and its heterojunction technology should be considered as more than a one-to-one Si replacement. Beyond outstanding power performance this technology offers additional new opportunities for integration. In contrast to most conventional power technologies, as power MOSFETs or IGBTs, the GaN heterojunction technology is laterally. This property enables the integration of several power devices side by side on one chip. Thus monolithically-integrated power topologies involving transistors, diodes and gate drivers are possible on a single power chip. These solutions feature reduced electric parasitics and improved reliability, due to on-chip interconnections, as well as lower module cost through reduced effort of assembly technologies. In this contribution an overview will be given on lateral GaN power devices ranging from epitaxial growth, the processing of high performance devices and circuits, packaging and system applications. The focus is on the technology already gained and remaining challenges for the future.