The Next Generation Bimode Insulated Gate Transistors Based on Enhanced Trench Technology The combined advantages of the low loss Enhanced Trench cell concept and BIGT chip integration sets a new milestone for delivering higher output power for the next generation BIGT power modules. By Munaf Rahimo, Chiara Corvasce, Maxi Andenna, Charalampos Papadopoulos and Arnost Kopta, ABB Switzerland Ltd, Semiconductors High voltage IGBTs have undergone major breakthroughs in the past two decades with respect to their power handling capabilities. Nowa- days the next step to enable higher output power capability for high voltage devices is following two different development paths. The first is an IGBT/Diode integration concept by combining both the IGBT and diode modes of operation in a single chip and hence eliminating the need for a separate antiparallel diode. This step was realized with the introduction of the high voltage and hard switched Reverse Conduct- ing RC-IGBT (or the Bimode Insulated Gate Transistor or BIGT). The BIGT was based on the Enhanced Planar (EP) MOS cell platform, called SPT + . The second development path was achieved with the in- troduction of an Enhanced Trench (ET) MOS cell or TSPT + to provide further plasma enhancement (i.e. losses reductions) combined with improved controllability. Both the BIGT and ET-IGBT device concepts provided separately an additional increase in the output power compared to state of the art HiPak 2 modules with current ratings reaching up to approxi- mately 1800A/3300V and 900A/6500V. The preferred choice of either approach depends heavily on the application in terms of topology, switching frequency, gate drive / control adaptations, and diode load- ing / surge current requirements. Figure (1) shows the nominal current carrying capability increase with each improved IGBT generation for the reference HiPak 2 modules rated at 3300V, 4500V and 6500V. Figure 1: High voltage standard HiPak 2 module (140 x 190 mm) cur- rent ratings for 3300V, 4500V and 6500V with different generations of IGBT technologies. In this article, we demonstrate how the next step in device evolu- tion for targeting even higher current ratings can be achieved by combining the ET-IGBT MOS cell and the BIGT integration structure. The reported results offer the possibility to reach another significant milestone where the current ratings can be doubled to 2400A/3300V and 1200A/6500V when compared to the first IGBT module products at these voltage ratings. THE ENHANCED TRENCH ET-BIGT The high power performance and advantages of the BIGT concept based on the EP MOS cell technology have been previously reported for different voltage ratings ranging between 3300V and 6500V. Also recently, lower losses and higher current ratings were achieved with an IGBT, which is based on the ET MOS cell technology. Therefore, it is natural to follow on the next step and provide the combined advantages of both design concepts by introducing a BIGT based on the ET MOS cell design. Figure 2: The Enhanced Trench ET-BIGT basic design concept includ- ing the wafer backside design. .