MOSFETs and fast recovery diodes are fundamental elements of power switching applications ranging from photovoltaic inverters to HID lamp ballasts and power supplies for telecoms and servers. Careful selection of power MOSFET technologies can make a big difference to the efficiency and the performance of a target system. The latest developments in semiconductor technology have allowed a fast recovery diode to be integrated into the body of the MOSFET, while maintaining the package size of the previous MOSFET, resulting in space savings and reduced component counts. This paper discusses how the DTMOS IV process, based on deep trench filling technology, reduces the amount of process steps, saving cost and improving performance of the superjunction MOSFETs at the same time.