Compatibility of VJFET Technology with MESFET Fabrication and Its Interest for System Integration: Fabrication of 6H and 4H-SiC 110 V Lateral MESFET

Abstract

Integration of Power devices with their control circuitry is a usual challenge in Si and SiC technologies to increase efficiency of power switch and systems. The purpose of this article is to evaluate the integration compatibility of lateral MESFETs within a Vertical power JFET fabrication technology. The interest of this method is to allow control circuitry based on MESFET devices to get both power devices and control circuits on the same die. Several possibilities can be foreseen for the realization of lateral SiC-MESFETs [1], using conductive substrates or semi-insulating wafers. Other possibilities, more compatible with a vertical power device process, are P and N well formation by ion implantation to form the lateral channel. The description of the fabrication process presented below is a part of the fabrication process of a VJFET designed for high voltage current limitation [2]. High energy implantation, RIE etching adjustment and metal contact annealing are the critical steps of the fabrication of this device and will be developed in the process description. Electrical characterization of fabricated MESFET exhibit specific on resistance of 38mΩ.cm² and a transconductance value of 0,4 mS.mm-1. These results demonstrate VJFET and MESFET fabrication technology compatibility. Keys points to improve for the next generation of devices will be presented as well.