Semiconductor device and method for producing same

Abstract

In this patent application, a new Metal Oxide Semiconductor MOS planar cell design concept is proposed. The inventive power semiconductor includes a planar cell forming a horizontal channel and a plurality of trenches, which are arranged orthogonally to the plane of the planar cells. A second p base layer is introduced which extends perpendicularly deeper than the source region and laterally to the same distance/extent as the source region. Therefore, a vertical channel is prevented from forming in the trench regions while allowing the horizontal channels to form. This is extremely important in order to avoid significant issues (i.e. shifts in Vth) encountered in prior art IGBT designs. The new cell concept adopts planar MOS channel and Trench technology in a single MOS cell structure. The new design offers a wide range of advantages both in terms of performance (reduced losses, improved controllability and reliability), and processability (narrow mesa design rules, reliable planar process compatibility) and can be applied to both IGBTs and MOSFETs based on silicon or wide bandgap materials such as Silicon Carbide SiC. Furthermore, the device is easy to manufacture, because the inventive design can be manufactured based on a self-aligned process with minimum number of masks, with the potential of additionally applying enhancement layers and/or reverse conducting type of structures.