Theoretical and numerical comparison between DMOS and trench technologies for insulated gate bipolar transistors

An accurate and comprehensive comparison between DMOS and Trench technologies for Insulated Gate Bipolar Transistors (IGBT) is presented. The study is performed using extensive two-dimensional numerical simulations and fundamental physical modeling. Various phenomena such as the influence of the channel density on the forward voltage drop and the effect of the channel mobility degradation on the on-state characteristics have been the object of controversial studies. The analysis performed here describes rigorously these phenomena and accounts for new physical effects such as the channel length modulation and PIN diode carrier dynamics. It is concluded that at relatively high voltage and high current densities (>100 A/cm²) an optimally designed Trench IGBT results in significant theoretical advantages over its conventional DMOS variant, mainly due to an increased packing density, PIN diode effect, reduced latch-up current density and elimination of the JFET effect