Thick Silicon Membrane Technology For Reliable And High Performance Operation Of High Voltage Ligbts In Power Ics

A step change in performance and reliability of thick SOI membrane devices compared to earlier generation of devices on ultra-thin SOI membranes is reported in here [1]. The membrane concept first reported offered a landmark improvement in the trade-off between switching losses and breakdown capability (in excess of 700V) but its current capability was limited by the thickness of the silicon membrane (around 30 A/cm(2) for LIGBTs on 0.25 mu m silicon membranes, achieving a loss related power density approaching 100W/cm(2)). This paper reports on membrane power devices with current densities which approach the best of those offered by vertical devices (current density greater than 100 A/cm(2) with power density of 180W/cm(2)), without sacrificing switching speed (t(off) < 60ns for 1.5 mu m membranes). HTRB results showing 1000 h+ operation at 125 degrees C at 80% of the rated voltage are also presented. Finally, it is shown that both the static and dynamic high temperature operation of thick membrane LIGBTs is superior to that of state-of-the-art integrated LDMOSFETs.