TC-LIGBTs on the Thin SoI Layer for the High Voltage Monolithic ICs With High Current Density and Latch-Up Immunity

A new 700 V tridimensional channel-lateral insulated-gate bipolar transistor (TC-LIGBT) structure on 1.5-μm-thin silicon on insulator (SoI) layer is presented in detail in this paper. There are numerous separated p-body cells located in the emitter region of the investigated TC-LIGBT, which can increase the efficient channel width, enhance electron injection, and attain a large current capability. By optimizing the doping of the middle doped n-type region between the adjacent p-body cells, a large current density of 568 A/cm² at VGE = 10 V, VCE = 20 V can be achieved, which has an improvement of 118% compared with the conventional SoI-LIGBT structure on the same thin SoI layer. To improve the latch-up capability, a highly doped p-buried layer has also been formed underneath the emitter region using 450-keV high-energy ion implantation. In this way, the proposed new TC-LIGBT can achieve almost the same latch-up immunity capability as with the conventional SoI-LIGBT structure.