SIMULATED DEVICE DESIGN OPTIMIZATION TO REDUCE THE FLOATING BODY EFFECT FOR SUB-QUARTER MICRON FULLY DEPLETED SOI-MOSFETS

Device design to reduce the abnormal operation due to the floating bod y effect was investigated for 0.2 mu m Fully depleted SOI-MOSFETs, by use of a two-dimensional device simulator. It was found that the criti cal drain voltage and the critical multiplication factor for the float ing body effect strongly depend on the potential profile which is rela ted to the doping concentration. Based on simulation results, a nonuni formly doped structure is proposed for optimizing the potential profil e to reduce the floating body effect. The applicable voltage of this s tructure was found to be 40% higher than that of the uniformly doped s tructure. A simple model is also derived to explain the above result.