THE EFFECTS OF RAPID THERMAL-PROCESSING ON ULTRA-SHALLOW JUNCTIONS FOR DEEP-SUBMICRON MOSFETS

Ultra-shallow (similar to 0.1 mu m) junctions are needed for sub-0.25 mu m MOSFET devices. These junctions can be made by implanting dopants into silicides and then drive out by RTA (Rapid Thermal Anneal). Comp ared to furnace processed junctions, however, the RTA processed juncti ons show a higher leakage current, coupled with a non-ideal diode beha vior. In addition, good junctions processed by furnace annealing showi ng ideal behavior and low leakage current are converted to leakier non -ideal diodes after an additional RTA. On the other hand, leaky juncti ons processed by RTA can be ''cured'' by an additional furnace anneali ng. We conclude that rapid thermal processing has to be carefully engi neered to produce useful shallow junctions for sub-0.25 mu m devices.