BF2+ Ion Implant for Isolation Gettering
Original Publication Date: 1985-Jan-01
Included in the Prior Art Database: 2005-Feb-18
This technique uses BF2+ ion implantation for boron doping in the sub-isolation region, resulting in closed dislocation loops rather than glide dislocations. Upon subsequent ROI (recessed oxide isolation) oxidation, both stacking faults and closed dislocation loops are restricted to p+ doped regions, rather than migrating into device areas. Dislocation generation beneath ROI in p+ diffused regions can cause major yield loss. 60Œ glide dislocations are generated after ROI oxidation due to ROI compressive stress and shrinkage of lattice constants in the boron-doped region. These glide dislocations can migrate into active device regions and cause pipes. BF2+ ion implantation is used for boron doping in the sub-isolation regions.