Spreading resistance profiling of ultra shallow junction fabricated with low energy as implantation and combination of spike lamp and laser annealing processes using scanning spreading resistance microscopy

Abstract

Depth profiles of a spreading resistance of ultra-shallow arsenic implanted into silicon with an energy of 2.0 keV and a dose of 1.0 × 1015 ions/cm2 activated with a combination of conventional spike lamp and laser annealing processes were measured using scanning spreading resistance microscopy (SSRM) with a depth resolution of less than 5 nm. The lowest resistances in the arsenic activated region by laser annealing with laser power densities of 0.33 kW/mm2 and 0.35 kW/mm2 followed by spike lamp annealing (a laser first process) were 44 and 88 % lower than those with spike lamp annealing followed by laser annealing (a spike first process) with the same laser power densities, respectively. The lowest resistance in the arsenic activated region by the laser first process with a laser power density of the 0.35 kW/mm2 was 42 % lower than that with a laser power density of 0.33 kW/mm2. The depth of p+.n junction by the laser first process with a laser power density of 0.35 kW/mm2 was 2 nm shallower than that by the spike first process with the same laser power density. The laser first process is more suitable for the fabrication of the sallow and low-resistance extension regions than the spike first process.