Ultrashallow (<10nm) p+∕n junction formed by B18H22 cluster ion implantation and excimer laser annealing

Abstract

In order to form an ultrashallow p+∕n junction, incorporation of a top amorphous-silicon (a-Si) layer is necessary so as to avoid channeling and to fully activate the dopant. Conventional ultrashallow junction processes require two-step implantation such as preamorphization by Si+ or Ge+ implantation and ultralow (<0.5keV) energy B+ implantation. In this report, the authors investigate B18H22+ implantation. Due to the heavy mass of cluster ions, one-step ion implantation at 5keV readily forms a 5-nm-thick a-Si layer and an ultrashallow junction without B channeling. By employing excimer laser annealing, the authors have obtained a shallow junction depth (∼9nm) and low Rs (∼830Ω∕◻).

Incorporation of tin in boron doped silicon for reduced deactivation of boron during post-laser-anneal rapid thermal processing

“…Laser annealing ͑LA͒ is a promising technique for the formation of ultrashallow junction with very low sheet resistance, [1][2][3] and has also been used to achieve high dopant concentration in polysilicon gates for reduction of gate depletion effects. Laser annealing ͑LA͒ is a promising technique for the formation of ultrashallow junction with very low sheet resistance, [1][2][3] and has also been used to achieve high dopant concentration in polysilicon gates for reduction of gate depletion effects.…”

Investigation of recrystallization and stress relaxation in nanosecond laser annealed Si1−xGex/Si epilayers

“…As a consequence, the annealing process timescale becomes shorter and shorter [3,4]. Nanosecond Laser Annealing (NLA), which enables to reach higher dopants activation in Si [5][6][7] or Ge [8,9], is very promising from that point of view. Ultraviolet NLA (UV-NLA) can also be used for 3D Integration, as its short pulse duration and its short wavelength result in high anneal temperatures near the surface while keeping embedded layers at much lower temperatures [10][11][12][13].…”

Investigation of Boron Distribution at the SiO2/Si Interface of Monolayer Doping

“…The highlighted circles are the conditions used for the XPS and SIMS analyses. (B) Sheet resistance as a function of junction depth ( X j at 1 × 10 18 /cm 3 ) for boron-doped Si by RTA and MWA, which is compared with boron monolayer doping from Ho et al, Ye et al, , and traditional implantation techniques. − …”