Study of Arsenic ion implantation of patterned strained Si NWs

A systematic study of the impact of As+ ion implantation on strain relaxation and dopant activation of biaxially strained SSOI layers and uniaxially strained/unstrained NWs is presented. Three aspects are investigated: (i) the quality of the single crystalline layers and the NWs, (ii) strain relaxation of the implanted NWs and (iii) dopant activation of the layers and NWs. Optimization of the doping conditions resulted into very low contact resistivities of NiSi contacts on strained and unstrained 70 nm SOI layers and Si NWs. For NW contacts values as low as 1.2 × 10−8 Ω cm2 for an As+ dose of 2 × 1015 cm−2 were achieved, which is 20 times lower than for planar contacts made under the same implantation and annealing conditions.

Research highlights
► The formation of highly doped strained Si NWs and layers on insulator is presented.
► Patterning of doped layers results in perfect crystalline doped strained Si NWs.
► Direct implantation of NWs at RT induces strong strain relaxation.
► Elastic strain is conserved by high temperature implantation.
► Dopant out-diffusion occurs during direct implantation of NWs.