Choice of electrolyte for doping profiling in Si by electrochemical C-V technique

Commonly used electrolytes (NH4F . HF and NaF/H2SO4) for doping profile ana lysis in Si are employed to clarify their capabilities and limitations usin g a boron-doped staircase test structure. The carrier density profiles at v arious measurement voltages for these electrolytes are compared with a SIMS profile of the structure. A variety of parameters affecting a carrier dens ity profile such as static current-voltage behaviour, dissipation factor, f lat band potential and series resistance at various doping levels are explo red to optimise the measurement conditions. It is found that both electroly tes can be employed for doping profiling in Si for a broad range of doping levels. However, electrolyte NaF/H2SO4 allows wider measurement voltage ran ge and suits better for profiling highly doped structures as indicated by l ower series resistance and hence lower dissipation factor, (C) 2001 Elsevie r Science B.V. All rights reserved.