Sequential Nitrogen Ion Implantation in Si-Based GaAs Matrix and Subsequent Thermal Annealing Process: Electrical Characterization

Physics

Abstract

The ion implantation is well-established techniques for device fabrication in III-V semiconductors. GaAs is grown on Silicon (Si) substrate using Germanium (Ge) as a buffer layer to reduce the lattice mismatch. The implantation of nitrogen ions in GaAs is done by sequential accumulation of doses from 0.4×10¹⁷ to 2.0×10¹⁷ cm^-2 with ion energies ranging from 80 keV to 120 keV to achieve more uniform ion distribution. A subsequent high temperature annealing is done for nanostructures formation and to improve the crystal quality. For the annealing process, rapid thermal annealing (RTA) and furnace annealing (FA) are used in temperature range of 700°C - 850°C under argon and nitrogen environment. Current-voltage (I-V) characterization are carried out to study the effect of the post-annealing process on the barrier height and ideality factor. The electrical parameters are observed to have a strong dependence on temperature. The inhomogeneity in barrier height gives rise the temperature dependence of barrier height.