Activation of Si implants into InAs characterized by Raman scattering

Studies of implant activation in InAs have not been reported presumably because of challenges associated with junction leakage. The activation of 20 keV, Si⁺ implants into lightly doped (001) p-type bulk InAs performed at 100 °C as a function of annealing time and temperature was measured via Raman scattering. Peak shift of the L₊ coupled phonon-plasmon mode after annealing at 700 °C shows that active n-type doping levels 5 × 10¹⁹cm^-3 are possible for ion implanted Si in InAs. These values are comparable to the highest reported active carrier concentrations of 8-12 × 10¹⁹cm^-3 for growth-doped n-InAs. Raman scattering is shown to be a viable, non-contact technique to measure active carrier concentration in instances where contact-based methods such as Hall effect produce erroneous measurements or junction leakage prevents the measurement of shallow n⁺ layers, which cannot be effectively isolated from the bulk.