Raman depth profiling in situ sputtering.

Raman scattering has been combined with in situ sputtering for a depth resolved Raman spectroscopic characterization of semiconductor structures. Using optical excitation in resonance with higher lying band gaps, such as the Esub1 band gap of GaAs, a depth resolution of a few nm can be achieved along with an enhanced sensitivity due to resonance effects in the scattering efficiency. The present experimental technique is demonstrated by recording a composition profile from a GaAs/AlsubxGasubyminusxAs multiple quantum well structure. Furthermore, the ability of lattice site selective depth profiling of dopant distributions is shown for Si incorporated on Ga and As lattice sites, respectively, in Sihighplus implanted and annealed GaAs.