In Situ and Real-Time Monitoring of Doping Levels by Reflectance Anisotropy Spectroscopy (RAS) during Molecular Beam Epitaxial (MBE) Growth of III/V Semiconductors

Figure 1

Sketch of the light path of the RAS system and, hence, for the explanation of the RAS principle. The light incidence is at least nearly normal to the wafer/sample surface, but it is drawn with a relatively large nonzero angle of incidence, just to make the sketch better understandable and not to have different devices drawn on top of each other. The shown angle of the wafer with respect to the direction of linear polarization of the incident light corresponds to those situations when the RAS signal is largest.