Angle-dependent SIMS artifact in the analysis of InP/InGaAs layers

Summary A hump-like distortion was observed in SIMS depth profiles of the beryllium dopant in an InGaAs layer of a MOVPE-grown structure, when the SIMS analysis was done with oxygen primary ions. In order to identify the origin of this effect, investigations were carried out with SIMS, SEM, TEM, and AES. The effect is correlated with the sputter-induced build-up of a ripple-topography in the sputter crater bottom and its influence on the dynamic equilibrium surface concentration of implanted oxygen primary ions. It is strongly dependent on the angle of primary ion incidence and can be avoided by oblique beam incidence with 45° (with reference to the sample normal).