Cross-sectional scanning tunneling microscopy on semiconductor heterostructures

Abstract Cross-sectional scanning tunneling microscopy on semiconductor structures is evolving into a technique to analyze structural, chemical and electronic properties on the atomic and nanometer scale in all spatial dimensions, in particular in the lateral and in-depth spatial dimensions of the structure. This technique has been used on the ultrahigh vacuum cleaved (110) plane of (001)-grown AlGaAs/GaAs heterostructures. We report on measurements of (i) interface roughness, alloy fluctuations and ordering, (ii) the variation in electronic properties over an interface as well as fluctuations within the alloy and (iii) the distribution of individual dopant sites.