Nondestructive and contactless microwave methods for profiling the mobility in active layers of multilayer structures grown on semiinsulating substrates

This paper presents a nondestructive microwave method allowing the determination of mobility and its depth profile in semiconductor multilayer structures on semiinsulating (SI) substrates. The method is based on magnetic-field-dependent measurements of the modulated reflectivity of a semiconductor structure arising due to modulation of the conductance of an internal layer in the structure. The basic principle of the mobility profiling is considered, along with the procedures permitting nondestructive and contactless modulation of the conductance of the internal active layer-buffer layer (n-SI) interfacial region. The application of the technique is demonstrated with GaAs n+ -n-i and GaAs/AlGaAs structures.